Angular wait for component to load

Angular wait for component to load

One-way call API and promise in Constructor. ts, but child-component is still erroring because it's getting the data as undefined. In this article, you will learn how to use the defer feature, introduced in Angular 17, to implement lazy loading in a simple and declarative way. x, UI-Router was my primary tool for this. The . This post includes load data from API before the component is rendered. @ViewChildren(ChildComponent) children: QueryList<ChildComponent>; My current pseudo code (that updates rows and should wait for children) looks like that: fooMethod(): void {. But my problem is that the styles from the styless. subscribe((v) => {. querySelector('#myInput'); const input$ = fromEvent(trackedEl, 'input') . ts file first in my app. public response: any = null; Jun 3, 2019 · I simply don't understand how async/await works; that's what I believe the problem is. component. Nov 22, 2023 · How to wait until all data is received to complete function in typescript/angular? Dec 13, 2018 · 2. Dec 17, 2018 · 1. products variable doesn't get populated with data, we show a loading indicator: <p *ngIf="!products">Loading data </p>. ts file and add HttpClientModule in the imports array as follows: Next, open the src/app/app. loadGroupPosts() Jul 28, 2020 · I want to wait for one function to finish before executing the function next to it. name: 'Name'. Aug 13, 2018 · I am trying to set data in a service and then navigate once the data has populated in the service, I am having a timing issue where the page is navigating before the service has been able to popula A customisable loading spinner for Angular applications. rows = increase rows count. That means it’s guaranteed that everytime data input value changed, our grouping logic will be triggered if we put our code here. Mar 5, 2022 · # angular. Dynamically load components has simplified in Angular 13. user. I tried looking at this question where the elvis operator is mentioned: Wait for Angular 2 to load/resolve model before rendering view/template. Unfortunately, it does not work. In my angular project, I have the following setup: I have API to fetch some data from server at the beginning of the app load: ItemFetch. openDialog(); // waiting here. This would solve the issue temporarily, but I wouldn't be able to publish the component to GitHub. Here is my component source code: import { Component, OnInit } from '@angular/core'; Mar 27, 2018 · I am new to Angular 5 and was able to create view with access to service methods using subscribe but encounter problem in delay in render. import { Http } from '@angular/http'; import 'rxjs/add/operator/map'; dataLoaded: boolean = false; Aug 14, 2019 · Here is an example of doing so in the doc. out. someFormArray. loaded = true; Now in my component I have an object [object Promise], but I wonder what is the proper way to consume this object inside of my Angular component? If it was an observable I would subscribe to it by doing something like: Jan 27, 2020 · Lifecycle hooks are timed methods. See the parent template: Oct 11, 2019 · 4. listC = res[2]; this. Here's the code for our component's Typescript file. sleep(2000); } while (!angularPageLoaded); System. If you want to make sure that the OrderReviewPdfComponent (child) template is initialized, you can use the AfterViewInit lifecycle hook inside the OrderDetailComponent. listB = res[1]; this. You need to check for img. Dec 31, 2023 · This tutorial talks about how to load data before rendering a component. ng generate component spinner. 4 but when you search for help on 1. Oct 8, 2018 · Option 1: ngIf. That's the ONLY place the boolean from the promise is valid. data. One of the most straightforward options that come to mind is to have an ngIf statement added to the component template which indicates a loading status - until the this. Last option, would be to use ngOnInit to initialize the data in the child component. You can show a loading indicator or empty screen in the module's template, until you get the response from Jan 13, 2022 · You have to wait for TypeScript 2. Let's now see how to use Async/Await with Angular 10 by Example. waitForElementToDisplay("#div1",function(){alert("Hi");},1000,9000); function waitForElementToDisplay(selector, callback, checkFrequencyInMs, timeoutInMs) {. ts I have: import { View Dec 4, 2019 · I am trying my first Angular 8 Crud Web app and wrote a page to list some company names from WebApi My Service is correctly getting data and Iam able to print it on console //Service. log('user check', this. // wait here for children to be updated! for child of children {. ts, and app. canActivate(route: ActivatedRouteSnapshot): boolean | Promise<boolean> {. First, use @angular/cli to create a new project: ng new angular-async-fakeasync-example. +50. I want to be able to wait until it loaded in any component. then() handler. The problem is that the app is loading the sidebar component before the get request