Meta Description:
Learn how to resolve the “ERROR undefined, HttpErrorResponse {headers: HttpHeaders, status: 404, statusText: “Not Found”}” issue in Angular and fix the undefined error by following a simple solution. Troubleshoot API requests and handle the “Not Found” error effectively.
Introduction
Facing errors while working with Angular can be frustrating, especially when they prevent your application from functioning as expected. One such error is the “ERROR undefined, HttpErrorResponse {headers: HttpHeaders, status: 404, statusText: ‘Not Found’}” that occurs when making API requests. In this article, we will dive into the causes of this error and explore a solution to resolve it.
Understanding the Error
When encountering the “ERROR undefined, HttpErrorResponse {headers: HttpHeaders, status: 404, statusText: ‘Not Found’}” error, it signifies that the requested resource is not found on the server. This typically occurs when the API endpoint you are trying to access does not exist or there is a typo in the URL.
Identifying the Problem
Let’s take a closer look at the code snippet provided to understand the issue further. In the given code, we have a TypeScript class CandidatePage that handles the API request. The ionViewWillEnter method is responsible for retrieving data using the HttpClient module. However, an error occurs due to the undefined value of the mtr variable.
code
ionViewWillEnter(mtr: string) {
return this.httpClient.get(this.url + '/' + this.mtr)
.subscribe(
data => {
this.data = JSON.stringify(data);
console.log(this.data);
},
error => {
console.log(error);
});
}
Upon examination, it is evident that the mtr variable is not properly assigned a value. In the provided code, it is declared as mtr: '45';, which results in an undefined value for mtr. To resolve this, we need to assign a string value to mtr.
Solution: Assigning a Value to mtr
To fix the undefined error, we need to assign a valid value to the mtr variable. Let’s update the code snippet to assign the value ’45’ to mtr.
code
mtr: string = '45';
Now, when the ionViewWillEnter method is called, it will utilize the correct value of mtr to make the API request.
Conclusion
The “ERROR undefined, HttpErrorResponse {headers: HttpHeaders, status: 404, statusText: ‘Not Found’}” error in Angular can be resolved by ensuring that the variables used in API requests are properly assigned values. In our case, assigning the correct value to the mtr variable fixed the undefined error. By understanding the causes of common errors and applying appropriate solutions, you can enhance your Angular development skills and build more robust applications.
