Why does Array.prototype.filter() throw an error in Magnolia JavaScript models?

Question

I\'m attempting to filter a FreeMarker list in a Magnolia JavaScript model using Array.prototype.filter().

List

[#assign list = [1, 2, 3         


        

Answer 1

The FreeMarker list you are passing to the model is a sequence, not a JavaScript array.

Sequence (3)
  0 = 1 (BigDecimal)
  1 = 2 (BigDecimal)
  2 = 3 (BigDecimal)

To solve the issue, convert the FreeMarker list you are passing to the model to a JavaScript array using Java.from(). For example:

var Model = function() {
  this.filterList = function(list) {
    return Java.from(list).filter(function(item) {
      return item === 2
    });
  }
};

new Model();