[UX][DX] Change the weight field in the taxonomy term form to a number field

[klonos]

This is currently a text field, so we also need a is_numeric() check in taxonomy_form_term_validate() to make sure there is no wrong input.

If this was a proper number field, then the user could use their keyboard up/down key to change, and there would also be no need for the check in the form validation function. Less code/complexity++ 😄

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PR by @klonos: backdrop/backdrop#2535

[klonos]

...we also have a '#type' => 'weight' field, but that field is by default limited to values ranging from -10 to 10 unless you specify a higher #delta. The #delta in the taxonomy listing pages, such as in /admin/structure/taxonomy/tags seems to be currently set to 30.

So question is do we want this field to be limited to a specific set of weights, or leave it as '#type' => 'number', which gives users more freedom?

[herbdool]

This looks okay to me. It seems to limit it to the number of terms. So with 4 terms it goes from minus to plus four.

[klonos]

It seems to limit it to the number of terms. So with 4 terms it goes from minus to plus four.

Sorry, what? I don't understand this, but it sounds like something that we should fix.

@jenlampton is of the opinion that we should change this to '#type' => 'weight', but as I said in #3593:

Sure. The only reason I may sound skeptical about using fields of type #weight is because they are limiting to a specific min/max value. Number fields are easy to use with the mouse scroll when focused (no additional clicks).

Having said that, I'm glad to switch the PR to #weight, but I need to know what to use for the #delta value for it?

What do you think @herbdool? ...others?

[herbdool]

@klonos seems like by design to me. It also works that way without this PR.

I don't know if I even tested this in the right place. It's not clear from the description.

[klonos]

OK, so changing weight fields to number fields, with min/max values instead of #delta (if that's required) seems like something we'll attempt in #3626.

Adding milestone tag for 1.12.6

[quicksketch]

The scope of backdrop/backdrop#2535 is limited and does exactly one thing (changing textfield to number) and doesn't get into the general weight field problems of #3626. I've merged the PR into 1.x and 1.12.x. Thanks @klonos and @herbdool!