Hello world¶

This tutorial shows you how to add a new page and print the text “Hello world” on it.

In this tutorial we will pretend your site’s URL is https://elgg.example.com.

First, you need to:

Install Elgg

Create a file called start.php at the root of your app.

Copy this code into start.php:

<?php

elgg_register_event_handler('init', 'system', 'hello_world_init');

function hello_world_init() {

}

This piece of code tells Elgg that it should call the function hello_world_init() once the Elgg core system is initiated.

Registering a page handler¶

The next step is to register a page handler which has the purpose of handling request that users make to the URL https://elgg.example.com/hello.

Update the start.php to look like this:

<?php

elgg_register_event_handler('init', 'system', 'hello_world_init');

function hello_world_init() {
    elgg_register_page_handler('hello', 'hello_world_page_handler');
}

function hello_world_page_handler() {
    echo elgg_view_resource('hello');
}

The call to elgg_register_page_handler() tells Elgg that it should call the function hello_world_page_handler() when user goes navigates to https://elgg.example.com/hello/*.

The hello_world_page_handler() passes off rendering the actual page to the resources/hello view.

Create views/default/resources/hello.php with this content:

<?php

$params = array(
    'title' => 'Hello world!',
    'content' => 'My first page!',
    'filter' => '',
);

$body = elgg_view_layout('content', $params);

echo elgg_view_page('Hello', $body);

We give an array of parameters to the elgg_view_layout() function, including:

The title of the page

The contents of the page

Filter which is left empty because there’s currently nothing to filter

This creates the basic layout for the page. The layout is then run through elgg_view_page() which assembles and outputs the full page.

You can now go to the address https://elgg.example.com/hello/ and you should see your new page!