Populate Component Templates in dropdown added directly Through "Link.aspx" in Hyperlink tag of RichText Field

Question

I have added a dropdown replacing Target field's textbox in Hyperlink tab of RichText toolbar using Link.aspx present at C:\Program Files (x86)\Tridion\web\WebUI\Editors\CME\Views\Popups\Link. The Dropdown is coming in the UI of Tridion.

I want to populate the Linked Component Templates in that dropdown according to the component selected, but I am unable to populate the Component Templates in this dropdown.

I used UI Extensions for this (JS and Config files added). I have added it to the system.config and created a virtual folder in IIS too.

I think I'm making some mistake in the Config file, as I am unaware of how many of it's tags should be used.

<?xml version="1.0"?>
<Configuration xmlns="http://www.sdltridion.com/2009/GUI/Configuration/Merge" xmlns:cfg="http://www.sdltridion.com/2009/GUI/Configuration" xmlns:ext="http://www.sdltridion.com/2009/GUI/extensions" xmlns:cmenu="http://www.sdltridion.com/2009/GUI/extensions/ContextMenu">
  <resources cache="true">
    <cfg:filters/>
    <cfg:groups>
      <cfg:group name="Extensions.Resources.NamedTargetDropdown" merger="Tridion.Web.UI.Core.Configuration.Resources.CommandGroupProcessor" merge="always">
        <cfg:fileset>
          <cfg:file type="script">/Commands/CT_Dropdown.js</cfg:file>
        </cfg:fileset>
        <cfg:dependencies>
          <cfg:dependency>Tridion.Web.UI.Editors.CME</cfg:dependency>
          <cfg:dependency>Tridion.Web.UI.Editors.CME.commands</cfg:dependency>
        </cfg:dependencies>
      </cfg:group>
    </cfg:groups>
  </resources>
  <definitionfiles/>
  <extensions>
    <ext:editorextensions>
      <ext:editorextension target="CME">
        <ext:editurls/>
        <ext:listdefinitions/>
        <ext:taskbars/>
        <ext:commands/>
        <ext:commandextensions/>
        <ext:contextmenus/>
        <ext:lists/>
        <ext:tabpages/>
        <ext:toolbars/>
        <ext:ribbontoolbars/>
      </ext:editorextension>
    </ext:editorextensions>
    <ext:dataextenders/>
  </extensions>
  <commands>
    <cfg:commandset id="Tridion.Cme.Views.NamedTargetDropdown">
      <cfg:command name="NamedTargetDropdown" implementation="Tridion.Cme.Views.Link.NamedTargetDropdown"/>
      <cfg:dependencies>
        <cfg:dependency>Extensions.Resources.Base</cfg:dependency>
      </cfg:dependencies>
    </cfg:commandset>
  </commands>
  <contextmenus/>
  <localization/>
  <settings>
    <defaultpage/>
    <navigatorurl/>
    <editurls/>
    <listdefinitions/>
    <itemicons/>
    <theme>
      <path/>
    </theme>
    <customconfiguration/>
  </settings>
</Configuration>

and the JS, I have written is:

Type.registerNamespace("Tridion.Cme.Views"); 

Tridion.Cme.Views.Link.NamedTargetDropdown = function Tridion.Cme.Views.Link$NamedTargetDropdown() { 
    Type.enableInterface(this, "Tridion.Cme.Views.Link.NamedTargetDropdown"); 
    this.addInterface("Tridion.Cme.View", ["NamedTargetDropdown"]); 
}; 

Tridion.Cme.Views.Link.NamedTargetDropdown.prototype.isAvailable = function NamedTargetDropdown$isAvailable(NamedTarget) { 
    return true; 
} 

Tridion.Cme.Views.Link.NamedTargetDropdown.prototype.isEnabled = function NamedTargetDropdown$isEnabled(NamedTarget) { 
    return true; 
} 

Tridion.Cme.Views.Link.NamedTargetDropdown.prototype._execute = function NamedTargetDropdown$_execute(NamedTarget) { 
    var p = this.properties;
    var previewItem = $models.getItem(p.itemId);
    if (previewItem && Type.implementsInterface(previewItem, "Tridion.ContentManager.VersionedItem") && previewItem.isVersion()) {
        var itemId = previewItem.getVersionlessId();
        previewItem = $models.getItem(itemId);
    }

    if (!previewItem) {
        return;
    }
    p.templateList = previewItem.getListComponentTemplates();
}

update

I think I need to add:

<ext:contextmenus>
  <ext:add>
    <ext:extension name=”NamedTargetDropdown" assignid="NamedTarget">
      <ext:menudeclaration externaldefinition=”">
        <ext:command>NamedTargetDropdown</ext:command>
      </ext:menudeclaration>
      <ext:dependencies>
        <cfg:dependency>Extensions.Resources.NamedTargetDropdown</cfg:dependency>
      </ext:dependencies>
      <ext:apply>
        <ext:view name=”PopupsView"/>
      </ext:apply>
    </ext:extension>
  </ext:add>
</ext:contextmenus>

But upon adding this I am getting the following error:

Loading configuration file "C:\Program Files (x86)\Tridion\web\WebUI\Editors\NamedTargetDropdown\NamedTargetDropdown.config" failed: Invalid character in the given encoding. Line 30, position 21

Answer 1

Few comments:

1. Modyfing existing CME popups is not supported action
2. Extension in this post is wrong. It looks like you are trying to add new command and associate new context menu option with this command, but configuration sections for this purpose are incorrect. Please, refer documentation or check existing exstensions on how to correctly write it.
3. New Command and Content Menu option will not help you to populate your new dropdown. That have to be done from View object implementation.