Sharepoint Tips n Tricks - Part 2

In continuation with earlier post -
Sharepoint Tips n Tricks
1) Check whether a given SPField exist or not before fetching value from it:

string columnValue = string.Empty;
string columnInternalName = string.Empty;
string fieldName = "Myfield";
SPListItem listItem; //Code to get SPListItem

//Check required SPField exist or not
if (listItem.ParentList.Fields.ContainsField(fieldName))
{
    //Get internal name of SPField   
    columnInternalName = listItem.ParentList.Fields[fieldName].InternalName;

    //Fetch column value based on internal name
    if (listItem[columnInternalName] != null)
        columnValue = listItem[columnInternalName].ToString();
}

2) SharePoint 2007 recommended guidelines for managing site collections, site, lists, and documents according to business needs:
· 50,000 site collections per content database
· 500 MB per site collection (default quota maximum)
· 50 MB file size limit (recommended) up to 2 GB (maximum)
· 2000 items per list view
3) Check whether page is in Edit Mode or not

if (Microsoft.SharePoint.SPContext.Current.FormContext.FormMode == SPControlMode.Display)
{
   // your code to support display mode
}
else if(Microsoft.SharePoint.SPContext.Current.FormContext.FormMode = SPControlMode.Edit)
{
   // your code to support edit mode
}

OR

WebPartManager wp = WebPartManager.GetCurrentWebPartManager(Page);
            
if (wp.DisplayMode == WebPartManager.BrowseDisplayMode)
    btnLink.InnerText = "Edit Page";
else if (wp.DisplayMode == WebPartManager.DesignDisplayMode)
    btnLink.InnerText = "Exit Edit Mode";
else
    btnLink.Visible = false;

Reference...
http://www.codeproject.com/KB/sharepoint/SwitchWPMode.aspx
http://mystepstones.wordpress.com/2008/09/23/detecting-the-current-mode-displayedit/
4) SPFeature to deploy page in a SharePoint site

Feature.xml
<?xml version="1.0" encoding="utf-8"?>
<Feature  Id="f08674ee-2b0e-41aa-8d28-24e788d03c11"
          Title="PageDeployment"
          Description="Description for PageDeployment"
          Version="12.0.0.0"
          Hidden="FALSE"
          Scope="Web"
          DefaultResourceFile="core"
          xmlns="http://schemas.microsoft.com/sharepoint/">
  <ElementManifests>
    <ElementManifest Location="elements.xml"/>
    <ElementFile Location="MyPage.aspx" />
  </ElementManifests>
</Feature>


Elements.xml
<?xml version="1.0" encoding="utf-8" ?>
<Elements xmlns="http://schemas.microsoft.com/sharepoint/">
  <Module  Name="Pages" Path="" Url="">
    <File Name=" MyPage.aspx" Url=" MyPage.aspx" IgnoreIfAlreadyExists="FALSE" NavBarHome="True"></File>
  </Module>
</Elements>

Code to download document from SharePoint Document Library

Following code snippet demonstrate the way to download a MS Word document (or any file) from SharePoint SPDocumentLibrary-

string siteURL = "http://localhost:80/"; //Write valid site URL 
//Get SPSite and SPWeb instance
using (SPSite spSite = new SPSite(sireURL))
{
    using (SPWeb spWeb = spSite.OpenWeb())
    {
        //Get time stamp to download file with unique name
        string strFileName = DateTime.Now.ToString("ddMMyyyy_HHmmss");

        //Get folder path
        string directoryPath = 
           Path.Combine(Environment.GetFolderPath
                          (Environment.SpecialFolder.LocalApplicationData),
                        "MyFolder");

        //Create directory if it not exist
        if (!(Directory.Exists(directoryPath)))
        {
            Directory.CreateDirectory(directoryPath);
        }

        //Get template url
        string documentUrl; //Write valid document URL

        //Download file in file system
        SPFile myFile = spWeb.GetFile(documentUrl);
        byte[] binFile = myFile.OpenBinary();

        //Generate file name
        filename = Path.Combine(directoryPath, strFileName + ".doc");

        //Do file write operation
        FileStream fs = 
             new FileStream(filename, FileMode.Create, FileAccess.ReadWrite);
        BinaryWriter bw = new BinaryWriter(fs);
        bw.Write(binFile);
        bw.Close();
    }
}