refactored query chaining

examples/ChainQueries/app.js

+/*
+  Title: Using the chainQueries function
+
+  This example demonstrates the use of chainQueries.
+*/
+
+var Sequelize = require(__dirname + "/../../lib/sequelize/Sequelize").Sequelize
+var sys = require("sys")
+var Class = function(){ sys.log("You've just created a new instance!") }
+Class.prototype.add = function(a,b,callback){
+  this.result = a + b
+  sys.log("The result: " + this.result)
+  callback(this.result)
+}
+
+
+
+
+sys.log("First of all the old and obsolete way:")
+
+Sequelize.chainQueries([
+  {add: (new Class()), params: [1, 2]},
+  {add: (new Class()), params: [2, 3]}
+], function() {
+  sys.log("And we did it!")
+})
+
+
+sys.puts("")
+sys.log("The new fashioned way is about removing the array and pass an arbitrary amount of parameters!")
+sys.log("Just pass as many hashes as you want, but at the end a function as callback!")
+
+Sequelize.chainQueries(
+  {add: new Class(), params: [1, 2]},
+  {add: new Class(), params: [2, 3]},
+  function() { sys.log("And we did it! Great!") }
+)
+
+
+sys.puts("")
+sys.log("As you see we add some values two times.")
+sys.log("Let's say you want to call a method on multiple objects with the same or no parameters!")
+
+Sequelize.chainQueries(
+  {add: [new Class(), new Class()], params: [1, 2]},
+  function() { sys.log("And we did it! Great!") }
+)
\ No newline at end of file

lib/sequelize/QueryChainer.js

+var sys = require("sys")
+
+var QueryChainer = function(Helper) {
+  this.Helper = Helper
+}
+
+var instanceMethods = {
+  splitQueryHash: function(queryHash) {
+    var method = this.Helper.Array.without(this.Helper.Hash.keys(queryHash), "params")[0],
+        object = queryHash[method]
+
+    return { method: method, object: object }
+  },
+  
+  splitArguments: function() {
+    var result = { queries: [], callback: null }
+
+    for(var i = 0; i < arguments.length; i++) {
+      var arg = arguments[i]
+      
+      if(typeof arg == 'function') result.callback = arg
+      else if(Array.isArray(arg)) arg.forEach(function(o) { result.queries.push(o) })
+      else result.queries.push(arg)
+    }
+
+    return result
+  },
+  
+  expandMultiQueries: function(queries) {
+    var self          = this,
+        result        = [],
+        multiQueries  = []
+    
+    queries.forEach(function(queryHash) {
+      var splittedQueryHash = self.splitQueryHash(queryHash),
+          method            = splittedQueryHash.method,
+          object            = splittedQueryHash.object
+
+      if(!Array.isArray(object))
+        result.push(queryHash)
+      else if(object.length > 0) {
+        for(var i = 0; i < object.length; i++) {
+          var newQueryHash = { params: queryHash.params }
+          newQueryHash[method] = object[i]
+          result.push(newQueryHash)
+        }
+      }
+    })
+
+    return result
+  },
+  
+  executeQuery: function(queries, index, callback) {
+    var self              = this,
+        queryHash         = queries[index],
+        splittedQueryHash = this.splitQueryHash(queryHash),
+        method            = splittedQueryHash.method,
+        object            = splittedQueryHash.object
+    
+    var iterator  = function() {
+      if(queries.length > (index + 1)) self.executeQuery(queries, index + 1, callback)
+      else if (callback) callback()
+    }
+
+    object[method].apply(object, this.Helper.Array.join(queryHash.params || [], [iterator]))
+  },
+  
+  chain: function() {
+    var self = this
+    var args     = this.splitArguments.apply(this, arguments),
+        queries  = args.queries,
+        callback = args.callback
+        
+    var expandedQueries = this.expandMultiQueries(queries)
+    
+    if(queries.length > 0) this.executeQuery(expandedQueries, 0, callback)
+    else if (callback) callback()
+  }
+}
+
+for(var methodName in instanceMethods)
+  QueryChainer.prototype[methodName] = instanceMethods[methodName]
+
+module.exports.QueryChainer = QueryChainer
\ No newline at end of file

lib/sequelize/Sequelize.js

@@ -61,39 +61,11 @@ var classMethods = {
     
     return Sequelize.Helper.evaluateTemplate(query, values)
   },
-  chainQueries: function( ) {
-    // queries = [{method: object}, {method: object, params: [1,2,3]}, {method: object}]
-    // example: Sequelize.chainQueries({save: a}, {destroy: b}, callback)
-    // example: Sequelize.chainQueries({save: [a, b]}, callback)
+  chainQueries: function() {
+    var QueryChainer = require("./QueryChainer").QueryChainer,
+        queryChainer = new QueryChainer(Sequelize.Helper)
     
-    var queries  = [],
-        callback = null
-    
-    for(var i = 0; i < arguments.length; i++) {
-      var arg = arguments[i]
-      if(typeof arg == 'function') callback = arg
-      else if(Array.isArray(arg)) arg.forEach(function(o) { queries.push(o) })
-      else queries.push(arg)
-    }
-
-    var executeQuery = function(index) {
-      var queryHash = queries[index],
-          method    = Sequelize.Helper.Array.without(Sequelize.Helper.Hash.keys(queryHash), "params")[0],
-          object    = queryHash[method],
-          iterator  = function() {
-            if(queries.length > (index + 1)) executeQuery(index + 1)
-            else if (callback) callback()
-          }
-          
-      if(!Array.isArray(object)) object = [object]
-      
-      object.forEach(function(o) {
-        o[method].apply(o, Sequelize.Helper.Array.join(queryHash.params || [], [iterator]))
-      })
-    }
-    
-    if(queries.length > 0) executeQuery(0)
-    else if (callback) callback()
+    queryChainer.chain.apply(queryChainer, arguments)
   }
 }
 

test/Table/associations.js

@@ -32,6 +32,7 @@ module.exports = {
     })
 
     beforeExit(function() {
+      assert.match(1,2)
       assert.isNotNull(assoc)
       assert.equal(assoc.length, 2)
     })