Improve navigation property names when reverse engineering a database

There a few things you need to change inside the .tt file. I choose to use the third solution you suggested but this requires to be formatted like FK_CollectionName_RelationName. I split them up with ‘_’ and use the last string in the array.
I use the RelationName with the ToEndMember property to create a property name. FK_Projects_TechnicalContact will result in

//Plularized because of EF. 
public virtual Contacts TechnicalContactContacts { get; set; }

and your projects will be like this.

public virtual ICollection<Projects> SalesContactProjects { get;  set; }
public virtual ICollection<Projects> TechnicalContactProjects { get;  set; }

Now the code you may ask. Ive added 2 functions to the CodeStringGenerator class in the T4 file. One which builds the propertyName recieving a NavigationProperty. and the other one generating the code for the property recieving a NavigationProperty and the name for the property.

//CodeStringGenerator class
public string GetPropertyNameForNavigationProperty(NavigationProperty navigationProperty)
{
    var ForeignKeyName = navigationProperty.RelationshipType.Name.Split('_');
    var propertyName = ForeignKeyName[ForeignKeyName.Length-1] + navigationProperty.ToEndMember.Name;
    return propertyName;
}

public string NavigationProperty(NavigationProperty navigationProperty, string name)
{
    var endType = _typeMapper.GetTypeName(navigationProperty.ToEndMember.GetEntityType());
    return string.Format(
        CultureInfo.InvariantCulture,
        "{0} {1} {2} {{ {3}get; {4}set; }}",
        AccessibilityAndVirtual(Accessibility.ForProperty(navigationProperty)),
        navigationProperty.ToEndMember.RelationshipMultiplicity == RelationshipMultiplicity.Many ? ("ICollection<" + endType + ">") : endType,
        name,
        _code.SpaceAfter(Accessibility.ForGetter(navigationProperty)),
        _code.SpaceAfter(Accessibility.ForSetter(navigationProperty)));
}

If you place the above code in the class you still need to change 2 parts. You need to find the place where the constructor part and the navigation property part are being build up of the entity. In the constructor part (around line 60) you need to replace the existing code by calling the method GetPropertyNameForNavigationProperty and passing this into the escape method.

      var propName = codeStringGenerator.GetPropertyNameForNavigationProperty(navigationProperty);
#>
      this.<#=code.Escape(propName)#> = new HashSet<<#=typeMapper.GetTypeName(navigationProperty.ToEndMember.GetEntityType())#>>();
<#

And in the NavigationProperties part (around line 100) you also need to replace the code with the following.

    var propName = codeStringGenerator.GetPropertyNameForNavigationProperty(navigationProperty);
#>
    <#=codeStringGenerator.NavigationProperty(navigationProperty, propName)#>
<#

I hope this helps and you can always debug the GetPropertyNameForNavigationProperty function and play a little with the naming of the property.

Leave a Comment