How to do IF/ELSE conditions inside LOOP in golang templates?

Question

I tried to do this test to figure out how to make conditions like this:

<h1>Country Index</h1> <style> .odd{ background: orange; color: black; font-size: 1.5em; } .even{ background: rgb(0, 121, 235); color: white; font-size: 1.5em; } </style> <ul> {{ range $index, $item := .Tee }} {{ if $index % 2 == 0 }} <li class="even">{{ $index }} - {{ $item }}</li> {{ else }} <li class="odd">{{ $index }} - {{ $item }}</li> {{ end }} {{ end }} </ul>

I got this error "unexpected "%" in operand".

Any suggestions to solve this?

I don't think you can perform arithmetic in templates, you'd have to write a user function. Or you could get rid of all the template logic and just do it in CSS. — Adrian
– Adrian, Commented Jun 26, 2018 at 17:57
I guess you can try opening an issue on the GitHub page. This one looks like your case, but complaining for the = operand. github.com/golang/go/issues/10608 — vahdet
– vahdet, Commented Jun 26, 2018 at 18:04
It doesn't matter how helpful you might find a recommendation. Questions asking us to recommend or find a book, tool, software library, tutorial or other off-site resource are off-topic for Stack Overflow as they tend to attract opinionated answers and spam. — Adrian
– Adrian, Commented Jun 26, 2018 at 18:06

Slotheroo · Accepted Answer · 2018-06-27 02:32:58Z

You can't use operators like +, -, *, /, or % in templates, unfortunately. Instead you have to write custom functions and use a funcMap to bring them into your template.

Here's an example on the Go Playground that detects even integers applied to a slightly modified version of your template text.

https://play.golang.org/p/LWEhE_TI31o

arturwwl · Accepted Answer · 2022-01-06 14:33:51Z

You can create bool helper variable and change its state every iteration.

{{$odd := true}} {{range $data := .Tee}} {{if $odd}} <p>action for odd.</p> {{else}} <p>action for not odd.</p> {{end}} {{$odd = not $odd}} {{end}}

Collectives™ on Stack Overflow

How to do IF/ELSE conditions inside LOOP in golang templates?

2 Answers 2

Comments

Comments

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Related