Handlebars syntax for the (get) helper

[mmun]

What do you think about introducing a "dynamic access" syntax for Handlebars to streamline or even replace the need for the get helper?

{{planets[name]}}

would be equivalent to {{get planets name}}, and

{{planets[name].closestPlanet[field]}}

would be equivalent to

{{get (get (get planets name) 'closestPlanet') field}}

The second example clearly demonstrates that using the dynamic access syntax makes it easier to understand what is being accessed.

[mmun]

This situation gets a bit more complicated if we include some allowances for subexpressions:

{{!-- How would these be represented with the dynamic access syntax? --}}

{{get (planets-near-star star) name}}
{{get planets (favourite-planet-name user)}}

I'd suggest

{{(planets-near-star star)[name]}}
{{planets[(favourite-planet-name user)]}}

[nightire]

Is this form allowed/reasonable?

{{planets[name[closestPlanet[field]]]}}

[mmun]

@nightire Yeah. I'd expect the grammar to be something as simple and generic as

GetExpression = Expression "[" Expression "]"

[buschtoens]

I think we can PoC or actually properly implement this as a template transform addon to avoid changing handlebars itself.

[mmun]

@buschtoens Unfortunately, {{planets[name]}} will fail to parse. For a PoC, you might be able to hijack the largely unknown and unused escaping syntax, {{planets.[name]}}, but it will be a be a little messy.

[Panman82]

How far of a difference between http://handlebarsjs.com/ and Ember's flavor are we at this point? In that, is this something that should be requested to be added to the official Handlebars.js project, or is Ember beyond that point? Also, adoption of editor syntax highlighters would probably be better if added to the official Handlebars.js project.

[rwjblue]

@Panman8201 - AFAICT @mmun is suggesting adding this to the main handlebars parser (which we would then update to in glimmer-vm)...

[rwjblue]

@mmun - I'm sold! 😸

[Panman82]

@rwjblue Guess I was questioning it because this place is for Ember RFC's. Does Handlebars.js have their own RFC process this should go through?

[btecu]

This introduces a very different syntax than what we currently have, as we don't have anything with [] in the template.

Since it's solving more of an edge case, I don't think it should be added as it would add to the list of things needed learn to use ember.

[buschtoens]

@btecu

Since it's solving more of an edge case, I don't think it should be added as it would add to the list of things needed learn to use ember.

If we did not add this syntax, users would still have to learn about the {{get something key}} helper.

I would argue that most Ember new-comers never worked with Handlebars before. And I can tell from my own and co-worker's experience, that most seem to intuitively expect the {{something[key]}} syntax to work.

So actually, I think this decreases the learning curve. 😊

[btecu]

@buschtoens yes, but the users are learning about helpers anyway, so that example of yours ({{get something key}}) will make complete sense as opposed to something that has [] in it.

[buschtoens]

@btecu Would {{someObj[someKey]}} not make sense to you? 🤔
This is exactly the same syntax as in JavaScript.

So far, {{get}} won't be deprecated. This is still pretty far ahead and might never be done at all. So you can still use {{get}}, if you prefer it. 😊

[btecu]

@buschtoens I get it, since I already read this RFC.

This is exactly the same syntax as in JavaScript.

Exactly my point, this is not React to have JS in the template. 😃

I'm not worried about {{get}} since I'm not sure I ever had to use it, it was more about introducing different syntax.

[robclancy]

I will give a kidney for this feature. no bamboozle