multiple web sites into your application.

你想要找回RSS和Atom feeds和考虑在这个items. 它允许你合并newsfeeds从多种web sites到你的应用程序

12.12.2解答
Use the MagpieRSS parser. Here’s an example that reads the RSS feed for the php.announce mailing list:

使用这个MagpieRss 剖析器。这里是一个例子阅读Rss feed到这个php.annouce邮件发送清单


?php
require 'rss_fetch.inc';
$feed = 'http://news.php.net/group.php?group=php.announce&format=rss';
$rss = fetch_rss( $feed );
print "<ul>\n";
foreach ($rss->items as $item) {
    print '<li><a href="' . $item['link'] . '">' . $item['title'] . "</a></li>\n";
}
print "</ul>\n";


12.12.3讨论

RSS (RDF Site Summary) is an easy-to-use headline or article syndication format written in XML.[] Many news

web sites, such as the New York Times and the Washington Post, provide RSS feeds that update whenever new

stories are published. Weblogs have also embraced RSS and having an RSS feed for your blog is a standard

feature. The PHP web site also publishes RSS feeds for most PHP mailing lists.
RSS(RDF主要摘要)是一个很容易使用和表达syndication 格式在XML.[]很多的新的web sites 。例如纽约时间和华盛顿时间

。规定RSS feeds 修正无论新的存储内容是pubished,博客同样经常使用RSS和蚩尤一个RSS feed在你的bolg是一个标准的特

质。这个PHP web站点同样订阅RSS feeds在更多的PHP mailing lists


[] RDF stands for Resource Definition Framework. RSS also stands for Rich Site Summary.


Atom is a similar XML syndication format. It extends many of the concepts in RSS, including a way to read and

write Atom data. It also attempts to provide a more well-defined syntax for syndication than RSS, as the RSS

specification doesn’t always clearly enumerate exactly what is or isn’t permissible in a feed.
Atom 是一个相似的XML syndication格式。它延展更多观念到RSS .包括一个办法去阅读和写Atom 数据。它同样尝试规定一

个更多的well-defined语法在syndication比RSS. 当作RSS规范不能明显的列举正确的

Using MagpieRSS, retrieving and parsing RSS and Atom feeds are simple:
使用MagpieRss。找回分解RSS和Atom feeds是简单的


?php
$feed = 'http://news.php.net/group.php?group=php.announce&format=rss';
$rss = fetch_rss($feed);


This example reads in the RSS feed for the php.announce mailing list. The feed is then parsed by fetch_rss( )

and stored internally within $rss.
这个例子阅读在这个RSS feed在这个php.announce mailing list 。这个feed是分解fetch_rss()和存储到$rss内

While this feed is RSS 0.93, there’s no need to specify this to MagpieRSS. Its fetch_rss( ) function detects

the syndication format, including Atom, and formats the document accordingly.
使用这个feed是RSS 0.93 ，它不需要指定这些到MagpieRSS .它的fetch_rss()函数发现这个syndication格式。包括Atom 和

这个格式
Each RSS item is then retrieved as an associative array using the items property:

每个RSS消息重新找回当作一个联合数组使用items 特质

?php
print "<ul>\n";
foreach ($rss->items as $item) {
    print '<li><a href="' . $item['link'] . '">' . $item['title'] . "</a></li>\n";
}
print "</ul>\n";


This foreach loop creates an unordered list of items with the item title linking back to the URL associated

with the complete article, as shown in Figure 12-1. Besides the required title and link fields, an item can

have an optional description field that contains a brief write-up about the item.
这个foreach循环创造一个无序目录消息在这个item字幕背景到联合URL和全部文章。例如在图像12-1.除此之外必须的标题和

链接域。一个item可以有一个可选择的描写 field包含一个主要write-up这个item

Each channel also has an entry with information about the feed, as shown in Figure 12-2. To retrieve that

data, call access the channel attribute:
每个channel同样有一个入口和这个feed的信息。例如在图像12-2,去重新找回那个数据调用访问这个频道的特质

?php
$feed = 'http://news.php.net/group.php?group=php.announce&format=rss';
$rss = fetch_rss($feed);
print "<ul>\n";
foreach ($rss->channel as $key => $value) {
    print "<li>$key: $value</li>\n";
}
print "</ul>\n";


PHP的XML延展名使用UTF-8。但是你的数据在一个不同的内容编码

12.11.2解答

Use the iconv library to convert it before passing it into an XML extension:

使用这个iconv library去转换它，到一个XML延展名


$utf_8 = iconv('ISO-8859-1', 'UTF-8', $iso_8859_1);


Then convert it back when you are finished:
然后转换它当你完成

12.11.3讨论
Character encoding is a major PHP 5 weakness. Fortunately, Unicode support is the major driver behind PHP 6.

Since PHP 6 is still under development, in the meantime, you can run into problems if you’re trying to use

XML extensions with arbitrary encoded data.

创造编码是PHP5的主要弱点、幸运的是。统一编码支持主驱动器在PHP6.之后。从PHP6之前一直不完善，同时，你可以运行它

的问题如果你尝试去使用XML延展名和任意编码数据

For simplicity, the XML extensions all exclusively use the UTF-8 character encoding. That means they all

expect data in UTF-8 and output all data in UTF-8. If your data is ASCII, then you don’t need to worry, UTF-8

is a superset of ASCII. However, if you’re using other encodings, then you will run into trouble sooner or

later.

对于简单的。这个XML延展名所有专用使用这个UTF-8编码。意思是所有的数据在UTF-8输出数据在UTF-8.如果你的数据是

ASCII, 然后你不需要担心。 UTF-8是扩展集，尽管如果你使用其他编码 然后当你运行故障或者更迟
 
To work around this issue, use the iconv extension to manually encode data back and forth between your

character sets and UTF-8. For example, to convert from ISO-8859-1 to UTF-8:

去运行这个issue。 使用这个图标的延长部分手动编辑数据来回鱼你的字符集和UTF-8。例如转换ISO-8859到UTF-8


$utf_8 = iconv('ISO-8859-1', 'UTF-8', $iso_8859_1);


The iconv function supports two special modifiers for the destination encoding: //TRANSLIT and //IGNORE. The

first option tells iconv that whenever it cannot exactly duplicate a character in the destination encoding,

it should try to approximate it using a series of other characters. The other option makes iconv silently

ignore any unconvertible characters.

这个图标函数支持两个特殊的修正目的文件的编辑://TRANSLIT和//IGNORE。这第一个选项告诉iconv不能正确的复制一个特

性在目的文件编辑，你应该尝试接近它使用一脸产的其他特质。这个其他选项会默默的忽视一些不能转换的特质

For example, the string $geb holds the text Gödel, Escher, Bach. A straight conversion to ASCII produces an

error:

例如。这个字符串$geb保存这个正文 Gödel,Escher, Bach.，一个整齐的变化到ASCII录制一个错误

echo iconv('UTF-8', 'ASCII', $geb);
PHP Notice:  iconv(): Detected an illegal character in input string...



echo iconv('UTF-8', 'ASCII//IGNORE', $geb);

However, the output isn’t nice, because the ö is missing:

尽管。这个输出不是最精密的。因为这个”ö”丢失


Gdel, Escher, Bach

The best solution is to use //trANSLIT:

这个最好的解答办法就是使用//trANSLIT


echo iconv('UTF-8', 'ASCII//TRANSLIT', $geb);


This produces a better-looking string:

它产生更好的字符串

Gdel, Escher, Bach


You want to make sure your XML document abides by a schema, such as XML Schema, RelaxNG, and DTDs.

你想要确认你的XML文件坚持一个计划。例如XML计划。RelaxNG.和DTDs

12.10.2解答

Use the DOM extension
使用这个DOM延展名

With existing DOM objects, call DOMDocument::schemaValidate( ) or DOMDocument::relaxNGValidate( ):

使用现有的DOM对象。调用DOMDocument::schemaVlidate()或者DOMDOcument::relaxNGValidate()


$file = 'address-book.xml';
$schema = 'address-book.xsd';
$ab = new DOMDocument
$ab->load($file);
if ($ab->schemaValidate($schema)) {
    print "$file is valid.\n";
} else {
    print "$file is invalid.\n";
}


If your XML document specifies a DTD at the top, call DOMDocument::validate( ) to validate it against the DTD.

如果你的XML文件指定一个DTD在这个top、调用DOMDocument::validate()去确认它相反的DTD

With XML in a string, call DOMDocument::schemaValidateSource( ) or DOMDocument::relaxNGValidateSource( ):

然后XML在一个字符串。调用ODMDocument::schemaValidateSource()或者DOMDocument::relaxNGValidateSource()


$xml = '<person><firstname>Adam</firstname></person>';
$schema = 'address-book.xsd';
$ab = new DOMDocument
$ab->&gt;load($file);
if ($ab->&gt;schemaValidateSource($schema)) {
    print "XML is valid.\n";
} else {
    print "XML is invalid.\n";
}


12.10.3讨论
Schemas are a way of defining a specification for your XML documents. While the goal is the same, there are multiple

ways to encode a schema, each with a different syntax.

