Item validator access already stored data instead of newly inputed data

Question

Im facing a problem with sitecore item validator when I try to save the data. The purpose of my validator (the class inherit from StandardValidator) is to simply check if, atleast, field A or field B has a value. If not, I prevent the data to be saved by throwing a ValidatorResult.CriticalError

However, sitecore is having a strange behaviour. Instead of doing the validation on the newly inputed data, he's getting the data already saved and trying to perform the validation on them.

I think the purpose of the validator is to validate the new data before saving, but at the moment it try to validate the data already saved. Is this a bug ? Or Am I missing something ?

By the way, here is how I retrieve my fields inside of the Evaluate() function

protected override ValidatorResult Evaluate()
{
    Sitecore.Data.Items.Item item = this.GetItem();
    Sitecore.Data.Fields.MultilistField first = item.Fields[FieldOne_Name];
    Sitecore.Data.Fields.MultilistField second = item.Fields[FieldTwo_Name];
    //Processing code here...
}

Any hint is more than welcome!

Thank's

Answer 1

My answer is incorrect. See Richard's answer below. Answer is "use fatal validation result instead of critical". Or use item:saving event like described in my answer.

---

You can use workflow and not allow to proceed to the final state if any of the validators failed.

Alternatively, you can use item:saving event instead of validation.

Another way is using saveUI pipeline.

You just need to use code like this to prevent item from being saved:

Sitecore.Web.UI.Sheer.SheerResponse.Alert(message, new string[0]); 
args.SaveAnimation = false; 
args.AbortPipeline(); 

More details can be found in John West blog post Intercepting Item Updates with Sitecore

Answer 2

So one thing to note - CriticalError - the user is warned before saving, but the data is still saved. FatalError will stop the item from being saved if validation fails.

But...

What you are trying to do is not possible in a validator.

The this.GetItem() method in the base validator, gets the item from the database. Remember that a validator works on a single field at a time. So it then updates that field in the item to have the new value for that field only.

So you would not be able to use it to get new values for 2 fields to validate those. Your only option there would be the item:saving event. But be careful with that, it will fire for the save of every single item you have, so you can easily make Sitecore run very slow there.

Answer 3

What is throwing you off, is the ambiguous labeling of method GetItem().

Here's what it looks like:

protected virtual Item GetItem()
{
  if (this.itemUri == (ItemUri) null)
    return (Item) null;
  Item obj = Database.GetItem(this.itemUri);
  if (obj == null || obj.Versions.Count == 0)
    return (Item) null;
  this.UpdateItem(obj);
  return obj;
}

The thing to note here is, it calls UpdateItem(), which is essentially loading up the proposed new item values into the in-memory copy of your Item.

So when you say you are getting "already saved" values, this actually isn't the case. Not if you abort the validation with a FatalError like described elsewhere here.

If you want to get field values as they are in the database right now, you need to mimic what GetItem() is doing, but avoiding the UpdateItem() functionality.

Like this, for example:

protected virtual Item GetStoredItem()
{
    return Database.GetItem(this.itemUri);
}

(parameter guarding omitted)

And if you then decide to throw a Fatal validation error on your field, the values will be rejected outright and never stored to DB.