LINQ to SharePoint and SPMetal : Adding Data Using LINQ (part 1) - Add Data Generation Buttons to LinqSampleApplication , Add Sample Contracts

LINQ to SharePoint is a data manipulation tool designed to deal with the actual data that’s associated with an individual item. The entity classes are created based on the fields defined in the associated content types as opposed to the properties of the object that manages the content. For example, most data items in SharePoint are represented by the object model as an SPListItem object. The SPListItem has many properties, such as Title, Url, and UniqueId. None of these properties is mapped to an entity object for use by LINQ to SharePoint; instead, LINQ to SharePoint focuses only on the values of the fields that are associated with the SPListItem. As a result, it’s impossible to manipulate any properties of an SPListItem object (or any other object) using LINQ to SharePoint. In the case of a Document-based item, we can’t create an object using LINQ, because items stored in a document library must have an associated file. Since File is a property of the SPListItem object, we cannot set it via LINQ.

Since we can’t add documents to our document library using LINQ, we can write some SharePoint code that makes use of the object model to insert some sample data quickly.

Add Data Generation Buttons to LinqSampleApplication

In the LinqSampleApplication project, open Form1.cs. From the toolbox, drag three button controls, a textbox, and a label onto the design surface. The form designer should look like this:

Add Sample Contracts

Double-click the Add Sample Contracts button to add some code for the on-click event, and then add the following code:

private void button1_Click(object sender, EventArgs e)
   {
       //Add some sample data to the hire contracts document library
       //disable the button to prevent concurrency problems
       button1.Enabled = false;
       using (SPSite mySite = new SPSite(SiteUrl.Text))
       {
           using (SPWeb myWeb = mySite.OpenWeb())
           {
               for (int x = 0; x < 3; x++)
               {
                   //Since we're not interested in the document contents,
                   //create a simple text document
                   string test = x.ToString("This is test contract" +
                                            " number 000");
                   byte[] content = System.Text.Encoding.UTF8.GetBytes(test);

                   //Get a reference to the Hire Contracts list

                   SPList HireContracts=myWeb.Lists["Hire Contracts"];

                  //Generate a sequential file name

                  string filename=x.ToString("SampleContract000.txt");

                  //Upload the file to the document library
                  SPFile newFile = HireContracts.RootFolder.Files.Add(filename,
                                                                       content);

                  //Get a reference to the SPListItem that is automatically
                  //created when the document is uploaded

                  SPListItem item =newFile.Item;

                  //populate the mandatory fields with sample data

                  item["ContractId"] = x.ToString("CONT-000");
                  item["Contract Start Date"] = DateTime.Now.AddMonths(0-x);
                  item["Contract End Date"] = DateTime.Now.AddMonths(x+12);

                  //Persist the changes to the content database
                  item.SystemUpdate();
               }
            }
        }
        //change the text on the button so that we know the job's done
        button1.Text += " - Done";
   }


					  

As you’ll see from the comments, this code simply creates a few dummy Hire Contract documents in our document library. Once the documents have been uploaded, the properties are set using indexed properties on the SPListItem object. You’ll notice that the field names and the name of the document are not strongly typed. This is the problem we are addressing by using LINQ.