How to programmatically set the value of a custom field of type checkbox?

Question

In articles, I have created a series of custom fields, including two date fields and a checkboxes field. Now, through a plugin in the onContentBeforeSave event I need to verify that if date 1 is less than date 2 then set the value of the checkbox field. For this I try the following

<?php

defined( '_JEXEC' ) or die( 'Restricted access' );

class plgContentAlertcustomfieldhandler extends JPlugin
{
    public function onContentBeforeSave($context, &$article, $isNew, $data)
    {
        if ($context === 'com_content.article') {
            $date1 = strtotime($data['com_fields']['date1']);
            $date2 = strtotime($data['com_fields']['date2']);

            if ($date1 < $date2) {
                $data['com_fields']['alert'][0] = 'alert';
            }
        }

        return true;
    }
}

I try to set the value in this line:

$data['com_fields']['alert'][0] = 'alert';

This custom field has only one checkbox, defined with the name Alert and with the value alert.

Update 1:

I am trying $data['com_fields']['alert'] = true; but I am getting the same result.

Update 2:

If I manually set a value to the checkbox, debugging I can verify that the value assigned to alert in $data is

array (
   0 => 'alert',
)

I try to apply this same value programmatically as follows

$data['com_fields']['alert'] = ['alert'];

But the value is not persisted, at the end of the process of saving and refreshing the view the checkbox remains unchecked

Update 3

Following the process of saving through debugging I identify that if I programmatically assign the value to the custom field through $data ['com_fields']['alert'] = ['alert']; when arriving to the save method in libraries/src/MVC/Model/AdminModel.php in the argument $data the value of alert is false, while if I set a value manually when arriving at this method in$data the value of the alert field is [0 => 'alert'] and consequently the value of the checkbox is assigned.

Update 4

The typo error pointed out by alexandreelise is now repaired. The problem still persists.

Update 5

Using debug I managed to identify that it doesn't matter which field within $ data['com_fields'] I modify in the onContentBeforeSave event once it delegates to the trigger method of the JEventDispatcher class located at libraries/joomla/event/dispatcher.php the argument $args that includes in the index 3 the data to be persisted including those of com_fields retain the values set by the user even if they have been programmatically modified as in the example I described. Eventually this data is passed to libraries/src/MVC/Model/AdminModel.php in the save method that has the argument $data the data to be inserted preserves the values set by the user. Right now I think that maybe the solution is to try to modify these values in another event maybe before onContentBeforeSave. Thanks again for any ideas

I appreciate your advice

Answer 1

Basically you needed to use onContentAfterSave rather then onContentBeforeSave and use the FieldsHelper in conjuction with the FieldsModelField.

Here is the code:

<?php
defined( '_JEXEC' ) or die( 'Restricted access' );

class plgContentAlertcustomfieldhandler extends JPlugin
{
   public function onContentAfterSave($context, &$article, $isNew)
   {

    if ($context === 'com_content.article') {
        $custom_fields = FieldsHelper::getFields($context, $article, true);
        $custom_fields_by_name = \Joomla\Utilities\ArrayHelper::pivot($custom_fields, 'name');

        $date1 = strtotime($custom_fields_by_name['date1']->value);
        $date2 = strtotime($custom_fields_by_name['date2']->value);

        if ($date1 < $date2) {
            //define the value you want to assign
            $your_custom_field_value = 'alert';

            JModelLegacy::addIncludePath(JPATH_ADMINISTRATOR . '/components/com_fields/models');
            /**
             * @var FieldsModelField $model_field
             */
            $model_field = JModelLegacy::getInstance('Field', 'FieldsModel', ['ignore_request' => true]);

            //set the value using field model instead to make change permanent in db
            $model_field->setFieldValue(
                $custom_fields_by_name['alert']->id,
                $article->id,
                $your_custom_field_value
            );
        }
    }

     return true;
     }
  }

UPDATE:

Second version of the code toggling on and off the checkbox when your requirement is not met.

<?php
defined( '_JEXEC' ) or die( 'Restricted access' );

class plgContentAlertcustomfieldhandler extends JPlugin
{
    public function onContentAfterSave($context, &$article, $isNew)
    {

    if ($context === 'com_content.article') {
        $custom_fields = FieldsHelper::getFields($context, $article, true);
        $custom_fields_by_name = \Joomla\Utilities\ArrayHelper::pivot($custom_fields, 'name');

        $date1 = strtotime($custom_fields_by_name['date1']->value);
        $date2 = strtotime($custom_fields_by_name['date2']->value);

        $your_custom_field_value = '';
        if ($date1 < $date2) {
            //define the value you want to assign
            $your_custom_field_value = 'alert';
        }
        JModelLegacy::addIncludePath(JPATH_ADMINISTRATOR . '/components/com_fields/models');
        /**
         * @var FieldsModelField $model_field
         */
        $model_field = JModelLegacy::getInstance('Field', 'FieldsModel', ['ignore_request' => true]);

        //set the value using field model instead to make change permanent in db
        $model_field->setFieldValue(
            $custom_fields_by_name['alert']->id,
            $article->id,
            $your_custom_field_value
        );
      }

      return true;
     }
 }