SID-01455: How to avoid contents to be copied? (Flash format?)

Status:	Answered	TWiki version:		Perl version:
Category:	CategorySecurity	Server OS:		Last update:	13 years ago

Hi.

Working with the last version of TWiki, I'm trying to know if it's possible not to allow users to copy contents from the wiki.

I mean, several people have the rights to edit contents with the regular web editor, but the rest of users will view the pages in, e.g., Flash format. Other possibilities could be PDF-protected format.

I know this is an odd issue, but I'm planning an internal corporate knowledge wiki and some managers do not want contents to be easily extracted.

Any similar experience is appreciated. Thank you very much in advance.

-- GuarriMan - 2012-04-26

Discussion and Answer

This is an unusual request, there are no ready-made solution.

I recommend to look into a server-side html to pdf converter, such as http://code.google.com/p/wkhtmltopdf/. Then you need to write a TWiki plugin that calls the converter to generate a pdf each time a TWiki page is updated.

There are disadvantages though:

• Depending on how the pdf is generated users might still be able to copy from the pdf. If the conversion is done on the pixel level instead of text level you should be OK.
• You get a bunch of pdf files with no link structure in between, e.g. navigation becomes impossible

A better approach might be to use a html to png converter. A TWiki plugin calls this converter on each topic save to generate the png.The plugin could convert only the page content, and add its own header, footer and sidebar as html to preserve the navigation.

One issue are links in the main page content. If you want to make them work you need to create an image map. The tricky part is to figure out the location of the links.

HTML5 offers a JavaScript solution to convert html to png, http://stackoverflow.com/questions/923885/capture-html-canvas-as-gif-jpg-png-pdf

Keep in mind though that this will make it impossible to access the site by people with certain disabilities.

-- PeterThoeny - 2012-04-26

Hi Peter. Thank you very much for your answer.

I take note of your proposals. In our case, our wiki will not have lots of internal links, so perhaps the PNG option could be ok.

Regards.

-- GuarriMan - 2012-05-03

If you answer a question - or someone answered one of your questions - please remember to edit the page and set the status to answered. The status selector is below the edit box.