pureComputed and arrayChange

[Glenn]

If I have a pureComputed based on an observableArray, should the arrayChange fire on update?

In my model I have:

SecurityRoles: ko.pureComputed({

  read: function () {

    var currentRoles = [];

    if (model.Roles() && model.Roles().length) {

      ko.utils.arrayForEach(model.Roles(), function (role) {

        if (!role.EntityState || role.EntityState !== "DELETED") {

          currentRoles.push(role.AppSecurityRoleCd);

        }

      });

    }

    return currentRoles;

  },

  write: function (valueArray) {

    var valueInArray = false,

      valueInArrayChanged = false;

    ko.utils.arrayForEach(valueArray, function (value) {

      // check to see if it had been deleted

      ko.utils.arrayForEach(model.Roles(), function (role) {

        if (role.AppSecurityRoleCd === value) {

          if (role.EntityState && role.EntityState === "DELETED") {

            if (role.RecordVersion) {

              // was saved to database

              role.EntityState = "UNCHANGED";

            } else {

              role.EntityState = "ADDED";

            }

            valueInArrayChanged = true;

          }

          valueInArray = true;

        }

      });

    });

    if (!valueInArray) {

      model.Roles.push({

        AppSecurityRoleCd: value,

        EntityState: "ADDED"

      });

    };

    if (valueInArrayChanged) {

      model.Roles.valueHasMutated();

    };

  },

  owner: model

})

I am using a modified version of bootstrap-multiselect that has the following:

listOfSelectedItems.subscribe(function (changes) {

var addedArray = [];

var deletedArray = [];

changes.forEach(function (change) {

if (change.moved === undefined) {

switch (change.status) {

case 'added':

addedArray.push(change.value);

break;

case 'deleted':

deletedArray.push(change.value);

break;

}

}

});

if (addedArray.length > 0) {

$(element).multiselect('select', addedArray);

};

if (deletedArray.length > 0) {

$(element).multiselect('deselect', deletedArray);

};

$(element).multiselect('buildDropdownOptions');

}, null, "arrayChange");

If I the listOfSelectedItems is an observableArray then it works, if it is based on a pureComputed which gets its values from an observable array, it doesn't.  

Thoughts?

[Glenn]

Update:

I added .extend({trackArrayChanges: true}); to the purComputed and the arrayChange event now fires.