计划是详细定义你的XML文件。当目标是一样的。有多种办法去编辑一个计划，每个不疼痛的语法

Some popular formats are DTDs (Document Type Definitions), XML Schema, and RelaxNG. DTDs have been around longer, but

they are not written in XML and have other issues, so they can be difficult to work with. XML Schema and RelaxNG are

more recent schemas and attempt to solve some of the issues surrounding DTDs.
一些通俗的格式是DTDs(Document Type Definitions)XML Schema 和RelaxNG. DTDs有一个比较久的，但是它不在XML和其他issues.所

以它不同于其他XML

PHP 5 uses the libxml2 library to provide its validation support. Therefore, it lets you validate files against all

three types. It is most flexible when you’re using XML Schema and RelaxNG, but its XML Schema support is incomplete.

You shouldn’t run into issues in most XML Schema documents; however, you may find that libxml2 cannot handle some

complex schemas or schemas that use more esoteric features.

PHP5使用这个libxml2库规定确认支持。因此它设置你的有效文件相反于全部的三个类型。它是大部分灵活的，当你使用XML Schema和

RealxNG，但是它XML Schema支持相反的。你需要运行到最多的XML Schema文件。尽管你可能找到那个libxml2不能处理多数复杂的

schemas或者schemas那个使用更多的深奥的features
Within PHP, the DOM extension supports DTD, XML Schema, and RelaxNG validation, while SimpleXML provides only an XML

Schema validator.

使用PHP.这个DOM延展名支持DTD。 XML Schema 和RealxNG确认。使用简单的规定唯一的一个XML Schema有效的

Validating any file using DOM is a similar process, regardless of the underlying schema format. To validate, call a

validation method on a DOM object (see Example 12-21). It returns true if the file passes. If there’s an error, it

returns false and prints a message to the error log. There is no method for “capturing” the error message

确认一些文件使用DOM是一个相似的处理方法，不管下面的schema格式。有效的调用一个有效的方法在一个DOM对象.它返回真实的文件

。如果是一个错误的。它返回错误然后打印出一个信息到这个错误行。它没有办法处理错误信息


$file = 'address-book.xml';
$schema = 'address-book.xsd';
$ab = new DOMDocument
$ab->load($file);
if ($ab->schemaValidate($schema)) {
    print "$file is valid.\n";
} else {
    print "$file is invalid.\n";
}


If the schema is stored in a string, use DOMDocument::schemaValidateSource( ) instead of schemaValidate( ).

如果这个schema存储在一个字符串。使用DOMDocument::scheemaValidateSource()代替SchemaValidate()

All of the validation methods behave in a similar manner, so you only need to switch the method name in the previous

example to switch to a different validation scheme.
所有的有效方法在某种意义上相似。所以你仅仅需要转换方法命在上一级的菜单例子到一个不同的scheme
Both XML Schema and RelaxNG support validation against files and strings. You can validate a DOM object only against

the DTD defined at the top of the XML document

所有的XML Schema和RllaxNG 支持确认相反的文件和字符串，你可以确认一个DOM对象唯一相反的DTD定义XML文件的顶部

你想要调用PHP函数从一个XSLT stylesheet

12.9.2解答
Invoke the XSLTProcessor::registerPHPFunctions( ) method to enable this functionality
调用XSLTProcessor::registerPHPFunctions()方法到functionlity

$xslt = new XSLTProcessor();
$xslt->registerPHPFunctions();


And use the function( ) or functionString( ) function within your stylesheet:
然后使用这个function()或者functionString()函数和你的风格

<xsl:stylesheet version="1.0"
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform”
    xmlns:php=”http://php.net/xsl”
    xsl:extension-element-prefixes=”php”>
<xsl:template match=”/”>
    <xsl:value-of select=”php:function(’strftime’, ‘%c’)” />
</xsl:template>
</xsl:stylesheet>


12.9.3讨论
XSLT parameters are great when you need to communicate from PHP to XSLT. However, they’re not very useful

when you require the reverse. You can’t use parameters to extract information from the stylesheet during the

transformation. Ideally, you could call PHP functions from a stylesheet and pass information back to PHP.

XSLT参数是重要的。当你需要沟通XSLT。他不是非常有用当你命令这个reverse，你不可以使用选出的信息从stylesheet在这

个转换。完美的。你可以调用PHP函数从一个stylesheet和通过信息到PHP

Fortunately, there’s a method that implements this functionality: registerPHPFunctions( ). Here’s how it’s

enabled:

幸运的。这是一个执行这个函数的方法:regiterPHP函数，当它激活

$xslt = new XSLTProcessor();
$xslt->registerPHPFunctions();


This allows you to call any PHP function from your stylesheets. It’s not available by default because it

presents a security risk if you’re processing stylesheets controlled by other people.
它允许你调用一些PHP函数从你的stylesheets。他不是一个可利用的，因为它出现在危险的。如果你处理限制它

Both built-in and user-defined functions work. Inside your stylesheet, you must define a namespace and call

the function( ) or functionString( ) methods, as shown in Example 12-17.

所有的内置和自定义函数工作。代替你的stylesheet。你必须定义一个名字和调用这个函数()或者fanctionString()方法。

例如在例子12-17

<?xml version="1.0" ?>
<xsl:stylesheet version="1.0"
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform”
    xmlns:php=”http://php.net/xsl”
    xsl:extension-element-prefixes=”php”>
<xsl:template match=”/”>
    <xsl:value-of select=”php:function(’strftime’, ‘%c’)” />
</xsl:template>
</xsl:stylesheet>

At the top of the stylesheet, define the namespace for PHP: http://php.net/xsl. This example sets the

namespace prefix to php. Also, set the extension-element-prefixes value to php so XSLT knows these are

functions.

在stylesheet的顶部。定义PHP的域名：http://php.net/xsl.这个例子规定这个前缀是php。设置延展名的元素智到PHP所有

XSLT知道这些函数

To call a PHP function, reference php:function( ). The first parameter is the function name; additional

parameters are the function arguments. In this case, the function name is strftime and the one argument is %

c. This causes strftime to return the current date and time.
去调用一个PHP函数，涉及PHP::function()，这第一个论点是这个函数。另外参数是函数论点，既然这样这个函数名是这个

时间和第一个%c。它导致返回正确的数据和时间
Example 12-18 uses this stylesheet, stored as stylesheet.xsl, to process a single-element XML document
例子12-18使用这个stylesheet。存储在stylesheet,xsl。去存储一个单一的元素XML论点


$dom  = new DOMDocument;
$dom->loadXML('<blank/>');
$xsl  = new DOMDocument
$xsl->load('stylesheet.xsl');
$xslt = new XSLTProcessor();
$xslt->importStylesheet($xsl);
$xslt->registerPHPFunctions();
print $xslt->transformToXML($dom);
Mon Jul 22 19:10:21 2004


This works like standard XSLT processing, but there’s an additional call to registerPHPFunctions( ) to

activate PHP function support.

这个工作就像XSLT的标准。但是它是一个复交的调用registerPHPFunctions()激活PHP函数

You can also return DOM objects. Example 12-19 takes the XML address book and mangles all the email addresses

to turn the hostname portion into three dots. Everything else in the document is left untouched.
你同样可以返回DOM对象。例子12-19调用这个XML地址和所有的email地址去转换这个名字的一部分到three格式。每个其他的

在这个文件是为改变的


function mangle_email($nodes) {
    return preg_replace('/([^@\s]+)@([-a-z0-9]+\.)+[a-z]{2,}/is',
                        ‘$1@…’,
                        $nodes[0]->nodeValue);
}
$dom  = new DOMDocument;
$dom->load(’address-book.xml’);
$xsl  = new DOMDocument
$xsl->load(’stylesheet.xsl’);
$xslt = new XSLTProcessor();
$xslt->importStylesheet($xsl);
$xslt->registerPhpFunctions();
print $xslt->transformToXML($dom);

Inside your stylesheet, create a special template for /address-book/person/email elements, as shown in

Example 12-20.

在你的stylesheet内部，包含一个特殊的模板。对于/address-book/person/email元素。例如在例子12-20

<?xml version="1.0" ?>
<xsl:stylesheet version="1.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform”
  xmlns:php=”http://php.net/xsl”
  xsl:extension-element-prefixes=”php”>
<xsl:template match=”@*|node()”>
  <xsl:copy>
    <xsl:apply-templates select=”@*|node()”/>
  </xsl:copy>
</xsl:template>
<xsl:template match=”/address-book/person/email”>
  <xsl:copy>
    <xsl:value-of select=”php:function(’mangle_email’, node())” />
  </xsl:copy>
</xsl:template>
</xsl:stylesheet>


The first template ensures that the elements aren’t modified, while the second passes the current node to PHP

for mangling. In the second template, the mangle_email( ) function is passed the current node, represented in

XPath as node( ), instead of a string. Be sure not to place the node inside quotation marks, or you’ll pass

the literal text node( ).

这第一个模板确保这个元素不能修改。当这第二个通用正确的网点到PHP。在第二个模板这个mangle_email()函数通过这个正

确的网点。表现在XPath当作node()。代替一个字符串、确认网点在引号内。。或者你通过文字正文
Nodes becomes DOM objects inside PHP and always arrive in an array. In this case, mangle_email( ) knows

there’s always only one object and it’s a DOMText object, so the email address is located in $nodes[0]-

>nodeValue.