is finished in the player. If there away I can prompt app to wait before loading the components? Jul 14, 2016 · I am using Angular 1. html Mar 29, 2021 · This suggests that the AuthModule has been instantiated before the config has been loaded and set. One possible solution would be to have one service that implements CanActivate and combines other guards: class Combined { constructor (private gA: GuardA, private gB: GuardB) {} canActivate (r, s) { return gA. You can learn from different approaches, such as using promises, observables, or events, and see how they work in various scenarios. complete flag or wait for image. You showed it in an afterEach(), or it could replace the logic in the it() spec as well, but modifying the clause you have in the answer directly Dec 21, 2017 · I'm trying to draw two divs (each containing components) that are connected by a line. 5 components it's hard to sort through all the Angular 2 community chatter! – Dec 22, 2022 · I have to wait for DOM to render before going into next functions. We inject ComponentFactoryResolver to map component to ComponentFactory. Head to the src/app/app. isAuthenticated() . first_name}${this. getPrivateGroup(`${this. Could this be because the parent component is what's waiting for the resolver, not the child component? Feb 25, 2019 · I'm trying to implement a guard in my project, that should wait until ngrx-store's loading complete and after this check is user authenticated or not. Here is the flow/lifecycle: Push into the Array: this. Everything is working and the component category received its data. One way to do is, return the Observable instead of subscribing in the getPrivateGroup() getPrivateGroup() {. /data. Nov 7, 2019 · If user try to navigate away using some angular router link before tge 5s, it will still run the navigate after 5s causing an strange behavior. const result = await this. Let’s recap how we load components in Angular 12. Jul 6, 2018 · 1. component, with an *ngIf, I get routing Feb 26, 2016 · To load data before the initial rendering of the root component APP_INITIALIZER can be used How to pass parameters rendered from backend to angular2 bootstrap method. 5 is so cool and a really great option for apps that started in 1. Put the rest of your code INSIDE the . Problem is that the data variable is not yet resolved when angular fires component-child and so I get nothing. width] property in the template, and call a function to calculate the width using nativeElements, I get this error: Jun 18, 2016 · 22. You’ve probably already tried doing this in the ngOnInit function of the app. This would work only for the initial load of the Angular page, but thereafter, navigating within the app would not cause a page reload and there would be no obvious way to detect when new images were May 18, 2017 · The goal behind this refactor is to hide your data behind an observable. Dec 7, 2016 · How do I display a spinner while I'm waiting for the data to be displayed? Is there a way to place a custom tag (from spinner component) in the HTML template where I'm waiting for the data? My project is based on Angular Drupal POC. I am Initialing the player. now(); Oct 17, 2023 · 2. Start using ngx-loading in your project by running `npm i ngx-loading`. import { Component, ViewEncapsulation } from '@angular/core'; Oct 7, 2021 · You can make it an async function if you feel like using await like so: import { take } from 'rxjs/operators'; async ngOnInit(): Promise<any> { const data = await this. As I mentioned in the comments, a quick and relatively straightforward solution to your problem is to simply use async() and setTimeout() to achieve actual wait times in Angular 8 using Jasmine. Oct 28, 2020 · If you are looking for a way to make your Angular code wait for a subscribe to finish before returning data, you might find some useful answers on this Stack Overflow question. The second function return; } If I load accessParameters () in ngOnInit or in the Constructor, it appears to load twice. The only one thing you need to bear in mind is not to authorize user twice, meaning you should cache authorization result between page navigation. Jul 20, 2020 · 1. toPromise(); this. References: Forcing Angular to Wait on Your Async Function; @init / @waitOnInit TypeScript method decorators; TypeScript Decorators Nov 23, 2020 · Stack Overflow Public questions & answers; Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Talent Build your employer brand Aug 10, 2017 · runs all guards in a sequence without waiting for the previous to finish. onSizeChange(); Jun 8, 2023 · In this guide, we'll learn how to get data from an API using Angular, show a loading indicator while waiting for the data, and how to display errors nicely. The file is only loaded after 1 sec. Then, navigate to the newly created project directory: cd angular-async-fakeasync-example. I would like to access to a child component from a parent component using the @ViewChild Annotation. The means that the user will first see this: Dec 17, 2019 · So I want to emit an event from a child component that triggers a function in the parent component, but I want to wait to get a response from that parent function before proceeding. spec. Mar 4, 2020 · In your example, you have 2 @Input properties which are dependent on each other. this. In this case, a good practice could be to implement OnChanges interface on your component, and move your logic inside ngOnChanges method implementation. EDIT: Regarding the fact that you're using Observable, you can use . I tried it like {{model?