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main.js:1 ERROR TypeError: Cannot read properties of undefined (reading 'filter')

  • 23 September 2023
  • 1 reply
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I have an angular project that is being built with the command:

 `npm run start`

which runs the script:

   

 "start": "set NODE_OPTIONS=--openssl-legacy-provider && ng serve --proxy-config proxy.conf.json --prod",

When the app is opened in "http://localhost:4200" it seems to load ok, but as soon as I change the user using the command:

   

 _setUser(window._user.sally_superAdmin);

The user info is returned but I get an error message in the console:

    

main.js:1 ERROR Malformed UTF-8 data
    rc @ main.js:1
    handleError @ main.js:1
    next @ main.js:1
    __tryOrUnsub @ main.js:1
    next @ main.js:1
    _next @ main.js:1
    next @ main.js:1
    next @ main.js:1
    emit @ main.js:1
    main.js:1 ERROR TypeError: Cannot read properties of undefined (reading 'filter')
        at a.project (main.js:1:4756133)
        at a._next (main.js:1:3551188)
        at a.next (main.js:1:3529941)
        at a._next (main.js:1:3551286)
        at a.next (main.js:1:3529941)
        at h._next (main.js:1:3557774)
        at h.next (main.js:1:3529941)
        at h._next (main.js:1:3530167)
        at h.next (main.js:1:3529941)
        at h._next (main.js:1:3560273)



I cannot figure out why I am getting the TypeError problem or even where to start looking. Has anyone any ideas?

I debugged the line in main.js (which is autogenerated via angular) and I get to this line of code. I just don't know where to look from here?


    

let i = (()=>{
            class f {
                constructor(g) {
                    this.http = g,
                    this.documents = [],
                    this.resource = "help"
                }
                query(g=!1) {
                    return this.http.get(`${this.resource}/query`).pipe((0,
                    o.q)(1), (0,
                    a.U)(v=>v.help), (0,
                    a.U)(v=>g ? v : v.filter(d=>"deleted" !== d.status)))
                }
                save(g) {
                    return this.http.post(`${this.resource}/save`, g).pipe((0,
                    a.U)(v=>v.help))
                }
                remove(g) {

 

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Best answer by Ankit Singh 25 September 2023, 08:07

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Userlevel 5
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@Darren 

The error messages you're seeing in the console indicate that there's an issue in your Angular application's JavaScript code. Let's break down the errors and try to figure out the cause.

  1. Malformed UTF-8 data error: This error typically occurs when there's an issue with encoding or decoding UTF-8 data. It might be related to how data is being received or sent, possibly from an API call.

  2. TypeError: Cannot read properties of undefined (reading 'filter'): This error suggests that you're trying to access the filter property of an object that is undefined. This often occurs when trying to perform an operation on an object that hasn't been properly initialized or retrieved.

Let's start by looking at the line in the generated main.js file where the error is occurring:
 

return this.http.get(`${this.resource}/query`).pipe((0,
o.q)(1), (0,
a.U)(v=>v.help), (0,
a.U)(v=>g ? v : v.filter(d=>"deleted" !== d.status)))


The error likely occurs in this section of the code. It's attempting to filter a response (v) from an HTTP GET request, but something is causing it to be undefined or malformed.
 

Here are some steps to further diagnose the issue:

  1. Check the HTTP response: Inspect the response from the http.get request to ensure it's in the expected format and contains the data you need.

  2. Check the value of v and g: Print the values of v and g before the filter operation to understand what's being passed to the filter function.

  3. Check the API or backend: Ensure that the API you're calling (${this.resource}/query) is working correctly and returning valid data.

  4. Verify the data structure: Make sure the data structure matches what your code is expecting. It's possible that the response doesn't have a filter method because the data structure is different than what the code expects.

  5. Check the _user.sally_superAdmin object: Ensure that window._user.sally_superAdmin is defined and contains the expected data structure.

  6. Check for any recent changes: If the code was working before, consider any recent changes that might have introduced this issue.

By systematically investigating these aspects, you should be able to pinpoint the root cause of the error and take appropriate steps to resolve it.

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