How can I pass JSON data into a Nunjucks template?

Question

I want to use Nunjucks templates but want to pass in my own JSON data to be used on the templates.

The documentation here is pretty sparse.

https://mozilla.github.io/nunjucks/templating.html

Thank you.

Answer 1

You can use gulp-data which allows you to pass json files to the task runner you're using to render Nunjucks.

gulp.task('nunjucks', function() {
  return gulp.src('app/pages/**/*.+(html|nunjucks)')
    // Adding data to Nunjucks
    .pipe(data(function() {
      return require('./app/data.json')
    }))
    .pipe(nunjucksRender({
      path: ['app/templates']
    }))
    .pipe(gulp.dest('app'))
});

Answer 2

Simply use dump and safe filters combined:

<script>
  const choices = {{ yourJsonVar | dump | safe }};
</script>

Answer 3

Found this gem here in 2019, but thought it'll be helpful for people like me, who have searched but didn't find anything.

First, create a template part with expected arguments in a macro

{% macro render(secTitle, secSubtitle) %}
    <h4 class="heading">
        {{ secTitle | safe }}, {{ secSubtitle | safe }}
    </h4>
{% endmacro %}

Save it as [yourname].tpl - in this case heading.tpl

Then, import this block and use a function specified in macro above (render() in this case)

{% block heading %}
    {% import "components/heading.tpl" as heading with context %}
    {{ heading.render(
        secTitle='Hello there',
        secSubtitle='General Kenobi'
    ) }}
{% endblock %}

This will result in:

<h4 class="heading">
    Hello there, General Kenobi
</h4>

Please notice | safe after strings in a component - this means it'll output the string with HTML formatting (eg. <br> will create a new line instead of outputting <br> in text).

Answer 4

You can use their async render to achieve that.

https://mozilla.github.io/nunjucks/api.html#render

$.getJSON('/path/to/file.json', function (result) {
        nunjucks.render('path/to/template/file.html', { result : result }, function (err, res) {
            // do something
        });
    });