cvs: phpdoc /en/reference/var/functions is-callable.xml

hholzgra Fri Jul 4 17:43:55 2003 EDT Modified files: /phpdoc/en/reference/var/functions is-callable.xml Log: is_callable documented as suggested in user note / bug #21124 credits go to php4 at developersdesk dot com Index: phpdoc/en/reference/var/functions/is-callable.xml diff -u phpdoc/en/reference/var/functions/is-callable.xml:1.3 phpdoc/en/reference/var/functions/is-callable.xml:1.4 --- phpdoc/en/reference/var/functions/is-callable.xml:1.3 Mon Nov 18 02:59:04 2002 +++ phpdoc/en/reference/var/functions/is-callable.xml Fri Jul 4 17:43:55 2003 @@ -1,11 +1,11 @@ <?xml version="1.0" encoding="iso-8859-1"?> -<!-- $Revision: 1.3 $ --> +<!-- $Revision: 1.4 $ --> <!-- splitted from ./en/functions/var.xml, last change in rev 1.87 --> <refentry id="function.is-callable"> <refnamediv> <refname>is_callable</refname> <refpurpose> - Find out whether the argument is a valid callable construct + Verify that the contents of a variable can be called as a function </refpurpose> </refnamediv> <refsect1> @@ -17,55 +17,76 @@ <methodparam choice="opt"><type>string</type><parameter>callable_name</parameter></methodparam> </methodsynopsis> <para> - &warn.undocumented.func; + Verify that the contents of a variable can be called as a function. + This can check that a simple variable contains the name of a valid + function, or that an array contains a properly encoded object and + function name. </para> -<!-- - <simpara> - The <parameter>var</parameter> parameter is the name of a function or method. - Also, class or object methods are specified by passing a numerical array with - two elements: the class or object, and a method name. - </simpara> - <simpara> - The optional <parameter>syntax_only</parameter> parameter will check - only for syntax and defaults to &false; The third <parameter> - callable_name</parameter> parameter is also optional. - </simpara> <para> - In our example below note, however, that despite the implication that - <literal>a::b()</literal> is a callable static method, this is not the - case. - <example> - <title>Using <function>is_callable</function></title> - <programlisting role="php"> + The var parameter can be either the name of a function stored in + a string variable, or an object and the name of a method within the + object, like this: + <screen>array( $SomeObject, 'MethodName' )</screen> + </para> + <para> + If the <parameter>syntax_only</parameter> argument is &true; the + function only verifies that <parameter>var</parameter> might be a + function or method. It will only reject simple variables that are + not strings, or an array that does not have a valid structure to be + used as a callback. The valid ones are supposed to have only 2 + entries, the first of which is an object or a string, and the + second a string. + </para> + <para> + The <parameter>callable_name</parameter> argument receives the + "callable name". In the example below it's + "someClass:someMethod". Note, however, that despite the + implication that someClass::SomeMethod() is a callable static + method, this is not the case. + </para> + <informalexample> + <programlisting> <![CDATA[ -<?php -class a -{ - var $c; - - function b() { - return($this->c); - } +<? php +// How to check a variable to see if it can be called +// as a function. + +// +// Simple variable containing a function +// + +function someFunction() { } -$d = new a; +$functionVariable = 'someFunction'; + +var_dump( is_callable( $functionVariable, false, $callable_name )); // bool(true) -if(is_callable(array($d, 'b'), FALSE, $name)) { +echo $callable_name, "\n"; // someFunction + +// +// Array containing a method +// + +class someClass { + + function someMethod() { + } - echo $name; } -/* The above will print: - - a:: +$anObject = new someClass(); + +$methodVariable = array( $anObject, 'someMethod' ); + +var_dump( is_callable( $methodVariable, true, $callable_name )); // bool(true) + +echo $callable_name, "\n"; // someClass:someMethod -*/ ?> ]]> - </programlisting> - </example> - </para> ---> + </programlisting> + </informalexample> </refsect1> </refentry>