[4.0] Media fields accessibility - second try

[astridx]

Pull Request for Issue #27571 .

Please see #27650 and #27712 (comment) for test instructions.

In this Pull Request I tried to implement a suggestion from this comment - I use the Subform Field.

Edit: 10th of February
Test Instructions - You do NOT need composer or npm

1. Create a Custom Field of type media and see, that this field did not include an alternative text in front end. I named this custom field old.
2. Apply this patch and create a new custom field of type media. See hat all parameters, for example directory, are working. I named this custom field new.
3. See, that the custom fields new is still shown correctly in front end. When you edit an article, the text field for the alternative text is not show for the old custom field at the begin. But when you delete the image temporarily the text field appear and you can use it.
4. Use the new form field regardless of custom field
   a) Add

		<field
			name="image2"
			type="accessiblemedia"
			label="COM_CONTACT_FIELD_PARAMS_IMAGE_LABEL"
			directory="banners"
		/>

somewhere for example in line 276 of /administrator/components/com_contact/forms/contact.xml.
b) If you use my example add

	`<?php echo $this->form->renderField('image2'); ?>`

in /administrator/components/com_contact/tmpl/contact/edit.php line 55.
c) See that you can use the field.

[brianteeman]

Awesome!!! - Works perfectly for me.

Two suggestions

1. Dont make it optional to add the alternative text when defining the field - you should always have one so no need for that option
2. You could instead have an option to make the alternative text a required field - not sure if that will be possible as it would only be required if you have an image

[brianteeman]

In the generated code when the field is presented you have a small bug as the generated code is

[brianteeman]

Sorry there is another small issue when using the field in the front end

Before

After

[SharkyKZ]

If the idea is to implement this just in media custom field, Joomla\CMS\Form\Field\AccessiblemediaField is not required. The form can be added directly in the plugin like here

joomla-cms/plugins/fields/subfields/subfields.php

Line 302 in a9f80d6

$parent_fieldset = $parent_field->appendChild(new DOMElement('form'));

.

Otherwise AccessiblemediaField should not have a dependency on media field plugin.

[SharkyKZ]

This has to be set on the media field.

[astridx]

@SharkyKZ Are you sure. If so, I don't understand it correctly. I want to overwrite this line:

joomla-cms/administrator/components/com_fields/Plugin/FieldsPlugin.php

Line 190 in a9f80d6

$node->setAttribute('type', $field->type);

[SharkyKZ]

I mean hide_default attribute.

[astridx]

OK. That is not part of this PR. I think we should do it in a separate PR, right?

[SharkyKZ]

It is part of this PR. $fieldNode is now a Subform field but hide_default property belongs on the media field which is now inside the subform.

Personally I'd just remove AccessiblemediaField and use Subfields as example. This is basic code for implementing the subform with media and alt fields:

// This is now the subform field.
$fieldNode->setAttribute('type', 'subform');

// Add form to subform.
$form = $fieldNode->appendChild(new DOMElement('form'));

// This is the media field.
$media = $form->appendChild(new DOMElement('field'));
$media->setAttribute('type', 'media');
$media->setAttribute('name', 'filename');
$media->setAttribute('hide_default', 'true');

// Thie is the alt field.
$alt = $form->appendChild(new DOMElement('field'));
$alt->setAttribute('type', 'text');
$alt->setAttribute('name', 'alt');

[SharkyKZ]

The same is needed for other parameters like directory. It's currently not working.

[astridx]

Your are right. I now understand what you mean.

[astridx]

@SharkyKZ The idea is to use a different form field if an alternative value can be entered. Not media, but accessiblemedia. And accessiblemedia inherits from subform.
This is not a nice object-oriented. I know. accessiblemedia should be a child of the media field semantically correct.

[astridx]

@brianteeman In the generated code when the field is presented you have a small bug as the generated code is

Thank you, done.

[astridx]

@brianteeman Sorry there is another small issue when using the field in the front end

Thanks again. Please see if you think that's good.

[Quy]

No image is selected, yet it is displayed on the frontend as a broken image.

[astridx]

@SharkyKZ I want to make sure I understand you correctly in the comment here: #27712 (comment)

In my opinion is the check you would like to have in the plugin not wrong in the field and I have now expanded it.

--

If I understand you correctly, you think that this check should be done in the plugin, since it is only necessary in the plugin. It is not necessary in the Field.

--

In the case of the plugin it could be, that we have an "old" custom field, that was created using the MediaField (not the AccessiblemediaField - That will be the case, if Joomla Version 3 is updated to Version 4). In this case, the value does not contain an alt text. It is a simple string, for example: "images/joomla_black.png".
For showing everything (image and alt text) correctly in back end the AccessiblemediaField need da json string like this: "{"imagefile":"images\/banners\/banner.jpg","alt_text":""}" because it is a child of the SubformField.
(I did not extend the MediaField, because I could reuse more. And as a SubformField we always have the possibility to add other things that belong to the field in the same way.)

--

You're right, I created this check in the field in order to make the value of the custom fields backwards compatible. But: A check at this point will correct other possible errors. In my opinion the check is even better at this point.

--

Do I see that correctly, or are there other reasons to check the value in the custom field that I don't see?

[SharkyKZ]

The check should be in the plugin because it looks like it is a workaround for the plugin. Library code should not have extension specific hacks. But if the intention is to have this field as a drop-in replacement for Joomla\CMS\Form\Field\MediaField in other places, maybe it's fine.

[astridx]

@SharkyKZ Thanks for the feedback.

The check should be in the plugin because it looks like it is a workaround for the plugin.

I don't see any way to do this in the plugin. But I like to be instructed when others prefer it.
In my opinion, it is even better as it is in this PR, because other possible errors are also caught here.

But if the intention is to have this field as a drop-in replacement for Joomla\CMS\Form\Field\MediaField in other places, maybe it's fine.

This field should be an alternative to the media field, where you don't have to add a text field for the alternative text in a form. Everything is together - it belongs together.
In my opinion it is not possible to replace the previous field with backward compatibility.

[richard67]

@astridx Shall I resolve the conflict in file plugins/fields/media/tmpl/media.php for you?

[astridx]

@richard67 I think I managed it myself. But it would be good if you could check. I am not good at conflict resolution. I usually delete the branch and do it from scratch.

[astridx]

@zero-24 I just saw that you requested a change. But I don't really know what to change. Can it be that this request is no longer current or can you help me?

[richard67]

@astridx Was an easy conflict and you solved it the right way. I was sure you can do that yourself, just offered my help because I saw if and thought maybe you are too busy with other things.

[richard67]

@astridx Possibly @zero-24 meant this comment #27712 (comment) about the missing doc block?

[wilsonge]

I'm merging this because it's definitely a step in the right direction and we can tweak this moving forwards as required. Thankyou very much @astridx

[Scrabble96]

This option to add 'Alt text' needs to be added to the "Image List" field as well:

[richard67]

@Scrabble96 Could you open a new issue for that it there is not already one found by a quick view? That would be helpful. Thanks in advance.

[Scrabble96]

I opened the new issue (#29640) as requested, but no-one except me has commented and adding/editing any code for a PR is way beyond me. Thanks.