How can i multiply data in nunjuncks?

Question

for instance

 <div class="price">{{blocks.quantity}} x {{blocks.price}} </div>

i want to multiply price by quantity

data from Json file.

Answer 1

var nunjucks  = require('nunjucks');
var env = nunjucks.configure();

env.addFilter('mysum', function (arr) {
    return arr
        .map(e => e.quantity * e.price) // get amount to each e
        .reduce((sum, e) => sum + e, 0) // calc total summa
});

var data = [
    {price: 10, quantity: 2},
    {price: 2, quantity: 7},
    {price: 5, quantity: 11}
]

var res = env.renderString(`{{ data | mysum }}`, {data});

console.log(res);