a bit of cleanup and better error handling for options

Author: ivaynberg

select2.js

@@ -435,40 +435,34 @@
         prepareOpts: function (opts) {
             var element, select, idKey;
 
+            element = opts.element;
+
+            if (element.get(0).tagName.toLowerCase() === "select") {
+                this.select = select = opts.element;
+            }
+
+            if (select) {
+                // these options are not allowed when attached to a select because they are picked up off the element itself
+                $.each(["id", "multiple", "ajax", "query", "createSearchChoice", "initSelection", "data", "tags"], function () {
+                    if (this in opts) {
+                        throw new Error("Option '" + this + "' is not allowed for Select2 when attached to a <select> element.");
+                    }
+                });
+            }
+
             opts = $.extend({}, {
                 formatResult: function (data) { return data.text; },
                 formatSelection: function (data) { return data.text; },
                 formatNoMatches: function () { return "No matches found"; },
                 formatInputTooShort: function (input, min) { return "Please enter " + (min - input.length) + " more characters"; },
                 minimumResultsForSearch: 0,
+                minimumInputLength: 0,
                 id: function (e) { return e.id; }
             }, opts);
 
             if (typeof(opts.id) !== "function") {
                 idKey = opts.id;
-                opts.id = function (e) { return e[idKey]; }
-            }
-
-            element = opts.element;
-
-            if (element.get(0).tagName.toLowerCase() === "select") {
-                this.select = select = opts.element;
-            }
-
-            // TODO add missing validation logic
-            if (select) {
-                /*$.each(["multiple", "ajax", "query", "minimumInputLength"], function () {
-                 if (this in opts) {
-                 throw "Option '" + this + "' is not allowed for Select2 when attached to a select element";
-                 }
-                 });*/
-                this.opts = opts = $.extend({}, {
-                    miniumInputLength: 0
-                }, opts);
-            } else {
-                this.opts = opts = $.extend({}, {
-                    miniumInputLength: 0
-                }, opts);
+                opts.id = function (e) { return e[idKey]; };
             }
 
             if (select) {