Libreoffice conference 2014 Easy hacks to improve writer - ooxml interoperability
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The document presents strategies to enhance interoperability between writers and OOXML formats, particularly focusing on LibreOffice. Key discussions include challenges in file imports and exports, addressing issues such as data loss and document crashes. Additionally, it highlights tools, examples, and contributions by Synerzip to improve LibreOffice functionality and reliability with Microsoft Word formats.
![6
DOCX File Structure
Docx File Package
_rels
docProps
word
_rels
Document.xml
header[n].xml
footer[n].xml
Styles.xml
media
themes
[content_types].xml
A lookup for each of the item referenced in document,
Header, footer (e.g. images, sounds, headers, footers)
The text of the document. Contains Links to
Other objects retrieved via lookup.
The text of the header, footer from
From documents. Also contains references
To other objects. (e.g. images used in header
Or footer)
charts
Contains the definitions for a set of styles used by
the document.
Contains media files like image, sounds, video
Which referenced in doument.xml(e.g.
image1.png)
Chart data folder. (chart[n].xml and chart[n].xml.rels)
..
Contains MIME type information for parts of the package](https://image.slidesharecdn.com/liboconeasyhackswriterooxmlinteroperability-140910004519-phpapp01/85/Libreoffice-conference-2014-Easy-hacks-to-improve-writer-ooxml-interoperability-6-320.jpg)
![20
File Export Types Of Corruptions
Invalid XML values exported
XML values are not exported as per ECMA specs
ECMA specs : valid
values for rotX are
between [-90,90]](https://image.slidesharecdn.com/liboconeasyhackswriterooxmlinteroperability-140910004519-phpapp01/85/Libreoffice-conference-2014-Easy-hacks-to-improve-writer-ooxml-interoperability-20-320.jpg)
Libreoffice conference 2014 Easy hacks to improve writer - ooxml interoperability
- 1. 1 Easy Hacks to Improve Writer - OOXML Interoperability Sushil Shinde sushil.shinde@synerzip.com LibreOffice Conference 2014, Bern in.linkedin.com/pub/sushil-shinde/18/65b/452/
- 2. 2 About Me Sr. Software Developer at Synerzip Softech India About 3 years of experience in C++ and OOXML Active contributor to LibreOffice product and community Member of TDF. Love to play, watch cricket Email: Sushil.shinde@synerzip.com IRC: #libreoffice-dev chat : sushils_
- 3. 3 Topics Interoperability OOXML and ECMA-376 DOCX File Structure Challenges during 'File Import' File Crash Data Loss Challenges during 'File Export' File Corruption Data Loss LibreOffice Hang Issues Some Useful Tools Examples
- 4. 4 Interoperability Many companies, Government Organizations, Individuals use MS Word File Formats. MS Word Formats: .doc (Binary file) .docx (OOXML File Format)
- 5. 5 OOXML and ECMA-376 Office Open XML (OOXML) Microsoft Office 2007 and later versions (like 2010, 2013) uses OOXML format. The ECMA-376 Standard This Standard defines OOXML's vocabularies and document representation and packaging details. Specifications are freely available on the ECMA website.
- 6. 6 DOCX File Structure Docx File Package _rels docProps word _rels Document.xml header[n].xml footer[n].xml Styles.xml media themes [content_types].xml A lookup for each of the item referenced in document, Header, footer (e.g. images, sounds, headers, footers) The text of the document. Contains Links to Other objects retrieved via lookup. The text of the header, footer from From documents. Also contains references To other objects. (e.g. images used in header Or footer) charts Contains the definitions for a set of styles used by the document. Contains media files like image, sounds, video Which referenced in doument.xml(e.g. image1.png) Chart data folder. (chart[n].xml and chart[n].xml.rels) .. Contains MIME type information for parts of the package
- 7. 7 Challenges In 'File Import' LibreOffice crash Data loss LibreOffice hangs
- 8. 8 File Import Crash issues Reasons can be- Programming mistakes Null pointer check Memory Leaks Some issues in import filters Some specific combinations of data
- 9. 9 Analyzing Crash Optimize File Check MS Office version (2007/2010/2013) using which file is created Use Divide and conquer method to optimize file Try to optimize file upto 1-2 pages with minimum data on it Identify XML part which is causing error Try to Identify MS Office feature which is causing error If confirmed, try to create .doc (binary version) file with same feature and check whether that file works Locate parsing and mapping of XML elements in import filters to identify root cause
- 10. 10 Crash - Example Problematic xml area fdo#79973
- 11. 11 Resolving Crash - Example Code reference : https://gerrit.libreoffice.org/#/c/9840
- 12. 12 File Import Types Of Data Loss Feature loss (ex. Text, shapes etc) Feature property loss (ex. Colors, line styles etc) Incorrect values (ex. Shape size, position etc)
- 13. File Import Reasons For Data Loss 13 MS Office feature is not supported Implement feature support Grab-bag XML Nodes not handled XML elements not mapped properly Properties lost in shape conversions (SwXShape SwXTextFrame)
