django formset add error classes

The code snippet you provided is a JavaScript/jQuery code that performs some actions on HTML elements. Let me explain what each line does:

1. $('ul[class="errorlist"]').each(function(i, obj) { ... });

This line selects all <ul> elements with the class attribute set to "errorlist" and then iterates over each of them using the .each() method. The .each() method allows you to perform a function on each element in the matched set.

2. $(obj).addClass('invalid-feedback');

Within the .each() function, this line adds the CSS class "invalid-feedback" to each <ul class="errorlist"> element. This class is likely used to style the error message display.

3. $(obj).siblings("input").addClass('is-invalid');

In the same .each() function, this line finds the sibling <input> elements of each <ul class="errorlist"> and adds the CSS class "is-invalid" to them. This class is likely used to indicate an input field with invalid data.

The overall purpose of this code appears to be enhancing the error handling and validation of a form. It's assuming that each error message is wrapped in a <ul class="errorlist"> element, and the corresponding input fields are siblings of those error list elements. By adding the specified CSS classes, the code aims to update the appearance of the error messages and associated input fields to provide visual feedback to the user.

Please note that this code is a snippet and may be part of a larger script or codebase, so its effectiveness and correctness depend on the context in which it is used.

              
                $('ul[class="errorlist"]').each(function(i, obj) {
          $(obj).addClass('invalid-feedback');
          $(obj).siblings("input").addClass('is-invalid');
          //test
        });