Javascript工作流引擎代码及实例

yangyi

最近在学习jBPM和Javascript，所以按照一些相关概念自己写了下面的200行代码的“工作流引擎”，工作流管理系统包含了流程定义，引擎，及应用系统三个主要部分，下面的代码实现了流程的分支合并，目前只支持一种环节上的迁移。下载html附件双击就可以跑起来。
/*/////////流程定义///////////  start   / \  1   \ / \   \4   5  2 \ /  /    \ /     3    |   end 测试流程如上图所示/////////////////////////////*/var workflowDef = {start:{fn:"begin", //对应处理方法可以在内部定义，也可以在外部定义next:["task1","task2"]},end:"end",tasks:[{id:"task1",fn:function(){alert("执行任务一");},before:function(){alert("执行任务一前");},after:function(){alert("执行任务一后");},next:["task4","task5"]},{id:"task2",fn:function(){alert("执行任务二");},before:function(){alert("执行任务二前");},after:function(){alert("执行任务二后");},next:["task3"]},{id:"task3",fn:function(){alert("执行任务三");},before:function(){alert("执行任务三前");},after:function(){alert("执行任务三后");},//定义合并的数量merge: 3,next:"EOWF"},{id:"task4",fn:function(){alert("执行任务四");},before:function(){alert("执行任务四前");},after:function(){alert("执行任务四后");},next:["task3"]},{id:"task5",fn:function(){alert("执行任务五");},before:function(){alert("执行任务五前");},after:function(){alert("执行任务五后");},next:["task3"]}]}
//////////定义引擎////////////Yi = {};Yi.Utils = {};Yi.Utils.execute = function(o){if(typeof o != 'function')eval(o)();elseo();}//工作流类Yi.Workflow = function(workflowDef){this.def = workflowDef;this.tasks = this.def.tasks;}//public按照环节id查找查找Yi.Workflow.prototype.findTask = function(taskId){for(var i=0;i<this.tasks.length;i++){if(this.tasks[i].id == taskId)return this.tasks[i];}}//public启动工作流Yi.Workflow.prototype.start = function(){this.currentTasks = [];Yi.Utils.execute(this.def.start.fn);for(var i=0;i<this.def.start.next.length;i++){this.currentTasks[i] = this.findTask(this.def.start.next[i]);Yi.Utils.execute(this.currentTasks[i].before);}}//privateYi.Workflow.prototype.findCurrentTaskById = function(taskId){for(var i=0;i<this.currentTasks.length;i++){if(this.currentTasks[i].id == taskId)return this.currentTasks[i];}return null;}//privateYi.Workflow.prototype.removeFromCurrentTasks = function(task){var temp = [];for(var i=0;i<this.currentTasks.length;i++){if(!(this.currentTasks[i] == task))temp.push(this.currentTasks[i]); }this.currentTasks = temp;temp = null;}//public触发当前环节Yi.Workflow.prototype.signal = function(taskId){//只处理当前活动环节var task = this.findCurrentTaskById(taskId);if(task == null){alert("工作流未流转到此环节!");return;}//对于合并的处理if(task.merge != undefined){if(task.merge != 0){alert("工作流流转条件不充分!");return;}else{Yi.Utils.execute(task.before);}}//触发当前环节Yi.Utils.execute(task.fn);//触发后动作Yi.Utils.execute(task.after);//下一步如果工作流结束if(task.next === "EOWF"){Yi.Utils.execute(this.def.end);delete this.currentTasks;return;}//遍历下一步环节this.removeFromCurrentTasks(task);for(var i=0;i<task.next.length;i++){var tempTask = this.findTask(task.next[i]);if(!tempTask.inCurrentTasks)this.currentTasks.push(tempTask);if(tempTask.merge != undefined){tempTask.merge--;tempTask.inCurrentTasks = true;}elseYi.Utils.execute(tempTask.before);}}//public获取当前的活动环节Yi.Workflow.prototype.getCurrentTasks = function(){return this.currentTasks;}//public获取流程定义Yi.Workflow.prototype.getDef = function(){return this.def;}
////////应用系统///////////////var wf = new Yi.Workflow(workflowDef);alert("启动工作流");wf.start();alert("尝试手工执行任务3,返回工作流没有流转到这里");wf.signal("task3");alert("分支开始");alert("手工执行任务1");wf.signal("task1");alert("手工执行任务2");wf.signal("task2");alert("手工执行任务4");wf.signal("task4");alert("手工执行任务5");wf.signal("task5");alert("手工执行任务3");wf.signal("task3");function begin(){alert("流程开始，该函数在外部定义");}function end(){alert("流程结束");}