Rewrite transport

src/js/transport.js

@@ -5,46 +5,40 @@
  */
 
 var Transport = (function() {
+  var concurrentConnections = 0,
+      maxConcurrentConnections;
 
   function Transport(o) {
-    var rateLimitFn;
-
     utils.bindAll(this);
 
     o = o || {};
 
-    rateLimitFn = (/^throttle$/i).test(o.rateLimitFn) ?
-      utils.throttle : utils.debounce;
+    maxConcurrentConnections = utils.isNumber(o.maxConcurrentConnections) ?
+      o.maxConcurrentConnections : maxConcurrentConnections || 6;
 
-    this.wait = o.wait || 300;
     this.wildcard = o.wildcard || '%QUERY';
-    this.maxConcurrentRequests = o.maxConcurrentRequests || 6;
 
-    this.concurrentRequests = 0;
-    this.onDeckRequestArgs = null;
+    this.ajaxSettings = utils.mixin({}, o.ajax, {
+      // needs to be true to jqXHR methods (done, always)
+      // also you're out of your mind if you want to make a sync request
+      async: true,
+      beforeSend: function() {
+        incrementConcurrentConnections();
+
+        if (o.ajax.beforeSend) {
+          return o.ajax.beforeSend.apply(this, arguments);
+        }
+      }
+    });
 
     this.cache = new RequestCache();
 
-    this.get = rateLimitFn(this.get, this.wait);
+    this.get = (/^throttle$/i.test(o.rateLimitFn) ?
+      utils.throttle : utils.debounce)(this.get, o.wait || 300);
   }
 
   utils.mixin(Transport.prototype, {
 
-    // private methods
-    // ---------------
-
-    _incrementConcurrentRequests: function() {
-      this.concurrentRequests++;
-    },
-
-    _decrementConcurrentRequests: function() {
-      this.concurrentRequests--;
-    },
-
-    _belowConcurrentRequestsThreshold: function() {
-      return this.concurrentRequests < this.maxConcurrentRequests;
-    },
-
     // public methods
     // --------------
 
@@ -57,25 +51,19 @@ var Transport = (function() {
         cb && cb(resp);
       }
 
-      else if (this._belowConcurrentRequestsThreshold()) {
-        $.ajax({
-          url: url,
-          type: 'GET',
-          dataType: 'json',
-          beforeSend: function() {
-            that._incrementConcurrentRequests();
-          },
-          success: function(resp) {
-            cb && cb(resp);
-            that.cache.set(url, resp);
-          },
-          complete: function() {
-            that._decrementConcurrentRequests();
-
-            if (that.onDeckRequestArgs) {
-              that.get.apply(that, that.onDeckRequestArgs);
-              that.onDeckRequestArgs = null;
-            }
+      else if (belowConcurrentConnectionsThreshold()) {
+        $.ajax(this.ajaxSettings)
+        .done(function(resp) {
+          cb && cb(resp);
+          that.cache.set(url, resp);
+        })
+        .always(function() {
+          decrementConcurrentConnections();
+
+          // ensures request is always made for the latest query
+          if (that.onDeckRequestArgs) {
+            that.get.apply(that, that.onDeckRequestArgs);
+            that.onDeckRequestArgs = null;
           }
         });
       }
@@ -87,4 +75,19 @@ var Transport = (function() {
   });
 
   return Transport;
+
+  // static methods
+  // --------------
+
+  function incrementConcurrentConnections() {
+    concurrentConnections++;
+  }
+
+  function decrementConcurrentConnections() {
+    concurrentConnections--;
+  }
+
+  function belowConcurrentConnectionsThreshold() {
+    return concurrentConnections < maxConcurrentConnections;
+  }
 })();

src/js/typeahead.js

@@ -5,13 +5,7 @@
  */
 
 (function() {
-  var initializedDatasets = {},
-      transportOptions = {},
-      transport,
-      methods;
-
-  jQuery.fn.typeahead = typeahead;
-  typeahead.configureTransport = configureTransport;
+  var initializedDatasets = {}, methods;
 
   methods = {
     initialize: function(datasetDefs) {
@@ -23,44 +17,46 @@
         throw new Error('no datasets provided');
       }
 
-      delete typeahead.configureTransport;
-      transport = transport || new Transport(transportOptions);
+      utils.each(datasetDefs, function(i, o) {
+        var transport, dataset;
 
-      utils.each(datasetDefs, function(i, datasetDef) {
-        var dataset,
-            name = datasetDef.name = datasetDef.name || utils.getUniqueId();
+        o.name = o.name || utils.getUniqueId();
 
         // dataset by this name has already been intialized, used it
-        if (initializedDatasets[name]) {
-          dataset = initializedDatasets[name];
+        if (initializedDatasets[o.name]) {
+          dataset = initializedDatasets[o.name];
         }
 
         else {
-          datasetDef.limit = datasetDef.limit || 5;
-          datasetDef.template = datasetDef.template;
-          datasetDef.engine = datasetDef.engine;
-
-          if (datasetDef.template && !datasetDef.engine) {
-            throw new Error('no template engine specified for ' + name);
+          if (o.template && !o.engine) {
+            throw new Error('no template engine specified for ' + o.name);
           }
 
+          transport = new Transport({
+            ajax: o.ajax,
+            wildcard: o.wildcard,
+            rateLimitFn: o.rateLimitFn,
+            maxConcurrentConnections: o.maxConcurrentConnections
+          });
+
           dataset = initializedDatasets[name] = new Dataset({
-            name: datasetDef.name,
-            limit: datasetDef.limit,
-            local: datasetDef.local,
-            prefetch: datasetDef.prefetch,
-            remote: datasetDef.remote,
-            matcher: datasetDef.matcher,
-            ranker: datasetDef.ranker,
+            name: o.name,
+            limit: o.limit,
+            local: o.local,
+            prefetch: o.prefetch,
+            remote: o.remote,
+            matcher: o.matcher,
+            ranker: o.ranker,
             transport: transport
           });
         }
 
+        // faux dataset used by TypeaheadView instances
         datasets[name] = {
-          name: datasetDef.name,
-          limit: datasetDef.limit,
-          template: datasetDef.template,
-          engine: datasetDef.engine,
+          name: o.name,
+          limit: o.limit,
+          template: o.template,
+          engine: o.engine,
           getSuggestions: dataset.getSuggestions
         };
       });
@@ -73,17 +69,13 @@
     }
   };
 
-  function typeahead(method) {
+  jQuery.fn.typeahead = function(method) {
     if (methods[method]) {
       methods[method].apply(this, [].slice.call(arguments, 1));
     }
 
     else {
       methods.initialize.apply(this, arguments);
     }
-  }
-
-  function configureTransport(o) {
-    transportOptions = o;
-  }
+  };
 })();