Return value from promise angular Even if you return a false value or nothing, the value will be considered resolved. 2 Why is this Angular 2 Pipe not returning data? 4 Make pipe return a custom component. In most cases, you should try and stick with using Observables in an Angular application. Because it's now a promise instead of a string, you can call then() on it. You can do it with async/await. I have tried observable but not getting the Angular 2 Pipe - can't return value inside a promise. I came across this solution which solved the problem perfectly for me. items = data; this. First thing, in service. has a "then" method), the returned promise will "follow" that thenable, adopting its eventual state; otherwise the returned promise will be fulfilled with the value. then(val => self. AngularJS: Return values from function How can I resolve this problem?. Angular 6 return Observable. Keep in mind that the service returns a promise from which the data needs to be extracted: var promise = myService. My first attempt was: this. How to correctly handle this Angular promise to return an array of object? Ask Question Asked 4 years, 7 months ago. How can I return a promise and data? 5. Modified 4 years, 7 months ago. The mayor difference is (at least I think) that the login returns data containing the user info and the logout doesn't return any data. storage. isLogged() { return this. You do not return the data that way, but a Promise and you would still have to "subscribe" to it (with then) to get I have a function that works absolutely fine. Extract returning data from an angular promise. latus_lead. At the moment, I can happily print the value of result to the console, but I need to be able to assign this value to myVal. percent --> Here I want to emit this percent value from this function. Commented Oct 21, 2019 at 9:26. Return a value from a self executed promise in angularJS. readPar How do I unwrap/yield the value inside that promise. There are also many libraries which implement the standard Promises API and provide additional Of course, it is not returning the string value as it is being returned as a promise. . When you attempt to alter the value by typing into the text field, angular notices the activity, and then reassigns/resets the value of item to the result of the promise (which hasn't changed). nextlink': string; } I would like to avoid using nested promises in my component so I am using Angular 6. How can I Well, one of the differences is that myStore$. In particular, try this page. Hot Network Questions What Color Would The Night Sky Would Be If The Day Sky Was Orange You just can't return the value directly because it is an async call. The function that called setTimeout (x in your example) will finish executing and return before the function you pass to setTimeout is even called. I need to assign a return value of function to a local variable using Type Script. Also i thought it was enough to give the credit in the answer but i will change the question as well then. This means if the “Complete” callback isn’t called, the Promise will hang indefinitely. I am new in angular and I have searched for this for so long. getBlock('latest'); return bl. Can only handle asynchronous data returns. I would much rather just get the correct value at start. If it is not, then the result value will be returned. ts code snippet, "connected" is being logged to console. filterData;" with just the data I need from promise as interface Data[] Another component : receiving the results, here I would like it be the interface Data[] active is the result and it is not returned from the canActivate method. The neatest way in my opinion is to return the promise and chain them 'down' instead of to the left, avoiding christmas tree-like callback hell. function byDepartment () { var result = null; deparmentService. A promise can be: 1. Commented Sep 14, 2016 at 7:51. but when I want to get the value its still a promise. pending- Hasn't fulfilled or rej In Angular, promises are commonly used with the HttpClient service to make HTTP requests to a server. I dont know if getUsers is async, so keep that in mind. Angular Let’s say you have a service that fetches data from an API and returns a promise: import { Injectable } from '@angular/core'; @Injectable({providedIn: 'root',}) export class To retrieve the actual records follow these steps: 1) Use the word ‘await’ before the method call (which returns a Promise) 2) Declare the original method as ‘async’ (the method In your first example, when you use promises, the code that is in the . In the angular I'm having trouble making a function that returns the data "array" that I want to consume using a Promise. Techiediaries; Community A promise is a JavaScript/TypeScript object that may produce a value at some point in time. . NET MVC application with an Angular front-end. Commented Apr 26, 2021 at 9:07. The main problem is that since the Algolia call returns a promise, I have no way to get that data from . After a second it is resolved and the value is written to status. Whatever you want to do with the value you get, you need to do it from the function you pass to setTimeout. then()-statement) the right number gets printed out in the console. then callback actually gets executed after the rest of the code in the function. get to get data from an API and assign it to a value in a component This is the method which is used to get data public getByUserName(username: Angular 2 - Return data directly from an Observable. => return promise; <= instead here I would like to "return this. resolve(['test']). you are in an async function and have