网点变成DOM对象代替PHP和总是到达一个数组。既然这样，mangle_email()知道这个总是唯一的对象和DOMText对象，所有这

个email地址在$nodes[0]->nodeVlue

When you know that you’re only interested in the text portion of a node, use the functionString( ) function.

This function converts nodes to PHP strings, which allows you to omit the array access and nodeValue

dereference:

当你知道唯一的在正文部分的一个网点。使用这个functionString(()函数，这个函数转换nodes到PHP字符串。那个允许你忽

略数组的访问和nodeValue参照


function mangle_email($email) {
    return preg_replace('/([^@\s]+)@([-a-z0-9]+\.)+[a-z]{2,}/is',
                        ‘$1@…’,
                        $email);
}
// all other code is the same as before


The new stylesheet template for /address-book/person/email is:
这个新的stylesheet模板对于/address-book/person/email是

<xsl:template match="/address-book/person/email">
  <xsl:copy>
    <xsl:value-of
       select="php:functionString('mangle_email', node())" />
  </xsl:copy>
</xsl:template>


The mangle_email( ) function now processes $email instead of $nodes[0]->nodeValue because the template now

calls the functionString( ) function.

这个mangle_email()函数处理$email代替$nodes[0]->nodeValue因为这个模板调用functionString()函数
 

You want to set parameters in your XSLT stylesheet from PHP.

你想要设置你的XSLT参数从PHP中

12.8.2解答
Use the XSLTProcessor::setParameter( ) method:

使用这个XSLTProcessor::setParameter()方法

// This could also come from $_GET['city'];
$city = 'San Francisco';
$dom  = new DOMDocument
$dom->load('address-book.xml');
$xsl  = new DOMDocument
$xsl->load('stylesheet.xsl');
$xslt = new XSLTProcessor();
$xslt->importStylesheet($xsl);
$xslt->setParameter(NULL, 'city', $city);
print $xslt->transformToXML($dom);


This code sets the XSLT city parameter to the value stored in the PHP variable $city.

这个代码设置XSLT参数到这个存储数值在PHP的变量$city

12.8.3讨论
You can pass data from PHP into your XSLT stylesheet with the setParameter( ) method. This allows you to do

things such as filter data in your stylesheet based on user input.

你可以通过PHP到你的XSLT类型和这个setParameter()方法、它允许你例如过滤数据到你的stylesheet早使用者的输出

For example, the program in Example 12-16 allows you to find people based on their city.
例如。这个程序在例子12-16允许你去寻找people在他们的city


// This could also come from $_GET['city'];
$city = 'San Francisco';
$dom  = new DOMDocument
$dom->load('address-book.xml');
$xsl  = new DOMDocument
$xsl->load('stylesheet.xsl');
$xslt = new XSLTProcessor();
$xslt->importStylesheet($xsl);
$xslt->setParameter(NULL, 'city', $city);
print $xslt->transformToXML($dom);

The program uses the following stylesheet:

这个程序使用下列stylesheet

<?xml version="1.0" ?>
<xsl:stylesheet version="1.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform“>
<xsl:template match=”@*|node()”>
  <xsl:copy>
    <xsl:apply-templates select=”@*|node()”/>
  </xsl:copy>
</xsl:template>
<xsl:template match=”/address-book/person”>
  <xsl:if test=”city=$city”>
    <xsl:copy>
      <xsl:apply-templates select=”@*|node()”/>
    </xsl:copy>
  </xsl:if>
</xsl:template>
</xsl:stylesheet>

The program and stylesheet combine to produce the following results:

这个程序和stylesheet联合录制下列结果
<code>
<?xml version=”1.0″?>
<address-book>
    <person id=”2″>
        <!–Adam Trachtenberg–>
        <firstname>Adam</firstname>
        <lastname>Trachtenberg</lastname>
        <city>San Francisco</city>
        <state>CA</state>
        <email>amt@php.net</email>
    </person>
</address-book>

The PHP script does a standard XSLT transformation, except that it calls $xslt->setParameter(NULL, ‘city’,

$city). The first argument is the parameter’s namespace, the second is the parameter’s name, and the third is

the parameter’s value.

这个PHP原本是一个标准XSLT转换。除了它调用$xslt->setParameter(NULL.’city’.$city)这第一个论点是这个参数。这第二

个论点是名字。第三个是参数的值

Here, the value stored in the PHP variable $city’in this case, San Francisco’is assigned to the XSLT

parameter city, which does not live under a namespace. This is equal to placing the following in an XSLT

file:

这里。这个数值存储在PHP变量$city。San Francisco的分配到这个XSLT参数city。哪个不能在一个名字下面。他们
相等于下列一个XSLT文件

<xsl:param name="city">San Francisco</xsl:param>

You usually access a parameter inside a stylesheet like you do a PHP variable, by placing a dollar sign ($)

in front of its name. The stylesheet example creates a template that matches /address-book/person nodes.
你经常访问一个参数在一个内部。像你的一个PHP变量在变量前面加一个$.这个stylesheet例子创造一个模块匹配网点

Inside the template, you test whether city=$city; in other words, is the city child of the current node equal

to the value of the city parameter? If there’s a match, the children are copied along; otherwise, the records

are eliminated.
在这个模板内部。你测试city=$city。换句话说。在这个city类相等的数值city 惨呼。如果匹配。这个子类将复制。另外。

记录将消除

In this case, city is set to San Francisco, so David’s record is removed and Adam’s remains.

既然这样。city到San Francisco、所以David的记录远离remains

You have an XML document and an XSL stylesheet. You want to transform the document using XSLT and capture the

results. This lets you apply stylesheets to your data and create different versions of your content for

different media.

你有一个XML文件和一个XSL stylesheet， 你想要转换文件使用XSLT和capure这个结果。它将你应用你的数据和创造不同的

版本在不同的媒体

12.7.2解答
Use PHP’s XSLT extension
使用PHP的XSLT延展名


// Load XSL template
$xsl = newDOMDocument;
$xsl->load('stylesheet.xsl');
// Create new XSLTProcessor
$xslt = new XSLTProcessor();
// Load stylesheet
$xslt->importStylesheet($xsl);
// Load XML input file
$xml = new DOMDocument;
$xml->load('data.xml');
// Transform to string
$results = $xslt->transformToXML($xml);
// Transform to a file
$results = $xslt->transformToURI($xml, 'results.txt');
// Transform to DOM object
$results = $xslt->transformToDoc($xml);

The transformed text is stored in $results
这个转换正文存储在$results

12.7.3讨论

XML documents describe the content of data, but they don’t contain any information about how that data should

be displayed. However, when XML content is coupled with a stylesheet described using XSL (eXtensible

Stylesheet Language), the content is displayed according to specific visual rules.

XML文件描述这个数据的内容。但是它不能包含一些必须显示的数据。当XML内容联合一个描述使用XSL、这个内容显示依照特

殊的规则

The glue between XML and XSL is XSLT (eXtensible Stylesheet Language Transformations). These transformations

apply the series of rules enumerated in the stylesheet to your XML data. So just as PHP parses your code and

combines it with user input to create a dynamic page, an XSLT program uses XSL and XML to output a new page

that contains more XML, HTML, or any other format you can describe
结合XML和XSL是XSLT这些转换应用列举规则在这你的XML数据风格，所以如果你的PHP分列你的代码和结合到使用者输出创造

一个动态页面。一个XSLT程序使用XSL和XML去输出一个新的页面包含更多的XML.HTML或者一些其他的格式

There are a few XSLT programs available, each with different features and limitations. PHP 5 supports only

the libxslt processor. This is a different processor than PHP 4 used
这是一个少量的XSLT程序变量。每个不同的的特质和限制，PHP5支持唯一的libxslt处理它是一个不同的处理跟PHP4相比
Using XSLT in PHP 5 involves two main steps: preparing the XSLT object and then triggering the actual

transformation for each XML file.

使用XSLT在PHP5包括两个主要的：准备XSLT对象和控制真正的变化到每个XML文件


// Load XSL template
$xsl = newDOMDocument;
$xsl->load('stylesheet.xsl');
// Create new XSLTProcessor
$xslt = new XSLTProcessor();
// Load stylesheet
$xslt->importStylesheet($xsl);

Now the transformer is up and running. You can transform any DOM object in one of three ways: into a string,

into a file, or back into another DOM object, as shown in Example 12-15.

现在这个变化的运动、你可以转换DOM对象在第三个路线、在一个字符串内的一个文件或者其他DOM对象。例如在例子12-15

// Load XML input file
$xml = new DOMDocument;
$xml->load('data.xml');
// Transform to string
$results = $xslt->transformToXML($xml);
// Transform to a file
$results = $xslt->transformToURI($xml, 'results.txt');
// Transform to DOM object
$results = $xslt->transformToDoc($xml);


When you call transformToXML( ) or transformToDoc( ), the extension returns the result string or object. In

contrast, transformToURI( ) returns the number of bytes written to the file, not the actual document.

