/// <summary>
/// Protected constructor for the abstract Base class.
/// This is the current contract between the subclass and the base class
/// If we decide some registration mechanism then this might change
///
/// NOTE : If you are using this constructor from your subclass or passing a null
/// for the content type parameter, be sure to implement the GetContentTypeCore
/// method, as that will be called to get the content type value. This is provided
/// to enable lazy initialization of the ContentType property.
///
/// </summary>
/// <param name="package">Package in which this part is being created</param>
/// <param name="partUri">uri of the part</param>
/// <param name="contentType">Content Type of the part, can be null if the value
/// is unknown at the time of construction. However the value has to be made
/// available anytime the ContentType property is called. A null value only indicates
/// that the value will be provided later. Every PackagePart must have a valid
/// Content Type</param>
/// <param name="compressionOption">compression option for this part</param>
/// <exception cref="ArgumentNullException">If parameter "package" is null</exception>
/// <exception cref="ArgumentNullException">If parameter "partUri" is null</exception>
/// <exception cref="ArgumentOutOfRangeException">If CompressionOption enumeration [compressionOption] does not have one of the valid values</exception>
/// <exception cref="ArgumentException">If parameter "partUri" does not conform to the valid partUri syntax</exception>
protected PackagePart(Package package,
Uri partUri,
string contentType,
CompressionOption compressionOption)
{
if (package == null)
{
throw new ArgumentNullException("package");
}
if (partUri == null)
{
throw new ArgumentNullException("partUri");
}
Package.ThrowIfCompressionOptionInvalid(compressionOption);
_uri = PackUriHelper.ValidatePartUri(partUri);
_container = package;
if (contentType == null)
{
_contentType = null;
}
else
{
_contentType = new ContentType(contentType);
}
_requestedStreams = null;
_compressionOption = compressionOption;
_isRelationshipPart = PackUriHelper.IsRelationshipPartUri(partUri);
}
/// <summary>
/// This method is for custom implementation for the underlying file format
/// Adds a new item to the zip archive corresponding to the PackagePart in the package.
/// </summary>
/// <param name="partUri">PartName</param>
/// <param name="contentType">Content type of the part</param>
/// <param name="compressionOption">Compression option for this part</param>
/// <returns></returns>
/// <exception cref="ArgumentNullException">If partUri parameter is null</exception>
/// <exception cref="ArgumentNullException">If contentType parameter is null</exception>
/// <exception cref="ArgumentException">If partUri parameter does not conform to the valid partUri syntax</exception>
/// <exception cref="ArgumentOutOfRangeException">If CompressionOption enumeration [compressionOption] does not have one of the valid values</exception>
protected override PackagePart CreatePartCore(Uri partUri,
string contentType,
CompressionOption compressionOption)
{
//Validating the PartUri - this method will do the argument checking required for uri.
partUri = PackUriHelper.ValidatePartUri(partUri);
if (contentType == null)
{
throw new ArgumentNullException(nameof(contentType));
}
Package.ThrowIfCompressionOptionInvalid(compressionOption);
// Convert Metro CompressionOption to Zip CompressionMethodEnum.
CompressionLevel level;
GetZipCompressionMethodFromOpcCompressionOption(compressionOption,
out level);
// Create new Zip item.
// We need to remove the leading "/" character at the beginning of the part name.
// The partUri object must be a ValidatedPartUri
string zipItemName = ((PackUriHelper.ValidatedPartUri)partUri).PartUriString.Substring(1);
ZipArchiveEntry zipArchiveEntry = _zipArchive.CreateEntry(zipItemName, level);
//Store the content type of this part in the content types stream.
_contentTypeHelper.AddContentType((PackUriHelper.ValidatedPartUri)partUri, new ContentType(contentType), level);
return(new ZipPackagePart(this, zipArchiveEntry.Archive, zipArchiveEntry, _zipStreamManager, (PackUriHelper.ValidatedPartUri)partUri, contentType, compressionOption));
}