List Merging

[t-andre]

Hi,

It's possible to merge two list and update all the properties?
Or update and let the deleted item in the target list?

Thanks

[SteveWilkes]

Hi!

I'm not completely sure what behaviour you're after - could you add an example showing what you're looking to achieve?

Cheers,

Steve

[t-andre]

Hi,

With this example:

var mapper = Mapper.CreateNew();
	
var source = new List<Customer>
{
new Customer { Id = 1, Name = "Rod", Description = "Customer Description 1" },
new Customer { Id = 2, Name = "Jane" , Description = "Customer Description 2" },
new Customer { Id = 4, Name = "Freddy" , Description = "Customer Description 4" }
};

var target = new Collection<CustomerViewModel>
{
new CustomerViewModel { Id = 2, Name = null, Description = "CustomerViewModel Description 2"  },
new CustomerViewModel { Id = 1, Name = "Bungle", Description = "CustomerViewModel Description 1"  },
new CustomerViewModel { Id = 3, Name = "Zippy", Description = "CustomerViewModel Description 3"  }
};

var result = mapper.Map(source).OnTo(target);

Have this result:

Id	Name	Description	Status
2	Jane	CustomerViewModel Description 2	Updated
1	Bungle	CustomerViewModel Description 1	Updated
3	Zippy	CustomerViewModel Description 3	Deleted
4	Freddy	Customer Description 4	New

But I would like to have this one:

Id	Name	Description	Status
2	Jane	Customer Description 2	Updated
1	Rod	Customer Description 1	Updated
3	Zippy	CustomerViewModel Description 3	Deleted
4	Freddy	Customer Description 4	New

Thanks in advance

[SteveWilkes]

Hi,

I think what you're after is an Overwrite mapping - instead of:

mapper.Map(source).OnTo(target);

...use:

mapper.Map(source).Over(target);

I've put together a .NET Fiddle and I think it does what you describe. Let me know if not!

Cheers,

Steve

[t-andre]

Thanks for the response.

Tried the Map Over.
With simple list I can go and check the deleted record, but I have many lists and it can be difficult to check then all.
The function I need if it's possible is to have Map Over and let the deleted record in the list.

Cheers

[SteveWilkes]

hi,

There's nothing out of the box - if I've understood what you're after correctly - but because the mapper identifies objects by ID and reuses them, you could try:

var mapper = Mapper.CreateNew();
	
var source = new List<Customer>
{
    new Customer { Id = 1, Name = "Rod", Description = "Customer Description 1" },
    new Customer { Id = 2, Name = "Jane" , Description = "Customer Description 2" },
    new Customer { Id = 4, Name = "Freddy" , Description = "Customer Description 4" }
};

var target = new Collection<CustomerViewModel>
{
    new CustomerViewModel { Id = 2, Name = null, Description = "CustomerViewModel Description 2"  },
    new CustomerViewModel { Id = 1, Name = "Bungle", Description = "CustomerViewModel Description 1"  },
    new CustomerViewModel { Id = 3, Name = "Zippy", Description = "CustomerViewModel Description 3"  }
};

// Use .ToList() to map over a List<T> copy of the target instead of the original Collection<T>:
var result = mapper.Map(source).Over(target.ToList());

// Get the objects which exist in the original target Collection<T>, but not the result List<T>:
var removedObjects = target.Except(result);

// Re-add the removed objects to the mapped List<T>:
result.AddRange(removedObjects);

// If you need a Collection<T> instead of a List<T>,
// re-assign 'target' to a new Collection<T> containing the objects:
target = new Collection<CustomerViewModel>(result);

Hope that helps,

Steve

[t-andre]

Hi,

Thank you for your help.

[SteveWilkes]

You're welcome! :)