Allow radio widget to work with indexes in a data tiddler (#2104)

* allow radio widget to set an index in a data tiddler

* updated RadioWidget docs, with same demo macro as for CheckboxWidget
in #2103
* removed docs in widget code (seems the wrong place)

* added from version to docs

* revert doc maros to master

* using wikitext-example-without-html and .tip macro now

* fix quotes

core/modules/widgets/radio.js

@@ -3,22 +3,7 @@ title: $:/core/modules/widgets/radio.js
 type: application/javascript
 module-type: widget
 
-Radio widget
-
-Will set a field to the selected value:
-
-```
-	<$radio field="myfield" value="check 1">one</$radio>
-	<$radio field="myfield" value="check 2">two</$radio>
-	<$radio field="myfield" value="check 3">three</$radio>
-```
-
-|Parameter |Description |h
-|tiddler |Name of the tiddler in which the field should be set. Defaults to current tiddler |
-|field |The name of the field to be set |
-|value |The value to set |
-|class |Optional class name(s) |
-
+Set a field or index at a given tiddler via radio buttons
 
 \*/
 (function(){
@@ -70,12 +55,20 @@ RadioWidget.prototype.render = function(parent,nextSibling) {
 };
 
 RadioWidget.prototype.getValue = function() {
-	var tiddler = this.wiki.getTiddler(this.radioTitle);
-	return tiddler && tiddler.getFieldString(this.radioField);
+	var value,
+		tiddler = this.wiki.getTiddler(this.radioTitle);
+	if (this.radioIndex) {
+		value = this.wiki.extractTiddlerDataItem(this.radioTitle,this.radioIndex);
+	} else {
+		value = tiddler && tiddler.getFieldString(this.radioField);
+	}
+	return value;
 };
 
 RadioWidget.prototype.setValue = function() {
-	if(this.radioField) {
+	if(this.radioIndex) {
+		this.wiki.setText(this.radioTitle,"",this.radioIndex,this.radioValue);
+	} else {
 		var tiddler = this.wiki.getTiddler(this.radioTitle),
 			addition = {};
 		addition[this.radioField] = this.radioValue;
@@ -96,6 +89,7 @@ RadioWidget.prototype.execute = function() {
 	// Get the parameters from the attributes
 	this.radioTitle = this.getAttribute("tiddler",this.getVariable("currentTiddler"));
 	this.radioField = this.getAttribute("field","text");
+	this.radioIndex = this.getAttribute("index");
 	this.radioValue = this.getAttribute("value");
 	this.radioClass = this.getAttribute("class","");
 	if(this.radioClass !== "") {
@@ -111,7 +105,7 @@ Selectively refreshes the widget if needed. Returns true if the widget or any of
 */
 RadioWidget.prototype.refresh = function(changedTiddlers) {
 	var changedAttributes = this.computeAttributes();
-	if(changedAttributes.tiddler || changedAttributes.field || changedAttributes.value || changedAttributes["class"]) {
+	if(changedAttributes.tiddler || changedAttributes.field || changedAttributes.index || changedAttributes.value || changedAttributes["class"]) {
 		this.refreshSelf();
 		return true;
 	} else {

editions/tw5.com/tiddlers/system/doc-macros.tid

@@ -106,4 +106,4 @@ This is an example tiddler. See [[Table-of-Contents Macros (Examples)]].
 	</blockquote>
 </$reveal>
 </$list>
-\end
+\end

editions/tw5.com/tiddlers/widgets/RadioWidget.tid

@@ -1,9 +1,9 @@
+caption: radio
 created: 20131212195353929
-modified: 20150220161302000
+modified: 20161217112444671
 tags: Widgets
 title: RadioWidget
 type: text/vnd.tiddlywiki
-caption: radio
 
 ! Introduction
 
@@ -15,22 +15,26 @@ The content of the `<$radio>` widget is displayed within an HTML `<label>` eleme
 
 |!Attribute |!Description |
 |tiddler |Title of the tiddler to manipulate (defaults to the [[current tiddler|Current Tiddler]]) |
-|field |The name of the field to which the radio button will be bound |
-|value |The value for the tiddler field |
+|field |The field of the //tiddler// bound to the radio button|
+|index|<<.from-version "5.1.14">> The index of the //tiddler// being [[DataTiddler|DataTiddlers]] bound to the radio button<<.tip "takes precedence over //field//">>|
+|value |The value for the //field// or //index// of the //tiddler//|
 |class |CSS classes to be assigned to the label around the radio button |
 
-! Example
+!! Field Mode
 
 This example uses the radio widget to change the `modifier` field of this tiddler:
 
-```
-<$radio field="modifier" value="JoeBloggs"> Joe Bloggs</$radio>
+<<wikitext-example-without-html """<$radio field="modifier" value="JoeBloggs"> Joe Bloggs</$radio>
+<$radio field="modifier" value="JaneBloggs"> Jane Bloggs</$radio>""">>
 
-<$radio field="modifier" value="JaneBloggs"> Jane Bloggs</$radio>
-```
 
-It renders as:
+!! Index Mode
 
-<$radio field="modifier" value="JoeBloggs"> Joe Bloggs</$radio>
+Using the radio widget in index mode requires the //index// attribute to specify the name of the index of a [[DataTiddler|DataTiddlers]] to which the specified //value// is assigned.
 
-<$radio field="modifier" value="JaneBloggs"> Jane Bloggs</$radio>
+This example sets the `Tree Frog` index in the tiddler AnimalColours:
+
+<$macrocall $name="wikitext-example-without-html" src="""<$tiddler tiddler="AnimalColours">
+<$radio index="Tree Frog" value="green"> green</$radio>
+<$radio index="Tree Frog" value="brown"> brown</$radio>
+</$tiddler>"""/>