a Promise to await. openConfirmDialogBox() { this. subscribe( (data:any) => { console. a promise that I believe the reason your first fiddle does not work is because you are essentially binding scope property item to a promise. Do all with Promises (or all Observables) can be easier : "return await this. An async call means it is running in the background (actually scheduled for later execution) while your code continues to execute. Viewed 4k times -3 . What's a JavaScript Promise? A promise is a JavaScript object that may produce a value at some point in time. I've had to read through the docs a few times to understand promises. In your example, that would be written as: As I said before, the returned values from the successCallback and errorCallback are considered values resolved for the promise. This How to use Promise to return value from assync Angular function into calling method? 0. 2. The old syntax looks a bit different. Its async and the calling code has moved on by the time the promise return is called. Also, whichever you use, you aren't going to see console. – Utilising the then() method to return the promise, I populate a variable free of the $ notation. Promise. Assign a return value of promise to the variable always undefined ionic2. on("httpUplaodprogress", (progress)=>{ const percent = progress. ; The someTimeoutAction returns a promise. timestamp; } So, further you can use it function like: const time = await latestTime(); return new Promise((resolve) => {this. Hot Network How to return value of promise using angular 2. 4. This medium article document should be a good starting point. – when i have console. You can use promises only. show(DemoModalComponent); this. I know this is because of promises but is there a design pattern I'm missing or a clean way of doing this. log("This should not run until both have returned"); wait until afterwards unless: 1. Angular Use Promise in a Boolean function. This works great though. Hot Network Questions This is my first time when I try to return data from promise inside JSON object and I stuck with this task. Angular, extract the value from a promise. I have a login method But I think the good approach for this case will be to return a Promise. I use javascript library that has api. getAttribute('value'). Thank you so much for your time! EDIT: When we convert an Observable to a Promise, what’s happening is the Promise is going to resolve with the last “next” data emitted from the Observable as soon as “Complete” method on the Observable is called. How to use angular 2 service which returns http promise. e below blocks wont be needed. How to return data as Promise type in Angular 2? 1. You should not create a new deferred and return that - you should just return the list from your internal call back and return directly from the method: Angular 2 Pipe - can't return value inside a promise. 3. In I may not get the concept right about Promise() in Angular, but how should I modify below code so that checkExistence() can return a boolean? public checkExistence(value: string): boolean{ var e I was trying to fetch values from Pouch DB through Angular , based on specific attribute values , say "fetch all records with the name 'Vijay'". Angular provides a built-in implementation of promises through the Promise class. reason because since you use promise, you need to wait until the promise returns the value, so best possible way is you have do rest of your functionality within promise. Add Promise return type to method in Angular. Add a comment | Angular httpClient returns property does not exist on object. If your observable doesn't return by the time you retrieve the result from myMethod() then the myVal value will be blank. then() to be returned from the function. I just want to return true or false depending on the promise. If I change. angular 5 httpClient and Promises. 13. It also has a method getValue() to get the current value. However I am stuck with getting the data out of promise and into somewhere I can use it. Angular recommends use of Observable to handle asynchronous operations. service. How to handle both a promise or variable return from a function. You're right, in order to work on the array - you need to first unwrap the promise with . Viewed 4k times 2 I'm trying to do a really simple translate pipe for angular2. In the service, i need a function "getElementByID(ID)" from the list the service fetched. profile$. AngularJS function returning promise with required parameter. isLogged(). get_events(1). Those are your only two choices. How do I do this. Or is it better to somehow sort the Object instead of changing it back to an array? The console. The Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company @HereticMonkey yes it does, because it's framework specific, it's observables. The most important being So what happens here? The mainFunction is called and calls someTimeoutAction. If the value is a promise, that promise is returned; if the value is a thenable (i. This isn't "complex stuff", this is RxJS basics. g. How can I access the value of a promise? 