Conditional Attributes

[tschuehly]

Currently I cannot use a @if conditional around a html attribute

<div @if(comment.parentComment() != null)
            x-init="$dispatch('${comment.parentComment().toString()}')"
        @endif
>

I get the following exception:

CommentComponent.jte, error at line 9: Illegal HTML attribute name @if(comment.parentComment()! @if expressions in HTML attribute names are not allowed. In case you're trying to optimize the generated output, smart attributes will do just that: https://jte.gg/html-rendering/#smart-attributes

I really would like to do that as I don't necessarily want to put my alpine.js code into my java code and instead put it into my template.

[kelunik]

If the attribute value is null, it will be omitted, hope that helps.

[tschuehly]

If the attribute value is null, it will be omitted, hope that helps.

Yes I know that but I would need to put the if else in a ternary operator which is uglier imo.

@casid If you think this is ok/possible I could take a crack at changing the behaviour. Or is there a certain reason why the behaviour is as it is?

[casid]

@tschuehly this is because jte by default only allows writing into safe slots of a template. The parser expects to find an attribute name within this div. This needs to be done in order to decide how to escape the attribute content, which is a safe slot to write to. Having logical expressions in here would let the complexity of the parser explode, and also make it impossible to guarantee properly escaped templates.

[tschuehly]

@tschuehly this is because jte by default only allows writing into safe slots of a template. The parser expects to find an attribute name within this div. This needs to be done in order to decide how to escape the attribute content, which is a safe slot to write to. Having logical expressions in here would let the complexity of the parser explode, and also make it impossible to guarantee properly escaped templates.

Is there a way to extend the parser? So I could write a plugin where I could implement that behaviour?

[casid]

No there is not. The parser is already quite complex and I fear opening this rabbit hole would make everything a lot harder to maintain, while the benefit to it is rather low. The risk on the other hand quite high, to accidentially introduce unsafe behavior or break user code.

[leonard84]

How about using a special constant OMIT that would remove the attribute from the output if it is encountered? Similar to the poison pill pattern. Then you could write it like this.

<div x-init="comment.parentComment() == null ? OMIT : $dispatch('${comment.parentComment().toString()}')">

[kelunik]

This constant already exists: null