What's new in the Open XML SDK

• Packages can now be saved on .NET Core and .NET 5+ if constructed with a path or stream (#1307).
• Packages can now support malformed URIs (such as relationships with a URI such as mailto:person@)
• Introduce equality comparers for OpenXmlElement (#1476)
• IFeatureCollection can now be enumerated and has a helpful debug view to see what features are registered (#1452)
• Add mime types to part creation (#1488)
• DocumentFormat.OpenXml.Office.PowerPoint.Y2023.M02.Main namespace
• DocumentFormat.OpenXml.Office.PowerPoint.Y2022.M03.Main namespace
• DocumentFormat.OpenXml.Office.SpreadSheetML.Y2021.ExtLinks2021 namespace

• When validation finds incorrect part, it will now include the relationship type rather than a class name
• IDisposableFeature is now a part of the framework package and is available by default on a package or part.

• .NET Standard 1.3 is no longer a supported platform. .NET Standard 2.0 is the lowest .NET Standard supported.
• Core infrastructure is now contained in a new package DocumentFormat.OpenXml.Framework. Typed classes are still in DocumentFormat.OpenXml. This means that you may reference DocumentFormat.OpenXml and still compile the same types, but if you want a smaller package, you may rely on just the framework package.
• Changed type of OpenXmlPackage.Package to DocumentFormat.OpenXml.Packaging.IPackage instead of System.IO.Packaging.Package with a similar API surface
• EnumValue<T> now is used to box a struct rather than a System.Enum. This allows us to enable behavior on it without resorting to reflection
• Methods on parts to add child parts (i.e. AddImagePart) are now implemented as extension methods off of a new marker interface ISupportedRelationship<T>
• Part type info enums (i.e. ImagePartType) is no longer an enum, but a static class to expose well-known part types as structs. Now any method to define a new content-type/extension pair can be called with the new PartTypeInfo struct that will contain the necessary information.
• OpenXmlPackage.CanSave is now an instance property (#1307)
• Removed OpenXmlSettings.RelationshipErrorHandlerFactory and associated types and replaced with a built-in mechanism to enable this
• IdPartPair is now a readonly struct rather than a class
• Renamed PartExtensionProvider to IPartExtensionFeature and reduced its surface area to only two methods (instead of a full Dictionary<,>). The property to access this off of OpenXmlPackage has been removed, but may be accessed via Features.Get<IPartExtensionFeature>() if needed.
• OpenXmlPart/OpenXmlContainer/OpenXmlPackage and derived types now have internal constructors (these had internal abstract methods so most likely weren't subclassed externally)
• OpenXmlElementList is now a struct that implements IEnumerable<OpenXmlElement> and IReadOnlyList<OpenXmlElement> where available (#1429)
• Individual implementations of OpenXmlPartReader are available now for each package type (i.e. WordprocessingDocumentPartReader, SpreadsheetDocumentPartReader, PresentationDocumentPartReader), and the previous TypedOpenXmlPartReader has been removed. (#1403)
• Reduced unnecessary target frameworks for packages besides DocumentFormat.OpenXml.Framework (#1471)
• Changed some spelling issues for property names (#1463, #1444)
• Model3D now represents the modified xml element tag name am3d.model3d (Previously am3d.model3D)
• Removed DocumentFormat.OpenXml.Office.SpreadSheetML.Y2022.PivotRichData.PivotCacheHasRichValuePivotCacheRichInfo
• Removed DocumentFormat.OpenXml.Office.SpreadSheetML.Y2022.PivotRichData.RichDataPivotCacheGuid
• Removed unused SchemaAttrAttribute (#1316)
• Removed unused ChildElementInfoAttribute (#1316)
• Removed OpenXmlSimpleType.TextValue. This property was never meant to be used externally (#1316)
• Removed obsolete validation logic from v1 of the SDK (#1316)
• Removed obsoleted methods from 2.x (#1316)
• Removed mutable properties on OpenXmlAttribute and marked as readonly (#1282)
• Removed OpenXmlPackage.Close in favor of Dispose (#1373)
• Removed OpenXmlPackage.SaveAs in favor of Clone (#1376)

• Added DocumentFormat.OpenXml.Office.Drawing.Y2022.ImageFormula namespace
• Added DocumentFormat.OpenXml.Office.Word.Y2023.WordML.Word16DU namespace

• Marked OpenXmlSimpleType.TextValue as obsolete. This property was never meant to be used externally (#1284)
• Marked OpenXmlPackage.Package as obsolete. This will be an implementation detail in future versions and won't be accessible (#1306)
• Marked OpenXmlPackage.Close as obsolete. This will be removed in a later release, use Dispose instead (#1371)
• Marked OpenXmlPackage.SaveAs as obsolete as it will be removed in a future version (#1378)

• Fixed incorrect file extensions for vbaProject files (#1292)
• Fixed incorrect file extensions for ImagePart (#1305)
• Fixed incorrect casing for customXml (#1351)
• Fixed AddEmbeddedPackagePart to allow correct extensions for various content types (#1388)

• .NET 6 target with support for trimming (#1243, #1240)
• Added DocumentFormat.OpenXml.Office.SpreadSheetML.Y2022.PivotRichData namespace
• Added DocumentFormat.OpenXml.Office.PowerPoint.Y2019.Main.Command namespace
• Added DocumentFormat.OpenXml.Office.PowerPoint.Y2022.Main.Command namespace
• Added Child RichDataPivotCacheGuid to DocumentFormat.OpenXml.Office2010.Excel.PivotCacheDefinition

• Removed reflection usage where possible (#1240)
• Fixed issue where some URIs might be changed when cloning or creating copy (#1234)
• Fixed issue in FlatOpc generation that would not read the full stream on .NET 6+ (#1232)
• Fixed issue where restored relationships wouldn't load correctly (#1207)

• Added DocumentFormat.OpenXml.Office.SpreadSheetML.Y2021.ExtLinks2021 namespace (#1196)
• Added durableId attribute to DocumentFormat.OpenXml.Wordprocessing.NumberingPictureBullet (#1196)
• Added few base classes for typed elements, parts, and packages (#1185)

• Adjusted LICENSE.md to conform to .NET Foundation requirements (#1194)
• Miscellaneous changes for better perf for internal services

• Removed the preview namespace DocumentFormat.OpenXml.Office.Comments.Y2020.Reactions because this namespace will currently create invalid documents.

• Restored the PowerPointCommentPart relationship to PresentationPart.

• The relationship between the PowerPointCommentPart and the PresentationPart is deprecated and will be removed in a future version.

• Added DocumentFormat.OpenXml.Office.Comments.Y2020.Reactions namespace (#1151)
• Added DocumentFormat.OpenXml.Office.SpreadSheetML.Y2022.PivotVersionInfo namespace (#1151)

• Moved PowerPointCommentPart relationship to SlidePart (#1137)

• Removed public API analyzers in favor of EnablePackageValidation (#1154)

• Added method OpenXmlPart.UnloadRootElement that will unload the root element if it is loaded (#1126)

• Schema code generation was moved to the SDK project using C# code generators

• Added samples for strongly typed classes and Linq-to-XML in the ./samples directory (#1101, #1087)
• Shipping additional libraries for some additional functionality in DocumentFormat.OpenXml.Features and DocumentFormat.OpenXml.Linq. See documentation in repo for additional details.
• Added extension method to support getting image part type (#1082)
• Added generated classes and FileFormatVersions.Microsoft365 for new subscription model types and constraints (#1097).

• Fixed issue for changed mime type model/gltf.binary (#1069)
• DocumentFormat.OpenXml.Office.Drawing.ShapeTree is now available only in Office 2010 and above, not 2007.
• Correctly serialize new CellValue(bool) values (#1070)
• Updated known namespaces to be generated via an in-repo source generator (#1092)
• Some documentation issues around FileFormatVersions enum

• Added generated classes for Office 2021 types and constraints (#1030)
• Added Features property to OpenXmlPartContainer and OpenXmlElement to enable a per-part or per-document state storage
• Added public constructors for XmlPath (#1013)
• Added parts for Rich Data types (#1002)
• Added methods to generate unique paragraph ids (#1000)

• Fixed some nullability annotations that were incorrectly defined (#953, #955)
• Fixed issue that would dispose a TextReader when creating an XmlReader under certain circumstances (#940)
• Fixed a documentation type (#937)
• Fixed an issue with adding additional children to data parts (#934)
• Replaced some documentation entries that were generic values with helpful comments (#992)
• Fixed a regression in AddDataPartRelationship (#954)

• Additional O19 types to match Open Specifications (#916)
• Added generated classes for Office 2019 types and constraints (#882)
• Added nullability attributes (#840, #849)
• Added overload for OpenXmlPartReader and OpenXmlReader.Create(...) to ignore whitespace (#857)
• Added HexBinaryValue.TryGetBytes(...) and HexBinaryValue.Create(byte[]) to manage the encoding and decoding of bytes (#867)
• Implemented IEquatable<IdPartPair> on IdPartPair to fix equality implementation there and obsoleted setters (#871)

• Fixed serialization of CellValue constructors to use invariant cultures (#903)
• Fixed parsing to allow exponents for numeric cell values (#901)
• Fixed massive performance bottleneck when UniqueAttributeValueConstraint is involved (#924)

• Deprecated Office2013.Word.Person.Contact property. It no longer persists and will be removed in a future version (#912)

• Fixed issue where CellValue may validate incorrectly for boolean values (#890)

• Fixed issue where OpenSettings.RelationshipErrorHandlerFactory creates invalid XML if the resulting URI is smaller than the input (#883)

• Fixed bug where properties on OpenXmlCompositeElement instances could not be set to null to remove element (#850)
• Fixed OpenXmlElement.RawOuterXml to properly set null values without throwing (#818)
• Allow rewriting of all malformed URIs regardless of target value (#835)

• Added OpenSettings.RelationshipErrorHandlerFactory to provide a way to handle URIs that break parsing documents with malformed links (#793)
• Added OpenXmlCompositeElement.AddChild(OpenXmlElement) to add children in the correct order per schema (#774)
• Added SmartTagClean and SmartTagId in place of SmtClean and SmtId (#747)
• Added OpenXmlValidator.Validate(..., CancellationToken) overrides to allow easier cancellation of long running validation on .NET 4.0+ (#773)
• Added overloads for CellValue to take decimal, double, and int, as well as convenience methods to parse them (#782)
• Added validation for CellType for numbers and date formats (#782)
• Added OpenXmlReader.GetLineInfo() to retrieve IXmlLineInfo of the underlying reader if available (#804)

• Fixed exception that would be thrown if attempting to save a document as FlatOPC if it contains SVG files (#822)
• Added SchemaAttrAttribute attributes back for backwards compatibility (#825)

• Removed explicit reference to System.IO.Packaging on .NET 4.6 builds (#774)

• Fixed massive performance bottleneck when IndexReferenceConstraint and ReferenceExistConstraint are involved (#763)
• Fixed CellValue to only include three most signficant digits on second fractions to correct issue loading dates (#741)
• Fixed a couple of validation indexing errors that might cause erroneous validation errors (#767)
• Updated internal validation system to not use recursion, allowing for better short-circuiting (#766)

• Fixed broken source link (#749)
• Ensured compilation is deterministic (#749)
• Removed extra file in NuGet package (#749)

• Ensure .NET Framework builds pass PEVerify (#744)
• OpenXmlPartContainer.DeletePart no longer throws an exception if there isn't a match for the identifier given (#740)
• Mark obsolete members to not show up with Intellisense (#745)
• Fixed issue with AttributeRequiredConditionToValue semantic constraint where validation could fail on correct input (#746)

• Added FileFormatVersions.2019 enum (#695)
• Added ChartSpace and chart elements for the new 2016 namespaces. This allows the connecting pieces for building a chart part with chart styles like "Sunburst" (#687).
• Added OpenXmlElementFunctionalExtensions.With(...) extension methods, which offer flexible means for constructing OpenXmlElement instances in the context of pure functional transformations (#679)
• Added minimum Office versions for enum types and values (#707)
• Added additional CompatSettingNameValues values: UseWord2013TrackBottomHyphenation, AllowHyphenationAtTrackBottom, and AllowTextAfterFloatingTableBreak (#706)
• Added gfxdata attribue to Arc, Curve, Line, PolyLine, Group, Image, Oval, Rect, and RoundRect shape complex types per MS-OI29500 2.1.1783-1799 (#709)
• Added OpenXmlPartContainer.TryGetPartById to enable child part retrieval without exception if it does not exist (#714)
• Added OpenXmlPackage.StrictRelationshipFound property that indicates whether this package contains Transitional relationships converted from Strict (#716)

• Custom derived parts did not inherit known parts from its parent, causing failure when adding parts (#722)

• Marked the property setters in OpenXmlAttribute as obsolete as structs should not have mutable state (#698)

• Ensured attributes are available when OpenXmlElement is initialized with outer XML (#684, #692)
• Some documentation errors (#681)
• Removed state that made it non-thread safe to validate elements under certain conditions (#686)
• Correctly inserts strongly-typed elements before known elements that are not strongly-typed (#690)

• Added initial Office 2016 support, including FileFormatVersion.Office2016, ExtendedChartPart and other new schema elements (#586)
• Added .NET Standard 2.0 target (#587)
• Included symbols support for debugging (#650)
• Exposed IXmlNamespaceResolver from XmlPath instead of formatted list of strings to expose namespace/prefix mapping (#536)
• Implemented IComparable<T> and IEquatable<T> on OpenXmlComparableSimpleValue to allow comparisons without boxing (#550)
• Added OpenXmlPackage.RootPart to easily access the root part on any package (#661)

• Updated to v4.7.0 of System.IO.Packaging which brings in a number of perf fixes (#660)
• Consolidated data for element children/properties to reduce duplication (#540, #547, #548)
• Replaced opaque binary data for element children constraints with declarative model (#603)
• A number of performance fixes to minimize allocations where possible
• 20% size reduction from 5.5mb to 4.3mb
• The validation subsystem went through a drastic redesign. This may cause changes in what errors are reported.

• Fixed some documentation inconsistencies (#582)
• Fixed ToFlatOpcDocument, ToFlatOpcString, FromFlatOpcDocument, and FromFlatOpcString to correctly process Alternative Format Import Parts, or "altChunk parts" (#659)

• Added a workaround for a .NET Native compiler issue that doesn't support calling Marshal.SizeOf<T> with a struct that contains auto-implemented properties (#569)
• Fixed a documentation error (#528)

• ListValue now implements IEnumerable<T> (#385)
• Added a WebExtension.Frozen and obsoleted misspelled Fronzen property (#460)
• Added an OpenXmlPackage.CanSave property that indicates whether a platform supports saving without closing the package (#468)
• Simple types (except EnumValue and ListValue) now implement IComparable<T> and IEquatable<T> (#487)

• Removed state that was carried in validators that would hold onto packages when not in use (#390)
• EnumSimpleType parsing was improved and uses less allocations and caches for future use (#408)
• Fixed a number of spelling mistakes in documentation (#462)
• When calling OpenXmlPackage.Save on .NET Framework, the package is now flushed to the stream (#468)
• Fixed race condition while performing strict translation of attributes (#480)
• Schema data for validation uses a more compact format leading to a reduction in dll size and performance improvements for loading (#482, #483)
• A number of APIs are marked as obsolete as they have simple workarounds and will be removed in the next major change
• Fixed some constraint values for validation that contained Office 2007, even when it was only supported in later versions
• Updated System.IO.Packaging to 4.5.0 which fixes some issues on Xamarin platforms as well as minimizes dependencies on .NET Framework

• Corrected package license file reference to show updated MIT License

• Default runtime directive for better .NET Native support.

• Fixed part saving to be encoded with UTF8 but no byte order mark. This caused some renderers to not be able to open the generated document.
• Fixed exceptions thrown when errors are encountered while opening packages to be consistent across platforms.
• Fixed issue on Mono platforms using System.IO.Packaging NuGet package (Xamarin, etc) when creating a document.
• Fixed manual saving of a package when autosave is false.
• Fixed schema constraint data and standardized serialization across platforms.
• Upgraded to System.IO.Packaging version 4.4.0 which fixes some consistency with .NET Framework in opening packages.

• Package now supports .NET 3.5 and .NET 4.0 in addition to .NET Standard 1.3 and .NET Framework 4.6

• Fixed issue where assembly version wasn't set in assembly.

• Fixed crash when validation is invoked on .NET Framework with strong-naming enforced.

• SDK now supports .NET Standard 1.3

• Moved to using System.IO.Packaging from dotnet/corefx for .NET Standard 1.3 and WindowsBase for .NET 4.5.
• Cleaned up project build system to use .NET CLI.

• Added hundreds of XUnit tests. There are now a total of 1333 tests. They take about 20 minutes to run, so be patient.

• Incorporated a replacement System.IO.Packaging that fixes some serious (but exceptional) bugs found in the WindowsBase implementation