Helper - Call to undefined function

Hi All,

I'm new to CI (just started this week).

I am trying to get my own custom helper to work, but I keep getting 'Call to undefined function' errors.

Here's my code:

app/Helpers/build_page.php

PHP Code:

<?php

function tester(){
    return "test";
} 


app/Controllers/News.php (snippet)

PHP Code:

public function index()
    {
        helper('build_page');
        echo tester(); 


As read in the manual I guess this should work?
But I keep getting:

Call to undefined function App\Controllers\tester()

What am I missing here.

It's not very clear in the documentation, but when you create a new helper, the filename must have the '_helper' suffix: https://codeigniter4.github.io/userguide...g-a-helper

So rename your file to build_page_helper.php and it should work. To load the file, you don't need the suffix, so keep this line as is: 

PHP Code:

helper('build_page'); 


CodeIgniter 4 tutorials (EN/FR) - https://includebeer.com
/*** NO support in private message - Use the forum! ***/

As @ includebeer said, all helper files need to be like this name_helper.php
you always have to save the file with the _helper.php extension.

What did you Try? What did you Get? What did you Expect?

Joined CodeIgniter Community 2009.  ( Skype: insitfx )

Hello dear CI4 experts

I'm in a similar situation

I have
/App/Helpers/isactive_helper.php

the content of isactive_helper.php is

PHP Code:

<?php 

if ( ! function_exists('setActive')){

    function setActive($uriCheck)
    {
        $uri = new \CodeIgniter\HTTP\URI();
        
        $uriSegment = $uri->getPath();

        if ( $uriSegment == $uriCheck ) {

            echo "active";

        }
    }
} 


I then use this helper inside a view (which is the main layout view of my app)

Code:

        24        <ul class="navbar-nav mr-auto">
        25            <li class="nav-item <?php setActive("tasks"); ?>">
        26                <a class="nav-link" href="<?= site_url("tasks") ?>">Tasks</a>
        27            </li>

but as I open the app URL, I get

Call to undefined function setActive()

and it is highlighted exactly line 25 of the view

Can you kindly hint with what's wrong?

Thank you

You need to load the file in your controller before you can use its functions in a view.

PHP Code:

helper(“isactive”); 


CodeIgniter 4 tutorials (EN/FR) - https://includebeer.com
/*** NO support in private message - Use the forum! ***/

You need to load the file in your controller before you can use its functions in a view

the "Call to undefined function" problem is solved

but ...

for the above code,

Code:

$uriSegment = $uri->getPath();

used inside the helper returns always "" , an empty string ( tested with dd() )

while used inside the view, it actually returns the path at right of the site_url

The URI class needs an actual URI to work with. So instead of creating one directly, you can get the current URI from the current request:

PHP Code:

// $uri = new \CodeIgniter\HTTP\URI();

$request = \Config\Services::request();

$uri = $request->uri; 


CodeIgniter 4: Build a Complete Web Application from Scratch

The URI class needs an actual URI to work with. So instead of creating one directly, you can get the current URI from the current request:

PHP Code:

// $uri = new \CodeIgniter\HTTP\URI();

$request = \Config\Services::request();

$uri = $request->uri; 


Thank you Dave

it works! , I conceived and created my first helper !

Though as seen in the layout HTML above, I went for

PHP Code:

        $request = \Config\Services::request();
        
        $uriSegment = $request->uri->getPath(); 


since in the navigation menu items, anybody and in any situation will use the same strings

Thank you