Server side paging with a generic data source (C#).
Server side paging with a generic data source (C#).
braden87
Posts: 17Questions: 5Answers: 0
I'm very new to using Datatables and I have recently picked up a project at work that uses the library. The way the previous developer set up the Datatables was to use a generic source:
public async Task<ActionResult> DataTableAsync<TEntity>(AlertModel alert, string viewName = null) where TEntity : class
{
// get data
var data = (from a in await Manager.AllAsync<TEntity>()
select a).ToList();
var response = new TableModel<TEntity>
{
Alert = alert,
Data = data
};
// return partial data view
return PartialView(viewName ?? $"_{typeof(TEntity).Name}Table", response);
}
The AllAsync method just returns the entire context set:
Context.Set<T>().ToListAsync();
And this is how the JavaScript for DataTables is set up:
function makeDataTable(id) {
var selector = '#' + id;
$(selector).DataTable({
order: [],
search: {
smart: false
},
stateSave: true,
columnDefs: [{
targets: 'no-sort',
orderable: false
},
{
targets: 'date-col',
type: 'date',
orderSequence: [
'desc',
'asc'
]
}],
lengthMenu: [
[10, 15, 20, -1],
[10, 15, 20, 'All']
]
});
$(selector).width('100%');
}
When the context set has a lot of records it will cause an out of memory exception. How can I use Skip and Take within this generic method to return portions of the data set at a time to the table?
This discussion has been closed.
Answers
Hi @braden87 ,
It sounds like you need to implement
serverSideprocessing - details on the protocol is here.Cheers,
Colin
Thank you for the reply @colin,
I understand that in the javascript setup for the server-side processing that I need to use Ajax. How would I point it in the direction of the generic data method (the DataTableAsync method)? Would it be:
Do I have to include any of the generic TEntity stuff? It just confuses me on how to use server side processing because of the generic nature of the source. I read somewhere that I can use Scroller as well to render only the first page upon loading.
That's up to the controller. If your routing is setup for that (which I think it normally is for .NET projects like this), then it will work just fine.
You'd need to have your server-side script handle the DataTables parameters that Colin linked to. That is not something .NET does out of the box.
Allan
@allan Like in the Ajax portion of the code example I pasted above?
That doesn't implement server-side processing for DataTables, but yes, that is the basis for getting Ajax sourced data.
Allan
Based off of the information Colin gave I thought that
set up server side processing? Unless I am missing something?
Hi @braden87 ,
I thinks there's a muddle here -
serverSidetells the client that the ordering, searching, etc will be done by the server. Allan was meaning that it still needs the server side script to do the grunt work.Cheers,
Colin
@colin are you meaning like a view or a stored procedure?
Full details on what server-side processing sends to the server and requires back are available in the link Colin posted above.
You can use a view or a stored procedure, but you need code around that to select the items you want from the db.
First things first. Do you actually need server-side processing? Do you had tens of thousands or more rows to display? See this section of the manual for more details.
Allan
The largest table that I have is returning 40,000+ rows.
The other option I've come across is using Skip() and Take() but I don't know if that can override the page numbers.
Yes, you could try using linq. You need to be a little careful with it since you don't want to pull all of the data out of the database, and then discard the majority.
With 40k rows I'd suggest you use client-side processing first. If you find the performance too slow, then spend the time looking into how to implement server-side processing.
Allan