当你调用transformToXML()或者transformToDoc()。这个延展名返回字符串结果或者对象对比transformtourl()返回这个
字节数字、不是真是的文件
 

你想要制造一个查询在你的XML数据和分解这个文件网点

12.6.2解答

Use XPath.
使用XPath
XPath is available in SimpleXML:
XPath是简单的可利用的

?php
$s = simplexml_load_file('address-book.xml');
$emails = $s->xpath('/address-book/person/email');
foreach ($emails as $email) {
    // do something with $email
}

And in DOM:

然后在DOM

?php
$dom = new DOMDocument;
$dom->load('address-book.xml');
$xpath = new DOMXPath($dom);
$email = $xpath->query('/address-book/person/email');
foreach ($emails as $email) {
    // do something with $email
}

12.6.3讨论
Except for the simplest documents, it’s rarely easy to access the data you want one element at a time. As your XML files become increasingly complex and your parsing desires grow, using XPath is easier than filtering the data inside a foreach.

除了简单的文件。它很容易去访问这个数据在你想要的一个元素。当作你的XML文件变成复杂的和你的分解要求生成。使用XPath是更加简单的过滤数据在一个foreach

PHP has an XPath class that takes a DOM object as its constructor. You can then search the object and receive DOM nodes in reply. SimpleXML also supports XPath, and it’s easier to use because it’s integrated into the SimpleXML object.

PHP有一个XPath类有一个DOM对象当作构造器。你可以搜索这个对象和接受DOM网点在这个回复。SimpleXML同样支持Xpath.然后容易使用因为它统一到一个SimpleXML对象
DOM supports XPath queries, but you do not perform the query directly on the DOM object itself. Instead, you create a DOMXPath object, as shown in Example 12-9.

DOM支持XPath查询。但是它不直接履行查询，例如在例子12-9

$dom = new DOMDocument;
$dom->load('address-book.xml');
$xpath = new DOMXPath($dom);
$email = $xpath->query('/address-book/person/email');

Instantiate DOMXPath by passing in a DOMDocument to the constructor. To execute the XPath query, call query( ) with the query text as your argument. This returns an iterable DOM node list of matching nodes (see Example 12-10).
例示DOMPath通过在一个DOMDocument 到这个构造器，去执行这个XPath查询。调用query()和query正文当作你的论点。它返回一个iterable DOM网点，看例子12-10

Using XPath with DOM in a basic example

$dom = new DOMDocument;
$dom->load('address-book.xml');
$xpath = new DOMXPath($dom);
$emails = $xpath->query('/address-book/person/email');
foreach ($emails as $e) {
    $email = $e->firstChild->nodeValue;
    // do something with $email
}

After creating a new DOMXPath object, query this object using DOMXPath::query( ), passing the XPath query as the first parameter (in this example, it’s /people/person/email). This function returns a node list of matching DOM nodes.
经过创造一个新的DOMXPath对象。查询这个对象使用DOMPath::query()。通过这个XPath query当作第一个参数
By default, DOMXPath::query( ) operates on the entire XML document. Search a subsection of the tree by passing in the subtree as a final parameter to query( ). For instance, to gather all the first and last names of people in the address book, retrieve all the people nodes and query each node individually, as shown in Example 12-11.

定义DOMXPath::query()操作在全部的XML文件。搜索一个分段的tree通过子树当作一个最后的参数到query()，例如集合所有的第一个和最后一个名字在这个住址名册。找回所有的people网点和查询每个个别的node,例如在例子12-11

$dom = new DOMDocument;
$dom->load('address-book.xml');
$xpath = new DOMXPath($dom);
$person = $xpath->query('/address-book/person');
foreach ($person as $p) {
    $fn = $xpath->query('firstname', $p);
    $firstname = $fn->item(0)->firstChild->nodeValue;
    $ln = $xpath->query('lastname', $p);
    $lastname = $ln->item(0)->firstChild->nodeValue;
    print "$firstname $lastname\n";
}
David Sklar
Adam Trachtenberg

Inside the foreach, call DOMXPath::query( ) to retrieve the firstname and lastname nodes. Now, in addition to the XPath query, also pass $p to the method. This makes the search local to the node.

在foreach内部，调用DOMXPath::query()重新找回第一个名和最后一个名nodes，现在在除了XPath查询。同样通过$p到这个方法。它确定搜索本地node

In contrast to DOM, all SimpleXML objects have an integrated xpath( ) method. Calling this method queries the current object using XPath and returns a SimpleXML object containing the matching nodes, so you don’t need to instantiate another object to use XPath. The method’s one argument is your XPath query.
和DOM对比。所有的SimpleXML对象有一个综合的xpath()方法。调用这个方法查询这个正确的对象使用XPath和返回一个SimoleXML对象包含匹配的nodes。所以你不需要例示其他对象使用XPath。这个方法的一个论点是你的XPath查询
Use Example 12-12 to find all the matching email addresses in the sample address book.

使用例子12-12去寻找所有的匹配email地址。在这个住址名册

$s = simplexml_load_file('address-book.xml');
$emails = $s->xpath('/address-book/person/email');
foreach ($emails as $email) {
    // do something with $email
}

This is shorter because there’s no need to dereference the firstNode or to take the nodeValue.

这个是简短的。因为它不需要废弃第一个站点或者获得价值

SimpleXML handles the more complicated example, too. Since xpath( ) returns SimpleXML objects, you can query them directly, as in Example 12-13.

SimpleXML也有很多复杂的例子。从xpath()返回Simple对象。你可以直接查询，例如在例子12-13


$s = simplexml_load_file('address-book.xml');
$people = $s->xpath('/address-book/person');
foreach($people as $p) {
    list($firstname) = $p->xpath('firstname');
    list($lastname) = $p->xpath('lastname');
    print "$firstname $lastname\n";
}
David Sklar
Adam Trachtenberg


Since the inner XPath queries return only one element, use list to grab it from the array.

从这个内部的XPath查询返回唯一的元素。使用目录夺取它的数组

你想要分解一个巨大的XML文件。这个文件是非常大、不切实际的使用SimpleXML或者DOM.因为你不希望全部的文件在memory。代替。你必须装在文件在一个部分

12.5.2解答
Use the XMLReader extension:

使用这个XMLReader延长名


?php
$reader = new XMLReader();
$reader->open('card-catalog.xml');
/* Loop through document */
while ($reader->read()) {
    /* If you're at an element named 'author' */
    if ($reader->nodeType == XMLREADER::ELEMENT && $reader->localName == 'author') {
        /* Move to the text node and print it out */
        $reader->read();
        print $reader->value . "\n";
    }
}

There are two major types of XML parsers: ones that hold the entire document in memory at once, and ones that hold only a small portion of the document in memory at any given time.

这是两个主要的XML剖析器类型、一个把握全部的文件在merory,然后一个希望唯一的小的一部分文件在memory在一些时间

The first kind are called tree-based parsers, since they store the document into a data structure known as a tree. The SimpleXML and DOM extensions, from Recipes 12.3 and 12.4, are tree-based parsers. Using a tree-based parser is easier for you, but requires PHP to use more RAM. With most XML documents, this isn’t a problem. However, when your XML document is quite large, then this can cause major performance issues.

这第一个调用tree-based的剖析器、从它们存储文件到一个数据结构是一个tree。这个SimpleXML和DOM扩展名从第12.3和12.4和tree-based剖析器对于你来说容易的。但是命令PHP去使用更多的RAM。和更多的XML文件。他不是一个问题。经当你的XML文件非常大。然后它导致主要的问题
The other kind of XML parser is a stream-based parser. Stream-based parsers don’t store the entire document in memory; instead, they read in one node at a time and allow you to interact with it in real time. Once you move onto the next node, the old one is thrown away’unless you explicitly store it yourself for later use. This makes stream-based parsers faster and less memory consuming, but you may have to write more code to process the document.
这个其他类型的XML剖析器是一个stream-based 

schema, or you need to use more esoteric XML features, such as processing instructions or comments.

你有一个复杂的XML文件。例如在你需要的内部文件去测定它的计划。或者你需要使用很多深奥的XML性质。例如处理指示或者

注释

12.4.2解答

Use the DOM extension. It provides a complete interface to all aspects of the XML specification
使用这个DOM延展名。它规定一个完整的界面到所有XML规范


?php
$dom = new DOMDocument;
$dom->load('address-book.xml');
foreach ($dom->getElementsByTagname('person') as $person) {
    $firstname = $person->getElementsByTagname('firstname');
    $firstname_text_value = $firstname->item(0)->firstChild->nodeValue;
    $lastname = $person->getElementsByTagname('lastname');
    $lastname_text_value = $lastname->item(0)->firstChild->nodeValue;
    print "$firstname_text_value $lastname_text_value\n";
}
David Sklar
Adam Trachtenberg


12.4.3讨论
The W3C’s DOM provides a platform- and language-neutral method that specifies the structure and content of a

document. Using the DOM, you can read an XML document into a tree of nodes and then maneuver through the tree

to locate information about a particular element or elements that match your criteria. This is called tree-

based parsing.
这个W3C’s DOM规定一个platform-和language-neutral 方法指定结构和内容的文件，使用这个DOM.你可以阅读一个XML文件到

一个tree站点然后机动穿过tree的站点信息的一个特殊元素或者元素匹配你的标准。它调用tree-based分解
 
Additionally, you can modify the structure by creating, editing, and deleting nodes. In fact, you can use the

DOM functions to author a new XML document from scratch; see Recipe 12.2.
另外、你可以修改结构创造。编辑和删除网点、事实上，你可以使用DOM函数去创造一个新的XML文件从新开始，看12.2 
One of the major advantages of the DOM is that by following the W3C’s specification, many languages implement