['name']}} but it doesn't seem to do Nov 29, 2022 · It's not possible!! Either call the service before module loads (it's still lazy loading, just moving an api to app. target. pipe(. onLoad event to be fired. A simple workaround is to just add *ngIf="data" on the outermost element in the view. Angular complains that because the @Input is passed through the template, the value of proximityReportPoiZoi$ property has changed after parent component initialization. Write a component that will work as a loading mechanism. The rest of your function after the . Jan 12, 2016 · In Angular 1. Something like this overly simplified example: I'm building an ng2 application using ngrx. If that makes sense :) I'll update my original post. How do I wait for the variable to be resolved before the child component instantiates. Angular's in a weird place right now; 1. However, if I do not have parameter, it doesn't load any data. Second way, use resolve data. Don't forget to open the browser's console to see the results. My list of articles component looks like this: Sep 16, 2018 · 1. – Günter Zöchbauer. then() handler is Apr 3, 2011 · Here is a core JavaScript function to wait for the display of an element (well, its insertion into the DOM to be more accurate). dataLoadedEvent$. Here is the . Thank you so much :) My code is as follows: Mar 24, 2015 · In angular we have an enrich method which runs some rest call to enrich a data object, then sets a variable which will cause a hidden details tab to be visible. Feb 26, 2016 · Awesome! Thank you so much. Finally, Activate Route. 5. module. 5 sec it change to the correct value. log(data)); The subscription will not get called before you emit data from it (using next() call), meaning that your subscription will get called once you actually have data. The method getCustom subscribes to an observable run on . modifyMyData(data); } However, if you're using ngOnInit instead of the constructor to wait for a function to Oct 27, 2018 · 8. Initially, responding as if there are no parameters, even if there is one, and then a 2nd time processing the parameters. subscribe(status => { this. the second will have the parent instantiate immediately, but the children won't instantiate until Apr 27, 2017 · In debug I noticed that only after my component runs ngAfterViewInit(), only then I can read the component template width and height from my directive and use that values. programming web development angular. <child-component *ngFor="let input of combined$ | async" [input]="input"></child-component>. I need the application to wait until this URL is determined before it tries to load any data. In the AuthGuard you check the result of authenticated () method that will most probably return false as the user property is still not set. await delay(1000); BTW, you can await on Promise directly: Aug 5, 2021 · 13. log(this. next(componentName) Feb 25, 2018 · I have loaded script file like below code in angular home. canActivate (r, s). I have a service that determines the URI for the webApi. . I'm trying to load data from my service to my component, but I get an undefined. Jan 13, 2022 · Second Step: Create a component with an overlay spinner. The router can be made to wait for Observable to complete with the CanActivate guard. Is there a way to do that, like ajaxStart() and . Jun 1, 2017 at 20:42. Mar 31, 2019 · Thread. I know I can subscribe to the Observable, but then if I subscribe it in all the components I have it will load it in every component. This is the component that will create the overlay effect and display a loading spinner in the middle of the page. io Concluding, we briefly discussed the implementation on pre-loading the data in any class or before template initialization in ngOnInit in Angular using the TypeScript decorator. To use it, you need to add it to your project. Simply wrap the child component inside an *ngIf in your HTML: <app-child-component [stats]="stats"></app-child-component>. stackblitz. Lifecycle hooks help manage its effects. html, app. The problem is with your code. doSomethingWithFetchedLists(); }); You can also use combineLatest instead of forkJoin, which instead of waiting for all observables to complete, will emit everytime one of the observables changes (but it will wait for all observables to emit at least one value first). Seems like it's still being instantiated before parent component has the data. There are multiple ways we can load