Action widget: confirm (#5037)

* added action widget: confirm

* Check for all attributes in refresh handler

* Always return a value from invokeActions

core/modules/widgets/confirm.js

@@ -0,0 +1,77 @@
+/*\
+
+title: $:/core/modules/widgets/action-confirm.js
+type: application/javascript
+module-type: widget
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+var Widget = require("$:/core/modules/widgets/widget.js").widget;
+
+var ConfirmWidget = function(parseTreeNode,options) {
+	this.initialise(parseTreeNode,options);
+};
+
+/*
+Inherit from the base widget class
+*/
+ConfirmWidget.prototype = new Widget();
+
+/*
+Render this widget into the DOM
+*/
+ConfirmWidget.prototype.render = function(parent,nextSibling) {
+	this.computeAttributes();
+	this.execute();
+	this.parentDomNode = parent;
+	this.renderChildren(parent,nextSibling);
+};
+
+/*
+Compute the internal state of the widget
+*/
+ConfirmWidget.prototype.execute = function() {
+	this.message = this.getAttribute("$message");
+	this.prompt = (this.getAttribute("$prompt","yes") == "yes" ? true : false);
+	this.makeChildWidgets();
+};
+
+/*
+Refresh the widget by ensuring our attributes are up to date
+*/
+ConfirmWidget.prototype.refresh = function(changedTiddlers) {
+	var changedAttributes = this.computeAttributes();
+	if(changedAttributes["$message"] || changedAttributes["$prompt"]) {
+		this.refreshSelf();
+		return true;
+	}
+	return this.refreshChildren(changedTiddlers);
+};
+
+/*
+Invoke the action associated with this widget
+*/
+ConfirmWidget.prototype.invokeAction = function(triggeringWidget,event) {
+	var invokeActions = true,
+		handled = true;
+	if(this.message && this.prompt) {
+		invokeActions = confirm(this.message);
+	}
+	if(invokeActions) {
+		handled = this.invokeActions(triggeringWidget,event);
+	}
+	return handled;
+};
+
+ConfirmWidget.prototype.allowActionPropagation = function() {
+	return false;
+};
+
+exports["action-confirm"] = ConfirmWidget;
+
+})();