DOM functions in a similar manner. Therefore, the work of translating logic and instructions from one

application to another is considerably simplified. PHP 5 comes with a new series of DOM methods that are in

stricter compliance with the DOM standard than previous versions of PHP.
一个有主要优势的DOM文件跟随这个W3C’s详述。很多语言执行DOM函数在某种意义上相似因此、这个工作翻译逻辑和指示从一

个应用到另一个相当的PHP5伴随一个新增序列的DOM方法是一个严格的DOM标准 
The DOM is large and complex. For more information, read the specification at http://www.w3.org/DOM/ or pick

up a copy of XML in a Nutshell.
这个DOM是巨大的复杂。例如信息。阅读详细的在http://www.w3.org/DOM或者精选一份XML

DOM functions in PHP are object oriented. To move from one node to another, access properties such as $node-

>childNodes, which contains an array of node objects, and $node->parentNode, which contains the parent node

object. Therefore, to process a node, check its type and call a corresponding method, as shown in Example 12-

5.
DOM函数在PHP的对象倒像、去移动一个网点到其他访问道具例如$node->childNodes。哪个包含一个数组站点对象。和$node-

>parentNOde。哪个包含亲代交点。因此。处理一个node。组织它的类型和调用一个相应的方法，例如在例子12–5

Parsing a DOM object

?php
// $node is the DOM parsed node <book cover="soft">PHP Cookbook</book>
$type = $node->nodeType; 
switch($type) {
case XML_ELEMENT_NODE:
    // I'm a tag. I have a tagname property.
    print $node->tagName;  // prints the tagname property: "book"
    break;
case XML_ATTRIBUTE_NODE:
    // I'm an attribute. I have a name and a value property.
    print $node->name;  // prints the name property: "cover"
    print $node->value; // prints the value property: "soft"
    break;
case XML_TEXT_NODE:
    // I'm a piece of text inside an element.
    // I have a name and a content property.
    print $node->nodeName;  // prints the name property: "#text"
    print $node->nodeValue; // prints the text content: "PHP Cookbook"
    break;
default:
    // another type
    break;
}

To automatically search through a DOM tree for specific elements, use getElementsByTagname( ). Example 12-6

shows how to do so with multiple book records.
自动的搜索一个DOM tree对于特殊的元素、使用getElementByTagname()。例如12-6显示怎么去多多样的账面记录

Card catalog in XML
<books>
    <book>
        <title>PHP Cookbook</title>
        <author>Sklar</author>
        <author>Trachtenberg</author>
        <subject>PHP</subject>
    </book>
    <book>
        <title>Perl Cookbook</title>
        <author>Christiansen</author>
        <author>Torkington</author>
        <subject>Perl</subject>
    </book>
</books>

Example 12-7 shows how to find all authors.
例子12-7显示怎么去找到所有的作者

Printing all authors using DOM
// find and print all authors
$authors = $dom->getElementsByTagname('author');
// loop through author elements
foreach ($authors as $author) {
    // childNodes holds the author values
    $text_nodes = $author->childNodes;
    foreach ($text_nodes as $text) {
         print $text->nodeValue . "\n";
    }
}
Sklar
Trachte nberg
Christiansen
Torkington


你想要产生XML。但是应该在一个organized路线代替使用print 和loops

12.2.2解答
Use the DOM extension to create a DOMDocument object. After building up the document, call DOMDocument::save(

) or DOMDocument::saveXML( ) to generate a well-formed XML document
使用这个DOM的延长区创造一个DOMDocument object、然后树立这个文件、调用DOMDocument::save()或者

DOMDocument::saveXML()去产生一个健康成型的文件

?php
// create a new document
$dom = new DOMDocument('1.0');
// create the root element, <book>, and append it to the document
$book = $dom->appendChild($dom->createElement('book'));
// create the title element and append it to $book
$title = $book->appendChild($dom->createElement('title'));
// set the text and the cover attribute for $title
$title->appendChild($dom->createTextNode('PHP Cookbook'));
$title->setAttribute('cover', 'soft');
// create and append author elements to $book
$sklar = $book->appendChild($dom->createElement('author'));
// create and append the text for each element
$sklar->appendChild($dom->createTextNode('Sklar'));
$trachtenberg = $book->appendChild($dom->createElement('author'));
$trachtenberg->appendChild($dom->createTextNode('Trachtenberg'));
// print a nicely formatted version of the DOM document as XML
$dom->formatOutput = true;
echo $dom->saveXML();
?>
<?xml version="1.0"?>
<book>
  <title cover="soft">PHP Cookbook</title>
  <author>Sklar</author>
  <author>Trachtenberg</author>
</book>


12.3.3讨论
The DOM methods follow a pattern. You create an object as either an element or a text node, add and set any

attributes you want, and then append it to the tree in the spot it belongs.
这个DOM方法允许仿制。你创造一个对象当作任意一个元素或者一个文件网点。增加移动一些你想要的属性。然后附加它到心

事驱动器的子目录结果
Before creating elements, create a new document, passing the XML version as the sole argument:
在创造元素之前。创造一个新建文档通过这个XML版本当作单一的论点

$dom = new DOMDocument('1.0');


Now create new elements belonging to the document. Despite being associated with a specific document, nodes

don’t join the document tree until appended:

现在创造一个新的元素属于文件。不管联合一个特殊文件网点不能链接文件直到设置数据文件的搜索路径


$book_element = $dom->createElement('book');
$book = $dom->appendChild($book_element);


Here a new book element is created and assigned to the object $book_element. To create the document root,

append $book_element as a child of the $dom document. The result, $book, refers to the specific element and

its location within the DOM object
这是一个新的文件元素创造分配到$book_element去保存这个文件证明，附加$book_element当作一个子类$dom文件。这个结果

$book，引用特殊的元素和位置内部DOM对象

All nodes are created by calling a method on $dom. Once a node is created, it can be appended to any element

in the tree. The element from which we call the appendChild( ) method determines the location in the tree 
所有的网点创造调用一个方法在$dom.从一个node创造，它可以附加一些元素在这个tree.这个元素从我们调用这个

appendChid()方法确定位置在这个tree，
You can also append a new child element to $book. Since $book is a child of $dom, the new element is, by

extension, a grandchild of $dom:

你同样可以附加一个新的子元素到$book.从$book是一个子类$dom。这个新的元素是延长一个孙类$dom


$title_element = $dom->createElement('title');
$title = $book->appendChild($title_element);


By calling $book->appendChild( ), this code places the $title_element element under the $book element.

调用$book->appendChild()。这个代码放置这个$titie_element .在这个$book元素

To add the text inside the <title></title> tags, create a text node using createTextNode( ) and append it to

$title:

去增加正文代替<title></title>标签，创造一个正文网点使用createTextNode()和append()它到$title


$text_node = $dom->createTextNode('PHP Cookbook');
$title->appendChild($text_node);

Since $title is already added to the document, there’s no need to re-append it to $book.

从$title是已经增加到这个文件。就不需要去附加到$book

$title_element = $dom->createElement('title');
$text_node = $dom->createTextNode('PHP Cookbook');
$title_element->appendChild($text_node);
$book->appendChild($title_element);


To add an attribute, call setAttribute( ) upon a node, passing the attribute name and value as arguments:

去增加一个属性。调用setAttribute()upon一个网点。通过这个attribute名字和数值当作论点

$title->setAttribute('cover', 'soft');

If you print the title element now, it looks like this:

如果你打印这个title元素。它会是这样

<title cover="soft">PHP Cookbook</title>

Once you’re finished, you can output the document as a string or to a file:

从前你完成。你可以输出文件就像一个字符串或者一个文件


// put the string representation of the XML document in $books
$books = $dom->saveXML();
// write the XML document to books.xml
$dom->save('books.xml');


parse.

你想要产生XML。例如。你想要规定一个XML版本的数据解析其他程序

12.1.2解答
Loop through your data and print it out surrounded by the correct XML tags:
通过你的数据打印出正确的XML标签

?php
header(’Content-Type: text/xml’);
print ‘<?xml version=”1.0″?>’ . “\n”;
print “<shows>\n”;
$shows = array(array(’name’     => ‘Simpsons’,
                     ‘channel’  => ‘FOX’,
                     ’start’    => ‘8:00 PM’,
                     ‘duration’ => ‘30′),

               array(’name’     => ‘Law & Order’,
                     ‘channel’  => ‘NBC’,
                     ’start’    => ‘8:00 PM’,
                     ‘duration’ => ‘60′));
foreach ($shows as $show) {
    print “    <show>\n”;
    foreach($show as $tag => $data) {
        print “        <$tag>” . htmlspecialchars($data) . “</$tag>\n”;
    }
    print “    </show>\n”;
}
print “</shows>\n”;;

12.1.3讨论
Printing out XML manually mostly involves lots of foreach loops as you iterate through arrays. However, there

are a few tricky details. First, you need to call header( ) to set the correct Content-Type header for the

document. Since you’re sending XML instead of HTML, it should be text/xml.

