Let's considerfalse as a way to disable the attribute? Andtrue would not generate the value part?

I guess that makes sense. I'd havefalse omit the attribute output altogether. Fortrue, I'd use something likename="name" for backwards compat with (X)HTML.

⚠️ "true" must be written "true" for some enumerated aria attributes.

Almost everywhere else, indeed,false should remove/hide the attribute.

"" should not happen, i guess, but should be dealt with attention, because the following have all the same meaning:

• disabled=""
• disabled
• disabled="false"
• disabled="disabled"

For the aria cases,if you want, there is some classic cases + docs here

https://github.com/symfony/ux/blob/647532ab688f79acfbcb1c895e88a8b2f1a502f6/src/Icons/src/Icon.php#L139-L162

with some test cases if you need toohttps://github.com/symfony/ux/blob/647532ab688f79acfbcb1c895e88a8b2f1a502f6/src/Icons/tests/Unit/IconTest.php#L226

(other similar in the TwigComponent / ComponentAttributes)

Except foraria-* attributes that support keyword and enumerated values. In some casesaria-* attributes supporttrue andfalse string values.

• https://hidde.blog/boolean-attributes-in-html-and-aria-whats-the-difference/
• https://html.spec.whatwg.org/multipage/common-microsyntaxes.html#keywords-and-enumerated-attributes
• https://www.w3.org/TR/wai-aria-1.1/#typemapping

Fortunately, Twig and PHP have separate types for strings and booleans. Passing the stringtrue orfalse will not trigger the special logic for boolean values.

@stof I guess what I was trying to say is that yes you could pass'true' or 'false' as parameters but this would require string coercion when setting the value.

The previous comment stated that:

Almost everywhere else, indeed, false should remove/hide the attribute.

I was pointing out thataria-* attributes do accept a string value of'false' and in those cases a coercion of boolfalse to string'false' might be warranted. This could also apply todata-* attributes.

IMO:

• null value always removes the attribute from the final string rendering.
• true andfalse values foraria-* attributes should coerce boolean to their string values'true' and'false'
• true andfalse values for all other attributes should act as boolean html attributes. ie true renders the attribute, false removes the attribute (as per@fabpotcomment).

We can maybe have a@param to better describe$arrays?

Maybe a@param for$args?

Not guaranteed that we have a number here.

Can we use[... ] when we can ? As it's slightly more performant than array_merge

@smnandre Like this?717f872

I'm not sure why this specific case for style.. i may have missed the reason earlier in the discussion ?

In casestyle is something like['color: red', 'font-weight: bold'].

I have two other questions then (sorry)

What if "aria" is something like['aria-disabled', 'aria-current'] ?

Does that mean i can do something like this ?

{{ html_attr(   {style: ['color: red;'] },   {style: {'color':'blue'} },   {style: {'color':'green'} },   {style: ['','color: black;'] },) }}

I'm shared between "i understand each of these usages" and "this could be very un-predictable when/if args are assembled from different layers / templates :|

Yes, definetly many edge cases I haven't thought through. Make sure you don't miss the inital idea in#3907, fwiw.

I think we should aim for behaviour similar toarray_merge andnot try to do any kind of parsing/interpretation. For example:

• html_attr_merge( { style: {'color': 'blue'} }, { style: {'color': 'green'} } } ) }} would be{ style: {'color': 'green'} }
• html_attr_merge( { style: ['color: blue'] }, { style: { ['color: green']} } } ) }} would be{ style: ['color: blue', 'color: green'] } – if you want "real" overrides, use semantic keys
• html_attr_merge( { aria: { 'aria-label': 'that' }, {'label': 'this'} } ) would be{ 'aria-label': 'this' } – I'd rewrite keys from thearia anddata sub-array to the "flat" values first and then merge those.

I hope I can come up with reasonable test cases for all those situations so we can discuss them before merge.

Should this be " Thehtml_attr_merge filter only…" . What if the exception is thrown when using thehtml_attr function.