Extend the HTML rendering mechanism to support attributes specified as macro invocations

core/modules/parsers/wikiparser/rules/html.js

@@ -190,13 +190,13 @@ exports.parseMacroParameter = function(source,pos) {
 };
 
 /*
-Look for a macro invocation. Returns null if not found, or {type: "macro-invocation", name:, parameters:, start:, end:}
+Look for a macro invocation. Returns null if not found, or {type: "macrocall", name:, parameters:, start:, end:}
 */
 exports.parseMacroInvocation = function(source,pos) {
 	var node = {
-		type: "macro-invocation",
+		type: "macrocall",
 		start: pos,
-		parameters: []
+		params: []
 	}
 	// Define our regexps
 	var reMacroName = /([^\s>"'=]+)/g;
@@ -218,7 +218,7 @@ exports.parseMacroInvocation = function(source,pos) {
 	// Process parameters
 	var parameter = this.parseMacroParameter(source,pos);
 	while(parameter) {
-		node.parameters.push(parameter);
+		node.params.push(parameter);
 		pos = parameter.end;
 		// Get the next parameter
 		parameter = this.parseMacroParameter(source,pos);

core/modules/rendertree/renderers/element.js

@@ -95,20 +95,30 @@ var ElementRenderer = function(renderTree,parentRenderer,parseTreeNode) {
 };
 
 ElementRenderer.prototype.computeAttributes = function() {
-	var changedAttributes = {};
+	var changedAttributes = {},
-	var self = this;
+		self = this,
+		value;
 	$tw.utils.each(this.parseTreeNode.attributes,function(attribute,name) {
 		if(attribute.type === "indirect") {
-			var value = self.renderTree.wiki.getTextReference(attribute.textReference,"",self.tiddlerTitle);
+			value = self.renderTree.wiki.getTextReference(attribute.textReference,"",self.tiddlerTitle);
-			if(self.attributes[name] !== value) {
+		} else if(attribute.type === "macro") {
-				self.attributes[name] = value;
+			// Get the macro definition
-				changedAttributes[name] = true;
+			var macro = self.renderTree.findMacroDefinition(self.parentRenderer,attribute.value.name);
+			if(!macro) {
+				value = "";
+			} else {
+				// Substitute the macro parameters
+				value = self.renderTree.substituteParameters(macro,attribute.value);
+				// Parse the text and render it as text
+				value = self.renderTree.wiki.renderText("text/plain","text/vnd.tiddlywiki",value,self.context);
 			}
 		} else { // String attribute
-			if(self.attributes[name] !== attribute.value) {
+			value = attribute.value;
-				self.attributes[name] = attribute.value;
+		}
-				changedAttributes[name] = true;
+		// Check whether the attribute has changed
-			}
+		if(self.attributes[name] !== value) {
+			self.attributes[name] = value;
+			changedAttributes[name] = true;
 		}
 	});
 	return changedAttributes;

core/modules/rendertree/renderers/macrocall.js

@@ -28,7 +28,7 @@ var MacroCallRenderer = function(renderTree,parentRenderer,parseTreeNode) {
 		childTree = [{type: "text", text: "<<Undefined macro: " + this.parseTreeNode.name + ">>"}];
 	} else {
 		// Substitute the macro parameters
-		var text = this.substituteParameters(macro.text,this.parseTreeNode,macro);
+		var text = this.renderTree.substituteParameters(macro,this.parseTreeNode);
 		// Parse the text
 		childTree = this.renderTree.wiki.parseText("text/vnd.tiddlywiki",text,{parseAsInline: !this.parseTreeNode.isBlock}).tree;
 	}
@@ -36,39 +36,6 @@ var MacroCallRenderer = function(renderTree,parentRenderer,parseTreeNode) {
 	this.children = this.renderTree.createRenderers(this,childTree);
 };
 
-/*
-Expand the parameters in a block of text
-*/
-MacroCallRenderer.prototype.substituteParameters = function(text,macroCallParseTreeNode,macroDefinition) {
-	var nextAnonParameter = 0; // Next candidate anonymous parameter in macro call
-	// Step through each of the parameters in the macro definition
-	for(var p=0; p<macroDefinition.params.length; p++) {
-		// Check if we've got a macro call parameter with the same name
-		var paramInfo = macroDefinition.params[p],
-			paramValue = undefined;
-		for(var m=0; m<macroCallParseTreeNode.params.length; m++) {
-			if(macroCallParseTreeNode.params[m].name === paramInfo.name) {
-				paramValue = macroCallParseTreeNode.params[m].value;
-			}
-		}
-		// If not, use the next available anonymous macro call parameter
-		if(!paramValue && macroCallParseTreeNode.params.length > 0) {
-			while(macroCallParseTreeNode.params[nextAnonParameter].name && nextAnonParameter < macroCallParseTreeNode.params.length-1) {
-				nextAnonParameter++;
-			}
-			if(!macroCallParseTreeNode.params[nextAnonParameter].name) {
-				paramValue = macroCallParseTreeNode.params[nextAnonParameter].value;
-				nextAnonParameter++;
-			}
-		}
-		// If we've still not got a value, use the default, if any
-		paramValue = paramValue || paramInfo["default"] || "";
-		// Replace any instances of this parameter
-		text = text.replace(new RegExp("\\$" + $tw.utils.escapeRegExp(paramInfo.name) + "\\$","mg"),paramValue);
-	}
-	return text;
-};
-
 MacroCallRenderer.prototype.renderInDom = function() {
 	// Create the element
 	this.domNode = this.renderTree.document.createElement(this.parseTreeNode.isBlock ? "div" : "span");

core/modules/rendertree/wikirendertree.js

@@ -155,6 +155,40 @@ WikiRenderTree.prototype.findMacroDefinition = function(renderer,name) {
 	return undefined;
 };
 
+/*
+Expand the parameters of a macro
+*/
+WikiRenderTree.prototype.substituteParameters = function(macroDefinition,macroCallParseTreeNode) {
+	var text = macroDefinition.text,
+		nextAnonParameter = 0; // Next candidate anonymous parameter in macro call
+	// Step through each of the parameters in the macro definition
+	for(var p=0; p<macroDefinition.params.length; p++) {
+		// Check if we've got a macro call parameter with the same name
+		var paramInfo = macroDefinition.params[p],
+			paramValue = undefined;
+		for(var m=0; m<macroCallParseTreeNode.params.length; m++) {
+			if(macroCallParseTreeNode.params[m].name === paramInfo.name) {
+				paramValue = macroCallParseTreeNode.params[m].value;
+			}
+		}
+		// If not, use the next available anonymous macro call parameter
+		if(!paramValue && macroCallParseTreeNode.params.length > 0) {
+			while(macroCallParseTreeNode.params[nextAnonParameter].name && nextAnonParameter < macroCallParseTreeNode.params.length-1) {
+				nextAnonParameter++;
+			}
+			if(!macroCallParseTreeNode.params[nextAnonParameter].name) {
+				paramValue = macroCallParseTreeNode.params[nextAnonParameter].value;
+				nextAnonParameter++;
+			}
+		}
+		// If we've still not got a value, use the default, if any
+		paramValue = paramValue || paramInfo["default"] || "";
+		// Replace any instances of this parameter
+		text = text.replace(new RegExp("\\$" + $tw.utils.escapeRegExp(paramInfo.name) + "\\$","mg"),paramValue);
+	}
+	return text;
+};
+
 exports.WikiRenderTree = WikiRenderTree;
 
 })();

