silverstripe-framework/docs/en/topics/rich-text-editing.md

12 KiB

Rich-Text Editing (WYSIWYG)

Introduction

Editing and formatting content is the bread and butter of every content management system, which is why SilverStripe has a tight integration with our preferred editor library, TinyMCE. On top of the base functionality, we use our own insertion dialogs to ensure you can effectively select and upload files. In addition to the markup managed by TinyMCE, we use shortcodes to store information about inserted images or media elements.

Usage

The framework comes with a [api:HTMLEditorField] form field class which encapsulates most of the required functionality. It is usually added through the [api:DataObject->getCMSFields()] method:

:::php
class MyObject extends DataObject {
	private static $db = array('Content' => 'HTMLText');
	
	public function getCMSFields() {
		return new FieldList(new HTMLEditorField('Content'));
	}
}

Configuration

To keep the JavaScript editor configuration manageable and extensible, we've wrapped it in a PHP class called [api:HtmlEditorConfig]. The class comes with its own defaults, which are extended through configuration files in the framework (and the cms module in case you've got that installed). There can be multiple configs, which should always be created / accessed using [api:HtmlEditorConfig::get]. You can then set the currently active config using set_active(). By default, a config named 'cms' is used in any field created throughout the CMS interface.

Caveat: currently the order in which the `_config.php` files are executed depends on the module directory names. Execution order is alphabetical, so if you set a TinyMCE option in the `aardvark/_config.php`, this will be overriden in `framework/admin/_config.php` and your modification will disappear.

This is a general problem with _config.php files - it may be fixed in the future by making it possible to configure the TinyMCE with the new configuration system.

Adding and removing capabilities

In its simplest form, the configuration of the editor includes adding and removing buttons and plugins.

You can add plugins to the editor using the Framework's [api:HtmlEditorConfig::enablePlugins] method. This will transparently generate the relevant underlying TinyMCE code.

:::php
// File: mysite/_config.php
HtmlEditorConfig::get('cms')->enablePlugins('media');

Note: this utilises the TinyMCE's PluginManager::load function under the hood (check the TinyMCE documentation on plugin loading for details).

Plugins and advanced themes can provide additional buttons that can be added (or removed) through the configuration. Here is an example of adding a ssmacron button after the charmap button:

:::php
// File: mysite/_config.php
HtmlEditorConfig::get('cms')->insertButtonsAfter('charmap', 'ssmacron');

Buttons can also be removed:

:::php
// File: mysite/_config.php
HtmlEditorConfig::get('cms')->removeButtons('tablecontrols', 'blockquote', 'hr');

Note: internally [api:HtmlEditorConfig] uses the TinyMCE's theme_advanced_buttons option to configure these. See the TinyMCE documentation of this option for more details.

Setting options

TinyMCE behaviour can be affected through its configuration options. These options will be passed straight to the editor.

One example of the usage of this capability is to redefine the TinyMCE's whitelist of HTML tags - the tags that will not be stripped from the HTML source by the editor.

:::php
// Add start and type attributes for <ol>, add <object> and <embed> with all attributes.
HtmlEditorConfig::get('cms')->setOption(
	'extended_valid_elements',
	'img[class|src|alt|title|hspace|vspace|width|height|align|onmouseover|onmouseout|name|usemap],' .
	'iframe[src|name|width|height|title|align|allowfullscreen|frameborder|marginwidth|marginheight|scrolling],' .
	'object[classid|codebase|width|height|data|type],' .
	'embed[src|type|pluginspage|width|height|autoplay],' .
	'param[name|value],' .
	'map[class|name|id],' .
	'area[shape|coords|href|target|alt],' .
	'ol[start|type]'
);

Note: the default setting for the CMS's extended_valid_elements we are overriding here can be found in framework/admin/_config.php.

Writing custom plugins

It is also possible to add custom buttons to TinyMCE. A simple example of this is SilverStripe's ssmacron plugin. The source can be found in the Framework's thirdparty/tinymce_ssmacron directory.

Here is how we can create a project-specific plugin. Create a mysite/javascript/myplugin directory, add the plugin button icon - here myplugin.png - and the source code - here editor_plugin.js. Here is a very simple example of a plugin that adds a button to the editor:

:::js
(function() {
	tinymce.create('tinymce.plugins.myplugin', {
		
		init : function(ed, url) {
			var self = this;
			
			ed.addButton ('myplugin', {
				'title' : 'My plugin',
				'image' : url+'/myplugin.png',
				'onclick' : function () {
					alert('Congratulations! Your plugin works!');
				}
			});
			
		},
		
		getInfo : function() {
			return {
				longname  : 'myplugin',
				author	  : 'Me',
				authorurl : 'http://me.org.nz/',
				infourl   : 'http://me.org.nz/myplugin/',
				version   : "1.0"
			};
		}
	});
	
	tinymce.PluginManager.add('myplugin', tinymce.plugins.myplugin);
})();

You can then enable this plugin through the [api:HtmlEditorConfig::enablePlugins]:

:::php
HtmlEditorConfig::get('cms')->enablePlugins(array('myplugin' => '../../../mysite/javascript/myplugin/editor_plugin.js'));

For more complex examples see the Creating a Plugin in TinyMCE documentation, or browse through plugins that come with the Framework at thirdparty/tinymce/plugins.

