ipython/ipython — pull request #7264 by dongweiming (2014-12-18 06:07:40+00:00)
Title: Update custom.js for 3.0

I use custom.js in development`3.0.0-dev`. but it not work. my custom.js like this:

```python
IPython.events.on('app_initialized.NotebookApp', function(){
function to(mode) {
var mode = mode || 'vim'
// first let's apply vim mode to all current cells
function to_mode(c) { return c.code_mirror.setOption('keyMap', mode);};
IPython.notebook.get_cells().map(to_mode);
// apply the mode to future cells created
IPython.Cell.options_default.cm_config.keyMap = mode;
}

require(["codemirror/keymap/emacs"],
function (emacs) {
to('emacs');
console.log('emacs.js loaded');
});
})

```

the broswer said:

```python
IPython.events.on is not a function
```
If use `$([IPython.events])` said:

```python
ReferenceError: $ is not defined
```

I think `main.js` should not depend on the `custom.js`, this make load custom.js first. but in custom.js, IPython has not been set up. I hope to have a better solution

```