Question

I have a view that has a list of items (which can be added to dynamically via jQuery).

When I POST the viewmodel back to the controller, if the code can’t find the ID, how do I insert new items and save them to the database.

My initial code is below – the updates are saved, but the new items aren’t saved:

    //
    // POST: /Objective/Edit/model
    [HttpPost]
    public ActionResult Edit(ObjectivesEdit model)
    {
        if (model.Objectives != null)
        {
             foreach (var item in model.Objectives)
            {
                // find the database row
                Objective objective = db.objectives.Find(item.ID);
                if (objective != null) 
                {
                    // Set the database row to the posted values

                    objective.objective = item.objective;
                    objective.score = item.score;
                    objective.possscore = item.possscore;
                }
                else  // database item not found, so add a new item
                {
                    // add a new objective 
                    // This doesn't seem to add/save a new record
                    Objective obj = new Objective();
                    obj.objective = item.objective;
                    obj.score = item.score;
                    obj.possscore = item.possscore;
                }
             }
            // Save the changes to the database
            db.SaveChanges();
        }
        return View(model);
    }

Thanks for any help,

Mark

Answer 1

You don’t add the newly created objective to your context.

else  // database item not found, so add a new item
{
    // add a new objective 
    // This doesn't seem to add/save a new record
    Objective obj = new Objective();
    obj.objective = item.objective;
    obj.score = item.score;
    obj.possscore = item.possscore;

    // Missing line.
    db.objectives.Add(obj);
 }  

if you’re using EF 4.0 (i.e. db is of type ObjectContext), you should use the db.AddObject(obj).

Update based on your comment:
One way is to retrieve all added items after saving changes. Another way is to modify your model when creating a new objective. Changed parts are marked with *:

foreach (var item in model.Objectives.ToList()) // *:Notice the ToList()
{
    // find the database row
    Objective objective = db.objectives.Find(item.ID);
    if (objective != null) 
    {
        // Set the database row to the posted values

        objective.objective = item.objective;
        objective.score = item.score;
        objective.possscore = item.possscore;
    }
    else  // database item not found, so add a new item
    {
          // add a new objective 
          // This doesn't seem to add/save a new record
          Objective obj = new Objective();
          obj.objective = item.objective;
          obj.score = item.score;
          obj.possscore = item.possscore;

         db.AddObject(obj)
         // Save the changes to the database
        db.SaveChanges(); // *: save in loop to get thee ID.

        item.ID = obj.ID; // *: assign the ID to the model.
     }
}

 return View(model);