diffopc⁺ : the diff tool for Open Packaging files

What : developer toolkit for Windows® ; diffing ; navigating ; validating
Where : Word® DOCX/DOCM, Excel® XLS/XLSX/XLSM/XLSB, Powerpoint® PPTX/PPTM, XPS documents, OpenOffice ODF documents (Calc, Writer, Impress, Draw, Base, Math)
Who : ARsT Design, independent software vendor

(1 MB)

How much does diffopc⁺ cost ? $59 US. To activate the license, simply download and install diffopc⁺, click the Register button in the main dialog, and use the serial number returned by Bluesnap to download the license file (diffopc.license.lic).

How to install and run the product :

1. Download the EXE file by clicking the button of your choice above
2. Once downloaded, double-click on diffopcplus.exe file to start it. There is no install step.

   If you are getting the "Windows protected your PC : Windows SmartScreen prevented an unrecognized app from starting" message with a blue background, click on More Info and then on Run anyway. The reason why this message appears is that Microsoft blocks applications by default for no other reason that they are new or have been recently updated.

   
   Bypassing Windows default application blocker, click on More Info then Run anyway.

System requirements :

• Windows 32-bit/64-bit
• There are no run-time dependencies.

Support :

Supported file formats

• Microsoft OOXML files (Office 2007 Word/Excel/Powerpoint)
• OpenOffice ODF files (Calc, Writer, Impress, Base, Draw, Math)
• Microsoft XPS files
• Binary XLS files
• regular ZIP files

The product in action

Experience diffopc⁺ in action here (OOXML file) or here (OpenOffice file).

The product in depth

While Microsoft® has posted specs for open packaging-based Microsoft® Office® 2007 files (Word®, Excel® and Powerpoint®), as well as XPS documents specs, there has not been much public visibility of tools for developers intending to directly access the file formats.

When you start programming with the file formats, you'll be trying to figure out the modifications in the parts before and after arbitrary changes you make. This work requires to manually crack-open zip files, possibly moving files to some working folder, opening up differing revisions of parts in a special diff tool. And that for every part. Without knowing which may have changed. Needless to say, this is time-consuming and error prone. In fact, this consumes much more time than your changes, and it only gets worse as you iterate and figure out complex changes. What's actually needed is a tool that automates this for you.

diffopc⁺ is just that. It presents a diff view of parts between revisions, automatically, and using an interactive html front-end.

It can also be used to view individual files without having to manually crack-open them by hand. Simply use the same file name in both edit boxes. To make that quick, diffopc tool lets you pick one or two files in the open file dialog, and fills the edit boxes accordingly.

The tool first shows a flat view of all parts side-by-side of two arbitrary OPC-based files, using colors to identify additions, deletions and changes (complete with the number of changes). Then it lets you click on any non-binary part to view the actual color-coded differences.

Here is an example of a diff between two revisions of an Excel® 2007 file where I have made some random changes by hand :

The older revision of the file appears on the left side, and the newer on the right. Notice that the report tells us that 4 zip entries out of the 18 zip entries in the file have changed.

Here is how the color coding works :

If you click a part, it then opens up the diff view for this part, side-by-side, using the same color coding. But this time, this really reflects the changes in the part between revisions. Here is the diff view if you click on [Content_Types].xml :

Text-based diffs are broken down in rows. Changes correspond to non-matching rows.

It gets better.

You can click on any part that has been detected as non-binary. Basically this means all xml, text, vml, html, rels, fdseq, and so on. Then, whenever the part is actually an XML stream, the diff tool automatically beautifies it (makes it wrapped and indented) so that the diff is easy to read.

Whenever binary parts are pictures, you can do a visual diff.

In the samples folder, there are a number of examples of what changes may look like. Here is the list of changes I made and the corresponding files :

Although its primary function is to generate diffs from separate files, it works very well with a single file : you can use it to view the content of the file without having to manually unzip it or work with folders which is tedious. The obvious bonus of using the tool to introspect a single file is that XML streams are made easy to read.

Corrupted ZIP entries, from a ZIP stand point, are detected. Whenever that occurs, there is a Corr label in the main html view.

diffopc⁺ options

There are a few options :

• hide/unhide Word 2007 review tags

  this option will appeal to those working with Word 2007 files and are overwhelmed by the many Word 2007 document review tags that obscure the XML streams. Note that it does not remove the tags in the file itself, only in the diff view. Hidden by default.

