Include index in each block helper, aka each_with_index

[rbu]

It would be really nice to have access to the index of an each iteration.
There are ready-to-use block helpers out there, but having this upstream would be nice.

I can provide a pull request if that helps.

See also

https://gist.github.com/1048968
https://gist.github.com/1966803
http://stackoverflow.com/questions/5021495/in-mustache-how-to-get-the-index-of-the-current-section

[mpetrovich]

The index of the current array item has been available for some time now via @index:

{{#each array}}
    {{@index}}: {{this}}
{{/each}}

For object iteration, use @key instead:

{{#each object}}
    {{@key}}: {{this}}
{{/each}}

Here's a live example using the latest build:
http://jsfiddle.net/mpetrovich/gER9M/

[nathanlogan]

Any chance of also getting an option for a 1-based index, in addition to the 0-based? Perhaps something like this:
{{@index-base-1}}


[mpetrovich]

What's your use case?

[nathanlogan]

Good point, mpetrovich, I should have included that.

The use case is outputting a numbered array when <ol> isn't the best HTML choice. For example, I have a list of questions (contained in an array) that I want to output as a table of data (given that there are also questions associated to each one). So the output would be something like this (where the circles are radio buttons in the app):

Select the best answer to these questions

#	Question	True	False
1.	I like peanut butter.	O	O
2.	I like Captain Kirk more than Captain Picard.	O	O

Make sense?

[mpetrovich]

A generalized math helper might be an even better fit for your needs: http://jsfiddle.net/mpetrovich/wMmHS/

Then, you could just do:

{{#each questions}}
    {{math @index "+" 1}}
{{/each}}

[cfjedimaster]

I know this issue is closed, but would there ever be a case where you would output, to a 'regular' use, a list that started with 0? It may make sense as coders, but I can't imagine the general public wanting a list like that, and since this is for output, shouldn't it probably default to starting with 1?

[perlun]

How do you use this when you use the {{#each foo in bar}} syntax? Seems like I get 'Cannot call method 'replace' of undefined' when trying to use it with that syntax. With the {{#each bar}} syntax, it works like it should.

Any ideas?

[mpetrovich]

@perlun, could you paste the code in question?

[jokesterfr]

@mpetrovich adding a math helper is a bad good idea. The JSON model has to be modified in that case.

[mpetrovich]

@jokesterfr Yes, agreed. It'd be nice to just be able to do this:

{{@index + 1}}

[perlun]

@mpetrovich: Trying to do something like this. http://jsfiddle.net/plundberg/3c5Pv/

However, I'm not sure if the {{#each item in array}} is an EmberJS-extension or if this is supposed to work with Handlebars. (I'm using EmberJS in my "real" use case.)

[mpetrovich]

@perlun I don't quite follow—why doesn't the first (working) template suffice?

[perlun]

I prefer to use the {{#each item in array}} syntax, since it doesn't pollute the context. Makes it easier to access stuff from the parent scope. That's why I tend to use the latter syntax.

[travisdahl]

Just curious if there are any other know ways of accessing the key or index. the @ symbol causes parse errors in my current grails project. I was hoping I could use something like {{this.index}} but that doesn't work, and it makes sense why, index isnt a part of that object. Just curious if there was any other syntax.

[mpetrovich]

@Index is currently the only way to access the current array index.

-Mike

Sent from my iPhone

On Mar 29, 2013, at 5:32 PM, Travis Dahl notifications@github.com wrote:

Just curious if there are any other know ways of accessing the key or index. the @ symbol causes parse errors in my current grails project. I was hoping I could use something like {{this.index}} but that doesn't work, and it makes sense why, index isnt a part of that object. Just curious if there was any other syntax.

—
Reply to this email directly or view it on GitHub.

[mickaeltr]

Is there a way to get the "index" or "key" of an upper level?

{{#each foo}}
    {{#each bar}}
        <!-- How to get the foo index here? -->
    {{/each}}
{{/each}}

This does not work:

@../index
../@index

Thanks!

[mpetrovich]

@mickaeltr Unless we're using the wrong syntax, it looks like that's not possible yet: http://jsfiddle.net/Z9g2q/2/

Sounds like a great feature request :)

[mickaeltr]

@mpetrovich There we go: #491

[lifeinafolder]

For an Object like this:

  data: {
        one: "un",
        two: "deux",
        three: "trois"
    }

Could we use the each helper to print it out?

  {{#each data}}
    {{@key}} : this
  {{/each}}

Expected Output:

  one : un
  two : deux
 three : trois

Doesn't seem to be working for me with Handlebars rc3

[mpetrovich]

You need to wrap "this" in double curly braces as well:

{{@key}}: {{this}}

Other than that, the syntax looks correct.

On May 6, 2013, at 2:07 PM, Rajat Mittal notifications@github.com wrote:

For an Object like this:

data: {
one: "un",
two: "deux",
three: "trois"
}
Could we use the each helper to print it out?

{{#each data}}
{{@key}} : this
{{/each}}
Expected Output:

one : un
two : deux
three : trois
Doesn't seem to be working for me with Handlebars rc3

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[lifeinafolder]

@mpetrovich Failing JSFiddle: http://jsfiddle.net/gdXfN/29/

[lifeinafolder]

It would be nice to get an answer on the failing jsFiddle. Sorely missing this.

[mitar]

I like the variables Django provides. So not just zero-based index but also others.

