Correct explanation of why readonly only affects text controls

[aaronadamsCA]

MDN URL

https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/readonly

What specific section or headline is this issue about?

Overview

What information was incorrect, unhelpful, or incomplete?

Note: Only text controls can be made read-only, since for other controls (such as checkboxes and buttons) there is no useful distinction between being read-only and being disabled, so the readonly attribute does not apply.

What did you expect to see?

Something more like this:

It's important to understand that READONLY merely prevents the user from changing the value of the field, not from interacting with the field. For many types of fields, READONLY is irrelevent because you don't normally change the value. In checkboxes, for example, you can check them on or off (thus setting the CHECKED state) but you don't change the value of the field. DISABLED, however, actually prevents you from using the field.

Source: http://www.faqs.org/docs/htmltut/forms/_INPUT_DISABLED.html

Do you have any supporting links, references, or citations?

No response

Do you have anything more you want to share?

No response

MDN metadata

Page report details

• Folder: en-us/web/html/attributes/readonly
• MDN URL: https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/readonly
• GitHub URL: https://github.com/mdn/content/blob/main/files/en-us/web/html/attributes/readonly/index.md
• Last commit: 942a529
• Document last modified: 2023-04-13T06:13:15.000Z

[Josh-Cena]

This note is directly copied from the HTML standard, so I'll take it as more technically accurate than a website from the 2000s. Is there anything fundamentally incompatible between their content?

[aaronadamsCA]

I think the readonly spec might be wrong, actually? It says "when specified, the element is not mutable." It defines mutability as "whether or not the user can modify the value or checkedness of a form control." But readonly does not affect the user's ability to modify checkedness.

I think it would be more correct if both the HTML spec and the MDN doc clearly stated that readonly controls whether or not the user can change the value of a text control.

And then I think a more helpful clarification in the MDN doc would be that the readonly attribute is only useful on text controls because it only prevents the user from modifying value, not checkedness; and that as a result, a user can still effectively change the submitted value of a readonly radio button or checkbox control by changing its checkedness.

I hope that makes sense.

[Josh-Cena]

Could you also send an issue to the HTML spec and see what they think? I'm okay to include more information but I don't want MDN and HTML to be different.

[aaronadamsCA]

Good idea, I just filed whatwg/html#9496 to see what they say. Thanks!