Returning Value from Promise

Question

I have a function getPackageName, and inside this function i defined a promise , i need to save the value of this promise and return the value outside , so whenever i call getPackageName,it will return promise result value ...

    getPackageName(modelName){
     let modelReq = new Ext.Promise(function(resolve, reject){
                        Ext.Ajax.request({
                            url: `db/code/pkgname?tablename=${modelName}`,
                            method: 'GET',
                            callback: function(options, success, response){
                            if (success){
                            if (response){
                                    resolve(response);
                                }
                                else{
                                    console.log("No response from server");
                                }
                            }
                        });
                    });

                    modelReq.then(res){
                            return res.res
                            }

    }

it's not working as expected , and whenever i call getPackageName, it will return undefined . Any help would be appreciated for sure .

Before `modelReq.then(res){`, add `return`. Then use `getPackageName("?").then(packageName => { ... });` — , May 29 '19 at 08:45
@ChrisG thanks for the tip , so this `return` should be inside `Ext.Promise` ? — Shah.m, May 29 '19 at 08:49
@ChrisG can you please provide an example ? i got confused a bit , appreciate your help — Shah.m, May 29 '19 at 08:52
currently, `getPackageName()` isn't returning anything. You need to return the Promise: `return modelReq.then(res => res.res);` — , May 29 '19 at 08:54
@ChrisG after adding this return , whenever i call `getPackageName()` it will return `Promise {}` — Shah.m, May 29 '19 at 09:20
Yes, that's because `getPackageName()` returns a Promise. Either use `async/await` or `.then()` (like I showed in my first comment...) — , May 29 '19 at 09:42
@ChrisG got it , thanks , so when i want to call the function i should use it like `getPackageName("?").then(packageName => { ... });` ? and instead of question mark , what should i use ? sorry im a bit new to promises concepts — Shah.m, May 29 '19 at 09:50
The parameter is called `modelName`, and it gets inserted into the Ajax URL as `tablename`. So if you want to request `db/code/pkgname?tablename=users` you need `getPackageName("users").then(result => ...)` This is your own code I'm explaining to you, shouldn't you know what to pass to `getPackageName()`? — , May 29 '19 at 09:54
@ChrisG thanks , i will try this logic based on your explanations . — Shah.m, May 29 '19 at 09:58
@ChrisG i tried to save it in a variable , but still it gives me that pending . `let modelPackage = getPackageName(modelName).then(result => {return result});` — Shah.m, May 29 '19 at 10:34
This is a well-solved standard problem. To get the result right away, you need to use `async/await`. See here: https://stackoverflow.com/questions/14220321/how-do-i-return-the-response-from-an-asynchronous-call — , May 29 '19 at 10:35

Returning Value from Promise

0 Answers0