Martin Donnelly d93ebb4466 init
2016-04-13 10:01:28 +01:00

73 lines
3.5 KiB
JavaScript

// If you want to make a custom template engine,
//
// [1] Inherit from this class (like ko.nativeTemplateEngine does)
// [2] Override 'renderTemplateSource', supplying a function with this signature:
//
// function (templateSource, bindingContext, options) {
// // - templateSource.text() is the text of the template you should render
// // - bindingContext.$data is the data you should pass into the template
// // - you might also want to make bindingContext.$parent, bindingContext.$parents,
// // and bindingContext.$root available in the template too
// // - options gives you access to any other properties set on "data-bind: { template: options }"
// // - templateDocument is the document object of the template
// //
// // Return value: an array of DOM nodes
// }
//
// [3] Override 'createJavaScriptEvaluatorBlock', supplying a function with this signature:
//
// function (script) {
// // Return value: Whatever syntax means "Evaluate the JavaScript statement 'script' and output the result"
// // For example, the jquery.tmpl template engine converts 'someScript' to '${ someScript }'
// }
//
// This is only necessary if you want to allow data-bind attributes to reference arbitrary template variables.
// If you don't want to allow that, you can set the property 'allowTemplateRewriting' to false (like ko.nativeTemplateEngine does)
// and then you don't need to override 'createJavaScriptEvaluatorBlock'.
ko.templateEngine = function () { };
ko.templateEngine.prototype['renderTemplateSource'] = function (templateSource, bindingContext, options, templateDocument) {
throw new Error("Override renderTemplateSource");
};
ko.templateEngine.prototype['createJavaScriptEvaluatorBlock'] = function (script) {
throw new Error("Override createJavaScriptEvaluatorBlock");
};
ko.templateEngine.prototype['makeTemplateSource'] = function(template, templateDocument) {
// Named template
if (typeof template == "string") {
templateDocument = templateDocument || document;
var elem = templateDocument.getElementById(template);
if (!elem)
throw new Error("Cannot find template with ID " + template);
return new ko.templateSources.domElement(elem);
} else if ((template.nodeType == 1) || (template.nodeType == 8)) {
// Anonymous template
return new ko.templateSources.anonymousTemplate(template);
} else
throw new Error("Unknown template type: " + template);
};
ko.templateEngine.prototype['renderTemplate'] = function (template, bindingContext, options, templateDocument) {
var templateSource = this['makeTemplateSource'](template, templateDocument);
return this['renderTemplateSource'](templateSource, bindingContext, options, templateDocument);
};
ko.templateEngine.prototype['isTemplateRewritten'] = function (template, templateDocument) {
// Skip rewriting if requested
if (this['allowTemplateRewriting'] === false)
return true;
return this['makeTemplateSource'](template, templateDocument)['data']("isRewritten");
};
ko.templateEngine.prototype['rewriteTemplate'] = function (template, rewriterCallback, templateDocument) {
var templateSource = this['makeTemplateSource'](template, templateDocument);
var rewritten = rewriterCallback(templateSource['text']());
templateSource['text'](rewritten);
templateSource['data']("isRewritten", true);
};
ko.exportSymbol('templateEngine', ko.templateEngine);