stringTemplateEngine.js

define(["knockout"], function(ko) {
    //define a template source that tries to key into an object first to find a template string
    var templates = {},
        data = {},
        engine = new ko.nativeTemplateEngine();

    ko.templateSources.stringTemplate = function(template) {
        this.templateName = template;
    };

    ko.utils.extend(ko.templateSources.stringTemplate.prototype, {
        data: function(key, value) {
            data[this.templateName] = data[this.templateName] || {};

            if (arguments.length === 1) {
                return data[this.templateName][key];
            }

            data[this.templateName][key] = value;
        },
        text: function(value) {
            if (arguments.length === 0) {
                var template = templates[this.templateName];

                if (typeof (template) === "undefined") {
                     throw Error("Template not found: " + this.templateName);
                }

                return template;
            }

            templates[this.templateName] = value;
        }
    });

    engine.makeTemplateSource = function(template, doc) {
        var elem;
        if (typeof template === "string") {
            elem = (doc || document).getElementById(template);

            if (elem) {
                return new ko.templateSources.domElement(elem);
            }

            return new ko.templateSources.stringTemplate(template);
        }
        else if (template && (template.nodeType == 1) || (template.nodeType == 8)) {
            return new ko.templateSources.anonymousTemplate(template);
        }
    };

    //make the templates accessible
    ko.templates = templates;

    //make this new template engine our default engine
    ko.setTemplateEngine(engine);
});