Introduce genesis widget (#6961)

* Initial Commit

* Fix version number

* Fix docs date

core/modules/utils/parsetree.js

@@ -12,12 +12,26 @@ Parse tree utility functions.
 /*global $tw: false */
 "use strict";
 
+/*
+Add attribute to parse tree node
+Can be invoked as (node,name,value) or (node,attr)
+*/
 exports.addAttributeToParseTreeNode = function(node,name,value) {
-	var attribute = {name: name, type: "string", value: value};
+	var attribute = typeof name === "object" ? name : {name: name, type: "string", value: value};
+	name = attribute.name;
 	node.attributes = node.attributes || {};
+	node.orderedAttributes = node.orderedAttributes || [];
 	node.attributes[name] = attribute;
-	if(node.orderedAttributes) {
+	var foundIndex = -1;
+	$tw.utils.each(node.orderedAttributes,function(attr,index) {
+		if(attr.name === name) {
+			foundIndex = index;
+		}
+	});
+	if(foundIndex === -1) {
 		node.orderedAttributes.push(attribute);
+	} else {
+		node.orderedAttributes[foundIndex] = attribute;
 	}
 };
 

core/modules/widgets/genesis.js

@@ -0,0 +1,108 @@
+/*\
+title: $:/core/modules/widgets/genesis.js
+type: application/javascript
+module-type: widget
+
+Genesis widget for dynamically creating widgets
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+var Widget = require("$:/core/modules/widgets/widget.js").widget;
+
+var GenesisWidget = function(parseTreeNode,options) {
+	this.initialise(parseTreeNode,options);
+};
+
+/*
+Inherit from the base widget class
+*/
+GenesisWidget.prototype = new Widget();
+
+/*
+Render this widget into the DOM
+*/
+GenesisWidget.prototype.render = function(parent,nextSibling) {
+	this.parentDomNode = parent;
+	this.computeAttributes({filterFn: function(name) {
+		// Only compute our own attributes which start with a single dollar
+		return name.charAt(0) === "$" && name.charAt(1) !== "$";
+	}});
+	this.execute();
+	this.renderChildren(parent,nextSibling);
+};
+
+/*
+Compute the internal state of the widget
+*/
+GenesisWidget.prototype.execute = function() {
+	var self = this;
+	// Collect attributes
+	this.genesisType = this.getAttribute("$type","element");
+	this.genesisRemappable = this.getAttribute("$remappable","yes") === "yes";
+	this.genesisNames = this.getAttribute("$names","");
+	this.genesisValues = this.getAttribute("$values","");
+	// Construct parse tree
+	var isElementWidget = this.genesisType.charAt(0) !== "$",
+		nodeType = isElementWidget ? "element" : this.genesisType.substr(1),
+		nodeTag = isElementWidget ? this.genesisType : undefined;
+	var parseTreeNodes = [{
+		type: nodeType,
+		tag: nodeTag,
+		attributes: {},
+		orderedAttributes: [],
+		children: this.parseTreeNode.children || [],
+		isNotRemappable: !this.genesisRemappable
+	}];
+	// Apply explicit attributes
+	$tw.utils.each($tw.utils.getOrderedAttributesFromParseTreeNode(this.parseTreeNode),function(attribute) {
+		var name = attribute.name;
+		if(name.charAt(0) === "$") {
+			if(name.charAt(1) === "$") {
+				// Double $$ is changed to a single $
+				name = name.substr(1);
+			} else {
+				// Single dollar is ignored
+				return;
+			}
+		}
+		$tw.utils.addAttributeToParseTreeNode(parseTreeNodes[0],$tw.utils.extend({},attribute,{name: name}));
+	});
+	// Apply attributes in $names/$values
+	this.attributeNames = [];
+	this.attributeValues = [];
+	if(this.genesisNames && this.genesisValues) {
+		this.attributeNames = this.wiki.filterTiddlers(self.genesisNames,this);
+		this.attributeValues = this.wiki.filterTiddlers(self.genesisValues,this);
+		$tw.utils.each(this.attributeNames,function(varname,index) {
+			$tw.utils.addAttributeToParseTreeNode(parseTreeNodes[0],varname,self.attributeValues[index] || "");
+		});
+	}
+	// Construct the child widgets
+	this.makeChildWidgets(parseTreeNodes);
+};
+
+/*
+Selectively refreshes the widget if needed. Returns true if the widget or any of its children needed re-rendering
+*/
+GenesisWidget.prototype.refresh = function(changedTiddlers) {
+	var changedAttributes = this.computeAttributes(),
+		filterNames = this.getAttribute("$names",""),
+		filterValues = this.getAttribute("$values",""),
+		attributeNames = this.wiki.filterTiddlers(filterNames,this),
+		attributeValues = this.wiki.filterTiddlers(filterValues,this);
+	if($tw.utils.count(changedAttributes) > 0 || !$tw.utils.isArrayEqual(this.attributeNames,attributeNames) || !$tw.utils.isArrayEqual(this.attributeValues,attributeValues)) {
+		this.refreshSelf();
+		return true;
+	} else {
+		return this.refreshChildren(changedTiddlers);
+	}
+};
+
+exports.genesis = GenesisWidget;
+
+})();