1. To hook into that we add a then handler onto the returned promise and set the loading boolean to false there, like so:. You have some options, like wrapping the subscription in a Promise. json() which results in a Promise being created will be resolved internally before the final chained . log(value) // here value passed on clicking ok will be printed in The rule is, if the function that is in the then handler returns a value, the promise resolves/rejects with that value, and if the function returns a promise, what happens is, the next then clause will be the then clause of the promise the function returned, so, in this case, the first example falls through the normal sequence of the thens and prints out values as one might Note that the Promise object will resolve any nested promises as part of its work, so resolving res. const self = this; this. It just removes the session in the service. Is there a straight forward way to do this? Return value of a promise to a function in AngularJS. Converts an observable to a promise by subscribing to the observable, and returning a promise that will resolve as soon as the first value arrives from the observable. This is to be used for testing purposes You get values out of a returned promise from a function you called with await or with . Follow One of the fundamental principles behind a promise is that it's handled asynchronously. Add a comment | 5 Using Promises in Angular. log the return value inside the promise (in the last . How to return promise? 1. then() handler is called. 7. Modified 8 years ago. rejected- The action relating to the promise failed 3. Below I have explained it clearly: getdetail1(store){ let Cust_id=this. Getting return value from angular custom pipe before service return value. ; Everything else just continues Return value from a promise in Angular. Let’s say you have a service that fetches data from an API and returns a promise: ” Delays the emission of values Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company The SearchService already returns a promise and calls resolve on that promise when this happens. I faced a difficulty in doing it. I have an HTTP request setup as a promise in a . Returning a promise value in Angular 2, Ionic 2. function getValueFromObservable() { this. Return value from subscription in function So the retrieveAllTeams returns a Promise of type RetrieveMultipleResponse. Don't be fooled into thinking that you just went from async to sync, async await it is just a wrapper around . However, while this gets rid of the digest cycle error, you still cannot call the function from the view--I suspect Angular is treating the return value (the promise itself) as a truthy value, rather than binding to the promise's resolved value. As an aside, there is a little antipattern in your code too. log) is called. find() which returns a Promise and not the actual result. then() on that returned value to get the value. Still, mixing Observable and Promise are complicated. In a calling method, I need to extract an array of categories (Category[]) from the returned value of this method. take(1) . – Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Added due to comment: An async function always returns a Promise, and in TypeScript it would look like: async function waitForPromise() { // let result = await any Promise, like: let result: Promise<string> = await Promise. action. AngularJS getting out a return value from a Promise. Angular would the apply the changed value and rearrange the DOM-Elements. Function is returning wrong return. log(myService. eth. then( value => { //this return will `return` value in chained manner return value ? true : false; }); } Caller this. Chronologically, the following happens: x is declared, x is returned (value is undefined), Promise resolves and changes the x inside the function but as undefined is already returned, it does effectively nothing. then( res => {return res. observable$ will be a hot Observable that effectively replays the Promises value to Subscribers. Observale way - PullUserDataFromServer(guid: string): Observable<UserDataEntity> { return this. How to get value from Promise Object Type in Angular? 1. then() handler is called some indeterminate time in the future. But if you really need to, you can switch to promises *if you are sure there will be no negative side effects* . Would like to articulate this last point but can't Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Visit the blog When I move the getMethod line into the factory the response is populated obviously but as soon as I come back to the controller, even with the return value from the factory being the response the result is undefined. – Sacho. Multiple Values: Promises resolve to a single value or reject with an error, while @Piotr, its really quite simple, read the original post. resolve(value) will return a Promise that is resolved to value. Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company This may/may not suit your needs, but you could just return the Promise from your service method, eg: Return value from a promise in Angular. Subscription to promise. then(function(response) { console. Modified 7 years, 2 months ago. The best way would be to return a new Promise holding your value from that method. Retrieve value inside Observable. Related questions. You can return either a promise or observable of UserDataEntity. A promisemay be in one of 4 possible states: fulfilled, rejected, pending or settled. It seems crazy that with all the rxjs methods, there is none that work like a deferred promise in angularjs. As I said. Now, instead of logging this string to console, the goal is simply to return the "connected" string to the parent service within You cannot return a value from a promise . Let’s check a simple Promise example using JavaScript ES6. Why are you converting the Observable to a Promise and then modifying the return value when you can do that before you convert it to a Promise with RxJS pipes and pipeable operators? – Edric. The closest you can get to that is using async/await. Hot Network Questions egrep -v The problem is, by using toPromise I can get DateTime but async methods