CODEWITHSUNDEEP
javascriptangularjsunderscore.jslodash
Non
Non

Reputation: 8589

Pure JS to lodash

I have some different statements here that I would like you to tell me if they are equivalent:

myApp.filter('myFilter', function() {

  var result, i, sport, y, contains, league;
  return function(sports, filterBy) {    
    if (angular.isUndefined(sports) || !filterBy) {
      return sports;
    }

    filterBy = filterBy.toLowerCase();
    result = [],
    contains = function(haystack, needle) {
      return haystack.toLowerCase().indexOf(needle) > -1;
    };

    for (i = 0; i < sports.length; i++) {
      sport = sports[i];
      if (contains(sport.name, filterBy)) {
        result.push(sport);
        continue;
      } else {
        for (y = 0; y < sport.leagues.length; y++) {
          league = sport.leagues[y];
          if (contains(league.name, filterBy)) {
            result.push(sport);
            break;
          }
        }
      }
    }
    return result;
  };
});

now with lodash:

myApp.filter('myFilter', function() {

  var result, i, sport, y, contains, league;
  return function(sports, filterBy) {    
    if (angular.isUndefined(sports) || !filterBy) {
      return sports;
    }

    filterBy = filterBy.toLowerCase();
    result = [],
    contains = function(haystack, needle) {
      return haystack.toLowerCase().indexOf(needle) > -1;
    };

  _.each(sports.length, function(sport) {
      if (contains(sport.name, filterBy)) {
        result.push(sport);
        continue;
      } else {
        _.each(sport.leagues.length, function(league) {
          if(contains(league.name, filterBy)) {
            result.push(sport);
            break;
          }
        });
      }
    });

just I am trying to get with the logic of lodash. I have that function in ALMOST pure JS, but once I tried to translate that to lodash, my app breaks down, so I would like to know where is the mistake ?

here I have this Plnkr with the pure js function, in the library section you will see that I have underscore because I do not know why lodash did not load, so, all I am trying is: translate that function into a lodash function using _.each instead of for loop

Upvotes: 0

Views: 898

Answers (1)

josephnvu
josephnvu

Reputation: 1242

You wouldn't use "each" in this situation. Also in "each" you don't get "continue" or "break". For me I would use "filter" to get a filtered result. So the code should look like this:

var result = sports.filter(function(sport){
  return (
      contains(sport.name, filterBy) 
    || (
      sport.leagues && sport.leagues.some(function(league) { 
        return contains(league.name, filterBy) 
      })
    )
  )
})

or for lodash/underscore

var result = _.filter(sports, function(sport) {
  return (
      contains(sport.name, filterBy) 
    || (
      sport.leagues && _.some(sport.leagues, function(league) { 
        return contains(league.name, filterBy);
      })
    )
  )
});

Upvotes: 1

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