scratchy_extensions.user.js

// ==UserScript==
// @name        Scratchy Extensions
// @namespace   http://aputurk.tk/
// @include     http://scratch.mit.edu/*
// @version     0.0.1
// @grant       none
// ==/UserScript==


(function(){
    enabled = false;
    activate = function(){
        if(enabled)return true;
        var str = ($("#instructions textarea").length > 0) ? $("#instructions textarea").text() : $("#instructions .overview").text();
        var matches = str.match(/\$\{.+?\}/);
        console.log(matches);
        if(matches==null || matches.length==0)return 0;
        var jsonm = JSON.parse(matches[0].substring(1));
        if(jsonm.hasOwnProperty("requires") && jsonm['requires'] instanceof Array){
            var warning = "Warning! Loading arbitrary scripts can be dangerous! Make sure you trust the following extensions before continuing:\n\n";
            for(i in jsonm['requires'])warning+=jsonm['requires'][i]+"\n";
            warning+="\nClick OK to continue, or Cancel to prevent loading these extensions";
            if(confirm(warning)){
                for(i in jsonm['requires']){
                    var scriptElement = document.createElement('script');
                    scriptElement.src = jsonm['requires'][i].replace(/raw.githubusercontent.com/g, "cdn.rawgit.com");
                    document.head.appendChild(scriptElement);
                }
                enabled = true;
                $("#enable-extensions").text("Enabled :)").css("background","#eee").css("border", "1px solid #ccc").css("color", "gray");
                return 1;
            }
            return -1;
        } else return 0;
    };
    $(document).ready(function(){
        if(location.href.match(/scratch.mit.edu\/projects\/[0-9]+/).length > 0){
            $("<div id='enable-extensions' class='button'><span>Enable Extensions</span></div>")
                .click(function(){
                    var success = (activate)();
                    if(success==0){
                        $(this).text("No exts found").css("background","#eee").css("border", "1px solid #ccc").css("color", "gray");
                    } else if(success==-1) {
                        $(this).attr("style", "");
                    }
                }).prependTo($("#project .buttons"));
        }
    });
})();