returns Promise and it's useless because I need only DateTime. Unwrapping a promise using the Promise type is handy, but what I Promise. rxjs return a value inside subscribe. Problem: The helper function returns a promise. resolve should be passed the value - Promise. Angular promise return. angular; firebase; promise; rxjs; angularfire2; return value in subscribe in angular. How can I return the string value? It is being called from an Angular function on the html. log(response. Now, I need to have a function that reads a specific value from the storage and returns it, and for some reasons I cannot accommodate a promise where I want to use this value. BehaviorSubject keeps the last emitted value and emits it immediately to new subscribers. retrieve('user'). What I am immediately trying to is create a function that returns a promise that gets resolved when an observed variable changes. Typescript, promises and multiples response types. – ste2425. Previously, an explicit return value from the constructor was used for the singleton pattern. I get a response from an ASP . But async functions still only return Promise objects. then(v => value = v); return value; } In the above case it seems like the function is not waiting for the promise to return, therefore I tried moving away from the getter style and declared the return type as WebDriver's promise: I've an Angular app using angularfire2 and I'm using a method which removes some information from a few different tables in firebase. How to multiple 2 async function values Angular. profile = val); I set a constant of self retaining the this global object otherwise the promise itself is referred to, rather than the parent. Return value from promise in another promise. What is the variable promise. changing the return type is not enough, you need to add headers to your requst as bellow Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Visit the blog Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company The Promise. Angular 4 Promise/Observable Undefined return values. then(usu => { //implement your other Remember that the subscribing takes place at the time of creating the dialog (and usually you are returning a value which is not known at that time), so setting the return value should be inside following lambda function result => { let dataToReturn = ; matDialogRef. Put the rest of your code INSIDE the . Improve this answer. then() handler. I can get the data to return inside of the getData() function however, the data is not passed on in the return statement, I just get an empty array in ngOnInit(); How to return value of promise using angular 2. 1. angular 5 consoling http toPromise() request returns Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company I want to write a function in AngularJS that returns a value (actually it is a string). If the value is a promise, that promise is returned; if the value is a thenable, Promise. data); }; You cannot have such a function return a boolean, because by the time the function itself ends, you don't have the information to return true or false. When trying to console. Modified 8 years, 6 months ago. js. That value is returned by a http request, but async is driving me crazy. And I do know a lot about Angular. Promises & TypeScript. So common way is something like this Generally if you want to use something that is updated asynchronously to appear in a view without having to write controller code as well (which is the case in your question, as you wanted to call the function inside ng-view), then you need to return a blank placeholder object, and either merge the result of the promise into it, or update a property of that object which you yes, ionic 2 storage returns promise of successful retrieval of data from storage and then angular 2 http post method returns Observable. Commented Jul 21, 2016 at 15:42 Angular automatically handles the unsubscription to the observable that is created in order to achieve this. Return a value from a promise in angular4 (Ionic 3) 0. callnetwork(arg1,callback(data){ //handle data } then i create service function to call api like this myFunction():Promise<any>{ libapi. baseUrl + "api/" + guid) } } It's not good practice to use promises in Angular. ts you don't need to subscribe, You should subscribe where you want to actually consume the data. This last method returns a Promise, and that is what I want to return as the result of the method removeTeam, is there a way to do that? Thanks. functionA(): Promise<string> { // api call returns Promise<string> } async functionB(): Promise<string> { const value = await this. You should also look into using the async / await syntax, which simplifies working with promises, and the async pipe in Angular allows you That doesn't work because the Promise is asynchrounous. I encourage you to view the source code of Awaited, which is recursive and has some very interesting edge cases it catches which my solution did not. – When a value is emitted, it is passed to subscribers and the Observable is done with it. functionA() // how to unwrap the value inside this I'm new to observables in angular. Modified 8 years, 4 months ago. Return a value from a promise in angular4 (Ionic 3) 1. 5. log("isLogged", value) ) A promise is a JavaScript object that may produce a value at some point in time. Angular Custom Pipe : Resolving promises won't work but I have problem of returning a value from a method, the value is always undefined and the promise will only yield the value after the method has returned. Commented Feb 11, 2020 at 5:29. get nameInput(): string { var value: string; this. log(url); let res; this. How to return the promise then()/catch() result to the function containing the promise? 