Angular2 filter parameter that necessitates specifying type

Struggling to filter an array before feeding data into my Angular component. The array contains hints, but I only want to display one hint initially.

The issue arises when trying to filter the array by a hint that matches the ID of 1. I keep receiving an error stating "'hint' implicitly has an 'any' type." in the CLI, even though it's just a counter.

I have disabled string injection parameters in my tsconfig.json and tried various methods to disable strict TypeScript injection rules, but Angular keeps asking for a type for the counter, preventing me from using the filter function.

import { Component, Input, OnInit } from '@angular/core';
import { SpecsService } from 'src/app/specs.service';
import {Hint} from './hint';

@Component({
  selector: 'app-hintbox',
  templateUrl: './hintbox.component.html',
  styleUrls: ['./hintbox.component.css']
})

export class HintboxComponent implements OnInit {
 currentHint: Hint[]=[]
 hint: Hint={hint:'',id:0}
 
  constructor(private specsService: SpecsService) { }
  ngOnInit(): void {

    this.specsService.getHints().subscribe((response)=> this.currentHint= response.filter(hint:Hint => hint.id===1));   
  }

}

Below is an image of my response object: https://i.sstatic.net/lrL6f.png

Any advice on a more reasonable way to filter the data later would be greatly appreciated. Here is my specs service function, which points to my dummy JSON server:

export class SpecsService {
  private apiUrl = 'http://localhost:3000'
  constructor(private http:HttpClient) {}


  getHints(): Observable<any>{
    return this.http.get(`${this.apiUrl}/Hints`)
  }
}

Answer №1

When your getHints() function returns an Observable with a type of Object, it may lead to assigning an unknown type. To address this issue, you can modify the function as shown below:


  getHints() {
    return this.http.get<any>(`${this.apiUrl}/Hints`)
  }

Although this change will resolve the error, it might not be the most effective solution.

A better approach would be to understand the expected object structure and specify the response type accordingly.

If your code suggests that you are expecting an array of items, you can define an interface like so:


interface IHintResponse {
  id: number;
  // Add other properties here
}

  getHints() {
    return this.http.get<IHintResponse[]>(`${this.apiUrl}/Hints`)
  }

Answer №2

I find it a bit perplexing to grasp the concept of your code structure. Personally, I steer clear of using JSON.stringify() in my own code base – Angular's HTTPClientModule is designed to handle JSON conversion automatically.

However, in a more general sense, you could define a class for the entity:

export class Model {
   id: number,
   name: string
}

To ensure type safety in your conversion process:

this.dataService.fetchModels().subscribe((response) => this.selectedModel = response.filter(model: Model => model.id === 1));

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