check how many arrays have length greater than 0 in javascript and angularjs

Question

I am trying to create a validation in my app.

What I have, is multiple lists with a toggle (true/false).

If the item is selected, it populates an array.

And I have a different array for each group.

Pretty much something like this:

$scope.selected = {
  group1: {
    values: []
  },
  group2: {
    values: []
  },
  group3: {
    values: []
  }
}

When I select something, let's say, from the list in group 1, $scope.selected changes to this:

$scope.selected = {
   group1: {
     values: [{cat: 1, id: 1},{cat:1, id:3}]
   }
}

The problem I've got is that I am trying to validate this.

What I need is to be able to display a message if multiple values arrays are greater than 0.

For instance if:

$scope.selected = {
   group1: {
     values: [{cat: 1, id: 1},{cat:1, id:3}]
   },
   group2: {
     values: [{cat: 2, id: 5},{cat:2, id:2}]
   }
}

a message should appear as I can't allow to submit multiple groups at once.

I know that I can have some sort of function that checks on the specific name for the groups, but I need something a bit more dynamic, as groups may (and will) increase at some point (ie. I will have more groups that the ones I have now).

Is there any way I can check that only one out of all my group arrays is not empty, and if multiple are not empty, I show something?

thanks and I hope it's clear enough

Working, minimal code snippet would be helpful.

kind user
– kind user

2017-03-29 09:22:08 +00:00
Commented Mar 29, 2017 at 9:22 — kind user
– kind user, Commented Mar 29, 2017 at 9:22

Juan · Accepted Answer · 2017-03-29 09:31:16Z

1

You can iterate through the object:

var count = 0;
for (var group in $scope.selected) {
   if ($scope.selected.hasOwnProperty(group) && group.values.length > 0) 
      count++;
}

if (count > 1)
   console.log("More than one group with values");

edited Mar 29, 2017 at 9:31

answered Mar 29, 2017 at 9:25

Juan

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Comments

Weedoze · Accepted Answer · 2017-03-29 09:43:12Z

1

You can use Array#filter and Object.keys(o)

const selected = {
   group1: {
     values: [{cat: 1, id: 1},{cat:1, id:3}]
   },
   group2: {
     values: [{cat: 2, id: 5},{cat:2, id:2}]
   }
};
const validSelected = {
   group1: {
     values: [{cat: 1, id: 1},{cat:1, id:3}]
   },
   group2: {
     values: []
   }
};

function validate(obj){
  return Object.keys(obj).filter(k=>obj[k].values.length>0).length === 1;
}



console.log(validate(selected)); //false
console.log(validate(validSelected)); //true

Without ES6 arrow :

Object.keys(obj).filter(function(k){return obj[k].values.length>0).length === 1});

edited Mar 29, 2017 at 9:43

answered Mar 29, 2017 at 9:23

Weedoze

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1 Comment

Nick Over a year ago

I am using CoffeeScript and the arrow function is a bit tricky to convert...can I have an example that doesn't use the arrow function please?

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