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>
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