Enable Readium to open File objects directly

[johanpoirier]

Readium can now open a File object (Blob) directly.

For example, if you're using the DeviceStorage API, you can read an epub file from the sdcard of a device :

var sdcard = navigator.getDeviceStorage('sdcard');
var request = sdcard.get("9782019111281.epub");
request.onsuccess = function () {
    var file = this.result;
    var readium = new Readium({ jsLibRoot: './libs/' }, { el: '#reader-frame' });
        readium.openPackageDocument(file, function (packageDocument, options) {
            // do whatever you want with your packageDocument...
        });
};

[danielweck]

Very interesting!
Although your code changes make perfect sense, we just need to double-check that there are no side effects, and to test across multiple platforms. Definitely worth pursuing, IMO.

[johanpoirier]

Hi @danielweck, did you had the time to test it across multiple platforms ?

[danielweck]

I am afraid not, as our current development priority is in the native ReadiumSDK at the moment.
By the way, is this something we could use for drag-n-drop'ing EPUB files onto the cloud reader? This would be a neat feature.

[danielweck]

Follow-up on this: as much as I love the idea of being able to open (zipped) EPUB from any data source that can ultimately provide a binary Blob (e.g. drag-n-drop, LocalStorage, SDcard, etc.), there are a number of serious caveats when using non-exploded/expanded EPUBs (regardless of the actual data source).

Documentation:
https://docs.google.com/document/d/1bwv89vSmLbUs4tHOwiqyeV546k5CG3RCJ1S6_-4wvvc/

In a nutshell, list of broken features:

• EPUB3 Media Overlays
• Any large video/audio HTML5 media
• Some SVG
• Any dynamically-injected resource (via scripting, i.e. not via static markup declarations)
• Dynamic hyperlinks
  ...basically, anything that can not easily be replaced with BlobURIs at parsing time (statically).

Thus the "low" priority on this issue / PR.

[danielweck]

@johanpoirier thank you very much for your PR! I adapted it and merged it to develop:
#115

[johanpoirier]

👍