Objectdatasource and Gridview : Sorting, paging, filtering

asp.netobjectdatasourcepagingsorting

Im using entity framework 1.0 and trying to feed out a Gridview with a objectdatasource that have access to my facade. The problem is, that it seems to be particulary difficult and haven't seen anything that realy do what i want it to do on the internet.

For those who know, a gridview feeded with an objectdatasource, it can't sort automaticaly then you must do it manually. It's not that bad. Where it becomes a nightmare, its when we add paging and filter settings to a gridview's datasource.

After many hours searching on the internet, i'm asking you, guys, if anyone knows a link that can explain me how to mix Pagging, Sorting and filtering for a gridview and an objectdatasource!

Thanks in advance and sorry for my english.

Best Answer

It may no longer be of interest for you, but I thought I post an answer nevertheless:

I am using Linq2Sql and a ObjectDataSource and it does Paging and Sorting very well.

I implemented a Class to be used as the ObjectDataSource. It has a Select and a Count method calling my business layer which uses Linq2SQL queries to retrieve data from the DB, should be similar with the EntityFramework. The select methods gets the first item index, page size and the sort expression as parameters automatically.

public List<EntityClass> Select(int startIndex, int pageSize, string sortBy) {}
public int Count() {}

In the ASPX, the DataSource is configured like this:

<asp:ObjectDataSource ID="ObjectDataSource1" runat="server"  
     SelectMethod="Select" EnablePaging="true"
     StartRowIndexParameterName="startIndex" 
     MaximumRowsParameterName="pageSize"
     SortParameterName="sortBy" SelectCountMethod="Count" >   
</asp:ObjectDataSource>

The Select and the Count method use Linq queries to retrieve the data from the DB. I use the Skip(), Take() and Orderby() methods. For the OrderBy to accept a string sort expression I use DynamicLinq There is not much to code, Databinding, paging and Sorting are automatically working.

If you are interested I could post more details of my code.

Related Solutions

Javascript – Sorting an array of objects by property values

Sort homes by price in ascending order:

homes.sort(function(a, b) {
    return parseFloat(a.price) - parseFloat(b.price);
});

Or after ES6 version:

homes.sort((a, b) => parseFloat(a.price) - parseFloat(b.price));

Some documentation can be found here.

For descending order, you may use

homes.sort((a, b) => parseFloat(b.price) - parseFloat(a.price));

Javascript – Sorting object property by values

Move them to an array, sort that array, and then use that array for your purposes. Here's a solution:

var maxSpeed = {
    car: 300, 
    bike: 60, 
    motorbike: 200, 
    airplane: 1000,
    helicopter: 400, 
    rocket: 8 * 60 * 60
};
var sortable = [];
for (var vehicle in maxSpeed) {
    sortable.push([vehicle, maxSpeed[vehicle]]);
}

sortable.sort(function(a, b) {
    return a[1] - b[1];
});

//[["bike", 60], ["motorbike", 200], ["car", 300],
//["helicopter", 400], ["airplane", 1000], ["rocket", 28800]]

Once you have the array, you could rebuild the object from the array in the order you like, thus achieving exactly what you set out to do. That would work in all the browsers I know of, but it would be dependent on an implementation quirk, and could break at any time. You should never make assumptions about the order of elements in a JavaScript object.

var objSorted = {}
sortable.forEach(function(item){
    objSorted[item[0]]=item[1]
})

In ES8, you can use Object.entries() to convert the object into an array:

const maxSpeed = {
    car: 300, 
    bike: 60, 
    motorbike: 200, 
    airplane: 1000,
    helicopter: 400, 
    rocket: 8 * 60 * 60
};

const sortable = Object.entries(maxSpeed)
    .sort(([,a],[,b]) => a-b)
    .reduce((r, [k, v]) => ({ ...r, [k]: v }), {});

console.log(sortable);

In ES10, you can use Object.fromEntries() to convert array to object. Then the code can be simplified to this:

const maxSpeed = {
    car: 300, 
    bike: 60, 
    motorbike: 200, 
    airplane: 1000,
    helicopter: 400, 
    rocket: 8 * 60 * 60
};

const sortable = Object.fromEntries(
    Object.entries(maxSpeed).sort(([,a],[,b]) => a-b)
);

console.log(sortable);

Best Answer

Related Solutions

Javascript – Sorting an array of objects by property values

Javascript – Sorting object property by values

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