editions/test/tiddlers/tests/test-html-parser.js

@@ -99,22 +99,22 @@ describe("HTML tag new parser tests", function() {
 			null
 		);
 		expect(parser.parseMacroInvocation("<<mymacro>>",0)).toEqual(
-			{ type : 'macro-invocation', start : 0, parameters : [  ], name : 'mymacro', end : 11 }
+			{ type : 'macrocall', start : 0, params : [  ], name : 'mymacro', end : 11 }
 		);
 		expect(parser.parseMacroInvocation("<<mymacro one two three>>",0)).toEqual(
-			{ type : 'macro-invocation', start : 0, parameters : [ { type : 'macro-parameter', start : 9, value : 'one', end : 13 }, { type : 'macro-parameter', start : 13, value : 'two', end : 17 }, { type : 'macro-parameter', start : 17, value : 'three', end : 23 } ], name : 'mymacro', end : 25 }
+			{ type : 'macrocall', start : 0, params : [ { type : 'macro-parameter', start : 9, value : 'one', end : 13 }, { type : 'macro-parameter', start : 13, value : 'two', end : 17 }, { type : 'macro-parameter', start : 17, value : 'three', end : 23 } ], name : 'mymacro', end : 25 }
 		);
 		expect(parser.parseMacroInvocation("<<mymacro p:one q:two three>>",0)).toEqual(
-			{ type : 'macro-invocation', start : 0, parameters : [ { type : 'macro-parameter', start : 9, value : 'one', name : 'p', end : 15 }, { type : 'macro-parameter', start : 15, value : 'two', name : 'q', end : 21 }, { type : 'macro-parameter', start : 21, value : 'three', end : 27 } ], name : 'mymacro', end : 29 }
+			{ type : 'macrocall', start : 0, params : [ { type : 'macro-parameter', start : 9, value : 'one', name : 'p', end : 15 }, { type : 'macro-parameter', start : 15, value : 'two', name : 'q', end : 21 }, { type : 'macro-parameter', start : 21, value : 'three', end : 27 } ], name : 'mymacro', end : 29 }
 		);
 		expect(parser.parseMacroInvocation("<<mymacro 'one two three'>>",0)).toEqual(
-			{ type : 'macro-invocation', start : 0, parameters : [ { type : 'macro-parameter', start : 9, value : 'one two three', end : 25 } ], name : 'mymacro', end : 27 } 
+			{ type : 'macrocall', start : 0, params : [ { type : 'macro-parameter', start : 9, value : 'one two three', end : 25 } ], name : 'mymacro', end : 27 } 
 		);
 		expect(parser.parseMacroInvocation("<<mymacro r:'one two three'>>",0)).toEqual(
-			{ type : 'macro-invocation', start : 0, parameters : [ { type : 'macro-parameter', start : 9, value : 'one two three', name : 'r', end : 27 } ], name : 'mymacro', end : 29 } 
+			{ type : 'macrocall', start : 0, params : [ { type : 'macro-parameter', start : 9, value : 'one two three', name : 'r', end : 27 } ], name : 'mymacro', end : 29 } 
 		);
 		expect(parser.parseMacroInvocation("<<myMacro one:two three:'four and five'>>",0)).toEqual(
-			{ type : 'macro-invocation', start : 0, parameters : [ { type : 'macro-parameter', start : 9, value : 'two', name : 'one', end : 17 }, { type : 'macro-parameter', start : 17, value : 'four and five', name : 'three', end : 39 } ], name : 'myMacro', end : 41 } 
+			{ type : 'macrocall', start : 0, params : [ { type : 'macro-parameter', start : 9, value : 'two', name : 'one', end : 17 }, { type : 'macro-parameter', start : 17, value : 'four and five', name : 'three', end : 39 } ], name : 'myMacro', end : 41 } 
 		);
 	});
 
