extension.js

(function(ext) {
    // Cleanup function when the extension is unloaded
    ext._shutdown = function() {};

    // Status reporting code
    // Use this to report missing hardware, plugin or unsupported browser
    ext._getStatus = function() {
        return {status: 2, msg: 'Ready'};
    };

    ext.get = function(v) {
	return vars[v];
    };

    // Block and block menu descriptions
    var descriptor = {
        blocks: [
            // Block type, block name, function name, param1 default value, param2 default value
            ['r', '%m.var', 'get', "Variable"],
        ]
    };

    // Register the extension
    ScratchExtensions.register('Sample extension', descriptor, ext);
})({});