Implementing Custom Code Completion

There is two ways of adding custom code completion to HippoEDIT:

• Implementing/registering own Completion provider. Recommended for most of use cases.
• Subscribing on Application.onCompletion event, and showing completion list by yourself. Can be used if you want to use different UI for completion.

There are several APIs and scripting object that helps implementing the code completion logic.

• Application.onCompletion

• View.ShowCompletionList - Show Completion list
• View.HideCompletionList - Hide Completion list
• Applicaiton.RegisterCompletionProvider - Register code completion provider for syntax
• Applicaiton.UnRegisterCompletionProvider - UnRegister code completion provider for syntax by instance
• Applicaiton.CompletionItem - CompletionItem object constructor
• Applicaiton.CompletionSet - CompletionSet object constructor
• Applicaiton.CompletionProvider - CompletionProvider object constructor

• CompletionItem - to be added to CompletionSet
• CompletionSet - used for displaing completion list
• CompletionProvider - implement to be called on building completion list

Implementing a custom code completion using Completion Providers is a preferred way. You can register to call back only for specific syntax (and all other syntaxes inherited from it) and been called exactly at the moment when items are necessary, with minimum service code from your side, to give items back. In addition to that, usage of completion providers, allows HippoEDIT to call collection from different providers in parallel, that speedups general processing.

code-completion1.hejs

function onCompletionCollect(view, selection, set) {
	// if we are not inside of comments or documentation (Style.Text == 1 ), add our items to the list
	if ( view.Document.GetStyleFromPos(selection.Start, true).Style.Text != 1 ) {
		// add item as string, ше would be displayed using default style
		set.Add("Variable1");
		// or explicitely as completion item, if you want to better item customizing options
		// for example, assigning of special style, as below
		set.Add(CompletionItem("Variable1", "variable"));	
	}
	return true;
}
 
// create and register completion provider to be used for JavaScript (id="js") and all syntaxes inherited from it
Application.RegisterCompletionProvider("js", Application.CompletionProvider(onCompletionCollect));

code-completion3.hejs

////////////////////////////////////////////////////////////////////////
// Register Code Completion Handler
Application.onCompletion = function(/*IRange*/ selection ) {
	if ( ActiveDocument.Syntax.IsInheritedFrom("js") ) {
		//var aSuggestions = ["Item1", "Item2", "Item3", "Item4", "Item5", "Item6", "Item7", "Item8", "Item9", "Item10"];
		//this.ShowCompletionList(selection, aSuggestions, false);
 
		var item5 = CompletionItem("Item5");
		item5.Pattern = "%CurrentWord%(%|%)";
		item5.onDescription = function () { return this.Text + "() ..."; };
		var item6 = CompletionItem("Item6");
		item6.onExpand = onExpand;
		item6.SubMenu = true;
		var aSuggestions = [CompletionItem("Item1", "js:methods"), CompletionItem("Item2", "variable"), CompletionItem("Item3"), CompletionItem("Item4", null, 11, 1, "Item4 Description", onExpand), item5, item6]; 
 
		var completion_set = CompletionSet(aSuggestions);	
		this.ShowCompletionList(selection, completion_set, true);
		return true; // processed	
	}
 
	return false;	 
};