- 14. 14 File Import How To Fix Data Loss Check XML Schema of missing feature Check ECMA 376 specs of missing properties Check XML properties are available in model.xml Identify LibreOffice UNO Properties for missing data Insert similar feature in LibreOffice and check properties that represent missing effects Create .doc file with same data Use XRAY tool to check properties Locate handling of those XML properties in dmapper Check XML values are properly mapped with UNO properties Hard-code UNO Properties to verify quickly
- 15. 15 Data Loss Example - shape TextBox Background image loss Original TextBox fill LO rendered before FIX LO rendered after fix
- 16. 16 Data Loss Example - shape Set proper UNO Property FillBitmapURL property for shape BackGraphicURL property for TextFrame Handled BackGraphicURL property in export if it is textframe Code Reference : https://gerrit.libreoffice.org/#/c/7259
- 17. 17 Data Loss Example - Table Original table Auto width How LO rendered LO Rendering After Fix LO : Export Before Fix After Fix
- 18. 18 Data Loss Example - Table XML Comparison Original LO Exported this.. Fixed Code Reference : https://gerrit.libreoffice.org/#/c/7593/ https://gerrit.libreoffice.org/#/c/7594/
- 19. 19 Challenges In 'File Export' MS Office not able to open 'saved file' Data loss LO crash
- 20. 20 File Export Types Of Corruptions Invalid XML values exported XML values are not exported as per ECMA specs ECMA specs : valid values for rotX are between [-90,90]
- 21. 21 File Export Types Of Corruptions XML tag mismatch Start and End tag not matching
- 22. 22 File Export Types Of Corruptions Missing target relationship entry Missing relationship file (ex. header.xml.rels) Exported 0 bytes file (Mostly in case of images/media folder contents) Relationship is present in header.xml But header.xml.rels file Is missing
- 23. 23 File Export Types Of Corruptions Invalid hierarchy Text box exported inside the another textbox Easy Hack
- 24. 24 File Export Corruption Issues Ms Office seems to have an internal limitation of 4091 styles and refuses to load .docx with more styles.
- 25. 25 Analyzing File Corruption Validate exported docx file Use OpenSDK tool to validate file (For windows only) Compare content of exported file with original file Use OOXML tool to compare file Check ECMA specs of invalid XML property Check relID's are exported properly Relationship target is present in rels xml file Check target file is available in exported file Search for export part of invalid XML in export files e.g. docxattributeoutput, docxsdrexport etc.
- 26. File Export Reasons For Data Loss 26 Features rendered properly are mostly preserved in export Reasons for Data loss can be- Mapping of UNO Properties to OOXML properties Invalid data conversion (from LO property to MSO valid XML value as per ECMA) e.g. Rotation Angle, Dashed Borders etc Required XML part is missing in exported file e.g. Fill properties from shape XML Schema
- 27. 27 File Export - How To Fix Data Loss Compare exported and original file Verify XML schema for missing feature or properties of missing feature are exported Check export code for missing XML part. Search for xml tag XML_elementname e.g. XML_rot. In export classes. Check xml parts are written under right parent elements.
- 28. 28 Data Loss - Example Numbered list is not preserved Original XML - <w:lvlText w:val="%1" /> Exported XML - <w:lvlText w:val="" /> Numbering.xml Original data Before Fix After Fix Code reference : https://gerrit.libreoffice.org/#/c/8768/
- 29. 29 LibreOffice Hang Issues LibreOffice Hangs while opening/saving docx file Reasons can be - Removed required UNO Properties PROP_PARA_LINE_SPACING Code reference : https://gerrit.libreoffice.org/#/c/9560 Not handled some required XML attributes Code reference : https://gerrit.libreoffice.org/#/c/8632/ Memory Leaks Code Reference : https://gerrit.libreoffice.org/#/c/6850
- 30. 30 Some Useful Tools Xray Tool OOXML Tools (Chrome Browser plug-in) Open XML SDK Productivity tool. (for windows)
- 31. 31 XRAY Tool
- 32. 32 OOXML Tools developed by Atul Moglewar from Synerzip. Drag and drop Compare two files
- 33. 33 Open SDK Tool
- 34. 34 More Examples
- 35. 35 Chart Wall color Wall Color was missing From exported file Lost Fixed
- 36. 36 Chart Original XML for Chart Wall Color LO : Export before fix Export After Fix Code References : https://gerrit.libreoffice.org/7739 https://gerrit.libreoffice.org/7792
- 37. 37 Doughnut chart Original chart Before fix After fix Code Reference : https://gerrit.libreoffice.org/#/c/6924
- 38. 38 Exploded Pie Chart Original chart Before fix After fix Code Reference : https://gerrit.libreoffice.org/#/c/6924
- 39. 39 Shapes in header Before Fix After Fix
- 40. 40 Fields Original XML Before Fix After Fix
- 41. 41 Smart Art Image Fills in smart are exported properly. Original File LO Export : Before Fix After Fix Code reference : https://gerrit.libreoffice.org/#/c/9121
- 42. 42 Synerzip's Contribution ~250 patches submitted by synerzip in last 1 year. 50+ scenarios of crash/corruption fixed. 270+ bugs filed on BugZilla. 200+ bugs resolved.
- 43. 43 Team Synerzip
- 44. 44 References http://cgit.freedesktop.org/libreoffice/core/log/?qt=author&q=synerzip http://msdn.microsoft.com/en-us/library/office/gg607163(v=office.14).aspx http://www.ecma-international.org/publications/standards/Ecma-376.htm http://www.datypic.com/sc/ooxml/ https://chrome.google.com/webstore/detail/ooxml-tools/bjmmjfdegplhkefakjkccocjanekbapn? https://wiki.documentfoundation.org/Macros
- 45. 45
- 46. 46 Thank You.