1. 9. Successfully call the Angular GetData() function on page load and I've traced to confirm that Home/DataRefresh is returning dat The above answered why you were getting undefined when calling getUser(), but if you want to work with the end result you also want to change how you're using the value you get from getUser - it returns a promise object, not the end result you're after, so your code wants to call the promise's then method when the promise gets resolved: The login() function needs to wait for a promise to finish before returning the User. If you want to have a current value, use BehaviorSubject which is designed for exactly that purpose. toPromise()". //I want this function to return a simple true or false!!! function isAppOnline() { This is the answer I wanted; I have a value; it's ready, I just want to wrap it in a Promise to satisfy APIs which expect Promises So while the OP asked, "Immediately return a resolved promise", what I wanted was to "return a Promise , It helps me understands how Promise actually works, I was rather looking for single service method which directly returns me string value from Promise and also wanted to wait for further code execution until than. com" console. and want to get it where it is from called. Therefore, all communication with the Facebook API is successful. processAsync asynchronous. No, I can't use a timeout, because they haven't the same purpose. resolve() will call the then() method with two callbacks it prepared; otherwise the returned promise will be fulfilled with the value. I have an AngularJS service, it fetches an array with JSON objects from a server. The Promise API is a new feature of ECMAScript 6 (ES2015), but it has good browser support already. The global variable is undefined import { Injectable } from '@angular/ Return value on exit of a promise in angular 4 [duplicate] Ask Question Asked 7 years, 2 months ago. setTimeout(() => { For example, when fetching data from a server, you might use the HttpClient service to return an observable, which can then be converted to a Promise using the toPromise () method. It's the return of the subscription. How to return value to function and access it via a variable. Return value will be `Promise, so in your case it will be: async function latestTime(): Promise<some primitive> { const bl = await web3. public showDialog(theNickname: string): string { to. How to return a promise from a function? 2. I have a problem where I want to return a value inside a subscribe method. then() handler executes BEFORE the promise finishes and before the . Promises in Angular: infinite calls when returning directly. fetchInfo() returns a Promise object. resolve('this is a sample promise'); } You can't get a return value from the function you pass to setTimeout. I'm currently trying to learn Angular 2, typescript, promises, etc. You make an HTTP call, it is transformed into a promise. value is synchronous, you don't need any async constructs to access it. Pouch DB has a neat API pouchdb. then(data=>{ let lead=data; this. log(data) } ) } getValueFromObservable() I need this to work, function to return value, and then: The issue is caused by a tiny difference, in local storage the "get" methd simply returns a value, but Ionic's storage "get" method returns a promise. upload(file). 5, we can now use the Awaited keyword, as TmTron wrote in their answer. query({ codDepartme Return after async function in Angular [duplicate] Ask Question Asked 8 years, 6 months ago. You need to subscribe in the component to get the data, but it is better to use async pipe in the template. The interface looks like that: export interface RetrieveMultipleResponse { value: Entity[]; '@odata. However as I need to sort tempArray based on a particular value after the resolve I need it as an array, not an Object. Current version which works. modalRef. Angular 10 HttpClient and JavaScript Promises by example. isGreaterThanZero starts with the value of "false" and gets changed to "true" if, and only if, the expected return value is received. So the returned response in the errorCallback will solve the promise instead reject it. The response is just this: true Using Promises in Angular is NOT recommended. How to properly return Boolean value only after finishing the service call in angular. text() and returns another promise, I want the value alone, and this does not work at all. In my controller code where I handle the click I would like to act on the value of the promise. it's not possible to return the result of a promise from within the function that initiated the promise). and thus returning a Promise. resolve() method returns a Promise object that is resolved with a given value. A promise may be in one of 4 possible states: upload(file: File){ return new Promise(resolve=>{ var file = file; bucket. As, front-end framework react to change itself, so instead of actual ask for this question to wait till getting value from Promise ES2015+: Promises with then(). but the registerWithEmailAndPassword does indeed return a Promise the method in the service A few things that I noticed. async function will return Promise anyway. We use resolve to fulfill the promise when the data is available and reject to reject it in case of an error. then(). Viewed 253 I would recommend to create a variable in your component and store the value there. Modified 3 years, 6 months ago. All async functions return a promise so you always have to use await or . You cannot "return" anything from inside a Promise or Reactive function since it executes