Node.js resolved promise返回未定义的,尽管它有值
我有一个令人沮丧的问题,我找不到它发生的原因 我的职能如下:Node.js resolved promise返回未定义的,尽管它有值,node.js,promise,es6-promise,Node.js,Promise,Es6 Promise,我有一个令人沮丧的问题,我找不到它发生的原因 我的职能如下: public async PageResult(searchRecord:Search,authorization:string,pageNumber:number,databaseName:string){ some codes ..... return new Promise((resolve, reject) => { this._resultsDatastore.bulkInsert(
public async PageResult(searchRecord:Search,authorization:string,pageNumber:number,databaseName:string){
some codes .....
return new Promise((resolve, reject) => {
this._resultsDatastore.bulkInsert(
databaseName,
objects
).then(succ => {
// I can see succ is printed successfully in console
console.log(succ);
// when I resolve it here I assume I am returning the result
resolve(succ)
}, err => {
console.log(err);
reject(err)
})
})
}
如您所见,我解析(succ),通过这种方式,我将succ返回给调用方函数
现在我有:
public async loadResults(
searchId: string,
authorization: string
) {
some code....
const results = udsQuery.pages.map(async (pageNumber: number) => await this.PageResult(searchRecord,authorization,pageNumber,databaseName))
let all: any=[];
await Promise.all(results).catch(e => {
console.log("^^^^^^^^^^^^^^^^^^^^^EEEERRRRRROR^^^^^^^^^^^^^^^^^^^^^^");
}).then(res=>{
console.log("suuuuuuuuuuuuuuucesssssssssssssss");
// issue is here: below prints undefined though succ has value
console.log(res);
all.push(res);
return res;
});
}
因此,现在我在映射中调用PageResult并使用promis.all来重新爱上它,而不是我在PageResult中返回的成功,我得到了未定义的结果,请参阅上述代码中的这一部分:
console.log("suuuuuuuuuuuuuuucesssssssssssssss");
// issue is here: below prints undefined though succ has value
console.log(res);
我遗漏了什么吗?不知何故,我不喜欢您编写代码的方式,我尝试先修改代码。我还看到另一个错误,您正在执行
PageResult()
函数,而应该由Promise.all
块执行
我没有测试代码,但应该是这样的:
public async PageResult(searchRecord:Search,authorization:string,pageNumber:number,databaseName:string){
try
{
const succ = await this._resultsDatastore.bulkInsert(
databaseName,
objects);
return succ;
}
catch (e)
{
throw e;
}
}
public loadResults(searchId: string, authorization: string )
{
const all: any=[];
const pormises: any=[];
const results = udsQuery.pages.map((pageNumber: number) =>
pormises.push(this.PageResult(searchRecord, authorization, pageNumber, databaseName)));
return new Promise((resolve, reject) =>
{
Promise.all(results)
.then(res=>
{
console.log("suuuuuuuuuuuuuuucesssssssssssssss");
// issue is here: below prints undefined though succ has value
console.log(res);
all.push(res);
return resolve(all);
})
.catch(e =>
{
console.log("^^^^^^^^^^^^^^^^^^^^^EEEERRRRRROR^^^^^^^^^^^^^^^^^^^^^^");
});
});
}
不知何故,我不喜欢您编写代码的方式,我尝试先修改代码。我还看到另一个错误,您正在执行
PageResult()
函数,而应该由Promise.all
块执行
我没有测试代码,但应该是这样的:
public async PageResult(searchRecord:Search,authorization:string,pageNumber:number,databaseName:string){
try
{
const succ = await this._resultsDatastore.bulkInsert(
databaseName,
objects);
return succ;
}
catch (e)
{
throw e;
}
}
public loadResults(searchId: string, authorization: string )
{
const all: any=[];
const pormises: any=[];
const results = udsQuery.pages.map((pageNumber: number) =>
pormises.push(this.PageResult(searchRecord, authorization, pageNumber, databaseName)));
return new Promise((resolve, reject) =>
{
Promise.all(results)
.then(res=>
{
console.log("suuuuuuuuuuuuuuucesssssssssssssss");
// issue is here: below prints undefined though succ has value
console.log(res);
all.push(res);
return resolve(all);
})
.catch(e =>
{
console.log("^^^^^^^^^^^^^^^^^^^^^EEEERRRRRROR^^^^^^^^^^^^^^^^^^^^^^");
});
});
}
避开这个!当出现拒绝和
.catch(e=>{console.log(“…ERROR…”);})时,您将得到未定义的,
。
请向我们显示您的确切代码。return
语句嵌套在任何函数中吗?@Bergi不,即使成功,我也认为它是未定义的。不,我是说,你不应该在该函数的任何地方使用new Promise(…)
。避免使用!当出现拒绝和.catch(e=>{console.log(“…ERROR…”);})时,您将得到未定义的,
。
请向我们显示您的确切代码。return
语句嵌套在任何函数中吗?@Bergi不,即使成功,我也认为它是未定义的。不,我是说你不应该在该函数的任何地方使用newpromise(…)
。