DisplayPromptAsync preselect initialValue in prompt for easy overwriting

[SvendK]

Description

With DisplayPromptAsync you can include an initialValue to be showed in the dialog shown.

I'd like a feature for this initialValue to be preselected so it is ready to be overwritten with a simple input, instead of the user needs to clear the field first.

Also requested on StackOverflow by another user.

Public API Changes

Not sure if I fill out this field correctly, but just add another optional parameter next to string initialValue named e.g. bool preselectInitialValue = false. In body, if new parameter is true, select all of the text in tne Entry. Also test scenariou where user enters input very quickly after rendering, as the .Text apparently can be null.

public Task<string> DisplayPromptAsync(
  string title, 
  string message, 
  string accept = "OK", 
  string cancel = "Cancel", 
  string placeholder = null, 
  int maxLength = -1, 
  Keyboard keyboard = null, 
  string initialValue = "", 
  bool preselectInitialValue = false) 
{
  (...)
  if (preselectInitialValue && !string.isNullOrEmpty(initialValue)) {
    x.SelectionLength = x.Text != null ? x.Text.Length : 0;
  }
  (...)
}

Intended Use-Case

Example:
User needs to enter number of copies to print. Most often this is 1, so that is set as initialValue. If user presses "2" to print two copies, it now says "12". If as requested, we could indicate the initialValue should be preselected (quite a normal UI functionality), then when user presses "2", it would overwrite "1" and instead the value entered would be "2".

[mattleibow]

Should the preselection now be the default? Isn't it always the fact that you want to replace whatever is in there?

[mattleibow]

One thing to consider is that sometimes we don't have direct access to whatever the prompt uses. Not sure on iOS or Android if you can access the text box, but maybe. We probably can also add an overload for these prompt/alert boxes that take like an AlertOptions or PromptOptions so not all things are parameters.

We've moved this issue to the Backlog milestone. This means that it is not going to be worked on for the coming release. We will reassess the backlog following the current release and consider this item at that time. To learn more about our issue management process and to have better expectation regarding different types of issues you can read our Triage Process.

[tiwahu]

This would be REALLY nice to have! Without it, I'd need to implement custom prompt dialogs to get the desired behavior. I was able to overcome adding keyboard accelerators to my .NET 7 MAUI app, but this usability one is tough. As @mattleibow mentions, preselection by default makes the most sense to me. There might be some rare cases of wanting partial selection or no selection, but that seems more suited to a custom control.

[SvendK]

Sorry for the late reply, @mattleibow . For my use case, and yes, probably most, a new default of always preselecting what is in the prompt, might be preferred, but my API changes proposal has no breaking changes for existing solutions, which often is preferred. But your call, as long as I can preselect the text if I want to :-)

Please reconsider this asap, as it is probably a very small change to make - especially my proposal.

Thanks :-)

[tiwahu]

We could look at browser implementations of window.prompt(message [, default]) as another justification for preselecting the text by default (or at least providing some way to do it, as @SvendK suggests):

window.prompt('test', 'is this preselected?');

I suspect many others would expect the DisplayPromptAsync in MAUI to behave similarly.