• custom CSS stylesheet

  the ability to specify your custom CSS stylesheet is handy if you don't like the color codings, or if you are color blind.

The tool has a command-line mode to allow automated diffing : diffopcplus.exe [-d] <file1> <file2> [<outputFolder>].

The -d option filters out useless timestamp differences such as <ModifiedDate> in a document summary part of OPC packages.

The html files are stored in a workdir folder right beneath the executable by default. The workdir folder can be specified by passing it in the command-line arguments.

How the tree view reveals the internal structure of packages

When viewing files individually, diffopc⁺ shows a tree structure whose indentation reflects the parent-children relations.

What we see in the screenshot above is that Book1.xlsx has a main part which has 3 child parts : docProps/app.xml, docProps/core.xml and xl/workbook.xml. And then we see that xl/workbook.xml has 3 child parts : xl/styles.xml, xl/theme/theme1.xml and xl/worksheets/sheet1.xml. And so on.

Likewise, the screenshot above shows the internal structure of OpenOffice documents, where meta-inf/manifest.xml is the main part, describing all child parts, indented accordingly.

Navigation and validation features

There is a validation layer that changes the color of part references to dark red. While those features benefit all OPC-based files, i.e. Word® 2007, Excel® 2007, Powerpoint® 2007 and MS XPS documents, I wanted to also add features that are specific to certain types of documents.

Here is the list of features of diffopc⁺, on top of what general purpose diffing features :

• [navigation] relations and relationships hyperlinks for all OPC-based files.
• [navigation] part hyperlinks for all OPC-based relations.
• [validation] validation layer for all individual relations/parts of OPC-based files.
• [validation] validation cross-layer for all relations/parts of OPC-based files.
• [navigation] links to theme colors for all Powerpoint, Word and Excel files.
• [navigation] additional hyperlinks for XPS documents
  • [navigation+validation] navigate internal fdseq, fdoc and fpage parts, as well as associated resources.
• [navigation] additional hyperlinks for Excel® spreadsheets
  • [navigation] navigate, introspect (tool-tip) and validate shared strings
  • [navigation] navigate shared formulas
  • [navigation] navigate styles and all their ramifications (number format, font, border, fill, theme style, indexed color)
  • [navigation] navigate conditional formatting styles
  • [navigation] navigate table named styles
  • [navigation] navigate external references (cell formulas, defined names, conditional formattings, charts)
• [navigation] additional hyperlinks for Word® documents
  • [navigation] navigate styles
  • [navigation] navigate footnotes and endnotes
  • [navigation] navigate bookmarks
• [navigation] navigational links for styles in OpenOffice files (Calc, Writer, Impress, Base, Draw, Math)
  • Calc (*.ODS, *.OTS, *.SXC, *.STC)
  • Word (*.ODT, *.OTT, *.SXW, *.STW)
  • Impress (*.ODP, *.OTP, *.SXI, *.STI)
  • Base (*.ODB)
  • Draw (*.ODG, *.OTG, *.SXD, *.STD)
  • Math (*.ODF, *.SXM)
• [navigation] navigational links for internal resources in OpenOffice files through xlink:href attributes
• [validation] validation for style inheritance across parts in OpenOffice files
  • :style-name anchors
  • style:___-name anchors
  • ___:___style-name anchors
  • parent-style-name and the likes
• [navigation] navigational links for the main parts of OpenOffice files
• [validation] validation layer for the main parts of OpenOffice files
• [validation] tracking of duplicate relationship part identifiers
• [readability] optional hiding/unhiding of Word 2007 review tags. Word 2007 documents contain a lot of review tags (w:rsidDel, w:rsidR, w:rsidRPr, w:rsidRDefault, w:rsidP, w:rsidSect, w:rsidTr) used for tracking changes made by users any time they save their documents. To hide/unhide the Word 2007 review tags, click on the Options button in diffopc+ and change the corresponding option.

To get perhaps a better sense at what this means, here are screen captures of the features :

History

diffopc.css

.N { background-color:white; } <!-- default -->

.C { background-color:#FFD71D; } <!-- changed -->

.A { background-color:#BBFFBB; } <!-- added -->

.D { background-color:#E0686E; } <!-- deleted -->

.CORR { background-color:#DDDDDD; } <!-- corrupted -->

.MISS { background-color:red; } <!-- missing -->

.B { color:#4444AA; } <!-- attributes -->