FR: Support comparing PDF files

[Gitoffthelawn]

It would be incredible if WinMerge supported comparing PDF files.

Even if it isn't perfect, it will be a great feature.

Thank you again for WinMerge!

[sdottaka]

You can use the xdocdiff WinMerge plugin to extract and compare text from PDF files.

http://freemind.s57.xrea.com/xdocdiffPlugin/en/index.html

(WinMerge version 2.16.13 includes a new ApacheTika plugin that allows you to extract and compare text content from PDF files.)

You can also compare PDF files as image files by specifying the .pdf extension in the "Image File Patterns" combo box in the Compare/Image category of the Options dialog.

[Gitoffthelawn]

@sdottaka Thank you! I will take a look at both of your suggestions, and report back after I have done so.

I still think a proper PDF compare will be great, but one of these ideas might be a big improvement.

Is there anything similar for JSON files, or should I create another issue report for that format?

[sdottaka]

For JSON and XML files, I am planning to create a Formatter plugin.

[Gitoffthelawn]

For JSON and XML files, I am planning to create a Formatter plugin.

Wonderful! I'm guessing the XML plugin will be able to handle HTML well. Is that correct?

[sdottaka]

I would like to be able to handle HTML files as well.

[jrathlev]

Here is another HTML plugin

[outsidecoder]

xdocdiffPlugin_1_0_6d.zip seems to have Trojan.Malware.300983.susgen Malware virus, according to MaxSecure on VirusTotal.com.

Has anyone else noticed this?

[JohnF-tfa]

WinMerge supports comparing PDF files via the Apache Tika plugin.
BUT it is broken because the URLs to download Tika and JAI are broken.

The fix is relatively easy, you need to find the tika.bat which is installed under your WinMerge program folder in the 'Commands\Apache-Tika' folder.
e.g. 'C:\Program Files\WinMerge\Commands\Apache-Tika' (if you've installed the x64 version)

You will probably need elevated privileges to backup and edit 'tika.bat'

Just in case, backup tika.bat before you edit it.

Replace the contents with the following

@echo off
setlocal EnableDelayedExpansion
set TikaVer=2.1.0
set JaiVer=1.4.0
set TikaJar=tika-app-%TikaVer%.jar
set JaiJar=jai-imageio-jpeg2000-%JaiVer%.jar
set DOWNLOAD_URL=https://repo1.maven.org/maven2/org/apache/tika/tika-app/%TikaVer%/%TikaJar%
set DOWNLOAD_URL_JPEG2000=https://repo1.maven.org/maven2/com/github/jai-imageio/jai-imageio-jpeg2000/%JaiVer%/%JaiJar%
set TIKA_PATH=Commands\Apache-Tika\%TikaJar%
set JAI_IMAGEIO_JPEG2000_PATH=WinMerge\Commands\Apache-Tika\%JaiJar%
set MESSAGE='Apache Tika is not installed. Do you want to download it and its dependences from %DOWNLOAD_URL% and %DOWNLOAD_URL_JPEG2000%?'
set TITLE='Apache Tika Plugin'

cd "%APPDATA%\WinMerge"
if not exist %TIKA_PATH% (
  cd "%~dp0..\.."
  if not exist %TIKA_PATH% (
    mkdir "%APPDATA%\WinMerge" 2> NUL
    cd "%APPDATA%\WinMerge"
    for %%i in (%TIKA_PATH%) do mkdir %%~pi 2> NUL
    powershell "if ((New-Object -com WScript.Shell).Popup(%MESSAGE%,0,%TITLE%,1) -ne 1) { throw }" > NUL
    if errorlevel 1 (
      echo "download is canceled" 1>&2
    ) else (
      start "Downloading..." /WAIT powershell -command "[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; Invoke-WebRequest %DOWNLOAD_URL% -Outfile %TIKA_PATH%"
      start "Downloading..." /WAIT powershell -command "[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; Invoke-WebRequest %DOWNLOAD_URL_JPEG2000% -Outfile %JAI_IMAGEIO_JPEG2000_PATH%"
    )
  )
)
java -Xbootclasspath/a:%JAI_IMAGEIO_JPEG2000_PATH% -jar %TIKA_PATH% %3 %4 %5 %6 %7 %8 %9 "%~1" > "%~2"
```

[Gitoffthelawn]

@JohnF-tfa Thank you for those details John!

[JohnF-tfa]

I find being able to do an image compare and a text compare of PDFs very useful.

[Gitoffthelawn]

@JohnF-tfa wrote:

I find being able to do an image compare and a text compare of PDFs very useful.

Hmmm... what do you mean?

I could see a text compare perhaps being helpful because often many of the strings within a PDF file are stored as plain text. But how do you find an image compare helpful?

[sdottaka]

@JohnF-tfa Thank you for the patch.
I changed the URL in commit 2e5cdec.
I'm sure the previous URL was fine before, but when I tried it now, it did indeed fail to download.