EEA Epub

A product which allows you to import in Plone epub files.

Contents

Introduction

EEA Epub product allows you to import in Plone epub files. On upload, Epub content will imported as Plone folders, files, images and documents.

Export to Epub is also available.

As of version 4.3 epub files created with Adobe InDesign CS4 and Sigil are tested and known to work with this package, previous versions of this package only supported epubs created with InDesign.

Main features

EEA Epub features:

1. Imports epub files as Plone content.
2. Stores the original epub in the main folder for easy retrieval.
3. Exports the Plone content back into an epub.
4. Clean filename as you import the epub and they contain characters that wouldn't be allowed as a Plone id. This behaviour is on by default but it can be disabled by unchecking the boolean flag at portal_properties/site_properties clean_epub_file_names. If you find that the Document Pages added by the Epub process has broken links try to re-upload without this boolean flag.
5. Possibility to temporarily disable dynamic ePub creation by adding an item called 'action-download-epub' within context
6. Asynchronously generate ePub files and notify users by email when ePub is ready

Epub compatibility

EEA Epub makes the following assumptions about the loaded epub:

1. You don't use unicode or other special characters into the name of the epub, images or links
2. You've created the epub with "Adobe InDesign CS4" or "Sigil" which uses some standards for the following:
   • The table of contents is named toc.ncx and is placed inside OEBPS
   • Book text & images are placed inside the folder OEBPS or other folders that are children of OEBPS
   • Items ids doesn't contain the following characters . / ( if possible stick to letters, numbers and - _ )

Best practices when creating an epub:

1. Chapter names should not be all uppercase or use special characters
2. Image names should not contain spaces, periods, / or other special characters

Debugging

At this moment any errors that would appear on the site are surpressed with a info message.

If you want to see the detailed error check the Plone instance log usually found in buildout-folder/var/log.

Installation

The easiest way to get eea.epub support in Plone 4 using this package is to work with installations based on zc.buildout. Other types of installations should also be possible, but might turn out to be somewhat tricky.

To get started you will simply need to add the package to your eggs and zcml sections, run buildout, restart your Plone instance and install the eea.epub package using the quick-installer or via the "Add-on Products" section in "Site Setup":

[instance]
eggs =
    eea.epub

zcml =
    eea.epub

You can download a sample buildout at:

https://github.com/eea/eea.epub/tree/master/buildouts/plone4

Asynchronous setup

By default all ePubs are NOT generated asynchronous. You'll need eea.pdf installed in order to be able to enable asynchronous download or you can provide an os environment called EEACONVERTER_ASYNC.

Also some extra config is needed within your buildout in order for this to work properly.

First of all you'll need a folder were to store generated ePub files. For this you can create it manually within buildout:directory/var/ or you can let buildout handle it:

[buildout]

parts +=
    media-downloads
    media-downloads-temp

media-downloads-path = ${buildout:directory}/var/downloads/pdf
media-downloads-temp = ${buildout:directory}/var/downloads/tmp

[media-downloads]
recipe = ore.recipe.fs:mkdir
path = ${buildout:media-downloads-path}
mode = 0700
createpath = true

[media-downloads-temp]
recipe = ore.recipe.fs:mkdir
path = ${buildout:media-downloads-temp}
mode = 0700
createpath = true

This will create a folder named downloads within buildout:directory/var/

Next, in order for this folder to be visible from your website and your users to be able to download generated ePubs you'll need to tell to your zope instances about it:

[buildout]

media-downloads-name = downloads
media-downloads-path = ${buildout:directory}/var/downloads/pdf
media-downloads-temp = ${buildout:directory}/var/downloads/tmp

[instance]

environment-vars +=
  EEADOWNLOADS_NAME ${buildout:media-downloads-name}
  EEADOWNLOADS_PATH ${buildout:media-downloads-path}
  EEACONVERTER_TEMP ${buildout:media-downloads-temp}
  EEACONVERTER_ASYNC True

Also, don't forget to setup plone.app.async

[buildout]

[instance]
eggs +=
    plone.app.async
zcml +=
    plone.app.async-single_db_worker

Getting started

Import

From "Add new" menu select "EpubFile" and upload an epub file.

