Treat [data-turbo-stream] as boolean attribute

[seanpdoyle]

Replace equality checks for [data-turbo-stream="true"] with presence
checks for [data-turbo-stream] to more closely match the canonical
behavior for boolean HTML attributes.

Turbo already supports other boolean attributes like
[data-turbo-permanent] and [data-turbo-confirm], so
[data-turbo-stream] should match the precedent.

[seanpdoyle]

@kevinmcconnell this is a follow-up to #612.

If this ships, could you update hotwired/turbo-site#103 to reflect the boolean nature of the attribute?

[dhh]

Looks good to me. Can you rebase?

[evgenyneu]

I want "data-turbo-stream" attribute in my form with POST to be "false", so it does not request turbo stream response, but still uses turbo (without page reload). Is it possible?

[marcoroth]

I want "data-turbo-stream" attribute in my form with POST to be "false"

In that case you can just omit the data-turbo-stream attribute on your form.

[kevinmcconnell]

@evgenyneu I don't think that's possible right now, unfortunately. We don't have a way to opt out of stream responses for POST forms, as that's the default behaviour.

Could you handle this on the server side instead, by not serving a turbo stream response for that case?

[evgenyneu]

@kevinmcconnell, do we want ability to opt out of turbo streams for POST forms? If yes I can create a PR, so we can use data-turbo-stream="false" for forms. But this will basically revert changes in this PR? I'm confused.

Could you handle this on the server side instead, by not serving a turbo stream response for that case?

Thanks, good idea, I can add a "no-turbo-stream" parameter to my form, and on server side render a standard html.erb view (instead turbo_stream.erb`) if it's present.

[kevinmcconnell]

do we want ability to opt out of turbo streams for POST forms? If yes I can create a PR, so we can use data-turbo-stream="false" for forms.

It sounds like a good idea to me. I've not personally run into a situation where I needed this, but I could see how it could be useful.

But this will basically revert changes in this PR?

It will, but there's a little more to it, too. The default behaviour is to accept stream responses for POST but not GET. And we have a way to opt-in to use them for all methods. If you also add a way to opt-out for all methods, there are now 3 settings. I think the clearest way that's also backwards compatible would be to turn data-turbo-stream into an enumerated attribute, with 3 values:

• auto - only accept stream responses for POST (the default, if not specified)
• true - accept stream responses regardless of method (also the "missing value default", so you can set true just by adding data-turbo-stream without a value)
• false - don't accept stream responses

What do you think? Or did you have another way in mind?

If you want to make a PR to solve it, I'd be happy to review when it's ready.

[evgenyneu]

@kevinmcconnell sounds like a good plan, I'll make a PR. What's the purpose of the auto value, if it's the same as the default (missing data-turbo-stream attribute)?

[kevinmcconnell]

I don't think you'd actually need to set auto in practice, I mostly just wanted to list the 3 states there for clarity :) That said, it might be clearer in the code to actually track these 3 states by name, and allow any of its values to specified explicitly for consistency. But it's up to you if you feel that helps or not in the PR.

[MatheusRich]

@evgenyneu any updates on that PR? I'm interested in the same feature and wondering if I should work on that.

[evgenyneu]

@MatheusRich no sorry I gradually became disinterested in it for some reason :D