Having trouble accessing a component property in Angular 2

Hello, I am currently diving into Angular 2 and working on a project that involves basic CRUD functionality. I am encountering an issue with my User component where I am trying to access its property in the ngAfterViewInit hook, but it keeps showing as undefined.

Take a look at the code snippet for the User component below:

export class UserComponent implements OnInit, AfterViewInit 
{

private users: User[];
private userRoles;

ngOnInit(){
           //get users from service
           this.getUserDetails();
        }
ngAfterViewInit() {
               console.log(this);
               console.log(this.users);
        }
getUserDetails() {    
            this._userService.getUsers().subscribe(users => this.users = users);            
         }    
}

Below are screenshots from the console. You can see that the object has the property users, but it still displays as undefined in the console. https://i.sstatic.net/I75no.png https://i.sstatic.net/ydxox.png

If you have any suggestions or if I missed something, please feel free to share. Thank you in advance.

Answer №1

Examine the user property within the getUserDetails function. Utilize the users property in your template. Refer to the component lifecycle hooks for a better understanding of the component lifecycle.

getUserDetails() {    
  this._userService.getUsers().subscribe((users) => {
    this.users = users;
    console.log(this.users);
  });
}

Answer №2

It appears that the issue at hand is not related to Angular 2... Rather, it seems to be a TypeScript problem involving accessing this instance globally.

One possible solution is to utilize the 'let' keyword and declare variables in TypeScript... When a JavaScript object is cloned to another object, any changes made to one object will automatically reflect in the other.

This problem also arises when attempting to access the TypeScript this object within jQuery functions.

let _this = this;
something.each(function() {
    console.log(_this); // the lexically scoped value
    console.log(this); // the library passed value
});

Similar questions

If you have not found the answer to your question or you are interested in this topic, then look at other similar questions below or use the search

Strings holding special arrangements of breaks in between

Currently, I am developing a portal that enables examiners to provide a problem statement, sample input, and sample output. However, I am facing an issue where the sample input/output values are stored as complete strings, causing line breaks to not render ...

Is it possible to upload an image-containing object to Mongodb with the help of Node.js?

I am struggling to upload an object containing an image to the mongodb database using Node.js. Angular File onSelectedFile(event){ this.edit_image = event.target.files[0]; } editProfile(e){ const user={ email:this.edit_email, img:this.edit_imag ...

I am having trouble getting the guide for setting up a NextJS app with Typescript to function properly

For some time now, I have been experimenting with integrating Typescript into my NextJS projects. Initially, I believed that getting started with Typescript would be the most challenging part, but it turns out that installing it is proving to be even more ...

The element's height appears to be fluctuating unexpectedly when I attempt to adjust it using percentage values within a narrow range

I'm utilizing React and Bootstrap in this project. Here's an overview of my code: I have an element with height set to 0, in rem. My goal is to make the height of this element increase as I scroll down the page, creating the illusion that it is ...

"Efficiently refresh the DOM by updating it solely upon changes in the

Within my AngularJS application, I have observed that the DOM refreshes each time a function is called, even if no $scope variables have been altered by that function. I am utilizing an ng-repeat directive to generate a series of checkboxes, as demonstrat ...

How can I adjust the scale and position of my image textures in Three.js?

Is there a way to adjust the scale and position of my image textures? The dimensions of my image are 1024px x 1024px. let textureMap = THREE.ImageUtils.loadTexture( 'texture.png' ); https://i.sstatic.net/wKd6f.jpg ...

Creating a multi-page form in AngularJS with Tab navigation

Hello, I am currently working on implementing a multi-stage form using AngularJS Tabs. Instead of using routes in this application, I am trying to achieve the desired functionality solely through tabs. app.controller('createProjectController', [ ...

Update the chat <div> automatically whenever a new message is added to the MySQL database

I have been looking online for a code that can update the chat <div> every time a new message is received from the other user. I have come across mentions of setTimeout() and setInterval(), but I would appreciate advice and assistance from more exper ...

A guide on incorporating dynamic information into JSON files with PHP

I am currently working on developing a checkbox tree where I require dynamic values for checkboxes. Below is my code snippet. Initially, I have static data in JSON format and now I need to retrieve dynamic data from a MySQL database. Despite trying vario ...

What is the process for transferring `Parentobject1` to `childobject2` and `childobject3` in Three.js?

I have created two objects doubleSquare and doubleSquare1. I was expecting the output to be Double Line Square Object, but I have tried two different formats and have not achieved the desired output. Can someone please provide me with a solution? I have lo ...

Show Data from API on Angular 6 Webpage

Hello everyone, I am a beginner in the world of frontend development and I'm currently facing a challenge with displaying API data in an Angular 6 application. I have managed to showcase values from the main level of the returned details, but I am str ...

Updating the redux state in react by passing a variable from a child component to the parent

I'm currently in the process of updating my Redux state within a component by utilizing a variable that has been passed up to the component from a child, specifically through a form submission callback. The form is responsible for submitting a user&ap ...

Utilizing the parameter "error" to distinguish unsuccessful tasks within async.mapLimit

In my coding process, I am using async.mapLimit to implement some parallel operations on an array with a limit of 10: async.mapLimit(files, 10, function(file, callback) { ... etc... }, function(error, files) { ... etc.. }); Within the main opera ...

Node.js reads and writes a JSON file, encountering issues with another application in the process

I'm currently facing an issue with my node.js server (express.js) and a json file used for reading and writing data through a simple API. Interestingly, when the node.js server is stopped, another application can add data to the json file without any ...

How can you stop queuing animations and timeouts in jQuery?

I'm facing a seemingly simple problem that I need help with. On my website, there's a hidden div.notification bar at the top. This bar can be displayed by adding either the success or warning class to it. There are two scenarios: either a messa ...

Touch interaction operates differently than mouse movement

Imagine three neighboring divs, div1, div2, and div3. When I click on div1 and then move my mouse to div2, the mousemove event is triggered with div2 as the target. However, on mobile devices, if I tap on div1 (touchstart) and slide my finger to div2, the ...

Check Image Dimensions prior to Image Loading

I've been working with JQuery Masonry and would like to incorporate Lazy Load using a WordPress plugin to load images only when they come into view. The issue I'm facing is that when Lazy Load is used, the masonry elements don't recognize t ...

Triggering the detection of changes even when the value linked to remains the same

I'm facing an issue with a component that is supposed to react to changes in input controls by reformatting the input and removing certain characters. If the removed character corresponds to the previous value, the component fails to detect any change ...

Concealing HTML content with a modal overlay

There are security concerns with my authentication overlay modal, especially for users familiar with CSS and HTML. Is there a way to hide the HTML behind the modal so it doesn't appear in the page source? The code below is just an example of a modal ...

NodeJS backend server used for managing AngularJS server session and authentication

My setup involves a front-end AngularJS server communicating with a back-end NodeJS server, which retrieves data from a MySQL database using middleware. I've developed a basic login form on the front-end that needs to send user authentication data to ...