Add new subtiddlerfields filter operator

core/modules/filters/subtiddlerfields.js

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+/*\
+title: $:/core/modules/filters/subtiddlerfields.js
+type: application/javascript
+module-type: filteroperator
+
+Filter operator for returning the names of the fields on the selected subtiddlers of the plugin named in the operand
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+/*
+Export our filter function
+*/
+exports.subtiddlerfields = function(source,operator,options) {
+	var results = [];
+	source(function(tiddler,title) {
+		var subtiddler = options.wiki.getSubTiddler(operator.operand,title);
+		if(subtiddler) {
+			for(var fieldName in subtiddler.fields) {
+				$tw.utils.pushTop(results,fieldName);
+			}
+		}
+	});
+	return results;
+};
+
+})();

editions/tw5.com/tiddlers/filters/examples/subtiddlerfields Operator (Examples).tid

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+created: 20180403164143915
+modified: 20180403164257147
+tags: [[plugintiddlers Operator]] [[Operator Examples]]
+title: subtiddlerfields Operator (Examples)
+type: text/vnd.tiddlywiki
+
+<<.operator-example 1 "[[$:/core/copyright.txt]subtiddlerfields[$:/core]]">>
+

editions/tw5.com/tiddlers/filters/subtiddlerfields Operator.tid

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+caption: subtiddlerfields
+created: 20180403164138703
+modified: 20180403164644231
+op-input: a [[selection|Title Selection]] of tiddler titles
+op-output: all field names present in the selected tiddlers within the plugin named <<.place P>>
+op-parameter: the title of a plugin
+op-parameter-name: P
+op-purpose: select all fields present in the selected tiddlers within a plugin
+tags: [[Filter Operators]] [[Special Operators]]
+title: subtiddlerfields Operator
+type: text/vnd.tiddlywiki
+
+<<.operator-examples "subtiddlerfields">>