aspell

There is a Javascript-only spellchecker available now from Doug Blank:

• Installation
• Demonstration

It is recommended to use the above spellchecker instead of the aspell-based one.

Aspell-based spell checker

This IPython notebook extension allows spellchecking using aspell (http://aspell.net/). It allows spell checking as you type in markdown cells or on demand using a toolbar button for any cell type.

The technical implementation is a server side spell checker, that communicates with the IPython notebook over a websocket.

A short demo video can be found here: http://www.youtube.com/watch?v=yk5ID5SAlLw

Installation

• First you need to have the program aspell installed on a computer.
• Next, you need the aspell-python package (https://pypi.python.org/pypi/aspell-python).
• Finally, start ipy-aspell-server.py. If you want to run it in background, use something like nohup python ipy-aspell-server.py &.

For now the spell check language is configured to english in the line s = aspell.Speller('lang', 'en') of ipy-aspell-server.py.

Now install the IPython notebook extension:

Add require(['/static/custom/aspell/ipy-aspell.js']) to your custom.js Copy the directory aspell to your /static/custom/ directory of your IPython profile and add

require(['/static/custom/aspell/ipy-aspell.js']);

to your custom.js file so it looks like this (IPython 2.x version):

$([IPython.events]).on('app_initialized.NotebookApp', function(){
    //...
    require(['/static/custom/aspell/ipy-aspell.js']);
});

If the computer ipy-aspell.py is running on is als running the IPython notebook server, add the line var wsUri = "ws://" + document.domain + ":8889/"+ "websocket"; to ipy-aspell.js. If you use another computer, pleas add var wsUri = "ws://" + "**my computer name**" + ":8889/"+ "websocket";

This extension needs some testing. Also, it does not do much error checking for now. Feedback and enhancements are welcome.

Note

As all text to be spellchecked is transferred over the network unencrypted, this can be a major security risk. Also, someone might modify the server program ipy-aspell-server.py to spy on you. Therefore, you should only use the spellchecker when it running on your local machine or setup.

Internals

The communication between the computer running ipy-aspell.py and the IPython notebook extension ipy-aspell.js running in your browser is realized using websockets at port 8989.

The notebook extensions sends each word to be spell checked using a JSON string "text":word, "line": i, "start":start, "end":end, "id":cell.cell_id and receives back antother JSON string "text":curWord, "line": cur.line, "start":start, "end":end, "id":cell.cell_id. If curWord is returned as true from aspell, then it is not a valid word in the dictionary and will be marked using CodeMirrors markText()`. The marking can be cleared either by typing on or by clicking on the trashcan toolbar symbol.