Check if key exists in array in nunjucks template (Node JS)

Question

I am creating an application in Node Js using Nunjucks template engine and I have to apply permissions on pages to show add, edit and delete links.

For this I have implemented an array of permissions like below :

var user_params = ['add_user', 'edit_user', 'delete_user'];

Now I want to check on pages that add_user exists in user_params array or not just like we do in php

in_array('add_user', user_params)

But I am being able to perform this task in nunjucks. So can anyone help me out ?

Thanks in advance

`user_params.indexOf('add_user')`. – Aikon Mogwai Apr 11 '17 at 10:45 — Aikon Mogwai, Apr 11 '17 at 10:45

score 11 · Answer 1 · answered Nov 11 '17 at 18:28

11

You should be able to do this:

{% if 'add_user' in user_params %}
   do stuff in html
{% endif %}

For indexOf, I'm not sure that works but even if it did, if zero evaluates to false that's not good either if you're testing the first row. would also need to check > -1

answered Nov 11 '17 at 18:28

WakeskaterX

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This does not work (at least not for v3.1.3), neither does indexOf... the only way is looping through the array – Sjeiti Jul 02 '18 at 13:03
Work like charm!! Great – Sadikhasan Jan 09 '19 at 12:03
`{% if (user_params or []).indexOf('add_user') > -1 %}` worked for me – Gerrie van Wyk Apr 28 '21 at 20:53

score 4 · Answer 2 · answered Jul 02 '18 at 13:09

4

The only way I found is looping through the array like so:

{% for param in user_params %}
    {% if param==='add_user' %}
        do stuff in html
    {% endif %}
{% endfor %}

Ugly and full of holes, but will fit most use cases.

You're probably better off making a custom filter

answered Jul 02 '18 at 13:09

Sjeiti

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This worked for me. Why do you say it's full of holes? – geochanto Dec 05 '18 at 21:53
1

Well one hole I can imagine is the target array including multiple of same instance. Which is not how indexOf or includes would work. – Sjeiti Dec 06 '18 at 07:04

Check if key exists in array in nunjucks template (Node JS)

2 Answers2