javascript - 适用于工作流的 SharePoint JavaScript API 引发错误

Question

我正在尝试访问有关在 SharePoint 列表中运行工作流的信息，但我遇到了工作流服务 JSOM 库的问题。我正在使用工作流服务，就像我能找到的每个示例一样，请参见下面的代码:

var context = SP.ClientContext.get_current();
var web = context.get_web();
var servicesManager = SP.WorkflowServices.WorkflowServicesManager.newObject(context, web);
var instanceService = servicesManager.getWorkflowInstanceService();

执行代码时，上面代码片段的最后一行抛出异常

TypeError: this.get_context is not a function.

Answer 1

可能会发生此错误，因为尚未加载 SharePoint JavaScript 库中的指定文件之一。

• SP.js
• SP.Runtime.js
• SP.WorkflowServices.js

为确保已加载指定文件，您可以考虑以下方法:

SP.SOD.registerSod('SP.ClientContext', SP.Utilities.Utility.getLayoutsPageUrl('sp.js'));
SP.SOD.registerSod('SP.WorkflowServices.WorkflowServicesManager', SP.Utilities.Utility.getLayoutsPageUrl('SP.WorkflowServices.js'));
SP.SOD.loadMultiple(['SP.ClientContext', 'SP.WorkflowServices.WorkflowServicesManager'], function(){

    var ctx = SP.ClientContext.get_current();
    var workflowServicesManager = SP.WorkflowServices.WorkflowServicesManager.newObject(ctx, ctx.get_web()); 
    var workflowSubscriptionService = workflowServicesManager.getWorkflowSubscriptionService();                
    //...    

});

SP.SOD.loadMultiple function is intended for loading on demand scripts which in turn is a part of SharePoint JavaScript Library. Alternatively you could utilize jQuery.getScript() from jQuery library.