Export

Go to Home page and click on download as ePub icon at the bottom of the page

or directly access http://localhost:8080/Plone/front-page/download.epub

Custom permissions

Custom permissions added by this package

Can download ePub (eea.epub.download)

Assign this permission to roles that you want to be able to download content as ePub Default: Owner, Manager, Editor

Can customize ePub (eea.epub.customize)

Assign this permission to roles that you want to be able to contextually customize the output ePub look and feel Default: Manager, Site Administrator

Content rules

This package uses Plone Content-rules to notify users by email when an asynchronous ePub job is done. Thus 3 custom content-rules will be added within Plone > Site Setup > Content-rules

ePub export succeeded

Notify the person who requested a ePub export that the ePub successfully exported and provide a link to the downloadable ePub

ePub export failed

Notify the person who requested a ePub export that the ePub export failed.

ePub export failed (admin)

Notify admin that there were issues while exporting ePub

Content rules email string substitution

In order to be able to easily customize emails sent by this package the following custom email template string substitutions can be made

${download_came_from_url}

The absolute URL of the Plone object which is downloaded as ePub

${download_email}

Email address of the user that triggered the download as ePub action

${download_error}

Error traceback when download as ePub job fails

${download_from_email}

Site Admin email address customizable via Plone > Site Setup > Mail

${download_from_name}

Site Admin name customizable via Plone > Site Setup > Mail

${download_title}

Title of the Plone object which is downloaded as ePub

${download_url}

The absolute URL where the generated output ePub can be downloaded

${download_type}

Download type. Default to EPUB for this package. It is package specific and it can be EPUB, PDF, etc.

Disable ePub export

You have the possibility to temporarily disable dynamic ePub export contextually by adding a static ePub file (or a Python Script, Page Template, etc) within context called action-download-epub. This way /download.epub will return this file instead of generating one based on context data.

Content rules

This package uses Plone Content-rules to notify users by email when an asynchronous ePub job is done. Thus 3 custom content-rules will be added within Plone > Site Setup > Content-rules

Troubleshooting

ePub files are generated asynchronously using a parallel zc.async queue.quota. The number of workers that will generate ePUBs in parallel is automatically calculated based on the number of zeo-clients registered with plone.app.async-*_db_worker.

As every db_worker can handle simultaneously maximum 3 jobs (hard-coded in zc.async Agent), if you have 2 workers then the maximum number of ePub files that will be generated at the same time will be 6 (2 workers * 3). Same if you have 5, you'll get 15 ePub files generated at the same time.

If for any reason you don't want them to be generated simultaneously you can set environment variable EEAEPUB_ASYNC_THREADS to 1 within buildout:

[buildout]

...

[instance]

...

environment-vars +=
    EEAEPUB_ASYNC_THREADS 1

Also, if you experience issues by having too many simultaneously ePub jobs, you can limit them in the same way as above.

Dependecies

1. BeautifulSoup
2. Lxml
3. Plone 4.x
4. plone.app.async
5. eea.converter
6. eea.downloads
7. eea.pdf (optional for advanced themes and asynchronous download)

Live demo

Here some live production demos at EEA (European Environment Agency)

1. https://www.eea.europa.eu/soer/synthesis

Source code

Latest source code (Plone 4 compatible):

https://github.com/eea/eea.epub

Plone 2 and 3 compatible:

https://github.com/eea/eea.epub/tree/plone25

Copyright and license

The Initial Owner of the Original Code is European Environment Agency (EEA). All Rights Reserved.

The EEA Epub (the Original Code) is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

More details under docs/License.txt

Links

1. EEA Epub wiki page: https://taskman.eionet.europa.eu/projects/zope/wiki/HowToEpub

Funding

EEA - European Enviroment Agency (EU)