手动打印出XML主要的foreach当作你重复的数组。尽管这是一个详细资料。首先你需要钓鱼hearder()去获得正确的Content-

Type.对于这个文件。从你过的XML代替HTML.它的text/xml
Next, depending on your settings for the short_open_tag configuration directive, trying to print the XML

declaration may accidentally turn on PHP processing. Since the <? of <?xml version=”1.0″?> is the short PHP

open tag, to print the declaration to the browser you need to either disable the directive or print the line

from within PHP. We do the latter in the Solution.

下面。依靠你的设置去short_open_tag配置指示。试着打印出XML声明可以转换PHP处理。从这个<?到<?xml version=”1.0″?>

是这个短的PHP tag去打印出这个声明到浏览器 你需要的任意显示这个指示或者打印出PHP。我们有解答在后面
Last, entities must be escaped. For example, the & in the show Law & Order needs to be &amp;. Call

htmlspecialchars( ) to escape your data.

最后实体必须逃脱。例如这个&在这个表面&需要到&amo、调用htmlspecialchars()去逃开你的数据
The output from the example in the Solution is shown in Example 12-1.

这个输出这个例子在这个解答在例子12-1

<?xml version="1.0"?>
<shows>
    <show>
        <name>Simpsons</name>
        <channel>FOX</channel>
        <start>8:00 PM</start>
        <duration>30</duration>
    </show>
    <show>
        <name>Law &amp; Order</name>
        <channel>NBC</channel>
        <start>8:00 PM</start>
        <duration>60</duration>
    </show>
</shows>


你需要收集统计到巨大的表格可以迅速的查询
11.7.2解答
Create a table that stores summary data from the complete log table, and query the summary table to generate

reports in nearly real time.

在全部的表格里创建一个表格去存储主要数据，然后查询一览表去产生报告在瞬间

11.7.3讨论

Let’s say that you are logging search queries that web site visitors use on search engines like Google and

Yahoo! to find your web site, and tracking those queries in MySQL. Your search term tracking log table has

this structure: 
在你的日志搜索查询这个web站点，访问者使用搜索引擎例如Google和Yahoo. 去寻找你的网络站点。然后跟踪这个查询在

MySQL。你查询一览表的结构


CREATE TABLE searches
(
  searchterm    VARCHAR(255) NOT NULL,  # search term determined from HTTP_REFERER
                                        parsing
  dt            DATETIME NOT NULL,      # request date
  source        VARCHAR(15) NOT NULL    # site where search was performed
);


If you are fortunate enough to be logging thousands or tens of thousands of visits from the major search

engines per hour, the searches table could grow to an unmanageable size over a period of several months.
如果你有足够数以千计的访问流量从主要的搜索路径每个小时。这个查询列表会有处理不了的尺寸在单月
You may wish to generate reports that illustrate trends of search terms that have driven traffic to your web

site over time from each major search engine so that you can determine which search engine to purchase

advertising with.

你可以希望产生报告举例搜索查询趋势交易到你的网络站点随着时间过去每个主要搜索引擎，你可以决定购买哪个搜索引擎的

广告

Create a summary table that reflects what your report needs to display, and then query the full dataset hourly

and store the result in the summary table for speedy retrieval during report generation. Your summary table

would have this structure:

创造一个一览表，当报告需要显示。然后每小时查询所有数据存储结果到这个一览表迅速的产生报告。你的一览表需要有它的

结构

CREATE TABLE searchsummary
(
  searchterm    VARCHAR(255) NOT NULL,  # search term
  source        VARCHAR(15) NOT NULL,   # site where search was performed
  sdate         DATE NOT NULL,          # date search performed
  searches      INT UNSIGNED NOT NULL,  # number of searches
  PRIMARY KEY (searchterm, source, sdate)
);

Your report generation script can then use PDO to query the searchsummary table, and if results are not

available, collect them from the searches table and cache the result in searchsummary:

你的报告产生原本的使用者PDO去查询表格。然后如果结果不可利用。收集搜索表格和存储结果到searchsummary

$st = $db->prepare('SELECT COUNT(*)
                     FROM
                        searchsummary
                     WHERE
                        sdate = ?');
$st->execute(array(date('Y-m-d', strtotime('yesterday'))));
$row = $st->fetch();
// no matches in cache
if ($row[0] == 0) {
    $st2 = $db->prepare('SELECT
                          searchterm,
                          source,
                          FROM_DAYS(TO_DAYS(dt)) AS sdate,
                          COUNT(*) as searches
                       WHERE
                          TO_DAYS(dt) = ?');
   $st2->execute(array(date('Y-m-d', strtotime('yesterday'))));

   $stInsert = $db->prepare('INSERT INTO searchsummary
                             (searchterm,source,sdate,searches)
                             VALUES (?,?,?,?)');
   while ($row->fetch(PDO::FETCH_NUM)) {
       $stInsert->execute($row);
   }
}


Using this technique, your script will only incur the overhead of querying the full log table once, and all

subsequent requests will retrieve a single row of summary data per search term.

使用这个方法。你的原本将唯一招致全部查询到表格然后给所有后来的请求会重新找回一个单一行的主要数据
   

你想要将大量的服务器进行可利用的数据存储到公用存储器
11.6.2解答

Use the pc_Shm class shown in Example 11-3. For example, to store a string in shared memory, used

the pc_Shm::save( ) method, which accepts a key/value pair
使用这个Pc_Shm类例如在例子11-3，例如去存储字符串到公用存储器。使用这个pc_Shm::save()方法，哪个认可一

个key/value

?php
$shm = new pc_Shm();
$secret_code = 'land shark';
$shm->save('mysecret', $secret_code);


Another process can then access that data from shared memory with the pc_Shm::fetch( ) method:

另外的处理方法可以从公用存储器里访问数据使用pc_Shm::fetch()方法

?php
$shm = new pc_Shm();
print $shm->fetch('mysecret');

11.6.3讨论

Occasionally there are times when you want to cache a value or set of values in shared memory for

rapid retrieval. If your web server is busy with disk I/O, it may make sense to leverage the shmop

functions to achieve greater performance with storage and retrieval of information in that cache.
有时候当你想要隐藏一个数值或者移动数值到共有存储器，如果你的网络服务器正工作于I/O磁盘,它可以起平衡作

用使这个shmop函数去完成存储和修复信息在这个存储区

The pc_Shm class has two convenient methods, pc_Shm::fetch( ) and pc_Shm::save( ), which abstract

away the need to set memory addresses or explictly open and close the shared memory segments.
这个pc_Shm类有两个方便的方法。pc_Shm::fetch()和pc_Shm::save().哪个主要函数需要获得存储地址或者打开关

闭这个公用存储器

<?php
$shm = new pc_Shm();
$shm->setSize(24576); // 24k
$shm->save('longstring', 'Lorem ipsum pri eu simul nominati...');


你想要存储session数据到公用存储器，以保持最佳状态

11.5.2解答

Use the pc_Shm_Session class shown in Example 11-3. For example:

使用这个pc_Shm_Session 类例如在例子11-3、例如

?php
$s = new pc_Shm_Session();
ini_get('session.auto_start') or session_start();

11.5.3讨论
As discussed in Recipe 11.4, the session module allows users to define their own session handling

methods. While this flexibility is most commonly used to store session data in a database, you may

find that performance suffers with the overhead of the database connection and the subsequent

queries. If sharing session data across a bunch of web servers is not a concern, you can boost

session handling performance by storing that data in shared memory.
在第11.4的讨论中，这个session模块允许使用者定义他们自己的session讨论方法，它适用大多一般的经常存储

session数据在一个数据库，你可以找到受损害的session在数据库链接上面和后发的问题。如果共享session数据

横过web服务器而不涉及，你可以推进session处理执行存储这个数据在公用存储器
Before deciding to use shared memory for session storage, make sure that you can spare the amount of

memory that your traffic plus your average session data size will consume. The performance boost of

shared memory session storage won’t matter if your site’s sessions consume all available memory on

your system!
决定使用公用存储器存储session。确认你可以节省内存数量加上你的平均session数据量可以消耗。这个执行推进

公用存储器存储session.不用担心如果你的站点sessions消耗所有可利用的内容在你的系统

To store session data in shared memory, you need to have the shared memory functions explicitly

enabled by building PHP with –enable-shmop. You will also need the pc_Shm class shown in Example

11-3, as well as the pc_Shm_Session class shown in Example 11-3.

