<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >Object property and method call overloading</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK REL="HOME" TITLE="PHP 手册" HREF="index.html"><LINK REL="UP" TITLE="函数参考" HREF="funcref.html"><LINK REL="PREVIOUS" TITLE="deaggregate" HREF="function.deaggregate.html"><LINK REL="NEXT" TITLE="overload" HREF="function.overload.html"><META HTTP-EQUIV="Content-type" CONTENT="text/html; charset=UTF-8"></HEAD ><BODY CLASS="reference" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#840084" ALINK="#0000FF" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >PHP 手册</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="function.deaggregate.html" ACCESSKEY="P" >上一页</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="function.overload.html" ACCESSKEY="N" >下一页</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="reference" ><A NAME="ref.overload" ></A ><DIV CLASS="TITLEPAGE" ><H1 CLASS="title" >CVI. Object property and method call overloading</H1 ><DIV CLASS="PARTINTRO" ><A NAME="AEN155830" ></A ><DIV CLASS="section" ><H1 CLASS="section" ><A NAME="overload.intro" >简介</A ></H1 ><P > The purpose of this extension is to allow overloading of object property access and method calls. Only one function is defined in this extension, <A HREF="function.overload.html" ><B CLASS="function" >overload()</B ></A > which takes the name of the class that should have this functionality enabled. The class named has to define appropriate methods if it wants to have this functionality: <TT CLASS="literal" >__get()</TT >, <TT CLASS="literal" >__set()</TT > and <TT CLASS="literal" >__call()</TT > respectively for getting/setting a property, or calling a method. This way overloading can be selective. Inside these handler functions the overloading is disabled so you can access object properties normally. </P ><DIV CLASS="warning" ><P ></P ><TABLE CLASS="warning" BORDER="1" WIDTH="100%" ><TR ><TD ALIGN="CENTER" ><B >警告</B ></TD ></TR ><TR ><TD ALIGN="LEFT" ><P >本扩展模块是<SPAN CLASS="emphasis" ><I CLASS="emphasis" >实验性</I ></SPAN >的。本模块的行为,包括其函数的名称以及其它任何关于此模块的文档可能会在没有通知的情况下随 PHP 以后的发布而改变。使用本扩展模块风险自担。</P ></TD ></TR ></TABLE ></DIV ><DIV CLASS="warning" ><P ></P ><TABLE CLASS="warning" BORDER="1" WIDTH="100%" ><TR ><TD ALIGN="CENTER" ><B >警告</B ></TD ></TR ><TR ><TD ALIGN="LEFT" ><P > This extension is not a part of PHP 5. PHP 5 supports <TT CLASS="literal" >__get()</TT >, <TT CLASS="literal" >__set()</TT > and <TT CLASS="literal" >__call()</TT > natively. See the <A HREF="language.oop5.overloading.html" >Overloading in PHP 5</A > page for more information. </P ></TD ></TR ></TABLE ></DIV ></DIV ><DIV CLASS="section" ><H1 CLASS="section" ><A NAME="overload.requirements" >需求</A ></H1 ><P >要编译本扩展模块无需外部库文件。</P ></DIV ><DIV CLASS="section" ><H1 CLASS="section" ><A NAME="overload.installation" >安装</A ></H1 ><P > In order to use these functions, you must compile PHP with the <CODE CLASS="option" >--enable-overload</CODE > option. Starting with PHP 4.3.0 this extension is enabled by default. You can disable overload support with <CODE CLASS="option" >--disable--overload</CODE >. </P ><P > <TT CLASS="literal" >PHP</TT > 的 Windows 版本已经内置该扩展模块的支持。无需加载任何附加扩展库即可使用这些函数。</P ><DIV CLASS="note" ><BLOCKQUOTE CLASS="note" ><P ><B >注意: </B > Builtin support for overload is available with PHP 4.3.0. </P ></BLOCKQUOTE ></DIV ></DIV ><DIV CLASS="section" ><H1 CLASS="section" ><A NAME="overload.configuration" >运行时配置</A ></H1 ><P >本扩展模块在 <TT CLASS="filename" >php.ini</TT > 中未定义任何配置选项。</P ></DIV ><DIV CLASS="section" ><H1 CLASS="section" ><A NAME="overload.resources" >资源类型</A ></H1 ><P >本扩展模块未定义任何资源类型。</P ></DIV ><DIV CLASS="section" ><H1 CLASS="section" ><A NAME="overload.constants" >预定义常量</A ></H1 ><P >本扩展模块未定义任何常量。</P ></DIV ><DIV CLASS="section" ><H1 CLASS="section" ><A NAME="overload.examples" >范例</A ></H1 ><P > Some simple examples on using the <A HREF="function.overload.html" ><B CLASS="function" >overload()</B ></A > function: <TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" CLASS="EXAMPLE" ><TR ><TD ><DIV CLASS="example" ><A NAME="AEN155873" ></A ><P ><B >例 1. Overloading a PHP class</B ></P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> <font color="#0000BB"><?php<br /><br /></font><font color="#007700">class </font><font color="#0000BB">OO </font><font color="#007700">{<br /> var </font><font color="#0000BB">$a </font><font color="#007700">= </font><font color="#0000BB">111</font><font color="#007700">;<br /> var </font><font color="#0000BB">$elem </font><font color="#007700">= array(</font><font color="#DD0000">'b' </font><font color="#007700">=> </font><font color="#0000BB">9</font><font color="#007700">, </font><font color="#DD0000">'c' </font><font color="#007700">=> </font><font color="#0000BB">42</font><font color="#007700">);<br /><br /> </font><font color="#FF8000">// Callback method for getting a property<br /> </font><font color="#007700">function </font><font color="#0000BB">__get</font><font color="#007700">(</font><font color="#0000BB">$prop_name</font><font color="#007700">, &</font><font color="#0000BB">$prop_value</font><font color="#007700">) <br /> {<br /> if (isset(</font><font color="#0000BB">$this</font><font color="#007700">-></font><font color="#0000BB">elem</font><font color="#007700">[</font><font