/// <summary>
/// Initializes a new instance of the <see cref="SpssDataDocument"/> class
/// and opens an existing SPSS file, or creates a new one.
/// </summary>
/// <param name="filename">The path of the file to open/create.</param>
/// <param name="access">The desired file access.</param>
protected SpssDataDocument(string filename, SpssFileAccess access)
{
this.Filename = filename;
this.AccessMode = access;
int handle;
switch (access)
{
case SpssFileAccess.Read:
SpssException.ThrowOnFailure(SpssSafeWrapper.spssOpenRead(filename, out handle), "spssOpenRead");
break;
case SpssFileAccess.Append:
SpssException.ThrowOnFailure(SpssSafeWrapper.spssOpenAppend(filename, out handle), "spssOpenAppend");
break;
case SpssFileAccess.Create:
SpssException.ThrowOnFailure(SpssSafeWrapper.spssOpenWrite(filename, out handle), "spssOpenWrite");
break;
default:
throw new ApplicationException("Unrecognized access level: " + access);
}
this.Handle = new SpssSafeHandle(handle, access);
if (access == SpssFileAccess.Create)
{
this.IsCompressed = true;
}
this.IsAuthoringDictionary = true;
this.Variables = new SpssVariablesCollection(this);
this.Cases = new SpssCasesCollection(this);
this.IsAuthoringDictionary = access == SpssFileAccess.Create;
}
/// <summary>
/// Opens an SPSS data document for reading or appending.
/// </summary>
/// <param name="filename">
/// The filename of the existing document to open.
/// </param>
/// <param name="access">
/// <see cref="FileAccess.Read"/> for read only access, or
/// <see cref="FileAccess.Write"/> for append access.
/// </param>
/// <returns>
/// The newly opened <see cref="SpssDataDocument">SPSS data document</see>.
/// </returns>
/// <remarks>
/// This method is only for opening existing data documents.
/// To create a new document, use the <see cref="Create(string)"/> method.
/// </remarks>
public static SpssDataDocument Open(string filename, SpssFileAccess access)
{
if (access == SpssFileAccess.Create)
{
throw new ArgumentOutOfRangeException("access", access, "Use Create method to create a new file.");
}
return new SpssDataDocument(filename, access);
}
/// <summary>
/// Initializes a new instance of the <see cref="SpssSafeHandle"/> class.
/// </summary>
/// <param name="handle">The SPSS handle.</param>
/// <param name="accessMode">The access mode the handle was opened with.</param>
public SpssSafeHandle(int handle, SpssFileAccess accessMode)
: base(true)
{
this.accessMode = accessMode;
this.SetHandle(new IntPtr(handle));
}
