Ways to manage an rxjs observable reaction that may potentially have no data?

Currently, I am working with Angular2 and Ionic2 using typescript and have a requirement to manage responses from the backend service.

  • The response may either be empty with http status 200
  • or it could be a json object containing an error message property that needs to be shown to the user.

This is how I'm sending my request:

this.http.put(***).subscribe((data) => {

The challenge I'm facing is that when the data parameter is provided, rxjs attempts to serialize it from JSON, causing an error if it's empty. On the other hand, if I don't provide the data parameter, I can handle the empty response but then how do I access the error message property if it exists?

I prefer not to make any changes on the backend side to ensure proper http error codes in case of an error. Is there a solution to deal with this situation?

angulartypescriptionic-frameworkrxjs

Answer №1

Have you attempted a similar approach as shown below?

const updateItem = (item: any): Observable<Response> => {
    return this._http
        .put("http://localhost/api/", JSON.stringify(item))
        .map(response => response ? response.json() : {});
}

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

Nativescript encountered an error due to an undefined variable called FIRAuth

I'm currently working on a project using Nativescript. While everything runs smoothly with Firebase on the local emulator, I encounter errors when testing the application on my iPhone. The specific error message is: CONSOLE LOG file:///app/vendor.js ...

iosiphonetypescriptfirebasenativescript

In React Typescript, the input type="checkbox" does not show any value in the value attribute

I'm facing an issue with displaying text next to a checkbox in React Typescript. When I try to use the value attribute, it doesn't seem to work as expected. Also, attempting to set innerHTML throws an error stating that input is a void element ta ...

htmlreactjstypescriptreact-typescript

Ionic 3: Struggling to Access Promise Value Outside Function

I've encountered an issue where I am unable to retrieve the value of a promise outside of my function. It keeps returning undefined. Here's what I have attempted so far: Home.ts class Home{ dd:any; constructor(public dbHelpr:DbHelperProvider ...

angulartypescriptionic-frameworkionic2ionic3

Error: Unable to load the parser '@typescript-eslint/parser' as specified in the configuration file '.eslintrc.json' for eslint-config-next/core-web-vitals

When starting a new Next.js application with the specific configuration below: ✔ What name do you want to give your project? … app ✔ Do you want to use TypeScript? … No / [Yes] ✔ Do you want to use ESLint? … No / [Yes] ✔ Do you want to use T ...

typescriptnext.jseslintprettiereslintrc

After installing the latest version of Node.js, the stability of the Ionic environment

After updating nodejs from v8.1 to v12, my ionic environment is experiencing instability. Any suggestions on what needs to be updated? [abc]$ ionic cordova emulate android When running ng run app:ionic-cordova-build --platform=android, an unhandled exce ...

node.jsangularcordovaionic-framework

Leveraging Observables in an Angular 2 component to broadcast data to multiple components

Is it possible to utilize Observables in components and which other components can subscribe to them? BugListComponent - The component is injected in the boot.ts file where all services are loaded (where bootstrap is located) import {Subject, BehaviorSub ...

asynchronousangularreactive-programmingobservable

Symfony seems to be dropping my session unexpectedly during certain requests

Currently dealing with angular 2, I am encountering issues with requesting symfony where certain requests cause the sessions to be lost. Strangely enough, some requests work perfectly fine while others do not. If anyone has any insight or advice on what co ...

phpangularjssymfonysessionangular

Setting the "status" of a queue: A step-by-step guide

I created a function to add a job to the queue with the following code: async addJob(someParameters: SomeParameters): Promise<void> { await this.saveToDb(someParameters); try { await this.jobQueue.add('job', ...

javascripttypescriptqueuetask-queuebull-queue

Retrieve information from two observables without the need for separate subscriptions

After my first observable emits user data from Firebase, I need to make a second call to retrieve additional user information from a different collection. While I can handle these operations separately, the second call should only be triggered once the fir ...

javascriptangularrxjsobservable

The specified property is not present on the given type

I am receiving data from an API, and I have defined its structure like this interface DailyData { dt: number; sunrise: number; sunset: number; moonrise: number; moonset: number; moon_phase: number; temp: {day: number, eve: number, max: number ...

jsontypescript

Connect store variables to components using Angular's ngrx

I am attempting to link the location variable in my component to another variable in the store using a selector with ngrx v13 in Angular. However, when I include the variable with the property in the HTML, I encounter an error: Error message: Property &ap ...

angularngrxngrx-storeangular-ngrx-dataangular13

How to access the audio element in Angular using ViewChild: Can it be treated as an

My goal is to include an audio element inside a component. Initially, I approached this by using traditional methods: $player: HTMLAudioElement; ... ngOnInit() { this.$player = document.getElementById('stream') } However, I wanted to follow T ...

angulartypescriptviewchild

Utilizing nested observables for advanced data handling

Consider the following method: public login(data:any): Observable<any> { this.http.get('https://api.myapp.com/csrf-cookie').subscribe(() => { return this.http.post('https://api.myapp.com/login', data); }); } I want to ...

javascriptangulartypescriptrxjsobservable

What are some effective methods for troubleshooting Vue.js computed properties and templates?

I am facing challenges with debugging in Vue.js, especially when it comes to debugging computed properties or data values in templates. Currently, I am using the IIFE method for debugging as shown in : <h2 dir="auto"> {{(function(){debugger;let ...

typescriptvue.jstemplatesdebuggingcomputed-properties

Ways to verify function arguments within an asynchronous function using Jest

I have a function that needs to be tested export const executeCommand = async ( command: string ): Promise<{ output: string; error: string }> => { let output = ""; let error = ""; const options: exec.ExecOptions = { ...

typescriptunit-testingjestjs

Creating a declaration file for a library's entry point involves outlining the structure and types

I have developed an npm library that is made up of several ES6 modules, which are then consolidated into a single js file. The directory structure looks like this: src main.ts one.ts two.ts three.ts types index.d.ts index.ts The index.ts fil ...

typescriptnpm

angular contains vulnerabilities of a moderate severity level

I am encountering an issue while trying to set up the json server for a web application I am developing using Angular. Can someone provide assistance in resolving this problem? The following dependencies are at risk due to vulnerable versions: node_m ...

node.jsangularnpmwebpack

Learn how to utilize the "is" status in Postma within your code, even when this particular status is not included in the response

Service.ts Upon invoking this function, I receive a JSON response similar to the following: public signupuser(user: Users): Observable<boolean> { let headers = new Headers(); headers.append('Content-Type', 'application/json&a ...

typescripthttpsnativescriptresponsestatus

Executing a function within the same file is referred to as intra-file testing

I have two functions where one calls the other and the other returns a value, but I am struggling to get the test to work effectively. When using expect(x).toHaveBeenCalledWith(someParams);, it requires a spy to be used. However, I am unsure of how to spy ...

javascriptangulartypescripttestingkarma-runner

Authenticating users with Facebook using Ionic, Angular, Capacitor, and Firebase, as well as implementing role-based authentication

I successfully implemented Facebook authentication in my Android app using Ionic, Angular, Capacitor, and Firebase. The authentication is fully functional. What I attempted: Implementing role-based authentication. My solution: Storing the user's Face ...

angularfirebaseionic-frameworkcapacitorrole-based-access-control