Checklist

• I have searched the issue tracker for open issues that relate to the same feature, before opening a new one.
• This issue only relates to a single feature. I will open new issues for any other features.

Is your feature request related to a problem?

Sometimes validation is more then just checking the string of an input. In my case, I have a lot of validation done after the user has already entered some data which can be from just entering data, loading the application or manual / periodic checks.

These validations are too heavy to be put in the Validator of an entry and so they are done in a different place. What I would like to achieve is to still make the entry look like it has a validation error.

Is it possible to construct a solution with the existing API?

Currently it is not possible to achieve this. Entry does have SetValidationError(), but that doesn't show the error if there is not a validator set and if the entry is not interacted with (aka dirty).

Describe the solution you'd like to see.

I have disussed the problem and possible solutions in the Discord, which resulted in the following:

An entry should have an optional flag (boolean) that can be set, something along the lines of ShowValidationErrorImmediately (I had AlwaysShowValidationError in mind because we always want to show validation errors if there are any)

Setting this flag will allow validation errors to be triggered without interaction. This comes down to two situations:

1. The entry has a validator: It will run the validator instantly without user interaction and reflect if it has any validation errors. If the entry does not have a validation error, it should show a checkmark because it passed the validator given.
2. The entry does not have a validator: It will reflect if a validation error has been set with SetValidationError(). If the entry does not have a validation error, it should not show a checkmark because it has no validator and thus behave like nothing happend.

I think these changes will benefit people who use more complex validators to still let the user know which inputs to change, while also providing benefits to people who add validators to their entries.