[4.0] Media fields accessibility - second try

administrator/language/en-GB/lib_joomla.ini

@@ -335,6 +335,9 @@ JLIB_FORM_FIELD_INVALID_MIN_TIME="The time you entered is before the minimum tim
 JLIB_FORM_FIELD_INVALID_TIME_INPUT="Invalid time format. Please use hh:mm."
 JLIB_FORM_FIELD_INVALID_TIME_INPUT_SECONDS="Invalid time format. Please use hh:mm:ss."
 JLIB_FORM_FIELD_INVALID_VALUE="This value is not valid"
+JLIB_FORM_FIELD_PARAM_ACCESSIBLEMEDIA_LABEL="Media"
+JLIB_FORM_FIELD_PARAM_ACCESSIBLEMEDIA_PARAMS_IMAGEFILE_LABEL="Image"
+JLIB_FORM_FIELD_PARAM_ACCESSIBLEMEDIA_PARAMS_ALT_TEXT_LABEL="Alt Text"	
 JLIB_FORM_FIELD_PARAM_CALENDAR_FORMAT_DESC="The date format to be used. This is in the format used by PHP to specify date string formats (see below). If no format argument is given, '%Y-%m-%d' is assumed (giving dates like '2008-04-16')."
 JLIB_FORM_FIELD_PARAM_CALENDAR_FORMAT_LABEL="Format"
 JLIB_FORM_FIELD_PARAM_CHECKBOX_MULTIPLE_DESC="Allow multiple values to be selected."

layouts/joomla/form/field/media/accessiblemedia.php

@@ -0,0 +1,23 @@
+<?php
+/**
+ * @package     Joomla.Site
+ * @subpackage  Layout
+ *
+ * @copyright   Copyright (C) 2005 - 2019 Open Source Matters, Inc. All rights reserved.
+ * @license     GNU General Public License version 2 or later; see LICENSE.txt
+ */
+
+defined('_JEXEC') or die;
+
+extract($displayData);
+
+$form = $forms[0];
+
+$formfields = $form->getGroup('');
+?>
+
+<div class="subform-wrapper">
+<?php foreach ($formfields as $field) : ?>
+	<?php echo $field->renderField(); ?>
+<?php endforeach; ?>
+</div>

libraries/src/Form/Field/AccessiblemediaField.php

@@ -0,0 +1,197 @@
+<?php
+/**
+ * Joomla! Content Management System
+ *
+ * @copyright  Copyright (C) 2005 - 2019 Open Source Matters, Inc. All rights reserved.
+ * @license    GNU General Public License version 2 or later; see LICENSE.txt
+ */
+
+namespace Joomla\CMS\Form\Field;
+
+\defined('JPATH_PLATFORM') or die;
+
+use Joomla\CMS\Filesystem\Path;
+use Joomla\CMS\Form\Field\SubformField;
+
+/**
+ * The Field to load the form inside current form
+ *
+ * @since  __DEPLOY_VERSION__
+ */
+class AccessiblemediaField extends SubformField
+{
+	/**
+	 * The form field type.
+	 *
+	 * @var    string
+	 * @since  __DEPLOY_VERSION__
+	 */
+	protected $type = 'Accessiblemedia';
+
+	/**
+	 * The preview.
+	 *
+	 * @var    string
+	 * @since  __DEPLOY_VERSION__
+	 */
+	protected $preview;
+
+	/**
+	 * The directory.
+	 *
+	 * @var    string
+	 * @since  __DEPLOY_VERSION__
+	 */
+	protected $directory;
+
+	/**
+	 * The previewWidth.
+	 *
+	 * @var    integer
+	 * @since  __DEPLOY_VERSION__
+	 */
+	protected $previewWidth;
+
+	/**
+	 * The previewHeight.
+	 *
+	 * @var    integer
+	 * @since  __DEPLOY_VERSION__
+	 */
+	protected $previewHeight;
+
+	/**
+	 * Layout to render
+	 *
+	 * @var    string
+	 * @since  __DEPLOY_VERSION__
+	 */
+	protected $layout;
+
+	/**
+	 * Method to get certain otherwise inaccessible properties from the form field object.
+	 *
+	 * @param   string  $name  The property name for which to get the value.
+	 *
+	 * @return  mixed  The property value or null.
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public function __get($name)
+	{
+		switch ($name)
+		{
+			case 'directory':
+			case 'preview':
+			case 'previewHeight':
+			case 'previewWidth':
+				return $this->$name;
+		}
+
+		return parent::__get($name);
+	}
+
+	/**
+	 * Method to set certain otherwise inaccessible properties of the form field object.
+	 *
+	 * @param   string  $name   The property name for which to set the value.
+	 * @param   mixed   $value  The value of the property.
+	 *
+	 * @return  void
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public function __set($name, $value)
+	{
+		switch ($name)
+		{
+			case 'directory':
+			case 'preview':
+				$this->$name = (string) $value;
+				break;
+
+			case 'previewHeight':
+			case 'previewWidth':
+				$this->$name = (int) $value;
+				break;
+
+			default:
+				parent::__set($name, $value);
+		}
+	}
+
+	/**
+	 * Method to attach a Form object to the field.
+	 *
+	 * @param   SimpleXMLElement  $element  The SimpleXMLElement object representing the <field /> tag for the form field object.
+	 * @param   mixed             $value    The form field value to validate.
+	 * @param   string            $group    The field name group control value.
+	 *
+	 * @return  boolean  True on success.
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public function setup(\SimpleXMLElement $element, $value, $group = null)
+	{
+		json_decode($value);
+
+		// Check if value is a valid JSON string.
+		if ($value !== '' && json_last_error() !== JSON_ERROR_NONE)
+		{
+			/**
+			* If the value is not empty and is not a valid JSON string,
+			* it is most likely a custom field created in Joomla 3 and
+			* the value is a string that contains the file name.
+			*/
+			if (file_exists(JPATH_ROOT . '/' . $value))
+			{
+				$value = '{"imagefile":"' . $value . '","alt_text":""}';
+			}
+			else
+			{
+				$value = '';
+			}
+		}
+
+		if (!parent::setup($element, $value, $group))
+		{
+			return false;
+		}
+
+		$this->directory = (string) $this->element['directory'];
+		$this->preview = (string) $this->element['preview'];
+		$this->previewHeight = isset($this->element['preview_height']) ? (int) $this->element['preview_height'] : 200;
+		$this->previewWidth = isset($this->element['preview_width']) ? (int) $this->element['preview_width'] : 200;
+
+		$xml = <<<XML
+<?xml version="1.0" encoding="utf-8"?>
+<form>
+	<fieldset 
+		name="accessiblemedia"
+		label="JLIB_FORM_FIELD_PARAM_ACCESSIBLEMEDIA_LABEL"
+	>
+		<field
+			name="imagefile"
+			type="media"
+			label="JLIB_FORM_FIELD_PARAM_ACCESSIBLEMEDIA_PARAMS_IMAGEFILE_LABEL"
+			directory="$this->directory"
+			preview="$this->preview"
+			preview_width="$this->previewWidth"
+			preview_height="$this->previewHeight"
+		/>
+
+		<field
+			name="alt_text"
+			type="text"
+			label="JLIB_FORM_FIELD_PARAM_ACCESSIBLEMEDIA_PARAMS_ALT_TEXT_LABEL"
+		/>
+	</fieldset>
+</form>
+XML;
+		$this->formsource = $xml;
+
+		$this->layout = 'joomla.form.field.media.accessiblemedia';
+
+		return true;
+	}
+}

