Adding custom fields/Implement into your component

Other languages:

Bahasa Indonesia • ‎Deutsch • ‎English • ‎Nederlands • ‎français • ‎中文（中国大陆）‎ • ‎中文（台灣）‎

Implementation into your component

Implement fields into your component[edit]

This article describes how to apply a basic implementation of the custom fields feature to your custom component.
Ever wanted to show additional attributes in your items? Through custom fields, you have a seamlessly integrated way to show them in the backend and frontend of your site.
Custom fields offers 15 different types, if you need more you can create your own plugin.
The custom fields extension is placed in core and can be used in a similar way to the categories extension. Basically there are just 2 files you need to extend with the following code for the basic backend part.
Note! In the example code we will use for your component the name com_example.

The Backend Part[edit]

How to add fields to the backend lists[edit]

Similar to com_categories there are just a few lines needed to add the fields in the backend view. Just add the following lines to the method addSubmenu in your component helper class.
The used context needs to match the context you want to implement the fields in. An example of context could be com_content.article or com_weblinks.weblink. We’re using com_example.item here as example. Only the context option needs to be changed.

if (JComponentHelper::isEnabled('com_fields'))
{
	JHtmlSidebar::addEntry(
		JText::_('JGLOBAL_FIELDS'),
		'index.php?option=com_fields&context=com_example.item',
		$vName == 'fields.fields'
	);

	JHtmlSidebar::addEntry(
		JText::_('JGLOBAL_FIELD_GROUPS'),
		'index.php?option=com_fields&view=groups&context=com_example.item',
		$vName == 'fields.groups'
	);
}

Implement the ACL[edit]

Now the ACL part needs to be done. You have to add the following lines to your access xml file just before the closing </access> in that file. Here they are defined and will allow your users to choose the ACL settings in your implementation of com_fields.

	<section name="fieldgroup">
		<action name="core.create" title="JACTION_CREATE" description="COM_FIELDS_GROUP_PERMISSION_CREATE_DESC" />
		<action name="core.delete" title="JACTION_DELETE" description="COM_FIELDS_GROUP_PERMISSION_DELETE_DESC" />
		<action name="core.edit" title="JACTION_EDIT" description="COM_FIELDS_GROUP_PERMISSION_EDIT_DESC" />
		<action name="core.edit.state" title="JACTION_EDITSTATE" description="COM_FIELDS_GROUP_PERMISSION_EDITSTATE_DESC" />
		<action name="core.edit.own" title="JACTION_EDITOWN" description="COM_FIELDS_GROUP_PERMISSION_EDITOWN_DESC" />
		<action name="core.edit.value" title="JACTION_EDITVALUE" description="COM_FIELDS_GROUP_PERMISSION_EDITVALUE_DESC" />
	</section>
	<section name="field">
		<action name="core.delete" title="JACTION_DELETE" description="COM_FIELDS_FIELD_PERMISSION_DELETE_DESC" />
		<action name="core.edit" title="JACTION_EDIT" description="COM_FIELDS_FIELD_PERMISSION_EDIT_DESC" />
		<action name="core.edit.state" title="JACTION_EDITSTATE" description="COM_FIELDS_FIELD_PERMISSION_EDITSTATE_DESC" />
		<action name="core.edit.value" title="JACTION_EDITVALUE" description="COM_FIELDS_FIELD_PERMISSION_EDITVALUE_DESC" />
	</section>

There is one more entry setting in that file:

    <action name="core.edit.value" title="JACTION_EDITVALUE" description="JACTION_EDITVALUE_COMPONENT_DESC" />

This entry should be made under the normal settings in your component (and also in the access xml file) as it allows users in the group to edit any value of custom fields submitted in your component.

Result[edit]

If you completed these steps, your backend part for fields implementation is done. The users can now create fields and assign them to an item.

The Frontend Part[edit]

Now let's go to the frontend part. It is easy as the fields are rendered, through the Plugin/Events/Content events on the frontend. To display fields on the frontend, you need to implement the content plugin events in your component.
Important here is where you pass the same context that you used in the backend to the events.

See:

After the onContentPrepare event is fired with the context you can find the attached fields in $item->jcfields property if you want to render the fields using in your layouts / views.

Tips, Tricks & Hidden Features[edit]

Here you can find some tips and tricks on what can be gone wrong with your implementation as well as some hidden features of com_fields.

The fields tab don’t show up in my component's edit view[edit]

In some components the edit views in backend and/or frontend are hardcoded and can't be changed / extended using plugins. But as the fields uses a plugin to add the fields to your component you need to support that in order to support fields. You can make sure that fields are rendered e.g. by implementing the following layout in your component edit view:

    <?php $this->ignore_fieldsets = array('general', 'info', 'detail', 'jmetadata', 'item_associations'); ?>
    <?php echo JLayoutHelper::render('joomla.edit.params', $this); ?>

The first line makes sure we ignore the (eventually hardcoded fieldsets) and than render the dynamic fields tab using the joomla.edit.params layout.

Public helper classes and API[edit]

The class FieldsHelper has some public API functions to work with fields.

    JLoader::register('FieldsHelper', JPATH_ADMINISTRATOR . '/components/com_fields/helpers/fields.php');
    $fields = FieldsHelper::getFields('com_example.item', $item, true);

The field model itself allows to get and store the value of a field.

    JModelLegacy::addIncludePath(JPATH_ADMINISTRATOR . '/components/com_fields/models', 'FieldsModel');
    $fieldModel = JModelLegacy::getInstance('Field', 'FieldsModel', array('ignore_request' => true));
    $fieldModel->setFieldValue($fieldId, $item->id, 'demo value');

ACL support[edit]

Every field has an access level
Every field has a new permission edit.value

JFactory::getUser()->authorise('edit.value', ‘com_example.item.field.' . (int) $field->id);

More Information[edit]

https://www.youtube.com/watch?v=7ikOaOKyo6s | JAB16 - Custom Fields in Joomla for developers - English
https://www.youtube.com/watch?v=F_Ni15icn1U | JD16AT - Custom fields since Joomla 3.7 - English
https://joomla.digital-peak.com/images/blog/JDD16%20Custom%20fields%20in%20Joomla%20for%20developers.pdf

Prev: What components are supporting custom fields

Next: Use custom fields in your overrides

J3.x