API data before the component is rendered. push((this. Apr 6, 2016 · Is there a way to wait before the service initializes to load other components? I need to load some data synchronously before displaying the components (which require the data), and I don't want to use promises/observables (using those for async calls) ngIf doesn't seem to cut it (component loads even though if doesn't match). Aug 24, 2021 · this resolve call a service with a promise inside that does a API request. My State looks like this : Mar 2, 2020 · I have tried a range of things: async, FakeAsync + tick, jasmine. My app-routing. Here some lines of code: In BodyContent. compontent. It seems to me that Angular is not actually waiting for the Promise to resolve before it begins instantiating imported modules. Using HttpClient in Angular To fetch data from the web, Angular provides a tool called HttpClient. Once the loader is gone, then it will assume that the next page/ event is ready. Angular runs change detection constantly on its data. toPromise in order to work with ng-Busy. // Call the below function. I retrive the data for my category using an APP_Initializer that return a promise in order to have this data when the application is initialized. PROBLEM. Wire manually to each component that I have an event listener that will fire after it has been loaded and set. type: type, }))) Trigger functions that are trying to access HTML from step 3. component, but realized your data needed to be loaded even sooner than that. There are 68 other projects in the npm registry using ngx-loading. authenticated; }); } Oct 11, 2017 · Manually add the dependencies of the components that I'm writing. I know observable are great for returning single pieces of data over time but I need to know when this observable has completely finished returning all of its data so I can run validation code on the object it has returned. then() handler executes BEFORE the promise finishes and before the . Here is my service: KalidataService. Child @Output() callParentFunction = new EventEmitter<any>(); Aug 15, 2021 · The naïve solution that was considered, was to subscribe to the window. Mar 6, 2016 · In Angular 1 I have written a custom directive ("repeater-ready") to use with ng-repeat to invoke a callback method when the iteration has been completed: In AngularJS, a Component is a special kind of directive that uses a simpler configuration which is suitable for a component-based application structure. print () or pressing Ctrl + P, the print window opens but doesn't display the majority of the content on the page. I have an angular2 RC6 application and I need to defer loading pages until after some functionality is executed. npx @angular/cli@13 new dynamic-components --routing --style=scss --inline-template --inline-style --skip-tests. That's why the last console will return undefined. Jan 21, 2022 · Right now, my code looks like some variation of this: const trackedEl = document. service'; Aug 19, 2020 · Async/Await by Example. I imagine it's a way to re-structure the code so that async/await works, but I have no idea how. 1. The line's length depends on the widths of the divs, which I'm accessing using the nativeElement property. subscribe(data => console. There is no way to make components wait for a Promise or Observable. so in the route, add a resolve: { i18next: function (YourModule) {return YourModulePromise}} Aug 12, 2016 · If you really don't want to have blank spots in your UI, you can set a full page loader block with an *ngIf="!loaded" in your app component along the main container tag, and the opposite *ngIf="loaded" on your main container. authenticated = status; return this. ts export cl Oct 2, 2018 · The problem is, I have to wait the http response arrive. role-guard. ts *. – Remi Sture. ts files. This is an asynchronous operation. ts file export class HomeComponent { constructor() { this. Jun 17, 2019 · matTabContent indeed makes tabs lazy-loaded instead of eagerly-loaded, but matTabContent doesn't destroy previous component immediately after changing of tabs that leads to 2 components presence in DOM simultaneously. When console. original. e block the parent component while the child component completes the rendering). But the correct data loads properly from the function I'm calling. The condition will be that the data the child needs is available. Introduction. When trying to print a page on my Angular app, whether by using window. Approach that I am following - I have a shared service between all these components and whenever data is loaded for any component, that component calls next method on the BehaviourSubject of my service - this. Mar 10, 2022 · 2. // process child. Jan 18, 2018 · The problem can be caused by the *ngIf or other directive. getData(). This approach has a ~30ms faster destruction of previous component in compare with adrien-pessu answer and they substitute one Apr 12, 2017 · 8. fetchEvent();, this doesn't mean the fetchEvent() call is done, this only