plugins/fields/media/media.php

@@ -9,11 +9,81 @@
 
 defined('_JEXEC') or die;
 
+use Joomla\CMS\Form\Form;
+
 /**
  * Fields Media Plugin
  *
  * @since  3.7.0
  */
 class PlgFieldsMedia extends \Joomla\Component\Fields\Administrator\Plugin\FieldsPlugin
 {
+	/**
+	 * Transforms the field into a DOM XML element and appends it as a child on the given parent.
+	 *
+	 * @param   stdClass    $field   The field.
+	 * @param   DOMElement  $parent  The field node parent.
+	 * @param   Form        $form    The form.
+	 *
+	 * @return  DOMElement
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public function onCustomFieldsPrepareDom($field, DOMElement $parent, Form $form)
+	{
+		$fieldNode = parent::onCustomFieldsPrepareDom($field, $parent, $form);
+
+		if (!$fieldNode)
+		{
+			return $fieldNode;
+		}
+
+		$fieldNode->setAttribute('type', 'accessiblemedia');
+
+		return $fieldNode;
+	}
+
+	/**
+	 * Before prepares the field value.
+	 *
+	 * @param   string     $context  The context.
+	 * @param   \stdclass  $item     The item.
+	 * @param   \stdclass  $field    The field.
+	 *
+	 * @return  void
+	 *
+	 * @since   __DEPLOAY_VERSION__
+	 */
+	public function onCustomFieldsBeforePrepareField($context, $item, $field)
+	{
+		// Check if the field should be processed by us
+		if (!$this->isTypeSupported($field->type))
+		{
+			return;
+		}
+
+		// Check if the field value is an old (string) value
+		$field->apivalue = $this->checkValue($field->value);
+	}
+
+	/**
+	 * Before prepares the field value.
+	 *
+	 * @param   string  $value  The value to check.
+	 *
+	 * @return  array  The checked value
+	 *
+	 * @since   __DEPLOAY_VERSION__
+	 */
+	private function checkValue($value)
+	{
+		json_decode($value);
+
+		if (json_last_error() === JSON_ERROR_NONE)
+		{
+			return (array) json_decode($value, true);
+		}
+
+		return array('imagefile' => $value, 'alt_text' => '');
+	}
 }

plugins/fields/media/tmpl/media.php

@@ -20,20 +20,22 @@
 	$class = ' class="' . htmlentities($class, ENT_COMPAT, 'UTF-8', true) . '"';
 }
 
-$value  = (array) $field->value;
+$value  = $field->apivalue;
 $buffer = '';
 
-foreach ($value as $path)
+if ($value)
 {
-	if (!$path)
+	$path = $value['imagefile'];
+	$alt = ' alt="' . htmlentities($value['alt_text'], ENT_COMPAT, 'UTF-8', true) . '"';
+
+	if (file_exists($path))
 	{
-		continue;
+		$buffer .= sprintf('<img loading="lazy" src="%s"%s%s>',
+			htmlentities($path, ENT_COMPAT, 'UTF-8', true),
+			$class,
+			$alt
+		);
 	}
-
-	$buffer .= sprintf('<img loading="lazy" src="%s"%s>',
-		htmlentities($path, ENT_COMPAT, 'UTF-8', true),
-		$class
-	);
 }
 
 echo $buffer;