in a completely separate context. The subscription will then be closed. categories_count = this. They represent asynchronous values (that may not be populated yet), so you can't just cast an asynchronous value to a synchronous one. The simplest way to do this is to just return How to process a returned promise object? What is promise chaining? Here is a detailed introduction of promise concept with the help of code examples wherever appropriate: Promises are committed to returning values in form of callbacks, either a success or a rejection. It needs to be returned because the function calling it will need the JWT of the User. leaddata = null; this. Here's an excerpt from the class: It's unclear what specifically you've tried with toPromise, but note that RxJS has various operators that can run observables in parallel. fulfilled- The action relating to the promise succeeded 2. The code snipped in the given example is correct. Return Promise From REST Call. Then do await deleteInvite(inviteId) on the consumer side to handle the returned Promise. I don't want to use a timeout function. Last example is returning a promise anyway, it suppose to return value instead a promise, I did await response. The solution provided by @asgoth sets/assigns the The function myMethod() should just return your component's myVal property, which is assigned AFTER the observable returns values from the subscription. insert_data(this. Ask Question Asked 8 years however in a secondary service which utilizes the requests from the restful service, I need to be able to return values from the request. Ask Question Asked 8 years, 4 months ago. a Promise, an Observable-like, an Array, an iterable or an array-like object) you may want to use from: How to return value inside subscribe Angular 4. Angular / Typescript Promises. – Máxima Alekz. In the topmost, facebook. Check Aldin's comment about take(1) vs first() and see which one best fits your You could not return value from a asynchronous function. Hope this helps someone simplify the process. Hot Network Questions I want to return value (any data) from service to component as an observable. You can update your service method as The problem. No, that method is asynchronous, so there is no way to access it without chaining on to the promise. It is an asynchronous method. Show return value of Function in Angular Typescript. You can add a wrapper around promise functionality to return an Observable to observer. subscribe method returns Subscription, not the response from the http api. When I duplicated angular/rxjs, async questions with that answer, people got confused and said thening the observable doesn't work; this is obvious for angular answerers but not to you apparently. checkIsActive()); then it print [object Object] still it does not return boolean. utility. Also because after the sort I am displaying it using: *ngFor. How to handle function that returns a Promise. I am not up to speed on promises. items, category); Update. Also, jqGrid doesn't accept a promise as a return value in beforeSubmit, so you're not going to have much luck trying to do an http call. Thoughts on this: Accessing a signal with to get its value is always synchronous and so if your observable doesn't have a Hi Rob, not sure why you would want to mock a call that a mock makes to another service surely you would want to test that when testing that function. Ask Question Asked 3 years, 6 months ago. getdetails(url). Note that in some cases Angular can deal with promises intelligently and it will 'just work'. If I were making the http request inside the controller, I would update the scope inside the If it does, a promise will be returned and the chain can continue. An old question, but I'd like to add my 2 cents. I found a hopeless solution like first I called the async method and set it's value to global property then called real method to use it. Then you can use it whenever you need it. I recently started learning Angular (4) and followed the tutorials of Angular. The take(1) variant is asynchronous but it is still using observables (recommended approach in my opinion if you want to go with async access for this value. This is an asynchronous operation. The return value from the constructor replaces the object that the new operator just produced, so returning a promise is not a good idea. Original. loginservice. close(dataToReturn); }) – async fetchTourStatus(id){return this. then. ; mainFunction waits for the Promise to resolve. – Youcef, you're trying to use an asynchronous paradigm in a synchronous way. If processAsync() is asynchronous, the code will look slightly different. Getting Undefined after subscribe successfully called in angular. I am using Angular and Typescript to make an validation when i insert a value into a SQL database it check if the value is already in the database table. factory and would like to send the result to a controller. io. details=lead[0]; res=lead[0]; }); I am learning to develop in Ionic 2 using Angular 2 and Typescript. getDatos. The tech stack that I'm using is Angular, Typescript and Express. http. So, the only place to Return value from a promise in Angular. You don't show it defined anywhere and you don't return anything from your justTesting() function. getFacebookEvents. – jfriend00. m_type let url="http:domain. I'm building an ASP. you put it in the callback; or 2. NET CORE API, if the value is already in the table database server will return true. Angular subscribe inside of foreach not returning a promise. I. getProjectByID(id). Returning subscription result as promise. modalRef = this. The . public showDialog(theNickname: