Kuba•16mo ago

kuba_huba – 17-21 Sep 2

I was building a form today and I stumbled upon weird behavior. When I swapped buttons that were conditionally rendered, the event was firing when submit button was rendered.

<div className="mb-4">
  <div className="flex gap-2">
    <Button
      className="w-2/3"
      variant="outline"
      onClick={handleNavigationBackward}
      disabled={pagination.isFirstPage}
    >
      <IoArrowBack className="mr-2" /> Poprzednie
    </Button>
    {!pagination.isLastPage ? (
      <Button
        className="w-2/3"
        type="button"
        variant="outline"
        key="navigation_button"
        onClick={handleNavigationForward}
      >
        Next
        <IoArrowForward className="ml-2" />
      </Button>
    ) : (
      <Button className="w-2/3" type="submit" key="submit_button">
        Submit <IoPaperPlane className="ml-2" />
      </Button>
    )}
  </div>
</div>

<div className="mb-4">
  <div className="flex gap-2">
    <Button
      className="w-2/3"
      variant="outline"
      onClick={handleNavigationBackward}
      disabled={pagination.isFirstPage}
    >
      <IoArrowBack className="mr-2" /> Poprzednie
    </Button>
    {!pagination.isLastPage ? (
      <Button
        className="w-2/3"
        type="button"
        variant="outline"
        key="navigation_button"
        onClick={handleNavigationForward}
      >
        Next
        <IoArrowForward className="ml-2" />
      </Button>
    ) : (
      <Button className="w-2/3" type="submit" key="submit_button">
        Submit <IoPaperPlane className="ml-2" />
      </Button>
    )}
  </div>
</div>

Can anyone help me understand why adding a key was a valid solution?

5 Replies

KubaOP•16mo ago

By weird behavior I mean that when the pagination.isLastPage changed and buttons also changed the submit event was fired instantly, despite button with type="submit" not being pressed.

KubaOP•16mo ago

This SO question (https://stackoverflow.com/a/74083342/7585847) helped me, but as explained:

This could also be the React virtual DOM not realizing it is a different button while the event is propagating through, and passing the reference that was to the "edit" button to the new "send" button and rendering it in place while the effect of the button click on edit button still propagating, therefore effectively, submitting when it hits the form.

Stack Overflow

Render a button[type="submit"] in a form trigger the onSubmit callback

With a edit boolean state, I conditionally render a button of type "submit" inside a form element. However as you can see when I set edit to true and render the button, the onSubmit callb...

KubaOP•16mo ago

I'm just missing why would the event on the button seem to "persist" after the element changes to a different one.

Unknown User•16mo ago

Message Not Public

reactibot•16mo ago

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