"required fields" don't allow empty string

[RajNZ]

If a model has what Breeze considers to be a "required field" string property (so far I have encountered key properties and TPH discriminator properties; in fact it will be any string property that is not nullable) then Breeze does not allow the value of the property to simply be empty string ("") - it generates a validation error :

'MyProperty' is a required field

We recently changed from using Breeze.Sharp.Standard.Fork (it came with the Blazor project template we use) to Breeze.Sharp 0.9.1. This was not a problem in Breeze.Sharp.Standard.Fork but is a problem in Breeze.Sharp.

Oddly, for some properties we get the error even if, at the time of saving, the property does contain a non-empty value; in this case the problem arises if the dto that we are saving was not initialised with a non-empty string set for the property, even if the property is set to something afterwards. The fix for this situation is to initialise the property to " " or similar.

I can remedy the problem by ensuring that all such properties both contain a non-empty value and are initialised with a non-empty value, but this is a real drag...

Is this behaviour intentional in Breeze.Sharp, or something unintended?

This is my example of a property, UMID, that is simply a non-nullable string and Breeze.Sharp 0.9.1 insists that it cannot be empty string "".

Data model

public partial class DATAMfgBomHeaderArticle
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int ArticleID { get; set; }

    [StringLength(10)]
    [Unicode(false)]
    public string UMID { get; set; }

      // many more properties...
}

DTO

public partial class DATAMfgBomHeaderArticle : BaseEntity
{
    
    [Key]
    public Int32 ArticleID
    {
        get { return GetValue<Int32> (); }
        set { SetValue(value); }
    }
    public String UMID
    {
        get { return GetValue<String> (); }
        set { SetValue(value); }
    }

   // many more properties...
}

Run this code

 DATAMfgBomHeaderArticle newItem = new DATAMfgBomHeaderArticle();
 newItem.UMID = "";
entityManager.AddEntity(newItem);
await entityManager.SaveChanges();

and it produces a validation error when attempting SaveChanges().

[steveschmitt]

It must be that the Validator applied to non-nullable string fields doesn't allow empty strings. That might be what some people want some of the time, but not all of the people all of the time. I don't know why it changed from the earlier fork; I'll look into it.

Thanks for submitting this.

[RajNZ]

Hi, are you able to provide a rough time frame where you might be able to look into this please? Just so I know whether to put our upgrade to Breeze.Sharp onto the long term back-burner. Thanks.