Extended subform field use own layout from template/html folder

Question

I've created an extended subform field type called families.php, basically I want to have my own custom layout for this custom field, it makes sense I don't want to mess up everything just for this case.

jimport('joomla.form.formfield');
require_once JPATH_LIBRARIES . '/joomla/form/fields/subform.php';

class JFormFieldFamilies extends JFormFieldSubForm {

    /**
     * Field specs
     */
    protected $type = 'Families';
    protected $formsource;
    protected $layout = 'joomla.form.field.families'; // THIS IS IMPORTANT PART, see below
    protected $groupByFieldset = false;

    /**
     * Cached large array of the families.
     */
    public static $families = array();

    /**
     * Method to attach a JForm object to the field.
     */
    public function setup(SimpleXMLElement $element, $value, $group = null)
    {
        if (!parent::setup($element, $value, $group))
        {
            return false;
        }

        // Get the field families/options, a cache of ::getFamilies();
        if ( empty(static::$families) ) {
            $cache = JFactory::getCache();
            static::$families = $cache->call( array( 'JFormFieldFamilies', 'getFamilies' ) );
        }

        foreach (array('formsource', 'layout', 'groupByFieldset') as $attributeName)
        {
            $this->__set($attributeName, $element[$attributeName]);
        }

        if ($this->value && is_string($this->value))
        {
            // Guess here is the JSON string from 'default' attribute
            $this->value = json_decode($this->value, true);
        }

        if ( !$this->formsource && is_array($this->value) )
        {
            // Set the formsource the content of the static::$families
            $this->formsource = '
<form>
  <field name="family" type="list" label="Family" default="" value="Johnsons">
    '. // a list of static::$families .'
  </field>
  <field name="girls" type="list" multiple="true" label="Girls" default="400">
    '. // a list of static::$families[$family][$girls] .'
  </field>
  <field name="boys" type="list" multiple="true" label="Boys" default="Robert">
    '. // a list of static::$families[$family][$boys] .'
  </field>
</form>';
    }

    // these function are unchanged, perhaps I can remove from this file
    protected function __get() {}
    protected function getInput() {}
    protected function getName($fieldName) {}
    // this one is probably most important for me, changed
    public function __set($name, $value)
    {
        switch ($name)
        {
            case 'formsource':
                $this->formsource = (string) $value;
                break;

            case 'groupByFieldset':
                if ($value !== null)
                {
                    $value = (string) $value;
                    $this->groupByFieldset = !($value === 'false' || $value === 'off' || $value === '0');
                }
                break;

            case 'layout':
                $this->layout = (string) $value;

                // Make sure the layout is not empty.
                if (!$this->layout)
                {
                    // HERE'S THE TRICKY PART
                    // $this->layout = 'templates.MYTEMPLATE.html.layouts.joomla.form.field.families';
                    $this->layout = 'joomla.form.field.families';
                }

                break;

            default:
                parent::__set($name, $value);
        }
    }

    // a full array of families
    static function getFamilies() {}
}

In my templates/MYTEMPLATE/html/layouts/joomla/form/field folder I have families.php, basically a copy of the subform/repeatable-table.php. So far, if I use joomla.form.field.subform.repeatable-table it's working fine, however, my layout file isn't working and I don't know how to handle this, it's beyond me.

Basically I see an empty <div class="controls"> inside my form.

Thanks for any inputs/suggestions.

Answer 1

Add custom paths with getLayoutPaths() in the field:

protected function getLayoutPaths()
{
    return array_merge(
        array(JPATH_ROOT . '/templates/your_template/html/layouts'),
        parent::getLayoutPaths()
    );
}

If you have a field like:

<field
    name="whatever"
    layout="joomla.form.field.families"
    type="families"
/>

This will render templates/your_template/html/layouts/joomla/form/field/families.php.

It's up to you what folder structure to use, but I would not use joomla folder. It's meant for core layouts.

Answer 2

OK so based on the new documentation resource I found, I can actually set an independent layout for anything related to custom form fields, exactly what I wanted really. I don't need to make this field generally available for users via com_fields, just a quick and totally Joomla based tool for building specific admin forms.

So I removed most of the code you see above, I basically re-purposed the getInput() method to just call the layout I need and let it go.

/**
 * Method to get the field input markup.
 */
protected function getInput()
{
    $value = $this->value ? (array) $this->value : array();

    // Prepare data for renderer
    $data    = parent::getLayoutData();
    $tmpl    = null;
    $forms   = array();
    $control = $this->name;

    try
    {
        // Prepare the form template
        $formname = 'subform.' . str_replace(array('jform[', '[', ']'), array('', '.', ''), $control);
        $tmpl = JForm::getInstance($formname, $this->formsource, array('control' => $control));

        // Prepare the forms for exiting values
        $tmpl->bind($value);
        $forms[] = $tmpl;
    }
    catch (Exception $e)
    {
        return $e->getMessage();
    }

    $data['tmpl']      = $tmpl;
    $data['forms']     = $forms;
    $data['control']   = $control;
    $data['fieldname'] = $this->fieldname;

    static $unique_subform_id = 0;
    $data['unique_subform_id'] = ('sr-' . ($unique_subform_id++));

    // Prepare renderer
    $layout = new JLayoutFile('families', JPATH_ROOT.'/ANY_PATH_TO/layouts');
    $html = $layout->render($data);

    // Render
    return $html;
}

While the original method pointed to an external renderer and a bunch of external layouts, something generic for a more broad use, I've added

 // Prepare renderer
 $layout = new JLayoutFile('families', JPATH_ROOT.'/ANY_PATH_TO/layouts');
 $html = $layout->render($data);

Now this custom field is unique and only uses its own layout for its purpose.