Nullable<System.DateTime> and BreezeJS - breeze

Question

I have this class:
public partial class VehicleSize
{
public VehicleSize()
{
}
public System.Guid VehicleSizeId { get; set; }
public int Title { get; set; }
public int SizeOrder { get; set; }
public System.DateTime DateCreated { get; set; }
public Nullable<System.DateTime> DateDeleted { get; set; }
}
I'm using with BreezeJS.
Handling of Nullable seems a bit odd. This field is meant to be optional. But it complains until I explicitly set DateDeleted = null from the javascript. If I don't set the field to null I'll get "Problem saving TypeError: entity.dateDeleted is null".
It seems if i inspect the .dateDeleted property in javascript it is a javascript Date object but getTime isNAN. Shouldn't it be null in this case instead and the BreezeJS validator skip validating it as the field is null.
The Meta data from the server defines the field as this:
"name": "DateDeleted",
"type": "Edm.DateTime",
"nullable": "true"
Does anyone have an idea on how I create an optional DateTime field?
Further to my original post. The problem seems to be related to exporting Entities from one entity manager to another. A Date field that starts out as "null" becomes "Invalid Date" after its imported again as demonstrated by this code:
var vehicleSizeId = 'E9DA5803-BB65-4751-AA22-17B54A1EE7C1';
alert('getting vehicle from db');
var query = breeze.EntityQuery
.from("VehicleSizes")
.where("vehicleSizeId", "==", vehicleSizeId);
var em = new breeze.EntityManager("api/Todo");
em.enableSaveQueuing(true);
var sandBoxEm = em.createEmptyCopy();
sandBoxEm.enableSaveQueuing(true);
em.executeQuery(query)
.then(function (data) {
alert('Found the vehicle size in the original entity manager')
var entity = data.results[0];
alert('Org Date Deleted == ' + entity.dateDeleted); // Its null at this point
var bundle = em.exportEntities();
sandBoxEm.importEntities(bundle, { mergeStrategy: breeze.MergeStrategy.OverwriteChanges });
});
sandBoxEm.executeQuery(query)
.then(function (data) {
alert('Found the vehicle size')
var entity = data.results[0];
alert('Date Deleted == ' + entity.dateDeleted); // Now its invalid date
entity.sizeOrder = entity.sizeOrder + 1;
entity.titleTranslation.text = entity.titleTranslation.text + "_x";
//entity.titleTranslation.dateDeleted = null;
//entity.dateDeleted = null;
try {
sandBoxEm.saveChanges().then(
function () {
alert('It saved ok');
}).fail(
function (error) {
var firstItem = error.entitiesWithErrors[0];
var firstError = firstItem.entityAspect.getValidationErrors()[0];
var msg = "prop: " + firstError.property.parentType.name + " = " + firstError.errorMessage;
alert(msg);
}
);
}
catch (ex) {
alert( "Problem saving " + ex );
}
}
).fail(
function () {
alert('Getting the vehicle size failed');
});

Answer 1

Edit: May 8, 2013 - The issue with importing a previously exported null date is now fixed in v 1.3.3 and available on the Breeze website.
Not sure what you are experiencing. I just wrote a unit test to try and confirm what you are seeing and are not able to repro your issue. I am running this against an Employee model where the "birthDate" also defined as a Nullable.
All tests pass on this:
var em = newEm(); // creates a new EntityManager
var emp = em.createEntity("Employee", { firstName: "Joe", lastName: "Smith" });
ok(emp.entityAspect.entityState === breeze.EntityState.Added, "entityState should be 'Added'");
var birthDate = emp.getProperty("birthDate");
ok(birthDate === null, "birthDate should be null");
var q = EntityQuery.from("Employees").where("birthDate", "==", null);
stop();
em.executeQuery(q).then(function(data) {
var empsWithNullBirthDates = data.results;
ok(empsWithNullBirthDates.length > 0, "should be at least 1 employee with a null birthdate");
empsWithNullBirthDates.forEach(function(emp) {
var birthDate = emp.getProperty("birthDate");
ok(birthDate === null, "queried birthDate should be null");
});
}).fail(testFns.handleFail).fin(start);