存储session数据在公用存储器，你需要明确公用存储器的函数记忆功能。激活建立PHP–enable-shmop你同样需要

这个pc_Shm 类例如在例子11-3当作pc_Shm_Session类。例如在例子11-3


class pc_Shm {
  var $tmp;
  var $size;
  var $shm;
  var $keyfile;
  function pc_Shm($tmp = '') {
    if (!function_exists('shmop_open')) {
      trigger_error('pc_Shm: shmop extension is required.', E_USER_ERROR);
      return;
    }
    if ($tmp != '' && is_dir($tmp) && is_writable($tmp)) {
      $this->tmp = $tmp;
    } else {
      $this->tmp = '/tmp';
    }
    // default to 16k
    $this->size = 16384;
    return true;
  }
  function __construct($tmp = '') {
    return $this->pc_Shm($tmp);
  }
  function setSize($size) {
    if (ctype_digit($size)) {
      $this->size = $size;
    }
  }
  function open($id) {
    $key = $this->_getKey($id);
    $shm = shmop_open($key, 'c', 0644, $this->size);
    if (!$shm) {
      trigger_error('pc_Shm: could not create shared memory segment', E_USER_ERROR);
      return false;
    }
    $this->shm = $shm;
    return true;
  }
  function write($data) {
    $written = shmop_write($this->shm, $data, 0);
    if ($written != strlen($data)) {
      trigger_error('pc_Shm: could not write entire length of data', E_USER_ERROR);
      return false;
    }
    return true;
  }
  function read() {
    $data = shmop_read($this->shm, 0, $this->size);
    if (!$data) {
      trigger_error('pc_Shm: could not read from shared memory block', E_USER_ERROR);
      return false;
    }
    return $data;
  }
  function delete() {
    if (shmop_delete($this->shm)) {
      if (file_exists($this->tmp . DIRECTORY_SEPARATOR . $this->keyfile)) {
        unlink($this->tmp . DIRECTORY_SEPARATOR . $this->keyfile);
      }
    }
    return true;
  }
  function close() {
    return shmop_close($this->shm);
  }
  function fetch($id) {
    $this->open($id);
    $data = $this->read();
    $this->close();
    return $data;
  }
  function save($id, $data) {
    $this->open($id);
    $result = $this->write($data);
    if (! (bool) $result) {
      return false;
    } else {
      $this->close();
      return $result;
    }
  }
  function _getKey($id) {
    $this->keyfile = 'pcshm_' . $id;
    if (!file_exists($this->tmp . DIRECTORY_SEPARATOR . $this->keyfile)) {
      touch($this->tmp . DIRECTORY_SEPARATOR . $this->keyfile);
    }
    return ftok($this->tmp . DIRECTORY_SEPARATOR . $this->keyfile, 'R');
  }
}

The pc_Shm class provides an object-oriented wrapper around PHP’s shmop functions. The

pc_Shm::_getKey( ) method provides a convenient way to transparently calculate a memory address,

which is often the biggest obstacle for people getting familiar with the shmop functions. By

abstracting the memory address, reading and writing from shared memory is as easy as manipulating a

value in an associative array.

这个pc_Shm类规定一个object_oriented环绕PHP的shmop函数。这个pc_Shm::_getKey()方法规定一个方便的方法去

明显的计算存储地址，那个是经常使用的大妨碍物人们获得熟悉的shmop函数，显示这个存储地址。读写公用存储

器更加简单熟练的一个值在一个联合数组 

pc_Shm creates 16k memory blocks by default. To adjust the size of the blocks used, pass a value in

bytes to the pc_Shm::setSize( ) method.

pc_Shm 创造16K存储区。整修使用者大小通过一个数值在pc_Shm::setSize()方法

With pc_Shm defined, pc_Shm_Session has what it needs to easily provide custom methods for

session_set_save_handler( ). Example 11-3 shows the pc_Shm_Session class.

定义pc_Shm 它可以容易的规定习惯方法对于session_set_save_handler(),例子11-3显示这个pc_Shm_Session类

class pc_Shm_Session {
  var $shm;
  function pc_Shm_Session($tmp = '') {
    if (!function_exists('shmop_open')) {
      trigger_error("pc_Shm_Session: shmop extension is required.",E_USER_ERROR);
      return;
    }
    if (! session_set_save_handler(array(&$this, '_open'),
                     array(&$this, '_close'),
                     array(&$this, '_read'),
                     array(&$this, '_write'),
                     array(&$this, '_destroy'),
                     array(&$this, '_gc'))) {
      trigger_error('pc_Shm_Session: session_set_save_handler() failed', E_USER_ERROR);
      return;
    }
    $this->shm = new pc_Shm();
    return true;
  }
  function __construct() {
    return $this->pc_Shm_Session();
  }
  function setSize($size) {
    if (ctype_digit($size)) {
      $this->shm->setSize($size);
    }
  }
  function _open() {
    return true;
  }
  function _close() {
    return true;
  }
  function _read($id) {
    $this->shm->open($id);
    $data = $this->shm->read();
    $this->shm->close();
    return $data;
  }
  function _write($id, $data) {
    $this->shm->open($id);
    $this->shm->write($data);
    $this->shm->close();
    return true;
  }
  function _destroy($id) {
    $this->shm->open($id);
    $this->shm->delete();
    $this->shm->close();
  }
  function _gc($maxlifetime) {
    $d = dir($this->tmp);
    while (false !== ($entry = $d->read())) {
      if (substr($entry, 0, 6) == 'pcshm_') {
        $tmpfile = $this->tmp . DIRECTORY_SEPARATOR . $entry;
        $id = substr($entry, 6);
        $fmtime = filemtime($tmpfile);
        $age = now() - $fmtime;
        if ($age >= $maxlifetime) {
          $this->shm->open($id);
          $this->shm->delete();
          $this->shm->close();
        }
      }
    }
    $d->close();
    return true;
  }
}


Versions of Microsoft Windows prior to Windows 2000 do not support shared memory. Also, when using

PHP in a Windows server environment, shmop functions will only work if PHP is running as a web

server module, such those provided by Apache or IIS. CLI and CGI interfaces to PHP do not support

shmop functions under Windows.

微软2000操作系统之前的版本都不支持公用存储器，同样当使用PHP在一个Windows服务器环境。shmop函数仅仅可

以工作。如果PHP运行在一个web服务器模块 例如那些Apache或者IIS。CLT和CGI界面不支持shmop函数在Windows


?php
ini_set('session.save_path', '/dev/shm');
ini_get('session.auto_start') or session_start();

 

session data is then mirrored across all the web servers.
你想要存储session数据在一个数据库代替在文件里。如果多样化网络服务器都有权使用一样的数据库。这个session数据在这个DOS访问所有 web服务器
11.4.2解答
Use a class or a set of functions in conjunction with the session_set_save_handler( ) function to define database-aware routines for

session management. For example, use PEAR’s HTTP_Session package for convenient database session storage:

使用一个类或者一个函数集和这个session_set_save_handler()函数定义database-aware程序管理、例如。使用REAR’s HTTP_Session 便利的存储session到

数据库


?php
require_once 'HTTP/Session/Container/DB.php';
$s = new HTTP_Session_Container_DB('mysql://user:password@localhost/db');
ini_get('session.auto_start') or session_start();

11.4.3讨论
One of the most powerful aspects of the session module is its abstraction of how sessions get saved. The session_set_save_handler( )

function tells PHP to use different functions for the various session operations such as saving a session and reading session data.

一个session 模块最有力的方面是怎么获得session.这个session_set_save_handler()函数告诉PHP去使用不同的函数在不同的session操作。例如获得一个

session和读出session的数据
The PEAR HTTP_Session package provides classes that take advantage of PEAR’s DB, MDB, and MDB2 database abstraction packages to store

session data in a database. If the database is shared between multiple web servers, users’ session information is portable across all

those web servers. So if you have a bunch of web servers behind a load balancer, you don’t need any fancy tricks to ensure that a user’s

session data is accurate no matter which web server she gets sent to.

这个PEAR HTTP_Session 规定利用PEAR’sDB 和MDB2数据库提交数据库包去存储session数据，如果这个数据库共享多个浏览器。使用者的session信息轻松越

过这些服务器。所有如果你有一个网络服务器的加载权衡，你不需要一些特别的窍门去确保使用者的session数据正确性

To use HTTP_Session_Container_DB, pass a data source name (DSN) to the class when you instantiate it. The session data is stored in a

table called sessiondata whose structure is:
去使用HTTP_Session_Container_DB。通过一个数据发起姓名(DSN)到这个类。当你示例时。这个session数据存储在一个sessiondata的表格里


CREATE TABLE sessiondata
(
  id CHAR(32) NOT NULL,
  data MEDIUMBLOB,
  expiry INT UNSIGNED NOT NULL,
  PRIMARY KEY (id)
);

If you want the table name to be different than sessiondata, you can set a new table name with an options array when instantiating the

HTTP_Session_Container_DB class:

如果你想要表格名字不同于sessiondata。 你可以设置一个新的表格名和一个选项数组当示例这个HTTP_Session_Container_DB类


?php
require_once 'HTTP/Session/Container/DB.php';
$options = array(
  'table'  => 'php_session',
  'dsn'    => 'mysql://user:password@localhost/db'
);
$s = new HTTP_Session_Container_DB($options);
ini_get('session.auto_start') or session_start();


你想要确认你的应用软件不容易遭到攻击session可以抵御攻击

11.3.2解答
Require the use of session cookies without session identifiers appended to URLs, and generate a new session ID frequently:

命令使用session cookies和session 表示符附加到URLs，然后产生一个新的session ID


ini_set('session.use_only_cookies', true);
session_start();
if (!isset($_SESSION['generated'])
    || $_SESSION['generated'] < (time() - 30)) {
    session_regenerate_id();
    $_SESSION['generated'] = time();
}

11.3.3讨论
In this example, we start by setting PHP’s session behavior to use cookies only. This overrides PHP’s default behavior of transparently

appending values such as ?PHPSESSID=12345678 to any URL on a page whenever a visitor’s session is started if he doesn’t have cookies

enabled in his browser.

