Javascript 已在处理程序中创建承诺,但未从中返回
我刚刚开始使用“蓝鸟承诺”,但我遇到了一个令人困惑的错误 代码摘要Javascript 已在处理程序中创建承诺,但未从中返回,javascript,promise,bluebird,Javascript,Promise,Bluebird,我刚刚开始使用“蓝鸟承诺”,但我遇到了一个令人困惑的错误 代码摘要 var jQueryPostJSON = function jQueryPostJSON(url, data) { return Promise.resolve( jQuery.ajax({ contentType: "application/json; charset=utf-8", dataType: "json", type: "POST",
var
jQueryPostJSON = function jQueryPostJSON(url, data) {
return Promise.resolve(
jQuery.ajax({
contentType: "application/json; charset=utf-8",
dataType: "json",
type: "POST",
url: url,
data: JSON.stringify(data)
})
).then(function(responseData) {
console.log("jQueryPostJSON response " + JSON.stringify(responseData, null, 2));
return responseData;
});
},
completeTask = function completeTask(task, variables) {
console.log("completeTask called for taskId: "+task.id);
//FIXME reform variables according to REST API docs
var variables = {
"action" : "complete",
"variables" : []
};
spin.start();
return jQueryPostJSON(hostUrl + 'service/runtime/tasks/'+task.id, variables)
.then(function() {
gwl.grrr({
msg: "Completed Task. Definition Key: " + task.taskDefinitionKey,
type: "success",
displaySec: 3
});
spin.stop();
return null;
});
}
jQueryPostJSON函数在其他地方使用时似乎可以正常工作,但在这种情况下,会从服务器返回数据
当它在complete task中使用时,POST是成功的,这在服务器端可以看到,但是then函数从未在控制台中调用,我得到了错误
completeTask called for taskId: 102552
bundle.js:20945 spin target: [object HTMLDivElement]
bundle.js:20968 spinner started
bundle.js:1403 Warning: a promise was created in a handler but was not returned from it
at jQueryPostJSON (http://localhost:9000/dist/bundle.js:20648:22)
at Object.completeTask (http://localhost:9000/dist/bundle.js:20743:14)
at http://localhost:9000/dist/bundle.js:21051:15
From previous event:
at HTMLDocument.<anonymous> (http://localhost:9000/dist/bundle.js:21050:10)
at HTMLDocument.handleObj.handler (http://localhost:9000/dist/bundle.js:5892:30)
at HTMLDocument.jQuery.event.dispatch (http://localhost:9000/dist/bundle.js:10341:9)
at HTMLDocument.elemData.handle (http://localhost:9000/dist/bundle.js:10027:28)
bundle.js:1403 Unhandled rejection (<{"readyState":4,"responseText":"","sta...>, no stack trace)
第一个函数调用api.getCurrentProcessInstanceTask()的输出似乎表明它工作正常,但这里仍然是
getCurrentProcessInstanceTask = function getCurrentProcessInstanceTask() {
if (!currentProcess || !currentProcess.id) {
return Promise.reject(new Error("no currentProcess is set, cannot get active task"));
}
var processInstanceId = currentProcess.id;
return Promise.resolve(jQuery.get(hostUrl + "service/runtime/tasks", {
processInstanceId: processInstanceId
}))
.then(function(data) {
console.log("response: " + JSON.stringify(data, null, 2));
currentProcess.tasks = data.data;
// if(data.data.length > 1){
// throw new Error("getCurrentProcessInstanceTask expects single task result. Result listed "+data.data.length+" tasks!");
// }
console.log("returning task id: "+data.data[0].id);
return data.data[0];
});
},
您收到警告是因为正如上面所说,您没有从
然后的处理程序返回承诺。
拒绝来自何处最好通过捕获并记录来跟踪。如果没有堆栈跟踪,则表明您(或您使用的某个lib)正在抛出一个非错误的普通对象。试着找到并修复它
您的呼叫应如下所示:
api.getCurrentProcessInstanceTask().then(function(task) {
return api.completeTask(task);
// ^^^^^^
}).catch(function(err) {
// ^^^^^
console.error(err);
});
你有一个未处理的拒绝和一个警告。请告诉我们什么是对象。completeTask
以及在第21050行附近可以找到什么。
api.getCurrentProcessInstanceTask().then(function(task) {
return api.completeTask(task);
// ^^^^^^
}).catch(function(err) {
// ^^^^^
console.error(err);
});