AngularJS ng-repeat to populate grid from array - arrays

Question

Thanks in advance for reading. I am trying to utilize angular's ng-repeat to render objects from an array into an Nx3 Table. For the sake of example let's consider a 3x3 table.
Here is a simplified example of the array:
objects = [{"text": "One, One"},{"text": "One, Two"},{"text": "One, Three"},
{"text": "Two, One"},{"text": "Two, Two"},{"text": "Two, Three"},
{"text": "Three, One"},{"text": "Three, Two"},{"text": "Three, Three"}];
The "text" field describes where in the 3x3 grid matrix each element should appear. I would like to use ng-repeat on objects to generate html that looks like this:
<table>
<tr>
<td>One, One</td>
<td>One, Two</td>
<td>One, Three</td>
</tr>
<tr>
<td>Two, One</td>
<td>Two, Two</td>
<td>Two, Three</td>
</tr>
<tr>
<td>Three, One</td>
<td>Three, Two</td>
<td>Three, Three</td>
</tr>
</table>
Is there any way to achieve this without needing to break up the array into separate arrays for each row?

Answer 1

Best possibly way would be to alter your view model in the controller and bind that to ng-repeat (But you already said you do not want to do that). If you ever plan to take that route you can also take a look at user #m59 answer where he creates a reusable filter to do it. However this is just a simple answer making use of built in filter's configurable evaluation expression where we can return truthy/falsy value to determine if they need to be repeated or not. This eventually has the only advantage of no need to create 2 ng-repeat blocks (But that is not so bad though). So in your controller add a function on the scope,
$scope.getFiltered= function(obj, idx){
//Set a property on the item being repeated with its actual index
//return true only for every 1st item in 3 items
return !((obj._index = idx) % 3);
}
and in your view apply the filter:
<tr ng-repeat="obj in objects | filter:getFiltered">
<!-- Current item, i.e first of every third item -->
<td>{{obj.text}}</td>
<!-- based on the _index property display the next 2 items (which have been already filtered out) -->
<td>{{objects[obj._index+1].text}}</td>
<td>{{objects[obj._index+2].text}}</td>
</tr>
Plnkr

Answer 2

I wanted to do the exact same thing.
Convert an array into a matrix/ grid
I have an array which i wanted to convert into a grid/matrix of column size 4. the following implementation worked for me. You can use the two counters : row and col as you like in side the nested ng-repeat
In my case number of columns is 3. But you can replace that 3 with a variable everywhere. h.seats is my array of the objects and i want to print either X or - based on value of element in that array
<div class="table-responsive">
<table class="table table-bordered">
<thead>
<tr>
<th ng-repeat="n in [].constructor(3 + 1) track by $index">{{$index}}</th>
</tr>
</thead>
<tbody>
<tr ng-repeat="(row, y) in getNumber(h.seats.length, 3) track by $index">
<td>{{row+1}}</td>
<td class="text-primary"
ng-repeat="(col, t) in h.seats track by $index"
ng-if="col >= (row)*3 && col < (row+1)*3">
<span ng-show="t.status"> X </span>
<span ng-show="!t.status"> - </span>
</td>
</tr>
</tbody>
</table>
</div>
<th ng-repeat="n in [].constructor(3 + 1) track by $index">{{$index}}</th> prints the header row with column number at the top. getNumber(h.seats.length, 3) returns me the number of rows of that table as follows
.controller('CustomViewController', function ($scope, Principal, $state) {
$scope.getNumber = function(length, columns) {
return new Array(parseInt(length / columns + 1, 10));
}
The line ng-if="col >= (row)*3 && col < (row+1)*3" is important logic to calculate which elements should be put in that row.
The output looks like below
0 1 2 3
1 e1 e2 e3
2 e4 e5 e6
3 e7 e8
Refer to following link for details of how row and col counters are used:
https://stackoverflow.com/a/35566132/5076414