Replace keys in a template from array of objects in javascript

Question

I have an array like this.

var arr = [
    {
        Id:1533248,
        Name:"HP",
        ParentId:33113319,
        ParentName:"Brand Name"
    },
    {
        Id:1533764,
        Name:"Samsung",
        ParentId:33113319,
        ParentName:"Brand Name"
    }    
]

And a template.

var template = 'a_{ParentName}:{ParentId}_({Name}:{Id})*'

I am trying to generate a string from template. All i have is the array of objects. Also section inside () can be repeated and separated by pipe.

This is the desired output.

var result = 'a_brand-name:33113319_hp:1533248|samsung:1533764|sony:1533438';

There could be many objects in array with same ParentId. I am trying to use regular expression but failing. I am no good at regular expressions.
Please help.

A number of JavaScript libraries are good for this. One that comes to mind is "Mustache". It might have a slightly differing syntax from your template, but will also grant advanced capabilities like looping (over an array). — Katana314
– Katana314, Commented Dec 7, 2015 at 14:31

akosel · Accepted Answer · 2015-12-07 15:32:34Z

1

You can use JS RegExp's along with replace to swap out the variables in your template. Additionally you can sanitize your strings into the desired format (based on what I see, replace white-space with a hyphen and convert the string to lower-case) with replace. It sounds like you have more data than is displayed above, so you may need to keep multiple templates (i.e. one for each parent) stored in an object where the keys are the parentId. Using that structure, you can iterate through the array, updating your template for each parentId pretty quickly.

var arr = [
    {
        Id:1533248,
        Name:"HP",
        ParentId:33113319,
        ParentName:"Brand Name"
    },
    {
        Id:1533764,
        Name:"Samsung",
        ParentId:33113319,
        ParentName:"Brand Name"
    }    
];


var template = 'a_{ParentName}:{ParentId}_({Name}:{Id})*';
arr.forEach(function(obj, i) {
  Object.keys(obj).forEach(function(key) {
    var newKey;
        if (typeof(obj[key]) === 'string') {
      newKey = obj[key].replace(/ /g, '-').toLowerCase();
    } else {
      newKey = obj[key];
    }

    var regex = new RegExp("{" + key + "}");
    template = template.replace(regex, newKey);
  });
  if (template.indexOf('({Name}:{Id})') === -1 && i < arr.length - 1) {
    template = template.replace(/\*/, '|({Name}:{Id})*');
  } else if(i === arr.length - 1) {
    template = template.replace(/[\*\(\)]/g, '');
  }
});

https://jsfiddle.net/mw3dwau7/2/

edited Dec 7, 2015 at 15:32

answered Dec 7, 2015 at 14:41

akosel

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6 Comments

Muhammad Raheel Over a year ago

Thanks for the answer but this is the result it is generating a_brand-name:33113319_hp:1533248|samsung

Muhammad Raheel Over a year ago

samsung is missing the id

Muhammad Raheel Over a year ago

sorry forgot to mention this {Name}:{Id}. This section can be repeated many times and separated by pipe character

akosel Over a year ago

Ok, so in your initial template string, is this a more accurate representation: 'a_{ParentName}:{ParentId}_{Name}:{Id}|{Name}:{Id}|*'?

Muhammad Raheel Over a year ago

i posted this as an example

|

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