gistfile1.js

function buildTemplate (spec, template) {
    return function (context) {        
        var allParamsExist = spec.every(function (key) {
            return context.hasOwnProperty(key) && (context[key] !== undefined)
        })
        
        if (!allParamsExist) {
            throw "Context object misses needed parameters"
        }
        
        // return Mustache.render(template, context)
        return allParamsExist;
    }
}

var templateString = "Langer Templatestring, den ich hier nicht abtippen will";


// Beispiel
var reminder = buildTemplate(["id", "activity", "has_attendees"], templateString)



console.log( reminder({ id: 1, activity: {}, has_attendees: false }) );
// -> true


console.log(reminder({ 
    foo: "foo",
    bar: "bar", 
    baz: "baz"
}));
// -> Exception