Converter to various book formats (PDF, epub, mobi)
XSLT CSS JavaScript CoffeeScript Other
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bin
css
src
static
xsl
README.md
index.js
package.json
step0.sh
step1.coffee
step1.sh
step3.coffee
step3.sh

README.md

What is this?

This is a mock implementation of a proposed API for generating PDFs and EPUBs in a federated OER Repository.

We are also exploring making MathML accessible for the visually impaired by converting the MathML to SVG with aural descriptions using MathJax and ChromeVox.

Ooh, let me see!

To start it up you'll need nodejs (see http://nodejs.org ) and the node package manager (npm).

To download the dependencies

npm install .
  • Install rsvg-convert (apt-get install rsvg on Debian/Ubuntu). Make sure rsvg-convert -v works from the command line.
  • Download phantomjs from http://phantomjs.org
  • Download PrinceXML from http://princexml.com

Optional: download the following libraries and toss them into ./static/lib

And, to start it up (all one line)

node bin/server.js
    --pdfgen ${PATH_TO_PRINCE_BINARY}
    --phantomjs ${PATH_TO_PHANTOMJS_BINARY}

Then, point your browser to the admin console at http://localhost:3001/

"Ok, so what now?"

Deposit a piece of content (example.cnxml) and watch all the tables populate. If they don't all end up completing successfully then probably the dependencies were not met or you passed in the wrong command line arguments.

"What are these tables?"

When you deposit a URL to a cnxml or collxml (eventually it'll only accept HTML files) several things happen:

  1. The local cache of that URL is invalidated
  2. The remote file is retrieved and converted to HTML using XSLT
  3. This intermediate HTML file is POSTed and stored at /intermediate/[id]

At this point none of the links or images have been converted; they still have the original hrefs but the HTML file has a few additional pieces in it:

  • A meta element that stores the original URL so links/images can be converted to absolute URLs
  • script tags for javascript tools like MathJax

The next step takes the HTML and

  1. Loads the javascript libraries
  2. Enqueues a task to GET the remote URLs and store them locally in /resources/[uuid]
  3. Convert links to absolute URLs
  4. If a link has the special class xinclude then a deposit is done to generate a PDF for that content (it may already be cached)
  5. Once all these tasks have spawned (since they're Promises we already know what their id/URL will be) the HTML is POSTed to /content/[id]

The next step takes the HTML with new local id's and waits until each piece of content is deposited to /content[id1,2,3].

  1. As they appear in /content each one is loaded and included in the DOM (these were links with .xinclude)
  2. The resulting HTML file is POSTed to /assembled/[id].

Finally, we can actually generate a PDF. All the modules have been assembled into one large HTML file and the images have been loaded and saved locally in /resources/.

The PDF is then stored at /content/[id].pdf.

"Cool! What else can I do?"

Here are some notes I haven't gotten around to rewriting:

From the admin page use the input box in "Deposit new content from a URL" to point to a CNXML/CollXML file. This will pull in and clean up all related documents. Some examples are on the admin page in a dropdown.

You can also download a collection and unzip it into the ./static directory. You will need to make the following changes to the collection.xml file:

  • change all of the @repository urls to be repository="/col123" (where col123 is the collection id)
  • change all the @version attributes to be version="index_auto_generated.cnxml"

Once you submit it, each piece of content goes through 4 phases:

  • /intermediate/ Converts CNXML to HTML (go to /intermediate/# to see either the list of content that is done or see the HTML of those that are completed)
  • /content/ Converts canvases and dynamic content to SVG, renames local hrefs to be absolute, requests xincluded content be converted
  • /assembled/ Includes the xincluded content into 1 big file
  • /content/#.pdf Uses HTML at /assembled/# to create a PDF (TODO)
  • /content/#.epub Uses HTML at /assembled/# to create an EPUB