CODEWITHSUNDEEP
javascriptangularjsregex
Anže Jenšterle
Anže Jenšterle

Reputation: 73

JS replace substring with keys in object

I am developing a general function inside a solution which would replace /endpoint/{item.id}/disable/{item.name} with /endpoint/123/disable/lorem where I pass the function the URL and item.

The item would be an object with keys id and name.

What would be the best way to find items with the structure {item.KEY} and replacing them with item.KEY?

Upvotes: 0

Views: 543

Answers (2)

Krzysztof Atłasik
Krzysztof Atłasik

Reputation: 22635

If you don't want to use eval, maybe use something like this:

var item = {
    id: 123,
    KEY: "lorem"
};

function pick(o, s) {
    s = s.replace(/\[(\w+)\]/g, '.$1'); // convert indexes to properties
    s = s.replace(/^\./, '');           // strip a leading dot
    var a = s.split('.');
    for (var i = 0, n = a.length; i < n; ++i) {
        var k = a[i];
        if (k in o) {
            o = o[k];
        } else {
            return;
        }
    }
    return o;
}

and then 

str.replace(/{.*?}/g, function(match){ // match {...}
    var path = match.substring(1,match.length-1); // get rid of brackets.
    return pick(scope, path); //get value and replace it in string.
});

Upvotes: 1

Wolfgang
Wolfgang

Reputation: 896

the best way to solve this is passing a function to handle a regex. I modified your parameters to make the mapping easier- I'm sure you can change this on your own if necessary

var url = '/endpoint/{id}/disable/{name}'; //I modified your parameters

var definition = { id: 123, name: 'lorem' };
url = url.replace(/{([^}]*)}/g, function (prop) {
  var key = prop.substr(1, prop.length - 2);
  if (definition[key])
    return encodeURIComponent(definition[key]);
  else
    throw new Error('missing required property "' + key + '" in property collection');
});

//alert(url);

fiddle: https://jsfiddle.net/wovr4ct5/2/

Upvotes: 2

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