How to debug scripted ePub3 in iBooks?

Question

I have an ePub3 book involving scripting which works fine with Readium, but only partially in iBooks. My guess is that the JavaScript is erroring out at some point (although as a standard web app the exact same code works fine in Safari). Any thoughts on how to go about debugging this?

Update: this problem turned out not to be a scripting problem, but rather missing content due to some apparent differences in how iBooks handles overflow in the CSS sense--it seems to hide overflow in some cases even when the CSS would indicate it should not. — , Aug 18 '12 at 17:44
Good question nevertheless. IBooks does allow for WebSockets so perhaps a solution could be built on top of it to provide debugging.. — Alex Nolasco, Aug 20 '12 at 19:39
Good idea. My initial solution was a real simple "console" which allows you to type in and evaluate JS expressions. — , Aug 22 '12 at 02:23
AlexanderN : Did you manage to establish an external connection from iBooks with WebSockets ? I cannot do that — fbdcw, Sep 17 '12 at 09:13
@AlexanderN I did not try, but if someone else manages to make this work, I'd love to hear the details. — , Sep 18 '12 at 12:28
iBooks will not allow JS to make external network connections of any kind, so WebSockets simply won't work. — Liza Daly, Jun 29 '13 at 03:10

score 6 · Answer 1 · answered Mar 01 '15 at 20:53

6

You can enable the Webkit Web Inspector in iBooks with this line in your terminal app to change its settings:

defaults write com.apple.iBooksX WebKitDeveloperExtras -bool YES

You'll find the inspector after re-starting iBooks in the context menu (More > Show Inspector). All the inspector tools are available including console etc.

answered Mar 01 '15 at 20:53

Nicolas Zimmer

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4
10

Doesn't seem to work anymore – Flavio Tordini Aug 03 '22 at 09:20

Paul Sweatte · Accepted Answer · 2014-12-19T22:05:36.060

Azardi Online can be used to read the file using the browser. The built-in or add-in console can be used from there to debug. Or a console shim can be created:

if(!console) {
  console = {
    "_log" : [],
    "log" : function() {
      var arr = [];
      for ( var i = 0; i < arguments.length; i++ ) {
        arr.push( arguments[ i ] );
      }
      this._log.push( arr.join( ", ") );
    },
    "trace" : function() {
      var stack;
      try {
        throw new Error();
      } catch( ex ) {
        stack = ex.stack;
      }
      console.log( "console.trace()\n" + stack.split( "\n" ).slice( 2 ).join( "  \n" ) );
    },
    "dir" : function( obj ) {
      console.log( "Content of " + obj );
      for ( var key in obj ) {
        var value = typeof obj[ key ] === "function" ? "function" : obj[ key ];
        console.log( " -\"" + key + "\" -> \"" + value + "\"" );
      }
    },
    "show" : function() {
      alert( this._log.join( "\n" ) );
      this._log = [];
    }
  };

  window.onerror = function( msg, url, line ) {
    console.log("ERROR: \"" + msg + "\" at \"" + "\", line " + line);
  }

  window.addEventListener( "touchstart", function( e ) {
    if( e.touches.length === 3 ) {
      console.show();
    }
  } );
}

References

Yes, or I could run it in Readium, but Readium is not iBooks and neithe is Azardi, unfortunately, as fine a product as that is. But running it in the browser on iPad with its minimalistic console support is a useful idea, thanks, accepting this answer. — , Jun 29 '13 at 14:59

How to debug scripted ePub3 in iBooks?

2 Answers2