color="#0000BB">$prop_name</font><font color="#007700">])) {<br /> </font><font color="#0000BB">$prop_value </font><font color="#007700">= </font><font color="#0000BB">$this</font><font color="#007700">-></font><font color="#0000BB">elem</font><font color="#007700">[</font><font color="#0000BB">$prop_name</font><font color="#007700">];<br /> return </font><font color="#0000BB">true</font><font color="#007700">;<br /> } else {<br /> return </font><font color="#0000BB">false</font><font color="#007700">;<br /> }<br /> }<br /><br /> </font><font color="#FF8000">// Callback method for setting a property<br /> </font><font color="#007700">function </font><font color="#0000BB">__set</font><font color="#007700">(</font><font color="#0000BB">$prop_name</font><font color="#007700">, </font><font color="#0000BB">$prop_value</font><font color="#007700">) <br /> {<br /> </font><font color="#0000BB">$this</font><font color="#007700">-></font><font color="#0000BB">elem</font><font color="#007700">[</font><font color="#0000BB">$prop_name</font><font color="#007700">] = </font><font color="#0000BB">$prop_value</font><font color="#007700">;<br /> return </font><font color="#0000BB">true</font><font color="#007700">;<br /> }<br />}<br /><br /></font><font color="#FF8000">// Here we overload the OO object<br /></font><font color="#0000BB">overload</font><font color="#007700">(</font><font color="#DD0000">'OO'</font><font color="#007700">);<br /><br /></font><font color="#0000BB">$o </font><font color="#007700">= new </font><font color="#0000BB">OO</font><font color="#007700">;<br />echo </font><font color="#DD0000">"</font><font color="#007700">\$</font><font color="#DD0000">o</font><font color="#007700">-></font><font color="#DD0000">a: $o</font><font color="#007700">-></font><font color="#DD0000">a</font><font color="#007700">\n</font><font color="#DD0000">"</font><font color="#007700">; </font><font color="#FF8000">// print: $o->a: 111<br /></font><font color="#007700">echo </font><font color="#DD0000">"</font><font color="#007700">\$</font><font color="#DD0000">o</font><font color="#007700">-></font><font color="#DD0000">b: $o</font><font color="#007700">-></font><font color="#DD0000">b</font><font color="#007700">\n</font><font color="#DD0000">"</font><font color="#007700">; </font><font color="#FF8000">// print: $o->b: 9<br /></font><font color="#007700">echo </font><font color="#DD0000">"</font><font color="#007700">\$</font><font color="#DD0000">o</font><font color="#007700">-></font><font color="#DD0000">c: $o</font><font color="#007700">-></font><font color="#DD0000">c</font><font color="#007700">\n</font><font color="#DD0000">"</font><font color="#007700">; </font><font color="#FF8000">// print: $o->c: 42<br /></font><font color="#007700">echo </font><font color="#DD0000">"</font><font color="#007700">\$</font><font color="#DD0000">o</font><font color="#007700">-></font><font color="#DD0000">d: $o</font><font color="#007700">-></font><font color="#DD0000">d</font><font color="#007700">\n</font><font color="#DD0000">"</font><font color="#007700">; </font><font color="#FF8000">// print: $o->d:<br /><br />// add a new item to the $elem array in OO<br /></font><font color="#0000BB">$o</font><font color="#007700">-></font><font color="#0000BB">x </font><font color="#007700">= </font><font color="#0000BB">56</font><font color="#007700">; <br /><br /></font><font color="#FF8000">// instantiate stdclass (it is built-in in PHP 4)<br />// $val is not overloaded!<br /></font><font color="#0000BB">$val </font><font color="#007700">= new </font><font color="#0000BB">stdclass</font><font color="#007700">;<br /></font><font color="#0000BB">$val</font><font color="#007700">-></font><font color="#0000BB">prop </font><font color="#007700">= </font><font color="#0000BB">555</font><font color="#007700">;<br /><br /></font><font color="#FF8000">// Set "a" to be an array with the $val object in it<br />// But __set() will put this in the $elem array<br /></font><font color="#0000BB">$o</font><font color="#007700">-></font><font color="#0000BB">a </font><font color="#007700">= array(</font><font color="#0000BB">$val</font><font color="#007700">);<br /></font><font color="#0000BB">var_dump</font><font color="#007700">(</font><font color="#0000BB">$o</font><font color="#007700">-></font><font color="#0000BB">a</font><font color="#007700">[</font><font color="#0000BB">0</font><font color="#007700">]-></font><font color="#0000BB">prop</font><font color="#007700">);<br /><br /></font><font color="#0000BB">?></font> </font> </code></TD ></TR ></TABLE ></DIV ></TD ></TR ></TABLE > </P ></DIV ></DIV ><DIV CLASS="TOC" ><DL ><DT ><B >目录</B ></DT ><DT ><A HREF="function.overload.html" >overload</A > -- Enable property and method call overloading for a class</DT ></DL ></DIV ></DIV ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="function.deaggregate.html" ACCESSKEY="P" >上一页</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >起始页</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="function.overload.html" ACCESSKEY="N" >下一页</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >deaggregate</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="funcref.html" ACCESSKEY="U" >上一级</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >overload</TD ></TR ></TABLE ></DIV ></BODY ></HTML >