Output friendly error message when Microplugin is missing

Fixes selectize#1137, poke selectize#701 selectize#1088

CHANGELOG.md

@@ -1,3 +1,8 @@
+*  Output friendly error message when Microplguin is missing (#1137).
+   Special thanks to @styxxx for proposing the improvement.
+
+   *Jonathan Allard* (@joallard)
+
 *  Fix open keyboard bug under iOS after closing selection (#1127)
 
    *@zeitiger*

src/selectize.js

@@ -86,7 +86,18 @@ var Selectize = function($input, settings) {
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
 MicroEvent.mixin(Selectize);
-MicroPlugin.mixin(Selectize);
+
+if(typeof MicroPlugin !== "undefined"){
+	MicroPlugin.mixin(Selectize);
+}else{
+	logError("Dependency MicroPlugin is missing",
+		{explanation:
+			"Make sure you either: (1) are using the \"standalone\" "+
+			"version of Selectize, or (2) require MicroPlugin before you "+
+			"load Selectize."}
+	);
+}
+
 
 // methods
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

src/utils.js

@@ -331,3 +331,17 @@ var domToString = function(d) {
 
 	return tmp.innerHTML;
 };
+
+var logError = function(message, options){
+	if(!options) options = {};
+	var component = "Selectize";
+
+	console.error(component + ": " + message)
+
+	if(options.explanation){
+		// console.group is undefined in <IE11
+		if(console.group) console.group();
+		console.error(options.explanation);
+		if(console.group) console.groupEnd();
+	}
+}