Cannot import/use a namespaced function in PHP

Question

I've got a namespaced file called test.php with a function and a class:

namespace Test;
function testFunc(){}
class TestClass{}

Then if, in another file I "use" both of these namespace elements, the class works but not the function:

use Test\testFunc,
    Test\TestClass;

include "test.php";
new TestClass();
testFunc();

The TestClass object is created fine, but I get a fatal error for testFunc():

Fatal error: Call to undefined function testFunc()

I thought functions were supported with namespaces. What am I doing wrong?

EDIT: Explanation here - http://www.php.net/manual/en/language.namespaces.faq.php#language.namespaces.faq.nofuncconstantuse

Treffynnon · Accepted Answer · 2011-04-13 10:24:16Z

See http://php.net/manual/en/language.namespaces.rules.php with particular attention to:

<?php
namespace A;
use B\D, C\E as F;

// function calls

foo();      // first tries to call "foo" defined in namespace "A"
            // then calls global function "foo"

\foo();     // calls function "foo" defined in global scope

my\foo();   // calls function "foo" defined in namespace "A\my"

F();        // first tries to call "F" defined in namespace "A"
            // then calls global function "F"

And

// static methods/namespace functions from another namespace

B\foo();    // calls function "foo" from namespace "A\B"

B::foo();   // calls method "foo" of class "B" defined in namespace "A"
            // if class "A\B" not found, it tries to autoload class "A\B"

D::foo();   // using import rules, calls method "foo" of class "D" defined in namespace "B"
            // if class "B\D" not found, it tries to autoload class "B\D"

\B\foo();   // calls function "foo" from namespace "B"

\B::foo();  // calls method "foo" of class "B" from global scope
            // if class "B" not found, it tries to autoload class "B"

So basically you can't import functions the same way as classes? The example doesn't make it clear about constants either, I assume they are the same? Actually, here's a clearer explanation - php.net/manual/en/…

Mark Teese · Accepted Answer · 2019-02-18 16:55:08Z

From PHP 5.6 and higher you can import/use functions from other PHP files as follows:

require_once __DIR__ . "/../../path/to/your/vendor/autoload.php";
use function myprogram\src\Tools\MyFunc;
//use the imported function
MyFunc();

However, for PHP 7.0, I needed to add the function to "files" in the composer.json:

"autoload" : {
    "psr-4" : {
      "myprogram\\src\\" : "myprogram/src/"
    },
"files" : [
      "myprogram/src/Tools/ScriptWithMyFunc.php"
    ]

And then run composer dump-autoload to update autoload.php.

ALTERNATIVELY:

You can also import functions from scripts directly without composer:

require_once full\path\to\ScriptWithMyFunc.php;
MyFunc();

But (at least for me) this only works when ScriptWithMyFunc.php does not have a namespace.

Thanks, addding the files property to composer.json file worked in my project.

Th. Ma. · Accepted Answer · 2014-09-24 06:29:07Z

0

I believe namespaced functions (port of use keyword for function and constants) will be part of PHP 5.6

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