[FoxGit]

Same problem as @lifeinafolder here. Any update available? :(

[bobjackman]

+1 for @lifeinafolder -- running into the same failure in 1.0.0

[machineghost]

I had to write a whole Handlebars helper:

register('plusOne', function(number) {
    return number + 1;
});

Just to be able to do:

{{plusOne @index}}

So that I could do:

Thing #{{plusOne @index}}

This seems like such a painfully obvious use case: please provide one-based indices! No one uses zero-based indices in the presentation layer; human beings like 1-based indices :)

[cfjedimaster]

Surprised this is still open. Would a pull request with this feature be ok? If so - I'll try taking a stab at adding it.

[cfjedimaster]

How is this a backwards compat issue, Mickael? This would be a new
variable.

On Sun, Jan 26, 2014 at 12:04 PM, Mickaël Tricot
notifications@github.comwrote:

-1, for backward compatibility reasons

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Reply to this email directly or view it on GitHubhttps://github.com//issues/250#issuecomment-33324928
.

Raymond Camden, Web Developer for Adobe

Email : raymondcamden@gmail.com
Blog : www.raymondcamden.com
Twitter: cfjedimaster

[mickaeltr]

Alright, then why not!
I would prefer having support for operators, that could do this, though:
{{@Index + 1}}

On 26/01/14 19:22, Raymond Camden wrote:

How is this a backwards compat issue, Mickael? This would be a new
variable.

[cfjedimaster]

So - it was - afaik - one line change:
base.js, line 123 is:

        data.index = i;

I then added

        data.indexPlusOne = i+1;

and it just plain worked. Maybe index1 would be nicer, but crap, it is time to end this thread. ;) Making a PR now.

[mitar]

I would suggest to have same naming as Django. Because index is currently 0-based, maybe then index1?

[tomasdev]

👍 for {{@Index + 1}}

[cfjedimaster]

I should point out - my PR was rejected. Afaik this is not going to happen. :\

[machineghost]

Well that's good, because every developer I know shows their users:

0. Item Unexpected string in simple template #1
1. Item Escaping quotes #2

etc.

[rbu]

For reference, @cfjedimaster's PR is #720.

[rebase-master]

The @key, @Index doesn't work me either in the #each block helper. Any idea why is this so?
I need to use the index in my code.

[rebase-master]

Upgraded to latest version of handlebars.js and it works!

[paynecodes]

@steady-daddy Which syntax works?

[rebase-master]

@jpdesigndev - @Index works inside #each block helper with handlebars v1.3.0

[paynecodes]

@steady-daddy Sorry. I hadn't paid close enough attention to the original issue. I was thinking you had gotten an @index + 1 to work without additional helpers. Seems this didn't ever happen, so I just used a simple helper.

[rebase-master]

@jpdesigndev - No issues mate!

[anshou]

Ended up at this issue due to needing this exact features: @Index + 1

I don't understand how this has not been added; using a source-1 counting scheme is preferred for user-facing content in all cases. People do not start counting at zero, computers do.

So, I solved this by installing the 'plusOne' @machineghost shared above.

So, thanks, @machineghost; at least you helped in this issue.

[machineghost]

Glad I could help. I started a new ticket to try and get the developer's attention back to this use case; hopefully it result in a legitimate (ie. not my hack) fix.

[ThomasGreiner]

Another way to achieve this is to use CSS counters which are supported by all major browsers.

[cssagogo]

Any way to set the start point for the index? The use case being setting a unique ID per row within view more paged UI? Below is a rough use case. Is there a way to set the index?

<div id="my-div{{math @index "+" 1}}">Item 1 - Page 1</div>
<div id="my-div{{math @index "+" 1}}">Item 2 - Page 1</div>
[ VIEW MORE BUTTON ]



<div id="my-div{{math @index "+" 1}}">Item 1 - Page 1</div>
<div id="my-div{{math @index "+" 1}}">Item 20 - Page 1</div>
<div id="my-div{{math @index "+" 1}}">Item 21 - Page 2</div>  <!-- How do I set to 21?
<div id="my-div{{math @index "+" 1}}">Item 40 - Page 2</div>
[ VIEW MORE BUTTON ]

[jokesterfr]

Common, why won't you modify the JSON object?
let's give an id and a label :

var obj = { pages: [
    { id: "my-div-1", label: "Item 1" },
    { id: "my-div-2", label: "Item 2" },
    { id: "my-div-3", label: "Item 3" }
]}

and use the following template:

{{#pages}}
<div id="{{id}}">{{label}}</div>
{{/pages}}

What the point with {{math @index + 1}} when you can construct your JSON object like you want? With plenty of JS features?

[aaronharding]

If it helps, this was my solution. I edited the execIteration function within the each helper.

handlebars-3.0.3, line 2375

...
data.index = index;
data.humanIndex = index + 1; // added
data.first = index === 0;
...

This could very easily be added in with a pull request.

[jblotus]

+1 for one based index

[kpdecker]

Locking this thread as we are set on the implementation here. Zero-based index will continue to be exposed from the native implementation. Those that need a 1-based index should write a simple helper to add this value. With subexpressions that helper can be used as arguments to other helpers too so this provides the option to have one-based anywhere without the overhead of tracking another field in the iteration logic that may or may not be used or breaking existing templates.

Handlebars.registerHelper('addOne', function(value) {
  return value + 1;
});

Like This: {{addOne @index}} or {{helper (addOne @index)}}