Regex for mustache-style double braces?

Question

I\'m using Mustache-style tags inside of AngularJS. What\'s the best regex to use to return an array of just the text inside the mustache braces?

Sample dat

Answer 1

Mod of Douglas Crockford's String.prototype.supplant

This will interpolate any {param} you have between handleBars ({}). I know this answer is somewhat extensive, but I assumed the question was probably regarding interpolation -- either way, I'd advise the reader to study the regex, regardless.

clear();

function interpolate(str) {
    return function interpolate(o) {
        return str.replace(/{([^{}]*)}/g, function (a, b) {
            var r = o[b];
            return typeof r === 'string' || typeof r === 'number' ? r : a;
        });
    }
}

var terped = interpolate('The {speed} {color} fox jumped over the lazy {mammal}')({
    speed: 'quick',
    color: 'brown',
    mammal: 'dog'
});

console.log(terped);

Hope this helps

Answer 2

If you use a global search with .match, JavaScript won't give the capture groups in its array output. As such, you need to do it twice: Once to find the {{...}} pairs, then again to extract the names from within them:

str.match(/{{\s*[\w\.]+\s*}}/g)
   .map(function(x) { return x.match(/[\w\.]+/)[0]; });

Answer 3

I really liked the answer @Cody provided, but ran into a scope issue if you wanted to make the object you pass more of a real object and not just a list, so I found an eval trick to change the scope so I thought I would share it.

function interpolate(str) {
    return function interpolate(o) {
        return str.replace(/{([^{}]*)}/g, function (a, b) {
            let r
            with(o){
              r = eval(b)
            }
            return r
        });
    }
}

var terped = interpolate('The {speed} {fox.color} {mammal[2]} jumped over the lazy {mammal[0]}')({
    speed: 'quick',
    fox: {
      color: 'brown'
    },
    mammal: ['dog', 'cat', 'fox']
});

console.log(terped)

Answer 4

You could try doing this with exec() instead:

var list = [],
    x = '"This could {{be }} a {{ string }} of {{ mustache_style}} words which {{could}} be pulled."',
    re = /{{\s*([^}]+)\s*}}/g,
    item;

while (item = re.exec(x))
    list.push(item[1]);

Answer 5

Something like this

/{{\s?([^}]*)\s?}}/

The values would be in first group (you know, not the 0-group, the 1-group :))

One more point - this regex is captures everything between {{ and }}, so all the punctuation marks, braces, dots, etc. If you need only words (possibly separated by underscore or whitespace) this would be more useful for you:

/{{\s?[\w\s]*\s?}}/