{{elsif}} or {{elseif}} or {{#elseif}}

[ramezrafla]

I am suggesting we add an {{elsif}} or {{elseif}} or whatever variation to avoid this ugly piece of code:

{{#if condition1}}
{{else}}
  {{#if condition2}}
  {{else}}
     {{#if condition3}}
     {{/if}}
  {{/if}}
{{/if}}

Imagine this instead

{{#if condition1}}
{{elseif condition2}}
{{elseif condition3}}
{{/if}}

I also think this will go a long way in making people more likely to adopt Blaze as it cleans up the code quite a bit for complex apps.

[mitar]

Does handlebars have it?

[mitar]

The issue is that this might seem a simple addition but would require a lot of changes internally. Like, a lot.

[ramezrafla]

Handlebars does not seem to have it.
I was thinking .. a preprocessor would do the trick :)

[Edit] To clarify, a preprocessor could simply use regexp (or some sort of parser) to replace the new syntax with the old one internally before it is processed.
Also, this preprocessor can allow future improvements without touching the code. Given it only runs once per template, the overhead is negligible.

[mitar]

Hmmm. Maybe. So at the level or parser. Like a syntactic sugar. This could work. You could look into spacebars parser if you feel adventurous. :-)

[ramezrafla]

Got it :) -- will start digging into it. Is the parser part of this repo or somewhere else?

[mitar]

https://github.com/meteor/blaze/tree/master/packages/spacebars-compiler

[AdrienTorris]

totally agreed with this issue. Simple if/else if/else is just so usefull

[akanix42]

I've been wanting this every time I write an ugly if else if else chain, and today it caught my interest, so I've implemented a version using {{elseif}} (example taken from original post):

{{#if condition1}}
{{elseif condition2}}
{{elseif condition3}}
{{/if}}

As suggested, it is simply sugar syntax. The above example is transformed into the compiled spacebars version of this:

{{#if condition1}}
{{else}}
  {{#if condition2}}
  {{else}}
     {{#if condition3}}
     {{/if}}
  {{/if}}
{{/if}}

[ramezrafla]

Excellent @nathantreid,
Can you PR with your changes?

[akanix42]

@ramezrafla Check out the PR link above my previous post. 😄

[ramezrafla]

Oops - sorry - I'll blame it on small iPhone screen :) thanks a lot!

[x5engine]

When is this coming out? coming soon this summer 2017?

[akanix42]

@capensisma: Quoting Mitar (from my pull request):

Waiting for #20 and that we release first community Blaze version. I would like that one to be without extra features, just bugfixes. And then we can start adding features.

[ramezrafla]

Is there anything gating this? @mitar, want me to run some tests first?

[mitar]

See the pull request #50. I would like that this is implemented compatible with Handlebars which allows any block helper to be used. So you can do:

{{#tab title="Foo"}}

{{else tab title="Bar"}}

{{else tab title="Baz"}}

{{/tab}}

Feel free to make a pull request like that. With tests and documentation. That would be great!

[ramezrafla]

Thanks @mitar, we can certainly adopt this syntax, but we can also add the other syntax above too. The two can be exclusive. Blaze has evolved quite a bit from Handlebars syntax. I personally like having elseif's -- it's more natural and less convoluted and would add value to developers.

[mitar]

With 2fa3cab I implemented the Handlebars syntax for chaining block tags. After further consideration I did not implement {{elseif}} as well because it opens a small backwards incompatibility (somebody could have a template helper named elseif). Let's try the {{else if}} syntax and see how it will work. I started to like it, especially because you can use it with custom block tags.

[mitar]

Released as 2.3.0. You have to update templating package.

[namirsab]

@mitar and the rest, first of all, thanks a lot for keeping blaze alive.

I'm writing here even if it's closed just to point one thing.
It was difficult to me to know which packages i had to update. meteor test was not building the app (because of the if/else if thingy) even if it had the correct blaze version and it was because templating was not up to date.

Is it written anywhere which packages are needed to be updated?

Again, thanks a lot!

[mitar]

meteor update should update all? So all packages in this repository.

[namirsab]

but meteor update also updates the meteor tool and so on. What if i just want to update blaze?

[maxfi]

Released as 2.3.0. You have to update templating package.

Is this mentioned somewhere in the docs? I couldn't find anything. Thanks.

[mitar]

It is documented here: http://blazejs.org/guide/spacebars.html#Chaining-of-Block-Helpers

[maxfi]

Thanks @mitar. I expected there to be a mention here: http://blazejs.org/guide/spacebars.html#If-Unless

[mitar]

Feel free to make a pull request. :-)

[wei170]

My blaze version is on 2.3.2. But I still cannot use
{{#if foo}} {{else if boo}} {{else}} {{/if}}

[mitar]

Which version of spacebars-compiler package you have?

[wei170]

My spacebars-compiler is @1.1.2

[mitar]

Then please create a small reproduction (a repo showcasing ony this issue).

[wei170]

{{#if isUserProfile}}
        <h3>User Profile</h3>
{{else if isLawyerProfile}}
        <h3>Lawyer Profile</h3>
{{else}}
        <h3>Test</h3>
{{/if}}

Error:

Errors prevented startup:
While processing files with templating-compiler (for target web.browser): client/profile/Profile.html:8: Expected `}}`
...ofile</h3>     {{else if isLawyerProfile}...

[mitar]

This is not a reproduction. Please create a small Meteor app in a git repo and provide a link to it here. Because the only thing I can tell you based on your snippet above is: it works for me.

[wei170]

Oh, I figured out. It was caused by templating-compiler version. I was on @1.2.15. When I updated it to @1.3.2, it works.

[Roshdy]

Can you please add this fix to the documentation of blaze