Moodle | Add and access custom elements in Blocks

In Totara how to add custom HTML elements (checkboxes, input boxes etc) and then access the value selected by user on server side:

1. Adding custom elements.
2. Accessing values of custom elements.

Each problem is discussed below: Overview:

In Totara, for blocks, we have some standard configuration settings. In these settings, we can change position, visibility, weight etc of the block. To access these settings:

Go on course page->turn editing on->click on ‘configure “your block name” block’:

On configuration page these standard settings are available for the block:

Problem 1:
How to add custom settings for the block on configuration page:

Above is a standard Totara page and we need to follow a process to add custom settings here:

Structure of folders and files in Totara:

Totara/
      blocks/
              abc/                                                       //custom block
                     lang/
                     db/
                     Abc_form.php
                    edit_form.php
              alerts/                                                   //standard block
                    lang/
                    db/
                    Alerts_form.php
                    edit_form.php
              …..
              edit_form.php

edit_form.php file contains standard settings. When we download a block template, edit_form.php is already present in this block.

Standard Code available in edit_form.php

class block_abc_edit_form extends block_edit_form {

protected function specific_definition($mform) {

// Section header title according to language file.
$mform->addElement('header', 'configheader', get_string('blocksettings', 'block'));

// A sample string variable with a default value.
$mform->addElement('text', 'config_text', get_string('blockstring', 'block_abc'));
$mform->setDefault('config_text', 'default value');
$mform->setType('config_text', PARAM_MULTILANG);

$mform->addElement('header', 'configheader', get_string('blocksettings1', 'block_abc'));
}

For adding custom settings we need to follow the Moodle api as we are overriding a standard class. In moodle api we have mform (moodle form ) elements in place of simple html elements.

Add the following code in block_abc_edit_form class (like we are going to add a custom checkbox):

$mform->addElement('advcheckbox','config_assignid'.$a,$label,null,
array('name' => 'config_'.$a),$a);

config_assignid’.$a is checkbox name and id.
$label is checkbox label (it will appear to the left of checkbox on UI)
null is checkbox label on right side.
$a is the value of checkbox (which will be sent to server on submit).

After adding these checkboxes our configuration page will look like this :

Problem 2: How to access the value of mform checkboxes on other pages of the block.

Solution: To achieve this we have to create an instance of the block and then access the variable/methods from there:

$coursecontext = context_course::instance($courseid);
$instance = $DB->get_record('block_instances', array('blockname'=>'abc', 'parentcontextid' => $coursecontext->id));
$block_abc= block_instance('abc', $instance);
echo "this";print_r($block_abc->config);
$coursecontext = context_course::instance($courseid);

Get context of course:

$instance = $DB->get_record('block_instances', array('blockname'=>'abc', 'parentcontextid' => $coursecontext->id));

This will fetch us configuration settings like weight, region, default value, config data for our block:

Output:

stdClass Object
(
    [id] => 63
    [blockname] => abc
    [parentcontextid] => 19
    [showinsubcontexts] => 0
    [pagetypepattern] => course-view-*
    [subpagepattern] => 
    [defaultregion] => side-pre
    [defaultweight] => 10
)
$block_abc= block_instance('abc', $instance);

It will display all the data (cron, context, page, config etc) associated to block:

e.g. block context and config

Here config holds the values of checkboxes:

[context] => context_block Object
        (
            [_id:protected] => 272
            [_contextlevel:protected] => 80
            [_instanceid:protected] => 63
            [_path:protected] => /1/3/19/272
            [_depth:protected] => 4
        )

    [config] => stdClass Object
        (
            [assignid9] => 9
            [assignid10] => 10
            [assignid11] => 11
            [assignid12] => 12
            [assignid13] => 13
            [assignid16] => 16
            )

To get only config data (checkbox values) we can do like this
echo “this :”;

print_r($block_abc->config);

Following output contains only values of checked checkboxes: