1. Open XML Packages, Parts and Relationships

2. Disclaimer
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3. Overview Introduction to the Open Packaging Convention
Working with System.IO.Packaging

4. Lesson: Introduction to the Open Packaging Convention
Open XML Formats Architecture
Components of the Open Packaging Convention

5. Elements of the Open Packaging Convention
Common Package Parts
Package Relationships
Core Properties
Digital Signatures
Specific Format Parts
Office Document
Part Relationships
Binary Part
XML Part
Part Rels
Etc…
Content Types Stream
Package – The container
Document Parts – The components of the document
Content Types Stream – defines content type of parts
Relationships – references to other parts of the document
“Start Part” – The root of the document

6. The Package A package is
A logical entity that holds a collection of parts
An aggregation of all pieces of a document in a single object
Not tied to a physical representation
ZIP, Database, loose files
Typically a ZIP file e.g. Rename *.docx to *.zip
Special features
Core properties
Thumbnail parts
Digital signatures

7. Document Parts A part is Content type is enforced
analogous to a file on the file system
stored inside the package in a specific location reachable via a URI
stored with a specific content type
mainly XML but other native types as well
Images, sounds, video, OLE objects
Content type is enforced
Example: cannot tag JPEG part as GIF
A part can use growth hints to allow uninterrupted content growth

8. Content Types Define the type of media stored in the part.
The content types stream
Defines mappings from part to content type
Is not directly addressable
Default values and part specific overrides
[Content_Types].xml
<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>
<Types>
<Default Extension="jpeg" ContentType="image/jpeg" />
<Default Extension="rels" ContentType=
"application/vnd.openxmlformats-package.relationships+xml" />
<Default Extension="xml" ContentType="application/xml" />
<Override PartName="/word/document.xml"
ContentType=
"application/vnd.openxmlformats-officedocument.wordprocessingml.document.main+xml"/>
</Types>
Defaults
Overrides

9. Relationships Relationships are stored in XML streams in the package
Ties elements inside the package to each other
Allows navigation of document without parsing parts
Package relationships stream URI: /_rels/.rels
Part relationships stream URI: _rels/[partname].rels
<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>
<Relationships xmlns="
<Relationship
Id=“rId1“
Type="
/2006/relationships/officeDocument"
Target="document.xml"/>
</Relationships>
Relationship ID
Relationship Type
Target URI

10. Relationships A relationship has its own type
The type gives meaning to the content in a part for a given context
A way to say “The styles part is stored at that location”
/document.xml
…wordprocessingml.document.main+xml
Part URI
Part content type
_rels/document.xml.rels
Rel. type
/styles.xml
Target URI
/styles.xml
…wordprocessingml.styles+xml
Part URI
Part content type

11. Inside an Open XML Package
demo
For this demo use MinimalImage.docx

12. Identifying the OfficeDocument “start part”
The OPC Package
Your
Code
Content Type Stream
[Content_Types].xml
Package Relationships
/_rels/.rels
Office Document Part
e.g. /document.xml
GetRelationship (Rel.Type) : “
PartUri : “/document.xml”
GetContentType (PartUri) : “/documents.xml”
Default extension
or URI override
ContentType :
“application/vnd…wordprocessingml.document.main+xml”
GetPart (PartUri) : “/document.xml”
Part: XML

13. Identifying implicitly related parts
The OPC Package
Your
Code
Content Type Stream
[Content_Types].xml
Doc.Part
document.xml
Part Relationships
/_rels/document.xml.rels
Related Part
/styles.xml
GetRelationship (Rel.Type): “
GetRelationship (Rel.Type): “
PartUri : “/styles.xml”
PartUri : “/styles.xml”
GetContentType (PartUri): “/styles.xml”
Default extension
or URI override
ContentType:
“application/vnd.openxmlformats-officedocument.wordprocessingml.styles+xml”
GetPart (PartUri): “/styles.xml”
Part: XML

14. Identifying explicitly related parts
The OPC Package
Your
Code
Content Type Stream
[Content_Types].xml
Doc.Part
document.xml
Part Relationships
/_rels/document.xml.rels
Related Part
/pict.png
GetRelationship (Rel.ID): “rId1”
GetRelationship (Rel.ID): “rId1”
PartUri : “/pict.png”
PartUri : “/pict.png”
GetPartType (PartUri): “/pict.png”
Default extension
or URI override
ContentType (Default extension or Override Uri):
“image/png”
GetPart (PartUri): “/pict.png”
Part: Binary

15. demo Package Explorer Open source tool written by Wouter van Vugt

16. Lesson: Working with System.IO.Packaging
Components of System.IO.Packaging
Traversing a Package
Manipulating a Package
Open XML Password Hashing

17. Components of System.IO.Packaging The library
Part of Windows Presentation Foundation
Installed with .NET 3.0+
Requires .NET 2.0 Runtime
Enables package manipulation for
Open XML File Formats
XML Paper Specification Files
Any Open Packaging Convention files
Open XML SDK 2.0 provides more advanced OPC manipulation tooling

18. Components of System.IO.Packaging The Package
Common Package Parts
Package Relationships
Core Properties
Digital Signatures
Specific Format Parts
Office Document
Part Relationships
XML Part
Part Rels
Etc…
Package class provides methods to create, enumerate and delete the following entities
Package
Package Properties
PackageRelationships
PackageParts

19. Components of System.IO.Packaging The PackageRelationship
Common Package Parts
Package Relationships
Core Properties
Digital Signatures
Specific Format Parts
Office Document
Part Relationships
XML Part
Part Rels
Etc…
Required to find parts (part names are not guaranteed)
Iterate through a RelationshipCollection by type or ID
Relationship Properties ID
Package
RelationshipType
SourceUri
TargetMode
TargetUri

20. Components of System.IO.Packaging The PackagePart
Common Package Parts
Package Relationships
Core Properties
Digital Signatures
Specific Format Parts
Office Document
Part Relationships
XML Part
Part Rels
Etc…
A PackagePart is the object of data within the Package
It provides support to create, enumerate and delete part relationships
Get data as a System.IO.Stream
PackagePart properties:
CompressionOption
ContentType
Package
Uri

21. Components of System.IO.Packaging The PackUriHelper
Find a related PackagePart by searching relationships, either by relationship type or relationship ID
This returns a list of PackageRelationship objects
A PackageRelationship defines two relative URIs
Source URI, pointing to the source PackagePart
Target URI, pointing to the target PackagePart
Retrieve a PackagePart by using a URI relative to the root of the Package
Translation of Source and Target URIs is required
Use the PackUriHelper class to aid in the translation

22. Traversing a Package Opening the “Start-Part”
<Relationships xmlns=“
<Relationship Id="rId2" Type=" relationships/metadata/core-properties" Target="docProps/core.xml" />
  <Relationship Id="rId1" Type="
officeDocument/2006/relationships/officeDocument" Target="word/document.xml" />
  </Relationships>

23. Traversing a Package Opening the “Start-Part”
<Relationships xmlns=“
<Relationship Id="rId2" Type=" relationships/metadata/core-properties" Target="docProps/core.xml" />
  <Relationship Id="rId1" Type="
officeDocument/2006/relationships/officeDocument" Target="word/document.xml" />
  </Relationships>
<w:document
xmlns:w="
wordprocessingml/2006/main">
<w:body>
<w:p>
<w:r>
<w:t>Hello World!</w:t>
</w:r>
</w:p>
</w:body>
</w:document>

24. Traversing a Package Opening the “Start-Part”
Now using the Packaging API
string relationshipType = "
using (Package package = Package.Open("mydocument.docx")) {
PackageRelationship relationship = null;
foreach (PackageRelationship searchRelation in
package.GetRelationshipsByType(relationshipType))
relationship = searchRelation;
break; }
Uri partUri = PackUriHelper.ResolvePartUri(
relationship.SourceUri, relationship.TargetUri);
PackagePart mainPart = package.GetPart(partUri);
// Do something with mainPart

25. Traversing a Package Opening a related document part
<Relationships xmlns="
  <Relationship Id="rId5" Type="
relationships/theme" Target="theme/theme1.xml" />
  </Relationships>

26. Traversing a Package Opening a related document part
<Relationships xmlns="
  <Relationship Id="rId5" Type="
relationships/theme" Target="theme/theme1.xml" />
  </Relationships>
<a:theme
xmlns:a="
name="Office Theme">
<a:themeElements>
<a:clrScheme name="Office">
<a:dk1>
<a:sysClr val="windowText" lastClr="000000" />
</a:dk1>

27. Traversing a Package Opening a related document part
You can retrieve a Part using a relationshipID
Or using the relationshipType
string relID= “rId1”;
PackageRelationship imagerelationship = mainPart.GetRelationship(relID);
Uri imagePartUri = PackUriHelper.ResolvePartUri(
imagerelationship.SourceUri, imagerelationship.TargetUri);
PackagePart imagepart = mainPart.Package.GetPart(imagePartUri);
string RT_Image = “
int imageCount = 0;
foreach (PackageRelationship relation in
mainPart.GetRelationshipsByType(RT_Image)) {
imageCount++; }
Console.WriteLine("The part references {0} unique images", imageCount);

28. Traversing a Package
demo

29. Creating a New Package
The Packaging API allows you to create new Packages based on a file or stream
Package.Open creates the Package when using the correct parameters
using (Package package = Package.Open("newFile.xlsx",
FileMode.OpenOrCreate, FileAccess.ReadWrite)) {
// the Package is now on disk, 0 bytes in size }

30. Creating a Part Create a PackagePart using
Location (Uri)
Content type (String)
You can not alter the content type later on
Make sure the location is not in use
Use a Stream to modify the PackagePart contents
string contentType = “application/vnd.openxmlformats-officedocument.spreadsheetml.sheet.main+xml”;
PackagePart part = package.CreatePart(
new Uri(“workbook.xml”, UriKind.Relative), contentType);
using (StreamWriter writer = new StreamWriter(
part.GetStream(FileMode.Create, FileAccess.Write))) {
using (StreamReader reader = new StreamReader(path))
writer.Write(reader.ReadToEnd()); }

31. Creating Part Relationships
Each PackagePart needs to be related to its child parts
Relationship ID, RelationshipType, TargetMode
using (Package package = Package.Open("newFile.xlsx",
FileMode.OpenOrCreate, FileAccess.ReadWrite)) {
PackagePart workbook = package.CreatePart(
new Uri(“/workbook.xml”, UriKind.Relative),
“application/vnd...sheet.main+xml”);
PackagePart sheet = package.CreatePart(
new Uri(“/sheet1.xml”, UriKind.Relative),
“application/vnd...worksheet.main+xml”, package);
package.CreateRelationship( new Uri("/workbook.xml", UriKind.Relative), TargetMode.Internal,
" "rId1");
workbook.CreateRelationship( new Uri("/sheet1.xml", UriKind.Relative), TargetMode.Internal,
" "rId1"); }
Start
Part
Related
Part

32. Digital Signatures Digital Signatures in the Package
Allows the validation of package integrity using X.509 certificates
You can sign
All parts, including digital signatures
All relationships, or a subset of a set of relationships
Navigate signatures with the Digital Signature Origin Part

33. Digital Signatures Relationship Relationship URI URI URI URI
Digital Signature Origin Part
Relationship
Relationship
Digital Signature XML Signature Part
Digital Signature XML Signature Part
URI
URI
URI
X.509
Signed Part
URI
Signed Part
Signed Part
Signed Part
X.509 Certificate Part

34. Where to get the Open XML SDK 2.0
Find links on homepage of Open XML Developer:
MSDN documentation:
MSDN support forum:

35. How to think about OPC packages
Files and folders – NO!
Parts and relationships – YES
The specific part names and folder structure are arbitrary implementation details that could change. (e.g., Corel, OpenOffice)
The relationship structure is the true logical structure of the document.

36. Resources OpenXMLDeveloper.org
Brian Jones’s and Zeyad Rajabi’s Office Solutions blog
Doug Mahugh’s blog
XPS Blog: