I am trying to create a custom DataGrid with built in support for sorting when combined with an EntityCollection as the DataSource.

My question is: Is it possible to sort a collection on a field if all you have is a field name?

Creating a SortExpression, from what I have been able to find, requires that you an pass <EntityName>FieldIndex. The problem is, the DataGrid doesn't know what concrete implementation of EntityBase is being used and there is no generic SortClauseFactory.Create(int fieldIndex,....) function. For example, the following line wouldn't work.

PrepareCollection(EntityCollectionBase collection, string fieldName)
{
   SortClause sorter = SortClauseFactory.Create(collection[0].Fields[fieldName].FieldIndex, (sortASC ) ? SortOperator.Descending : SortOperator.Ascending); 
}

That is as simple as I can try to explain it. I hope someone will be able to help me.

Hrmmm.. I really thought someone would reply to this by now. Seemed like the kind of thing where someone would post some blatantly obvious code that I hadn't thought about...

Still can't figure this one out.

alexdresko wrote:

Hrmmm.. I really thought someone would reply to this by now. Seemed like the kind of thing where someone would post some blatantly obvious code that I hadn't thought about...

Still can't figure this one out.

The sorting routines are for sorting the output as it comes from the database. I do not think there is in-memory or in collection sorting at this time.

You could of course roll your own and return the answer in another collection.

John

John wrote:

alexdresko wrote:

Hrmmm.. I really thought someone would reply to this by now. Seemed like the kind of thing where someone would post some blatantly obvious code that I hadn't thought about...

Still can't figure this one out.

The sorting routines are for sorting the output as it comes from the database. I do not think there is in-memory or in collection sorting at this time.

You could of course roll your own and return the answer in another collection.

John

Actually, I'm not doing anything llblgen can't do except specify a string for a sort column instead of an _ EntityName_FieldIndex. The most frustrating thing is that _ EntityName_FieldIndex is just an enum that returns an int anyway.. So why can't I just specify the index manually?

alexdresko wrote:

Actually, I'm not doing anything llblgen can't do except specify a string for a sort column instead of an _ EntityName_FieldIndex. The most frustrating thing is that _ EntityName_FieldIndex is just an enum that returns an int anyway.. So why can't I just specify the index manually?

BTW, as far as I can tell, the only problem with allowing the developer to specify their own int is a bounds checking issue if a field position is specified that doesn't exist.

Not a big deal if you ask me for the added functionality.

You can convert from a field name string into the field index enum:

C#:
<entityname>FieldIndex mySortField = (<entityname>FieldIndex)Enum.Parse(typeof(<entityname>FieldIndex), "mysortfield", true);

Just replace <entityname> with the name of the entity your working with and "mysortfield" can be any string matching a fieldname.

alexdresko wrote:

Hrmmm.. I really thought someone would reply to this by now. Seemed like the kind of thing where someone would post some blatantly obvious code that I hadn't thought about...

Still can't figure this one out.

I've send you an email with a reply on your question on Tuesday. Did you receive it or was it eaten by a spamfilter or something?

Otis wrote:

alexdresko wrote:

Hrmmm.. I really thought someone would reply to this by now. Seemed like the kind of thing where someone would post some blatantly obvious code that I hadn't thought about...

Still can't figure this one out.

I've send you an email with a reply on your question on Tuesday. Did you receive it or was it eaten by a spamfilter or something?

I got it. I still have to figure out how to do implement your suggestion, I just haven't had time yet. Thanks though!

Ok