The error message "Identifier 'title' is not defined. '{}' does not contain such a member angular 8" indicates that the title variable is not recognized or defined in the

Here is the code snippet of my component:

import { Router, ActivatedRoute } from '@angular/router';
import { Component, OnInit } from '@angular/core';
import { CategoriesService } from 'src/app/categories.service';
import { ProductService } from 'src/app/product.service';
import 'rxjs/add/operator/take';

@Component({
  selector: 'app-product-forms',
  templateUrl: './product-forms.component.html',
  styleUrls: ['./product-forms.component.css']
})
export class ProductFormsComponent implements OnInit {

categories$;
product: {};

  constructor(categoryservice: CategoriesService , private productservice: ProductService , private router: Router,
              private route: ActivatedRoute) {
    this.categories$ = categoryservice.getcategories();

    let id = this.route.snapshot.paramMap.get('id');
    if (id) { this.productservice.get(id).take(1).subscribe(p => this.product = p); }
   }

   save(product) {
     this.productservice.create(product);
     this.router.navigate(['/admin/products']);
   }

  ngOnInit() {
  }

}

This is the HTML template file:

 <!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <title >Title</title>
</head>

</html>

<div class="row">
  <div class="col-md-6">

    <form #f="ngForm" (ngSubmit)="save(f.value)">

      <div class="form-group">
        <label for="title">Title</label>
        <input #title="ngModel" [(ngModel)]="product.title" name="title" id="title" type="text" class="form-control" required>
        ***<!-- ERROR  : Identifier 'title' is not defined. '{}' does not contain such a member -->***
        <div class="alert alert-danger" *ngIf="title.touched && title.invalid">
          Title is required
        </div>
      </div>

      <div class="form-group">
        <label for="price">Price</label>
        <div class="input-group-prepend">
          <span class="input-group-text">$</span>
        <input #price="ngModel" [(ngModel)]="product.price" name="price" id="price" type="number" class="form-control" required [min]="0">
      <!--ERROR  :  Identifier 'price' is not defined. '{}' does not contain such a member -->
      </div>
        <div class="alert alert-danger" *ngIf="price.touched && price.invalid">
          <div *ngIf="price.errors.required">Price is required</div>
          <div *ngIf="price.errors.min">Price must be 0 or higher than zero</div>
        </div>
      </div>

      <div class="form-group">
        <label for="category">Cateogary</label>
        <select #category="ngModel" [(ngModel)]="product.category" name="category" id="category"  class="form-control" required>
<!--ERROR  :  Identifier 'category' is not defined. '{}' does not contain such a member -->
          <option value=""></option>
          <option *ngFor="let c of categories$ | async" [value]="c.$key">

            {{ c.name }}

          </option>
        </select>
        <div class="alert alert-danger" *ngIf="category.touched && category.invalid">
          Category is required
      </div>
      </div>

      <div class="form-group">
        <label for="imageurl">Image Url</label>
        <input #imageUrl="ngModel" [(ngModel)]="product.imageurl" name="imageUrl" id="imageurl" type="text" class="form-control" required url>
        <!--ERROR  :  Identifier 'imageurl' is not defined. '{}' does not contain such a member -->
        <div class="alert alert-danger" *ngIf="imageUrl.touched && imageUrl.invalid">
          <div *ngIf="imageUrl.errors.required">ImageUrl is required</div>
          <div *ngIf="imageUrl.errors.url">ImageUrl is required</div>

      </div>
      </div>

      <button class="btn btn-primary">Save</button>

      </form>
  </div>

  <div class="col-md-6">
    <div class="card" style="width: 18rem;">
      <img [src]="product.imageUrl" class="card-img-top" alt="..." *ngIf="product.imageUrl">
      <div class="card-body">
        <h5 class="card-title"> {{product.title}} </h5>
         <!-- ERROR  : Identifier 'title' is not defined. '{}' does not contain such a member -->
        <p class="card-text"> {{product.price | currency:'USD':true}} </p>

      </div>
    </div>
  </div>
</div>
  • Whenever I deploy my project, these following errors occur:

    • Identifier 'imageurl' is not defined. '{}' does not contain such a member
    • Identifier 'title' is not defined. '{}' does not contain such a member
    • Identifier 'category' is not defined. '{}' does not contain such a member
    • Identifier 'price' is not defined.'{}' does not contain such a member
    • Identifier 'title' is not defined. '{}' does not contain such a member

Answer №1

If you want to structure your code better, consider creating a class or interface that contains all the necessary fields for a product, such as `imageurl`, and then importing this into your component file. Instead of declaring `product: {}`, define it as `product: Product;` where `Product` is the new type you created.

For example, create a new file named `product.ts`:

export class Product
{
    imageUrl: string;
    title: string;
    // Add more fields here if needed
}

In the existing `component.ts` file:

import { Router, ActivatedRoute } from '@angular/router';
import { Component, OnInit } from '@angular/core';
import { CategoriesService } from 'src/app/categories.service';
import { ProductService } from 'src/app/product.service';
import { Product } from 'src/app/product';
import 'rxjs/add/operator/take';

@Component({
  selector: 'app-product-forms',
  templateUrl: './product-forms.component.html',
  styleUrls: ['./product-forms.component.css']
})
export class ProductFormsComponent implements OnInit {

categories$;
product: Product;

  constructor(categoryservice: CategoriesService , private productservice: ProductService , private router: Router,
              private route: ActivatedRoute) {
    this.categories$ = categoryservice.getcategories();

    let id = this.route.snapshot.paramMap.get('id');
    if (id) { this.productservice.get(id).take(1).subscribe(p => this.product = p); }
   }

   save(product) {
     this.productservice.create(product);
     this.router.navigate(['/admin/products']);
   }

  ngOnInit() {
  }

}

When making the HTTP call to fetch product data, remember to import and specify the `Product` type:

get(): Observable<Product> {
  return this.http.get<Product>(exampleUrl);
} 

Answer №2

In your code, you have defined a variable called product with no properties assigned to it: product: {};. This error indicates that product has not been given any specific attributes such as title, price, etc. You need to add these properties in order for the code to function correctly.

product: {
   title: string;
   price: number;
   //etc.
};

Answer №3

To begin, it is necessary to design an object known as Product interface

export interface Product {
   name: string,
}

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