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mirror of https://github.com/Jermolene/TiddlyWiki5 synced 2024-11-20 00:34:50 +00:00
TiddlyWiki5/core/modules/widgets/setvariable.js
jeremy@jermolene.com f636349007 Introduce true global variables
The basic idea is that if we don't find a variable `foo` then we fallback to retrieving the value from the tiddler `$:/global/foo`, if it exists.

This allows us to replace the usual importvariables-based mechanism for global definitions, avoiding cluttering up the variable namespace with every macro.

In order to permit subprocedures to be overridden, we also introduce a mechanism for conditional definitions: preceding the word definition|procedure|function|widget with a + causes the definition only to occur if the specified variable doesn't already exist. In the next commit we'll apply this mechanism to the tabs macro
2022-05-28 12:23:50 +01:00

130 lines
4.2 KiB
JavaScript
Executable File

/*\
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.setSelect = this.getAttribute("select");
this.setTiddler = this.getAttribute("tiddler");
this.setSubTiddler = this.getAttribute("subtiddler");
this.setField = this.getAttribute("field");
this.setIndex = this.getAttribute("index");
this.setValue = this.getAttribute("value");
this.setEmptyValue = this.getAttribute("emptyValue");
this.setConditional = this.getAttribute("conditional","no") === "yes";
// Set context variable, checking for a conditional assignment
if(!this.setConditional || this.getVariableInfo(this.setName).text === undefined) {
if(this.parseTreeNode.isMacroDefinition) {
this.setVariable(this.setName,this.getValue(),this.parseTreeNode.params,true);
} else if(this.parseTreeNode.isFunctionDefinition) {
this.setVariable(this.setName,this.getValue(),this.parseTreeNode.params,undefined,{isFunctionDefinition: true});
} else if(this.parseTreeNode.isProcedureDefinition) {
this.setVariable(this.setName,this.getValue(),this.parseTreeNode.params,undefined,{isProcedureDefinition: true, configTrimWhiteSpace: this.parseTreeNode.configTrimWhiteSpace});
} else if(this.parseTreeNode.isWidgetDefinition) {
this.setVariable(this.setName,this.getValue(),this.parseTreeNode.params,undefined,{isWidgetDefinition: true, configTrimWhiteSpace: this.parseTreeNode.configTrimWhiteSpace});
} else {
this.setVariable(this.setName,this.getValue());
}
}
// Construct the child widgets
this.makeChildWidgets();
};
/*
Get the value to be assigned
*/
SetWidget.prototype.getValue = function() {
var value = this.setValue;
if(this.setTiddler) {
var tiddler;
if(this.setSubTiddler) {
tiddler = this.wiki.getSubTiddler(this.setTiddler,this.setSubTiddler);
} else {
tiddler = this.wiki.getTiddler(this.setTiddler);
}
if(!tiddler) {
value = this.setEmptyValue;
} else if(this.setField) {
value = tiddler.getFieldString(this.setField) || this.setEmptyValue;
} else if(this.setIndex) {
value = this.wiki.extractTiddlerDataItem(this.setTiddler,this.setIndex,this.setEmptyValue);
} else {
value = tiddler.fields.text || this.setEmptyValue ;
}
} else if(this.setFilter) {
var results = this.wiki.filterTiddlers(this.setFilter,this);
if(this.setValue == null) {
var select;
if(this.setSelect) {
select = parseInt(this.setSelect,10);
}
if(select !== undefined) {
value = results[select] || "";
} else {
value = $tw.utils.stringifyList(results);
}
}
if(results.length === 0 && this.setEmptyValue !== undefined) {
value = this.setEmptyValue;
}
} else if(!value && this.setEmptyValue) {
value = this.setEmptyValue;
}
return value || "";
};
/*
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.select || changedAttributes.tiddler || (this.setTiddler && changedTiddlers[this.setTiddler]) || changedAttributes.field || changedAttributes.index || changedAttributes.value || changedAttributes.emptyValue || changedAttributes.conditional ||
(this.setFilter && this.getValue() != this.variables[this.setName].value)) {
this.refreshSelf();
return true;
} else {
return this.refreshChildren(changedTiddlers);
}
};
exports.setvariable = SetWidget;
exports.set = SetWidget;
})();