aidan Sat Sep 25 05:06:38 2004 EDT
Modified files:
/phpdoc/en/reference/classobj/functions class-exists.xml
Log:
Added simple example
Cleaned initial example
Added links to autoload
http://cvs.php.net/diff.php/phpdoc/en/reference/classobj/functions/class-exists.xml?r1=1.5&r2=1.6&ty=u
Index: phpdoc/en/reference/classobj/functions/class-exists.xml
diff -u phpdoc/en/reference/classobj/functions/class-exists.xml:1.5
phpdoc/en/reference/classobj/functions/class-exists.xml:1.6
--- phpdoc/en/reference/classobj/functions/class-exists.xml:1.5 Thu Jul 1 23:07:07
2004
+++ phpdoc/en/reference/classobj/functions/class-exists.xml Sat Sep 25 05:06:35
2004
@@ -1,5 +1,5 @@
<?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.5 $ -->
+<!-- $Revision: 1.6 $ -->
<!-- splitted from ./en/functions/classobj.xml, last change in rev 1.11 -->
<refentry id="function.class-exists">
<refnamediv>
@@ -8,26 +8,37 @@
</refnamediv>
<refsect1>
<title>Description</title>
- <methodsynopsis>
- <type>bool</type><methodname>class_exists</methodname>
- <methodparam><type>string</type><parameter>class_name</parameter></methodparam>
- <methodparam
choice="opt"><type>bool</type><parameter>autoload</parameter></methodparam>
- </methodsynopsis>
- <note>
- <para>
- The <parameter>autoload</parameter> parameter was added in PHP 5
- </para>
- </note>
+ <methodsynopsis>
+ <type>bool</type><methodname>class_exists</methodname>
+ <methodparam><type>string</type><parameter>class_name</parameter></methodparam>
+ <methodparam
choice="opt"><type>bool</type><parameter>autoload</parameter></methodparam>
+ </methodsynopsis>
<para>
This function returns &true; if the class given by
<parameter>class_name</parameter> has been defined,
&false; otherwise.
</para>
<para>
- <function>class_exists</function> will attempt to call __autoload by
- default, if you don't want <function>class_exists</function> to
- call __autoload(), you can set the parameter <parameter>autoload</parameter>
- to &false;.
+ <example>
+ <title><function>class_exists</function> example</title>
+ <programlisting role="php">
+<![CDATA[
+<?php
+// Check the class exists before trying to use it
+if (class_exists('MyClass')) {
+ $myclass = new MyClass();
+}
+
+?>
+]]>
+ </programlisting>
+ </example>
+ </para>
+ <para>
+ <function>class_exists</function> will attempt to call &link.autoload; by
+ default, if you don't want <function>class_exists</function> to
+ call &link.autoload;, you can set the parameter <parameter>autoload</parameter>
+ to &false;.
</para>
<para>
<example>
@@ -35,26 +46,33 @@
<programlisting role="php">
<![CDATA[
<?php
- function __autoload($class) {
- include($class . '.php');
+function __autoload($class)
+{
+ include($class . '.php');
- /* Check to see it the include defined the class */
- if ( !class_exists($class, false) ) {
- trigger_error("Unable to load class $class", E_USER_ERROR);
- }
+ // Check to see if the include declared the class
+ if (!class_exists($class, false)) {
+ trigger_error("Unable to load class: $class", E_USER_WARNING);
}
+}
- if( class_exists('MyClass') ) {
- $myclass = new MyClass();
- }
+if (class_exists('MyClass')) {
+ $myclass = new MyClass();
+}
?>
]]>
</programlisting>
</example>
</para>
+ <note>
+ <para>
+ The <parameter>autoload</parameter> parameter was added in PHP 5
+ </para>
+ </note>
<simpara>
- See also <function>get_declared_classes</function>.
+ See also <function>interface_exists</function>, and
+ <function>get_declared_classes</function>.
</simpara>
</refsect1>
</refentry>
