Open XML in the Sandbox

Sometime back I was given the task of taking information in an email and automating it into a specifically formatted word document (kind of a strange request I know). With me being a complete OpenXML noob, I have to admit it turned out to be much more difficult than I originally thought. Also, I had to build the solution as a sandbox solution, which made this task even more difficult.

Now I don’t know if the task that I was working on was either not very practical or just plain difficult, but one thing I do know is there is not much online about using OpenXML in a sandbox solution. In fact, there are a few people saying it can’t be done…well, they’re Wrong! Also, there are a bunch of posts about creating a Console Application using the Managed Client Object Model, but that honestly was not what I was looking for. Needless to say, it took a few different iterations using different SharePoint Object Models to get this right…I originally tried to use the Silverlight Client Object Model, but unfortunately you can’t add the OpenXML assembly to a Silverlight project. Then I tried a console application just to verify it would work. Then finally I went with a Sandbox Web Part using the SharePoint Object Model.

With all that being said, this post will go through how to create a very simple Sandbox Web Part that will create a Word document from the items in a Task List and finally save the document to the Shared Documents library in SharePoint.

The first thing you need to do to get started is to download the OpenXML SDK. For this project you will only need the SDK, not the Productivity Tools, however you can download that too if you want to.

Once you have installed the SDK we are ready to get started. The first step is to create a SharePoint project with a Web Part.

1. Fire up Visual Studio 2010, create a new SharePoint 2010 Empty project, and name it something like ExportListToWord
2. When prompted, ensure Sandbox solution is selected
3. Next right click on the ExportListToWord project and select Add >> New Item
4. Click Web Part (not Visual Web Part) and name it something like ListToWordWebPart

Next we need to add a few assembly references to our project. We need to add the OpenXML assembly and the WindowsBase assembly (for some crazy reason that I care not to get into).

1. Within the solution explorer, right click on References and click Add Reference
2. Click the .NET tab, select WindowsBase, and click OK
3. Right click on References again and select Add Reference
4. Click the Browse tab, navigate to C:\Program Files\Open XML SDK\V2.0\lib (if default SDK install), select DocumentFormat.OpenXML.dll, and click OK

Next before we get to the code we need to make sure our OpenXML assembly is included in our SharePoint Solution Package (wsp) so that we don’t need to worry about installing the SDK to the SharePoint servers.

1. Within the solution explorer expand the Package folder
2. Double click Package.package
3. At the bottom of the window click the Advanced tab
4. Click the Add button and select Add Existing Assembly
5. Click the ellipsis, browse for the DocumentFormat.OpenXML assembly as before, and click OK

Finally we get to the code. Our code will simply iterate through all items in a Tasks list on the current site, add some of the list information to a Word document, and save the document to the Shared Documents library on the current site.

The first bit of code to add are a few using statements:

using DocumentFormat.OpenXml;

using DocumentFormat.OpenXml.Packaging;

using DocumentFormat.OpenXml.Wordprocessing;

using System.IO;

Next add the following control declarations to the class:

private Button btnExportToWord;

private Label lblMessages;

Next add the following code to the CreateChildControls method:

btnExportToWord = new Button();

btnExportToWord.Text = "Export to Word";

btnExportToWord.Click += new EventHandler(btnExportToWord_Click);

this.Controls.Add(btnExportToWord);

lblMessages = new Label();

this.Controls.Add(lblMessages);

Lastly, add the following method after the CreateChildControls method:

private void btnExportToWord_Click(object sender, EventArgs e)

{

    /* Try to create the document and save to SharePoint */

    try

    {

        /* Memory stream used to build the file */

        using (MemoryStream memoryStream = new MemoryStream())

        {

            /* WordprocessingDocument used to build the Word Document */

            using (WordprocessingDocument doc = WordprocessingDocument.Create(memoryStream, WordprocessingDocumentType.Document))

            {

                // Setup main parts of the document

                MainDocumentPart mainPart = doc.AddMainDocumentPart();

                mainPart.Document = new Document();

                Body body = new Body();

                Paragraph paragraph = new Paragraph();

                Run run = new Run();

                Text text;

                SPList list = SPContext.Current.Web.Lists["Tasks"];

                /* foreach item in the list add a new text child to the run */

                foreach (SPListItem item in list.Items)

                {

                    text = new Text(String.Format("Title: {0}", item["Title"].ToString()));

                    run.AppendChild(text);

                    run.AppendChild(new Break());

                    text = new Text(String.Format("Priority: {0}", item["Priority"].ToString()));

                    run.AppendChild(text);

                    run.AppendChild(new Break());

                    text = new Text(String.Format("Status: {0}", item["Status"].ToString()));

                    run.AppendChild(text);

                    run.AppendChild(new Break());

                    run.AppendChild(new Break());

                }

                // Append parts up the Document tree

                paragraph.Append(run);

                body.Append(paragraph);

                mainPart.Document.Append(body);

            }

            memoryStream.Seek(0, SeekOrigin.Begin); // Set stream position to the beginning

            SPFolder folder = SPContext.Current.Web.Lists["Shared Documents"].RootFolder; // SharePoint library to store the file

            string fileName = "Tasks.docx";

            folder.Files.Add(fileName, memoryStream.ToArray(), true); // Add the file to the library and overwrite if necessary

            lblMessages.Text = "Document saved to: <a href='" + folder.ServerRelativeUrl + "/" + fileName + "'>" + folder.ServerRelativeUrl + "/" + fileName + "</a>";

            }

        }

        /* Catch any exceptions and output the error to the Messages Label */

        catch (Exception ex)

        {

            lblMessages.Text = "Error: " + ex.Message;

        }

    }

So if you look at the code block above you see the first thing we do is create a WordprocessingDocument within the MemoryStream. Next we setup the main parts of the document. Next we cycle all items in the Tasks list and create new Text Objects for each piece of the list item, separated with Breaks. Then we close out each part of the document by appending each child element to its parent. Next we take what is in the memory stream (our document) and add it to the Shared Documents library.

As you can see there really isn’t much to it. The hardest part I think is figuring out the OpenXML API, but hopefully the example above is pretty straight forward.

So there you have it! OpenXML in the Sandbox.

Note: It looks like OpenXML is not currently supported in SharePoint Online (Office 365). If you attempt to activate a solution which contains the DocumentFormat.OpenXML.dll you will receive the following error:

Error validating assembly ‘DocumentFormat.OpenXml.dll’.
This solution references prohibited type ‘System.Runtime.Remoting.ObjectHandle’ and cannot be used on this site collection.

The error implies that the OpenXML assembly uses System.Runtime.Remoting.ObjectHandle which makes no sense to me. Either way, this does still work in On Premise SharePoint 2010 Sandbox…still pretty weak though…

The post Open XML in the Sandbox appeared first on MetroStar Systems Blog.