nunjucks-set-async

Like set, but for async functions.

Usage

You can use this extension in the following 4 easy steps:

• Create a new nunjucks Environment. let env = new nunjucks.Environment();
• Add the nunjucks-set-async to the environment. env.addExtension('SetAsyncExtension', new SetAsyncExtension())
• In your template, call the extension as follow: {% setAsync 'variable', functionName, [functionArguments] %} variable is the name of the variable that will hold the results of functionName with [functionArguments]. If the function functionName does not take any arguments, you need to still pass an empty array {% setAsync 'variable', functionName, [] %}.
• Use {{ variable }} to render the value of variable anywhere after the setAsync block.

Example

In this example we are simulating getting the number of astronauts currently in space with an asynchronous function:

• index.js

let getNumberOfAstronauts =  function(cb) {
  setTimeout(function() {
    cb(null, 12);
  }, 10);
}
env.addGlobal('getNumberOfAstronauts', getNumberOfAstronauts);
env.addExtension('SetAsyncExtension', new SetAsyncExtension())

• template.html

{% setAsync 'numberofAstronauts', getNumberOfAstronauts, [] %}
<p> There are {{numberofAstronauts}} in space right now! </p>

Or you can also use setAsync with parens as follow:

{% setAsync('numberofAstronauts', getNumberOfAstronauts, []) %}
<p> There are {{numberofAstronauts}} in space right now! </p>

• index.js

env.render('template.html', function(err, res) {
  console.log(res);
});