在这个例子，我们首先安装PHP’s session去使用唯一cookies、它不考虑PHP的默认行为附加值例如PHPSESSID=1234567到一些URL的页面，当访问者的

session已经开始，否则cookies在浏览器激活
Once the session is started, we set a value that will keep track of the last time a session ID was generated. By requiring a new one to

be generated on a regular basis’every 30 seconds in this example’the opportunity for an attacker to obtain a valid session ID is

dramatically reduced.

一旦session启动。我们给定值，它会产生上次的一个session ID，它命令新的一个session在每30秒产生一个正规的元素。在这个例子攻击者的机会是获得

一个有效的session ID简化

These two approaches combine to virtually eliminate the risk of session fixation. An attacker has a hard time obtaining a valid session

ID because it changes so often, and since sessions IDs can only be passed in cookies, a URL-based attack is not possible. Finally, since

we enabled the session.use_only_cookies setting, no session cookies will be left lying around in browser histories or in server referrer

logs.

这两个联合方法事实上排除了有风险的固定session。攻击者很困难去获得一个有效的session ID.因为它是经常变化的。从前的session IDs已经被传递到

cookies。一个基于URL的攻击不可能存在。最后我们激活这个session.use_only_cookies设置。没有session cookies将被丢失在浏览器历史或者在浏览器提

交日志

11.2.2解答
Allow passing of session IDs via cookies only, and generate an additional session token that is passed via URLs. Only requests that

contain a valid session ID and a valid session token may access the session:

允许通过session IDs到唯一的cookies。然后产生一个另外的session表示通过URLs、唯一的请求包含一个有效的session ID和一个有效的session表示可以

访问这个session


?php
ini_set('session.use_only_cookies', true);
session_start();
$sat     = 'YourSpecialValueHere';
$tokenstr = (str) date('W') . $salt;
$token    = md5($tokenstr);
if (!isset($_REQUEST['token']) || $_REQUEST['token'] != $token) {
    // prompt for login
    exit;
}
$_SESSION['token'] = $token;
output_add_rewrite_var('token', $token);

If you’re using a PHP version earlier than 4.3.0, output_add_rewrite_var( ) is not available. Instead, use the code in Example 11-1.
如果你使用一个早于4.3.0的PHP版本。output_add_rewrite_var()不可用。代替它，使用这个代码在例子11-1
Adding a session token to links
增加一个session的链接

?php
ini_set('session.use_only_cookies', true);
session_start();
$salt     = 'YourSpecialValueHere';
$tokenstr = (str) date('W') . $salt;
$token    = md5($tokenstr);
if (!isset($_REQUEST['token']) || $_REQUEST['token'] != $token) {
    // prompt for login
    exit;
}
$_SESSION['token'] = $token;
ob_start('inject_session_token');
function inject_session_token($buffer)
{
    $hyperlink_pattern = "/<a[^>]+href=\"([^\"]+)/i";
    preg_match_all($hyperlink_pattern, $buffer, $matches);
    foreach ($matches[1] as $link) {
        if (strpos($link, '?') === false) {
            $newlink = $link . '?token=' . $_SESSION['token'];
        } else {
            $newlink = $link .= '&token=' . $_SESSION['token'];
        }
        $buffer = str_replace($link, $newlink, $buffer);
    }
    return $buffer;
}

The regular expression for matching hyperlinks in the inject_session_token( ) function isn’t bulletproof; it will not catch hyperlinks

with href attributes quoted with single quotes.
这个正则表达式匹配超链接在这个inject_session_token()函数不是bulletproof.他不能捕捉超链接和href使用单引号

11.2.3讨论
This example creates an auto-shifting token by joining the current week number together with a salt term of your choice. With this

technique, tokens will be valid for a reasonable period of time without being fixed.

这个例子创造一个auto-shifting表示连接通用的星期数加之你选择的一个salt期限。用这个方法表示一个有效合理的时段

We then check for the token in the request, and if it’s not found, we prompt for a new login.

然后我们阻止这个请求。然后如果它找不到。我们提示一个新的注册

If it is found, it needs to be added to generated links. output_add_rewrite_var( ) does this easily. Without output_add_rewrite_var( ),

we continue generating the page and declare an output buffer callback function that will make sure that any hyperlinks on the page are

modified to contain the current token before the page is displayed.

如果建立。它需要增加连接。output_add_rewrite_var()可以更加简单。使用output_add_rewrite_var()，我们连续产生这个页面声明输出缓冲器回收函数

。它可以确认一些超链接在这个页面修正、包含当前通用的页面显示
Note that the inject_session_token( ) function in the example does not address imagemaps, form submissions, or Ajax calls; make sure that

you adjust any such functionality on a page to include the session token that’s been generated and stored in the session
注意这个inject_session_token()函数在这个例子不能显示图像。或者Ajax钓鱼。确认你调整这些功能性在一个页面包含session产生存储在这个session

11.1.1问题
You want to maintain information about a user as she moves through your site
你想要维护使用者的信息移动到你的站点

11.1.2解答
Use the sessions module. The session_start( ) function initializes a session, and accessing an element in the auto-global $_SESSION array tells PHP to keep track of the corresponding variable:

使用者这个session模块。这个seesion_start()函数初始化一个session。然后访问一个元素在全局变量$_SESSION数组告诉PHP相应的变量


?php
session_start();
$_SESSION['visits']++;
print 'You have visited here '.$_SESSION['visits'].' times.';


11.1.3讨论
The session function keep track of users by issuing them cookies with randomly generated session IDs.

这个session函数保存使用者的cookies和未知的sessionIDs

By default, PHP stores session data in files in the /tmp directory on your server. Each session is stored in its own file. To change the directory in which the files are saved, set the session.save_path configuration directive to the new directory in php.ini or with ini_set( ). You can also call session_save_path( ) with the new directory to change directories, but you need to do this before starting the session or accessing any session variables

By default。PHP存储session数据在文件在你的服务器目录、每个session存储它自己的文件。去改变目录这个文件保存在哪里。移动这个session.save_path配置指示新的目录在php.ini或者ini_set()，你同样可以调用session_save_path()和这个新的目录去改变目录，但是你需要之前已经开始的session或者访问一些session的变量
To start a session automatically on each request, set session.auto_start to 1 in php.ini. With session.auto_start, there’s no need to call session_start( ).

自动开始一个session在每个索引。设置session.auto_start到1在php.ini.使用session.auto_start，就不需要调用session_start()

With the session.use_trans_sid configuration directive turned on, if PHP detects that a user doesn’t accept the session ID cookie, it automatically adds the session ID to URLs and forms.[] For example, consider this code that prints a URL:

使用这个session.use_trans_sid配置指示开始。如果PHP发现这个使用者不接受session ID cookie。它自动的增加session Id 到URLs和forms.[]例如考虑这个代码打印出一个URL

?php
print '<a href="train.php" mce_href="train.php">Take the A Train</a>';

If sessions are enabled, but a user doesn’t accept cookies, what’s sent to the browser is something like:

如果sessions激活。但是使用者不接受cookies。发送浏览器重要

?php
<a href="train.php?PHPSESSID=2eb89f3344520d11969a79aea6bd2fdd" mce_href="train.php?PHPSESSID=2eb89f3344520d11969a79aea6bd2fdd">Take the A Train</a>

 

In this example, the session name is PHPSESSID and the session name is 2eb89f3344520d11969a79aea6bd2fdd. PHP adds those to the URL so they are passed along to the next page. Forms are modified to include a hidden element that passes the session ID.

在这些例子。这个session名字是PHPSESSID和这个session名字是2eb89f3344520d11969a79aea6bd2fdd.PHP增加这些URL,所以它通过下一个页面。改良包括隐藏的元素到这个sessionID
Due to a variety of security concerns relating to embedding session IDs in URLs, this behavior is disabled by default. To enable transparent session IDs in URLs, you need to turn on session.use_trans_sid in php.ini or through the use of ini_set(’session.use_trans_sid’, true) in your scripts before the session is started.

由于一个多种安全涉及embedding session IDs在URLs.这些行为是丧失能力的。能够显然的sessions IDs在URLs.你需要转换session.ues_trans_sid在php.ini或者通过这些使用ini_set(’session.use_trans_sid’,ture)在你的原本session开始
Although session.use_trans_sid is convenient, it can cause you some security-related headaches. Because URLs have session IDs in them, distribution of such a URL lets anybody who receives the URL act as the user to whom the session ID was given. A user that copies a URL from his web browser and pastes it into an email message sent to friends unwittingly allows all those friends (and anybody else to whom the message is forwarded) to visit your site and impersonate him.

通过session.use_trans_sid很方便。它可以使你有一些安全，因为URLs有sessionIDs在这些。分配这些就像一个URL任何接收URL获得使用者的ID.一个使用者复制一个URL从它的浏览器，然后粘贴它到一个email信息无意的发送到一个好友允许所有好友访问你的站点
Separately, redirects with the Location header aren’t automatically modified, so you have to add a session ID to them yourself using the SID constant:

个别的改变方向位置标题不能自动修改。所有你需要增加一个session ID到这些yourself使用者SID常量


$redirect_url = 'http://www.example.com/airplane.php';
if (defined('SID') && (!isset($_COOKIE[session_name()]))) {
    $redirect_url .= '?' . SID;
}
header("Location: $redirect_url");
</code>
The session_name( ) function returns the name of the cookie to the session ID is stored in, so this code appends the SID constant to $redirect_url if the constant is defined, and the session cookie isn't set.