alasql/src/99worker.js

AlaSQL.js - JavaScript SQL database library for relational and graph data manipulation with support of localStorage, IndexedDB, and Excel

if (typeof importScripts === 'function') {
	// Nothing
} else if(typeof exports != 'object') {

alasql.worker = function(path, paths, cb) {
//	var path;
	if(path === true) path = undefined;
	if (typeof path == "undefined") {
		var sc = document.getElementsByTagName('script');
		for(var i=0;i<sc.length;i++) {
			if (sc[i].src.substr(-16).toLowerCase() == 'alasql-worker.js') {
				path = sc[i].src.substr(0,sc[i].src.length-16)+'alasql.js'; 
				break;
			} else if (sc[i].src.substr(-20).toLowerCase() == 'alasql-worker.min.js') {
				path = sc[i].src.substr(0,sc[i].src.length-20)+'alasql.min.js';
				break;
			} else if (sc[i].src.substr(-9).toLowerCase() == 'alasql.js') {
				path = sc[i].src; 
				break;
			} else if (sc[i].src.substr(-13).toLowerCase() == 'alasql.min.js') {
				path = sc[i].src.substr(0,sc[i].src.length-13)+'alasql.min.js'; 
				break;
			};
		};
	};

	if(typeof path == "undefined") {
		throw new Error('Path to alasql.js is not specified');
	} else if(path !== false) {

		var js = "importScripts('";
			js += path;
			js+="');\
		self.onmessage = function(event) {\
		alasql(event.data.sql,event.data.params, function(data){\
		postMessage({id:event.data.id, data:data});\
		});\
		}";

		var blob = new Blob([js], {"type": "text\/plain"});
		alasql.webworker = new Worker(URL.createObjectURL(blob));

		alasql.webworker.onmessage = function(event) {
			var id = event.data.id;
//			console.log('onmessage',alasql.buffer,id);
			alasql.buffer[id](event.data.data);
			delete alasql.buffer[id];
		};

		alasql.webworker.onerror = function(e){
			throw e;
		}

		if(arguments.length > 1) {
			var sql = 'REQUIRE ' + paths.map(function(p){
				return '"'+p+'"';
			}).join(",");
			alasql(sql,[],cb);
		}

	} else if(path === false) {
		delete alasql.webworker;
		return;
	}; 
};

};