TiddlyWiki Attribute Modules

attribute-module-support.js

// widget.js

/*
Compute the current values of the attributes of the widget. Returns a hashmap of the names of the attributes that have changed
*/
var AttributeTypes = null;

Widget.prototype.computeAttributes = function() {
	var changedAttributes = {},
		self = this,
		value;
	if (!this.attributeGizmos) {
		if (!AttributeTypes) {
			AttributeTypes = {};
			$tw.modules.applyMethods("attributevalue", AttributeTypes);
		}
		// First-time attribute preparation
		this.attributeGizmos = {};
		$tw.utils.each(this.parseTreeNode.attributes,function(attribute,name) {
			// Try to instantiate an attribute type.
			var AttributeType = AttributeTypes[attribute.type];
			if (AttributeType) {
				self.attributeGizmos[name] = new AttributeType(self, attribute);
				self.attributes[name] = self.attributeGizmos[name].value;
				changedAttributes[name] = true;
				return true;
			}
			// Unknown attribute types are treated as strings.
			// String attributes don't change after the first computeAttributes().
			self.attributes[name] = attribute.value;
			changedAttributes[name] = true;
			return true;
		});
	}
	else {
		$tw.utils.each(this.attributeGizmos,function(gizmo,name) {
			// Full recompute (no selectivity is available)
			value = gizmo.compute();
			if(self.attributes[name] !== value) {
				self.attributes[name] = value;
				changedAttributes[name] = true;
			}
		});
	}
	return changedAttributes;
};


// parseutils.js

/*
Look for an HTML attribute definition. Returns null if not found, otherwise returns {type: "attribute", name:, valueType: "string|indirect|macro", value:, start:, end:,}
*/
var AttributeRules = null;

exports.parseAttribute = function(source,pos) {
	var node = {
		start: pos
	};
	// Define our regexps
	var reAttributeName = /([^\/\s>"'=]+)/g,
		reUnquotedAttribute = /([^\/\s<>"'=]+)/g,
		reFilteredValue = /\{\{\{(.+?)\}\}\}/g,
		reIndirectValue = /\{\{([^\}]+)\}\}/g;
	// Skip whitespace
	pos = $tw.utils.skipWhiteSpace(source,pos);
	// Get the attribute name
	var name = $tw.utils.parseTokenRegExp(source,pos,reAttributeName);
	if(!name) {
		return null;
	}
	node.name = name.match[1];
	pos = name.end;
	// Skip whitespace
	pos = $tw.utils.skipWhiteSpace(source,pos);
	// Look for an equals sign
	var token = $tw.utils.parseTokenString(source,pos,"=");
	if(token) {
		pos = token.end;
		// Skip whitespace
		pos = $tw.utils.skipWhiteSpace(source,pos);
		// Look for a string literal
		var stringLiteral = $tw.utils.parseStringLiteral(source,pos);
		if(stringLiteral) {
			node.type = "string";
			node.value = stringLiteral.value;
			node.end = stringLiteral.end;
			return node;
		}
		// Load attribute rules if needed
		if (!AttributeRules)
		{
			AttributeRules = {};
			$tw.modules.applyMethods("attributerule", AttributeRules);
		}
		// Look for an attribute rule
		var match = null;
		$tw.utils.each(AttributeRules, function(rule) {
			match = rule(source,pos,node);
			return !match;
		});
		if (match) return match;
		// Look for a unquoted value
		var unquotedValue = $tw.utils.parseTokenRegExp(source,pos,reUnquotedAttribute);
		if(unquotedValue) {
			node.type = "string";
			node.value = unquotedValue.match[1];
			node.end = unquotedValue.end;
			return node;
		} else {
			node.type = "string";
			node.value = "true";
		}
		//*/
	} else {
		node.type = "string";
		node.value = "true";
	}
	// Update the end position
	node.end = pos;
	return node;
};