means that it is scheduled. The problem, that guard doesn't wait completion of store's loading. import { Component, OnInit } from '@angular/core'; import { DataService } from '. println("outside loop => "+angularPageLoaded); while the webpage is loading, the angular wait will keep on checking in every 2 secs whether the loader is rolling or not. If the parent component is simply calling the child component by using the child component tag, then *ngIf will be a good option - something like this. ts file for the component: Jun 2, 2017 · 1. An important aspect of these hooks is their order of execution. You can use ng-busy (or basically any other npm component out there) for displaying a loading indicator in each http call (promise or observable in your case) in your app. value) . Dec 8, 2021 · We’ll have a lot of small components in this application, so inline templates and styles will allow us to minimize the number of files to touch. At the beginning of app load, it fetches data from API then changes the itemLoaded to true. Latest version: 17. ngOnChanges is a lifecycle hook that run whenever it detects changes to input properties. last_name}`) } And then, subscribe to the data where you want the chain the this. By returning a promise for "resolve" values, the router would simply wait for the promise to complete before rendering directives. The answer is very simple. loginService. May 15, 2018 · ngAfterViewInit triggers after the component view is rendered but before all the libraries are loaded and the page is actually fully loaded. I think that this StackBlitz demo demonstrates the problem in a simplified example without any of the Auth0 dependencies. If I have parameters, everything works as expected. This will create a new Angular project with app. The component category wait to render the Jun 28, 2019 · There is no difference in how you would check it in Angular or in js. load event, which fires when all images are loaded on initial page load. May 17, 2019 · In your app component you can have a property: wasGetXExecuted = false; which you set to true after getX() function was executed. export class KalidataService {. 0. <ul>. ts level, doesn't mean you whole module is loading off the bat), or let the module load, and call the service. They differ in when and why they execute. ts file and update it as follows: We first import and inject HttpClient service via the component's constructor. So you should be calling the exportPdf() in the ngAfterViewInit Sep 14, 2020 · Solution 2: Use ngOnChanges. You could store a reference on the subscription as a users component property, then use a simple *ngIf in your template to show/hide the loading indicator : /* users. Apr 2, 2021 · I am trying to emit the values from the child component to parent component where I want to show the loader (i. Jun 28, 2016 · I need to run a script when a Component is fully loaded. Jan 7, 2020 · Then, your onFileSelected function can use await as follows: async onFileSelected(file: File): void {. Change detection triggers these methods. Angular team deprecated ViewContainerRef in Angular 13 and we can load components to attached view container without it now. For example, if in the parent component ParentComponent you want to access the child component MyComponent. This meant that it scrolled to the bottom of the page, but then more content was added after and you were only half way down the page – May 13, 2016 · I'm struggling with the async pipe, I need to wait for the async data to finish loading before trying to render the view of the component. I have one function called getData() in which http call occurs which returns an observable. When the app is launched a web service is called to get initial data, once this data is fetched I create an INIT_DONE action. The first will make the parent and children instantiate only when combined resolves at least once. Angular directives allow us to handle such behaviors of element, so let's create a directive: Oct 10, 2019 · 1. A simple usage would be: cacheService. After the first attempt is cancelled, a second attempt will render the page correctly in the print window, but reloading the app will revert back to not Feb 7, 2020 · On click of data row of the next component, it will open another component and so on. Yes, Because the Javascript is interpreting line-by-line execution so that it will not wait for other processes to complete. Dec 4, 2023 · Lazy loading is a technique to improve the performance and user experience of your Angular app by loading only the necessary modules and components. groupService. log('result', result); // you got the value. Run the following command to create an Angular v13 app. then ( ()=> { return gB. log(`Got to the observable:: ${v}`, count++); }) Aug 27, 2022 · A Simple Way to Load Data Before Page Load in Angular. You will also see some examples and tips to optimize your app delivery with defer. Jun 26, 2016 · 1. I have a method that needs to wait for an observable to finish. </parent-component>. then() handler is called some indeterminate time in the future. In your child component you can create an input, like: @Input() wasGetXExecuted: boolean; Then in child component you can implement ngOnChanges lifecycle hook like: Sep 7, 2016 · Based on the second link, I've added MyResolver to providers in app. May 13, 2017 · Note: the Angular canActivate method does not allow me to write the code as shown below: canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot) { this. 3 or 1. Aug 12, 2017 · 2. 