string): any { it still doesn't When the promise resolves and the UI element renders I can then click on that UI element. The problem is, if I put the return in the then() it will say: [ts] A function whose declared type is neither 'void' nor 'any' must return a value. Hot Network Questions and you really would not need to have catch and return false unless you need to really track the return value since dialog already resolves/rejects the promise based on cancel or Ok, i. Await the Promise to resolve the active value and then return the active value from canActivate. Didn't see any code to mock the result of router How can you return a value from a promise and include it in a global variable? I'm trying to make this formed, but to no avail. I've setup a small app for developer tools and a service that just returns hard-coded data. 0. then and then use the fact the return value is another promise. toPromise(). libapi. then( (value) => console. the main thing is that how can i directly return something from inside promise success ? Although can you plz share code snippet of converting to Observable only ? it might help to solve the issue. In your Service, create this function. Commented Aug 20, 2014 at 9:02. but of course the http request used by the service is asynchronous so the return value is not immediately available and comes up undefined in the controller. Promise within Observable: Not able to return data. That's the ONLY place the boolean from the promise is valid. Share. This function flattens nested layers of promise-like objects (e. content. Return value from a promise in Angular. Read the original post from Angular 14 Promises example. 286. – Talg123. It's a hot Observable because the producer (in this case the Promise) is created outside of the Observable. then(console. checkIsActive(); promise. Ask Question Asked 6 years, 6 months ago. If subscribing is not an option and you want to do it the Observable way then this problem can't be solved. store. nameElement. resolve() static method "resolves" a given value to a Promise. sharedata. getCategories() : Promise< Now, let’s summarize the key differences between Promises and Subscriptions in Angular: Single Value vs. AngularJS promises returning object rather than resolved value. The HttpClient service returns an observable, which can be converted to a promise using In this example, we define a function fetchData that returns a Promise. In that way, the subscription is cleaned up by Angular when the component is cleaned up. If you want better help, you need to describe what problem you're trying to solve rather than just showing us code that is so "off" that it doesn't even illustrate what you're really trying to do. Returning a promise within a promise. At this point in my angular code I already know that the promise is resolved. Call a Promise from an Angular @ShinDarth You can add this function in your service and call this funcion whenever required. get<UserDataEntity>(this. The Promise. Emit and complete 0, 1, or multiple values over a period of time In Angular, promises are a way to handle asynchronous operations. This class is used to create new promises and handle the results of asynchronous operations. subscribe((value) => { console. post(). How return a request inside a promise. Function not returning Value in angular? 1. However, if you want to convert a given value (e. then(data => {this. Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company My answer transforms Observables to Promises, which fullfills your title Return Promise HttpClient Subscribe Response. So far, I've tried a lot of things Return promise from Angular service. As of TypeScript 4. 2 Getting return value from angular custom pipe before service return value. You can make it look different using async/await, but it is just syntactic sugar. The rest of your function after the . Angular - mock Promise method for Jasmine unit test. Ask Question Asked 8 years ago. e. Viewed 1k times You can return to the outer function not value, but promise, and subscribe to it in the outer function – Ted Romanus. But because the function is called from a then(), the value will be wrapped into a promise anyway (at least in raw Javascript). For example: I also know that I can return a single type (like a Promise) which can itself be of multiple sub-types: private active(): Promise<void|null> { However, in the context of angular2 custom form validators, a single signature (one parameter of type FormControl ) can return two distinct types: an Object with form errors, or null to indicate the ANGULAR OBSERVABLES ANGULAR PROMISES Can handle both synchronous and asynchronous events. This means that you cannot create a promise and then immediately use its result synchronously in your code (e. A promise may be in one of 4 possible states: fulfilled, I recommend you read up on how to work with promises in JS and Angular. I have to apply a decryption on the body of the return of a request via Interceptor, however the method of decrypting is asynchronous and returns a promise. then(function() { return true; }, function() { return false; }); So I need just a value from it to be returned, nothing else. I need to be able to get the value of this Promise object and assign the value of it to a variable that I can then use later on in my code. log of the returned Promise is displayed underneath. tour; }) }; but then it returns a zoneawarepromisewhich has a value of true but I'm not even sure how I would check that in my template file. modalService. I'm new to angular and I've been trying to use http.
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