Link-Target Feature

The Link-Target Plugin extends CKEditor’s Link Feature by selection of a target attribute for an existing link. It is stored in model as linkTarget attribute.

A document post-fixer exists, so that linkTarget attribute cannot exist without linkHref attribute set. This ensures smooth integration into CKEditor’s link feature, as buttons for target selection will be added to the LinkActionsView of CKEditor’s link feature.

Integration
Configuration
CoreMedia RichText 1.0 Integration
- CKEditor 4 Behavior

Integration

import LinkTarget from "@coremedia/ckeditor5-coremedia-link/linktarget/LinkTarget";

ClassicEditor
  .create(document.querySelector("#editor"), {
    plugins: {
      // ...
      LinkTarget,
    },
    // ...
    link: {
      toolbar: [
        // ...
      ],
      targets: [
        // ...
      ],
      defaultTargets: [
        // ...
      ]
    }
  })
  .then(...)
  .catch(...);

Configuration

The plugin can be configured as part of CKEditor’s Link Feature configuration. In order to change the link targets, displayed inside the link balloon, they need to be added to the corresponding link.toolbar configuration. This toolbar usually also consists of a field to preview the link, separators and other buttons. This is a configuration that holds two additional buttons that set link targets: _self and _blank:

ClassicEditor
  .create(document.querySelector("#editor"), {
    // ...
    link: {
      toolbar: [
        "linkPreview",
        "editLink",
        "|",
        "_self",
        "_blank",
        "|",
        "unlink",
      ],
    }
  })
  .then(...)
  .catch(...);

Default Configuration
Advanced Configuration

Default Configuration

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Default Configuration

Advanced Configuration

Default-Target Configuration

The default toolbar for the link balloon is configured inside CKEditor’s Link Feature plugins and includes no buttons for link targets. Please add a configuration like shown in the example above to configure any buttons that change the linkTarget.

The following table shows linkTarget buttons that can be added to the toolbar:

Target / Button Name	Label
`_self`	Open in Current Tab
`_blank`	Open in New Tab
`_embed`	Show Embedded
`_other`	Open in Frame

Predefined: _self

This is the default state for unset linkTarget attribute in model. When pressed, an explicit linkTarget="_self" will be applied to the model.

Recommended: If you skip this option, you may find none of the option buttons being active for a newly created link, as new links will not be created having a linkTarget attribute set.

Predefined: _blank

This is the same as the standard HTML attribute value _blank.

Predefined: _embed

This is an artificial target derived from xlink:show="embed" (and used by CoreMedia RichText 1.0 for example, see below). It is represented similar to the standard target names with an underscore as prefix.

Predefined: _other

The name corresponds to xlink:show="other". It represents any other value of linkTarget which is not known by any of the other configured targets. If pressed, an editor will pop up to specify any custom value for linkTarget such as my-named-frame.

Recommended: It is strongly recommended adding at least _other to your configuration, as it serves as fallback for any otherwise unknown value of linkTarget. Thus, if your model includes linkTarget="_self" without _self being part of your configuration, this option will become active and provide an editor containing _self as text.

Corner Cases for _other

_other is most likely the most flexible state, as it serves as fallback for any unknown value of target and yet must be able to understand any possible mapping from xlink:show and xlink:role as required for CoreMedia RichText 1.0 (see below). Thus, there are some corner cases to respect:

Special Value _other:

If the model states linkTarget="_other" it is defined to represent xlink:show="other" without recommended, but not enforced attribute xlink:role.

The UI, in this state, will mark Open in Frame as active, while the corresponding FormView for editing the target will show an empty editor.
Press Save on empty editor:

We decided, that the editor wants to signal not to set any target. Thus, if editors select _other and save with empty text, linkTarget attribute will be removed. As no linkTarget defaults to Open in Current Tab, the UI will toggle to the corresponding button and turn it on.

Note, that this will also cause, that if the model value was _other as stated above, you open the target editor and save, then _other will be removed from as target.
Handle unregistered standard-target such as _blank:

If the standard-target has not been registered, but is written into the model, the _other state becomes active. Opening the editor will show _blank within its input field, just as any other custom target attribute value.
Manually enter registered standard-target such as _blank:

If _blank is registered as standard-target, a (more or less) hidden feature kicks in: When editors write _blank into the input field, the value will be written directly to model. As a result, after Save, not the Open in Frame button becomes active, but the Open in New Tab.

Having this, editors may decide to manually type any standard-target instead of clicking toggle-buttons in the UI.
Manually enter _other:

Similar to the previous approach for _blank, the value _other will be directly written into the model. As a result, next time you open the editor, it will show an empty text field (see specification above). In the model you will find linkTarget="_other" and on data-processing it will be transformed to xlink:show="other" without xlink:role attribute for CoreMedia RichText 1.0.
Raw mode for unexpected values such as _blank_someRole:

As can be seen in details on data-processing below, some artificial, unexpected states of xlink:show and xlink:role attributes may result in similar artificial values for linkTarget.

The general contract for _other states, that it becomes active for any other unknown value.

The same applies to artificial values of linkTarget such as _blank_someRole, which is the resulting mapping for xlink:show="new" xlink:role="someRole". Thus, instead of the button Open in New Tab becoming active, the _other button will become active. Once editors click to editor the target, they will see _blank_someRole as raw text within the input field.

The same applies to a value linkTarget="_other_someThing", which will not be understood as xlink:show="other" xlink:role="someThing" but instead xlink:show="other" xlink:role="_other_someThing". I.e., on Save it will be directly written as linkTarget="_other_someThing" into the model.