Image and Media Insertion

The [api:HtmlEditorField] API also handles inserting images and media files into the managed HTML content. It can be used both for referencing files on the webserver filesystem (through the [api:File] and [api:Image] APIs), as well as hotlinking files from the web.

We use shortcodes to store information about inserted images or media elements. The [api:ShortcodeParser] API post-processes the HTML content on rendering, and replaces the shortcodes accordingly. It also takes care of care of placing the shortcode replacements relative to its surrounding markup (e.g. left/right alignment).

oEmbed: Embedding media through external services

The "oEmbed" standard is implemented by many media services around the web, allowing easy representation of files just by referencing a website URL. For example, a content author can insert a playable youtube video just by knowing its URL, as opposed to dealing with manual HTML code.

oEmbed powers the "Insert from web" feature available through [api:HtmlEditorField]. Internally, it makes HTTP queries to a list of external services if it finds a matching URL. These services are described in the Oembed.providers configuration. Since these requests are performed on page rendering, they typically have a long cache time (multiple days). To refresh a cache, append ?flush=1 to a URL.

To disable oEmbed usage, set the Oembed.enabled configuration property to "false".

Doctypes

Since TinyMCE generates markup, it needs to know which doctype your documents will be rendered in. You can set this through the element_format configuration variable. It defaults to the stricter 'xhtml' setting, for example rendering self closing tags like <br/> instead of <br>. In case you want to adhere to HTML4 instead, use the following configuration:

:::php
HtmlEditorConfig::get('cms')->setOption('element_format', 'html');

By default, TinyMCE and SilverStripe will generate valid HTML5 markup, but it will strip out HTML5 tags like <article> or <figure>. If you plan to use those, add them to the valid_elements configuration setting.

Also, the [api:SS_HTMLValue] API underpinning the HTML processing parses the markup into a temporary object tree which can be traversed and modified before saving. The built-in parser only supports HTML4 and XHTML syntax. In order to successfully process HTML5 tags, please use the 'silverstripe/html5' module.

Recipes

Customizing the "Insert" panels

In the standard installation, you can insert links (internal/external/anchor/email), images as well as flash media files. The forms used for preparing the new content element are rendered by SilverStripe, but there's some JavaScript involved to transfer back and forth between a content representation the editor can understand, present and save.

Example: Remove field for "image captions"

:::php
// File: mysite/code/MyToolbarExtension.php
class MyToolbarExtension extends Extension {
	public function updateFieldsForImage(&$fields, $url, $file) {
		$fields->removeByName('Caption');
	}
}

:::php
// File: mysite/_config.php
HtmlEditorField_Toolbar::add_extension('MyToolbarExtension');

Adding functionality is a bit more advanced, you'll most likely need to add some fields to the PHP forms, as well as write some JavaScript to ensure the values from those fields make it into the content elements (and back out in case an existing element gets edited). There's lots of extension points in the [api:HtmlEditorField_Toolbar] class to get you started.

Security groups with their own editor configuration

Different groups of authors can be assigned their own config, e.g. a more restricted rule set for content reviewers (see the "Security" ) The config is available on each user record through [api:Member->getHtmlEditorConfigForCMS()]. The group assignment is done through the "Security" interface for each [api:Group] record. Note: The dropdown is only available if more than one config exists.

Using the editor outside of the CMS

Each interface can have multiple fields of this type, each with their own toolbar to set formatting and insert HTML elements. They do share one common set of dialogs for inserting links and other media though, encapsulated in the [api:HtmlEditorField_Toolbar] class. In the CMS, those dialogs are automatically instanciated, but in your own interfaces outside of the CMS you have to take care of instanciation yourself:

:::php
// File: mysite/code/MyController.php
class MyObjectController extends Controller {
	public function EditorToolbar() {
		return HtmlEditorField_Toolbar::create($this, "EditorToolbar");
	}
}

:::ss
// File: mysite/templates/MyController.ss
$Form
<% with EditorToolbar %>
	$MediaForm
	$LinkForm
<% end_with %>

Note: The dialogs rely on CMS-access, e.g. for uploading and browsing files, so this is considered advanced usage of the field.

:::php
// File: mysite/_config.php
HtmlEditorConfig::get('cms')->disablePlugins('ssbuttons');
HtmlEditorConfig::get('cms')->removeButtons('sslink', 'ssmedia');
HtmlEditorConfig::get('cms')->addButtonsToLine(2, 'link', 'media');

Developing a wrapper to use a different WYSIWYG editors with HTMLEditorField

WYSIWYG editors are complex beasts, so replacing it completely is a difficult task. The framework provides a wrapper implementation for the basic required functionality, mainly around selecting and inserting content into the editor view. Have a look in HtmlEditorField.js and the ss.editorWrapper object to get you started on your own editor wrapper. Note that the [api:HtmlEditorConfig] is currently hardwired to support TinyMCE, so its up to you to either convert existing configuration as applicable, or start your own configuration.