Numbas geogebra extension

geogebra.js

Numbas.addExtension('geogebra',[],function(extension) {
    window.geogebraIdAcc = window.geogebraIdAcc || 0;

    var delay = 10;
    var container;
	$(document).ready(function() {
        container = document.createElement('div');
        container.setAttribute('id','numbasgeogebracontainer');
        container.setAttribute('class','invisible');
        document.body.appendChild(container);
	});

    var injectedDeployScript = false;
    var loadGGB = new Promise(function(resolve,reject) {
        if(window.GGBApplet) {
            resolve(GGBApplet);
        } else {
            if(!injectedDeployScript) {
                var s = document.createElement('script');
                s.setAttribute('type','text/javascript');
                s.setAttribute('src','https://www.geogebra.org/scripts/deployggb.js');
                document.head.appendChild(s);
                injectedDeployScript = true;
            }
            var int = setInterval(function() {
                if(window.GGBApplet) {
                    clearInterval(int);
                    resolve(GGBApplet);
                }
            },delay);
        }
    });

    var injectApplet = function(options) {
        options.id = 'ggbApplet'+(window.geogebraIdAcc++);
        console.log(options.id);
        var applet = new GGBApplet(options, true);
        var el = document.createElement('div');
        container.appendChild(el);
        applet.inject(el, 'preferHTML5');

        return new Promise(function(resolve,reject) {
            var int = setInterval(function() {
                var app = applet.getAppletObject();
                if(app) {
                   clearInterval(int);
                    resolve({app:app,el:el});
                }
            },delay);
        });
    }

    var constructionFinished = function(app,names) {
        return new Promise(function(resolve,reject) {
            var int = setInterval(function() {
                if(!app.exists) {
                    console.log(app);
                    reject("app.exists does not exist");
                }
                if(names.every(function(name) { return app.exists(name)})) {
                    clearInterval(int);
                    resolve(app);
                }
            },delay);
        });
    }

    extension.createGeogebraApplet = function(options,names) {
        names = names || [];
        var element;
        return loadGGB
            .then(function() { return injectApplet(options)})
            .then(function(d){ element=d.el; return constructionFinished(d.app,names)})
            .then(function(app) { return new Promise(function(resolve,reject) { resolve({app:app,element:element}); }) })
        ;
    }

	var types = Numbas.jme.types;
	var funcObj = Numbas.jme.funcObj;
    var TString = types.TString;
	var TList = types.TList;
    var THTML = types.THTML;

    function jmeCreateGeogebraApplet(material_id,replacements,results) {
        // create a container element, which we'll return
        // when the applet has been loaded, we'll attach it to the container element
        var el = document.createElement('div');
        el.innerHTML = 'GeoGebra applet loading...';

        extension.createGeogebraApplet({material_id:material_id},replacements.map(function(r){return r[0]}))
        .then(function(d) {
            var app = d.app;
            var int = setInterval(function() {
                if(el.parentNode) {
                    el.innerHTML = '';
                    el.appendChild(d.element);
                    clearInterval(int);
                    replacements.forEach(function(r){
                        app.evalCommand(r[0]+'='+r[1]);
                    });
                    if(app.isExercise()) {
                        console.log('is exercise');
                        function check() {
                            var result = app.getExerciseResult();
                            console.log('result',result);
                        }
                        app.registerUpdateListener(check);
                        app.registerAddListener(check);
                        app.registerUpdateListener(check);
                    }
                }
            },delay);
        })
        .catch(function(e) {
            throw(new Numbas.Error("Problem encountered when creating GeoGebra applet: "+e));
        });

        return el;
    }

    extension.scope.addFunction(new funcObj('geogebra_applet',[TString],THTML,function(material_id) {
        return jmeCreateGeogebraApplet(material_id,[]);
    },{unwrapValues:true}));
    extension.scope.addFunction(new funcObj('geogebra_applet',[TString,TList],THTML,jmeCreateGeogebraApplet,{unwrapValues:true}));
});