Advanced Configuration

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Default Configuration

Advanced Configuration

Default-Target Configuration

You may add any custom button for predefined linkTarget values. For example to support standard HTML option values _top and _parent you may add them to the link.toolbar configuration just as all other options. There is a prerequisite though: Custom targets have to be registered as valid targets by also adding them to the link.targets:

ClassicEditor
  .create(document.querySelector("#editor"), {
    // ...
    link: {
      toolbar: [
        // ...
        "_parent",
        "_top",
        "_other"
      ],
      targets: [
        // ...
      ],
    }
  })
  .then(...)
  .catch(...);

You may configure custom icons by adding SVGs or referencing SVGs:

import parentIcon from 'path/to/parentIcon.svg';

ClassicEditor
  .create(document.querySelector("#editor"), {
    // ...
    link: {
      toolbar: [
        // ...
        "_parent",
        "_top",
        "_other"
      ],
      targets: [
        {
          name: "_parent",
          icon: parentIcon,
        },
        {
          name: "_top",
          icon: "<svg ...>...</svg>",
          title: "Open at topmost browsing context"
        },
      ],
    }
  })
  .then(...)
  .catch(...);

title: As can be seen in the example, you may also provide a text for the tooltip. The text is handed over to Locale.t() for translation, so that you may provide labels translated to your UI language. Translations must be provided by using the function translation-service.add(). For more information regarding translation-service.add() consult the CKEditor 5 documentation.

The title defaults to the name of the target option if unset.

icon: Icons will be scaled to 20×20. Thus, it is recommended providing SVGs having this initial size. Note, that, if no icon is configured, the button labels will just contain the plain text value.

Default-Target Configuration

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Default Configuration

Advanced Configuration

Default-Target Configuration

You can add defaults for link targets. These defaultTargets define how a link is opened, based on the type of the link. The config for these targets distinguishes between content links and external links, where content links are all links to contents in CoreMedia Studio and external links are links, prefixed with https://.

ClassicEditor
  .create(document.querySelector("#editor"), {
    // ...
    link: {
      defaultTargets: [
        {
          type: "externalLink",
          target: "_blank"
        }
      ],
    }
  })
  .then(...)
  .catch(...);

Please note, that you can also set a filter property instead of a type to specify additional default targets:

ClassicEditor
  .create(document.querySelector("#editor"), {
    // ...
    link: {
      defaultTargets: [
        {
          filter: (url: string) => (url ? url.startsWith("http://") : false),
          target: "_embed"
        }
      ],
    }
  })
  .then(...)
  .catch(...);

It’s important to know that the order of default targets is relevant. For each link, all target rules will be applied in the exact order, determined by the config. If there are multiple matching types or filters, the last one will always be applied.

CoreMedia RichText 1.0 Integration

The following is not part of the LinkTarget plugin, but included in the CoreMedia RichText plugin. Having this, it is perfectly fine, if you do not include the LinkTarget plugin, but use for example CKEditor’s decorator approach instead, as it will be automatically recognized by the RichText plugin.

CoreMedia RichText 1.0 does not know about the target attribute. General contract is, to model it with XLink Attribute xlink:show and xlink:role.

While in the original specification xlink:role is meant to hold only Legacy extended IRIs as values, it is used within CoreMedia CMS to store any non-predefined target value, such as the name of a frame.

The general contract for mapping target attributes during RichText data-processing is as follows:

`xlink:show`	`xlink:role`	`target`
`new`		`_blank`
`replace`		`_self`
`embed`		`_embed`
`none`		`_none`
`other`	`frameName`	`frameName`

Targets for embed and none are artificial mappings, as if they were defined as standard attribute values for the target attribute. This is required, as the target attribute does not provide any alternative to these states of xlink:show.

_none: Note, that _none is not one of the default targets provided by LinkTarget plugin. If you want to support it, you may add it as part of the Advanced Configuration.

For other well-known values regarding the target attribute, these will be mapped with xlink:show="other":

`xlink:show`	`xlink:role`	`target`
`other`	`_parent`	`_parent`
`other`	`_top`	`_top`

Mappings in data processing should ensure, that more artificial states (from CoreMedia CMS) perspective are also represented meaningfully.

A general recommendation is providing artificial targets for xlink:show states, which are not expected to have a value in xlink:role. For example if the CMS provides xlink:show="replace" xlink:role="frameName" it may be represented as _self_frameName, where _self is the default mapping for replace.

The following artificial states may occur:

`xlink:show`	`xlink:role`	`target`
`new`	`frameName`	`_blank_frameName`
`replace`	`frameName`	`_self_frameName`
`embed`	`frameName`	`_embed_frameName`
`none`	`frameName`	`_none_frameName`
`other`		`_other`
	`frameName`	`_role_frameName`

Without further configuration, LinkTarget plugin will assume the values to be custom targets just as any other unmatched string. Just as for _none you may decide to provide an Advanced Configuration for these combined targets.

CKEditor 4 Behavior

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CKEditor 4

Some details on the CKEditor 4 integration in CoreMedia Studio and its behavior regarding different states of xlink:show and xlink:role are shown here. It is important to note, that for CKEditor 4 we kept xlink:show and xlink:role as extra hidden attributes within CKEditor HTML and all actions modifying these behaviors, knew about them.

For CKEditor 5 we decided to stick to the more generic target attribute as representation within CKEditor. This makes it obsolete adding some special paste handler transforming such target attributes for example on copy and paste from external sources.

CoreMedia CKEditor 5 Plugins

CoreMedia's CKEditor 5 Plugins provides plugins for CKEditor 5 with focus on integration into CoreMedia CMS.

Link-Target Feature

Integration

Configuration

Default Configuration

Predefined: _self

Predefined: _blank

Predefined: _embed

Predefined: _other

Corner Cases for _other

Advanced Configuration

Default-Target Configuration

CoreMedia RichText 1.0 Integration

CKEditor 4 Behavior