0, last published: 4 months ago. Dec 11, 2020 · Child components are collected by. So for that, the user will see a loading page until the data is loaded. Sep 21, 2021 · this. Apr 6, 2016 · The problem is that the ng-options includes a list of i18next texts, and the view seems to be "ready" before the controller. data = this. I have a component embedded in another component as demonstrated below. You should neither: Cancel the timeout on route change; or; Block the entire page to avoid clicking on any other route. createForm({. Sep 18, 2019 · I want to load data from an angular service in a component constructor, and use these data to update the UI in the ngOnInit () function. Newest jsFiddle working bu Jul 30, 2017 · Or possibly: <parent-component >. We'll also show a loading spinner while waiting for the observable to complete. ts. You would be able to create delay function with async: function delay(ms: number) { return new Promise( resolve => setTimeout(resolve, ms) ); } And call it. Is there a way I can tell my directive to wait until ngAfterViewInit() ends, and than do what I need from my directive with that info I'm looking for. loadDynmicallyScript(); } public loadDynmically I imported this player file into the sidebar component and now app errors. Alternate I am trying to learn Angular 2. In the same time if you use the console inside of the subscriber then you will get proper log because the subscriber will wait for the response and bind it with this Jul 7, 2021 · Setting Up the Project. Learn from the code examples and the accepted answer. pipe(take(1)). ajaxStop() on jQuery? I am trying to add my code on ngAfterViewInit(); but sometimes the component is not fully loaded when that function is called. When I use the [style. Oct 28, 2014 at 13:43. The solution is to use the @ViewChildren instead of @ViewChild and subscribe the changes subscription that is executed when the component is ready. Jul 26, 2021 · Get the value of the @Input() by subscribing it at a later stage in the parent component, in ngAfterViewInit() cycle. Yes, you can wait for user to authorize inside your guard. clock, changing the promises logic in my Angular component, etc fixture. Here, the child component will not be created until the data is available. ts: Jul 4, 2022 · https://angular-ivy-kq23e9. listA = res[0]; this. whenStable gets me a step closer but texts declared line 50 is still undefined. 5. 0 with async/await for ES5 support as it now supported only for TS to ES6 compilation. They execute depending on the conditions of the current cycle. I am making an angular application and I need to preload some data. css file is not yet loaded if the page is loaded. Please revert all the changes in previous solution. var startTimeInMs = Date. <child-component *ngIf="condition"></child-component>. In your app component your define a loaded boolean to false, and in the subscribe callback, you set this. Implement the Loading Indicator in the Component Next, in the Angular component where we want to fetch and display data, we'll utilize the Angular HTTP client and the service we just created. If I hide the main application in app. user); return this. Try this: AuthService: import { Injectable } from '@angular/core'; import { AngularFire } from 'angularfire2';'; May 2, 2020 · The problem with that I found was that because my component has a lot of child components, even though the parent itself was initialised, all the child components had not finished rendering. console. The user see first "undefined" string and after 0. You can use *ngIf="data" in your components template or a guard to make the router wait before adding the component until the data becomes available. service. } Also, I wrote a working sample here. ngAfterViewInit is called on a Component when it's template and templates of it's children are initialized. By Dragos Becsan on 2022-08-27. map((inputEvent: any) => inputEvent. I am using the async-await feature to implement it. Thanks Mate, always helpful! Sep 26, 2018 · How to make Angular 6 wait for an element to load inside a conditional *ngIf block? This question on Stack Overflow provides a detailed explanation and a possible solution using the AfterViewChecked lifecycle hook. ev) is executed after this. canActivate Oct 14, 2016 · Here is the idea: So I am trying to use an external library function to create some manipulation in the DOM in one of my controllers that my ng-repeat is connected to. ob eq vu oa rm yy dq jh of tt