text: /*\
  title: $:/core/modules/widgets/set.js
  type: application/javascript
  module-type: widget
  
  Set variable widget
  
  \*/
  (function(){
  
  /*jslint node: true, browser: true */
  /*global $tw: false */
  "use strict";
  
  var Widget = require("$:/core/modules/widgets/widget.js").widget;
  
  var SetWidget = function(parseTreeNode,options) {
  	this.initialise(parseTreeNode,options);
  };
  
  /*
  Inherit from the base widget class
  */
  SetWidget.prototype = new Widget();
  
  /*
  Render this widget into the DOM
  */
  SetWidget.prototype.render = function(parent,nextSibling) {
  	this.parentDomNode = parent;
  	this.computeAttributes();
  	this.execute();
  	this.renderChildren(parent,nextSibling);
  };
  
  /*
  Compute the internal state of the widget
  */
  SetWidget.prototype.execute = function() {
  	// Get our parameters
  	this.setName = this.getAttribute("name","currentTiddler");
  	this.setFilter = this.getAttribute("filter");
  	this.setValue = this.getAttribute("value");
  	this.setEmptyValue = this.getAttribute("emptyValue");
  	// Set context variable
  	var value = this.setValue;
  	if(this.setFilter) {
  		var results = this.wiki.filterTiddlers(this.setFilter,this);
  		if(!this.setValue) {
  			value = $tw.utils.stringifyList(results);
  		}
  		if(results.length === 0 && this.setEmptyValue !== undefined) {
  			value = this.setEmptyValue;
  		}
  	}
  	this.setVariable(this.setName,value,this.parseTreeNode.params);
  	// Construct the child widgets
  	this.makeChildWidgets();
  };
  
  /*
  Selectively refreshes the widget if needed. Returns true if the widget or any of its children needed re-rendering
  */
  SetWidget.prototype.refresh = function(changedTiddlers) {
  	var changedAttributes = this.computeAttributes();
  	if(changedAttributes.name || changedAttributes.filter || changedAttributes.value || changedAttributes.emptyValue) {
  		this.refreshSelf();
  		return true;
  	} else {
  		return this.refreshChildren(changedTiddlers);		
  	}
  };
  
  exports.setvariable = SetWidget;
  exports.set = SetWidget;
  
  })();
  