@@ -177,10 +177,10 @@ describe("HTML tag new parser tests", function() {
 			null
 		);
 		expect(parser.parseTag("<$mytag attrib3=<<myMacro one:two three:'four and five'>>>",0)).toEqual(
-			{ type : 'element', start : 0, attributes : { attrib3 : { type : 'macro', start : 7, name : 'attrib3', value : { type : 'macro-invocation', start : 16, parameters : [ { type : 'macro-parameter', start : 25, value : 'two', name : 'one', end : 33 }, { type : 'macro-parameter', start : 33, value : 'four and five', name : 'three', end : 55 } ], name : 'myMacro', end : 57 }, end : 57 } }, tag : '$mytag', end : 58 }
+			{ type : 'element', start : 0, attributes : { attrib3 : { type : 'macro', start : 7, name : 'attrib3', value : { type : 'macrocall', start : 16, params : [ { type : 'macro-parameter', start : 25, value : 'two', name : 'one', end : 33 }, { type : 'macro-parameter', start : 33, value : 'four and five', name : 'three', end : 55 } ], name : 'myMacro', end : 57 }, end : 57 } }, tag : '$mytag', end : 58 }
 		);
 		expect(parser.parseTag("<$mytag attrib1='something' attrib2=else thing attrib3=<<myMacro one:two three:'four and five'>>>",0)).toEqual(
-			{ type : 'element', start : 0, attributes : { attrib1 : { type : 'string', start : 7, name : 'attrib1', value : 'something', end : 27 }, attrib2 : { type : 'string', start : 27, name : 'attrib2', value : 'else', end : 40 }, thing : { type : 'string', start : 40, name : 'thing', value : 'true', end : 47 }, attrib3 : { type : 'macro', start : 47, name : 'attrib3', value : { type : 'macro-invocation', start : 55, parameters : [ { type : 'macro-parameter', start : 64, value : 'two', name : 'one', end : 72 }, { type : 'macro-parameter', start : 72, value : 'four and five', name : 'three', end : 94 } ], name : 'myMacro', end : 96 }, end : 96 } }, tag : '$mytag', end : 97 }
+			{ type : 'element', start : 0, attributes : { attrib1 : { type : 'string', start : 7, name : 'attrib1', value : 'something', end : 27 }, attrib2 : { type : 'string', start : 27, name : 'attrib2', value : 'else', end : 40 }, thing : { type : 'string', start : 40, name : 'thing', value : 'true', end : 47 }, attrib3 : { type : 'macro', start : 47, name : 'attrib3', value : { type : 'macrocall', start : 55, params : [ { type : 'macro-parameter', start : 64, value : 'two', name : 'one', end : 72 }, { type : 'macro-parameter', start : 72, value : 'four and five', name : 'three', end : 94 } ], name : 'myMacro', end : 96 }, end : 96 } }, tag : '$mytag', end : 97 }
 		);
 	});
 

editions/test/tiddlers/tests/test-wikitext.js

@@ -20,8 +20,9 @@ describe("WikiText tests", function() {
 	wiki.addTiddler({title: "TiddlerOne", text: "The quick brown fox"});
 	wiki.addTiddler({title: "TiddlerTwo", text: "The rain in Spain\nfalls mainly on the plain"});
 	wiki.addTiddler({title: "TiddlerThree", text: "The speed of sound\n\nThe light of speed"});
+	wiki.addTiddler({title: "TiddlerFour", text: "\\define my-macro(adjective:'groovy')\nThis is my ''amazingly'' $adjective$ macro!\n\\end\n\n<$link to=<<my-macro>>>This is a link</$link>"});
 
-	it("should render tiddlers with no special markup render as-is", function() {
+	it("should render tiddlers with no special markup as-is", function() {
 		expect(wiki.renderTiddler("text/plain","TiddlerOne")).toBe("The quick brown fox");
 	});
 	it("should preserve single new lines", function() {
@@ -41,6 +42,10 @@ describe("WikiText tests", function() {
 	it("should use double new lines to create paragraphs", function() {
 		expect(wiki.renderTiddler("text/html","TiddlerThree")).toBe("<p>\nThe speed of sound</p><p>\nThe light of speed</p>");
 	});
+	it("should support attributes specified as macro invocations", function() {
+		expect(wiki.renderTiddler("text/html","TiddlerFour")).toBe("<p>\n<a class='tw-tiddlylink tw-tiddlylink-internal tw-tiddlylink-missing' href='This%20is%20my%20amazingly%20groovy%20macro!'>\nThis is a link</a></p>");
+	});
+
 
 });
 

editions/tw5.com/tiddlers/concepts/WikiText.tid

@@ -230,6 +230,20 @@ This is my nice and simple block of text. HelloThere
 </article>
 ```
 
+Attributes in HTML tags can be specified as a transclusion or a macro invocation. For example, here the value of the `href` attribute will be set to the value of the tiddler MyLinkDestination:
+
+```
+<a href={{MyLinkDestination}}>link</a>
+```
+
+Here an attribute is specified as a macro invocation:
+
+```
+<a href=<<MyMacro "Brian">>>link</a>
+```
+
+* As a macro invocation 
+
 ! Widgets
 
 Widgets provide rich functionality within WikiText. For example, the `<$video>` widget can be used to embed videos from YouTube, Vimeo or the Internet Archive: