Notebook: Syntax highlighting not working in Safari

[apleonhardt]

This may be a minor issue but is probably worth reporting: For some reason, Julia syntax highlighting doesn't work for IJulia notebooks in Safari on Mac OS X 10.9. I've tried to pin down the issue:

• Highlighting works in Python mode.
• Highlighting works in Chrome (calling up the very same IPython instance).
• No JS errors are thrown when IJulia boots up.

I'm not very knowledgeable when it comes to JS. A couple of amateurish observations: The language setting for all cells is correctly set to Julia. Loading up the notebook in Julia mode does throw up loads of CSS warnings whereas loading a Python notebook doesn't. Maybe it's something trivial. Can any Mac user confirm this observation?

[apleonhardt]

Might belong to #17.

[stevengj]

@malmaud, any ideas?

[lucasb-eyer]

• Same for me in Firefox 28.0 on Arch Linux.
• Highlighting doesn't work for loaded existing cells in Firefox.
• Highlighting does work in Chrome.
• Highlighting does work in newly created cells.
• Highlighting does work when changing the cell type e.g. to markdown and then back to code.
• I think it started failing when I updated my IPython from 1.2.? to 2.0.

It looks like some "lazy" highlighting upon loading the notebook is being too lazy (aka never called) in Firefox and Safari but not in Chrome?

[padawanphysicist]

• Same problem in Firefox 29.0-1 on Arch Linux. Only highlights new cells.
• Highlight working in Opera and Chrome

[stevengj]

@Carreau, did something change in IPython 2.0 about how syntax highlighting is applied to cells when they are loaded?

[Carreau]

Nop nothing should have changed.

Can you try pasting this in the JS console ?

    CodeMirror.requireMode('julia', function(){
        cells = IPython.notebook.get_cells();
        for(var i in cells){
            c = cells[i];
            if (c.cell_type === 'code'){
                c.auto_highlight()
            }
        }
    })

If it works we might want to wrap this also in the notebook_loaded.NotebookApp event.

[apleonhardt]

It doesn't. A manual call to a cell's auto_highlight() doesn't either.

This, on the other hand, works:

cells = IPython.notebook.get_cells();
cells[0].code_mirror.setOption("mode", "julia");

The architecture is a bit puzzling, so I can't tell if it's an issue with CodeMirror, IPython or IJulia. It seems similar to IHaskell/IHaskell#71, though! Any ideas?

[Carreau]

Weird.
What does cells[0].code_mirror.getOption("mode") says ?
Cause I can fix it in customjs, but it will probably double the time of loading notebook has it will highlight things twice.

[malmaud]

@stevengj Hmm, it still works for me. I have no special insight on what's going wrong.

[Carreau]

That's probably a race condition between codemirror requiring the "julia" . So Codemirror try to parse in julia mode but as it is not defined, or initialized yet the highlighting default to 'plain/text'( even if the option is set to 'julia') for newly created cell, julia mode is defined so it works.

auto_highlight() look at the mode, see julia, so does nothing (otherwise all the highlighting is re-done, which ~ double the loading time of notebook).

It should not happend has the autohilight is triggered only once julia mode is loaded, but it might come from the fact that the actual highlighting of codemirror is done in a pseudo-background thread using callbacks .

[apleonhardt]

@Carreau cell.code_mirror.getOption("mode") always returns julia, regardless of highlighting status. The race condition idea sounds reasonable. It's a minor annoyance because toggling the cell type twice restores proper highlighting. Seems sufficiently widespread, though, and doesn't give an ideal first impression...

[staticfloat]

I run into a problem that is very similar, but I'm not certain it's the same. When I open an existing IJulia notebook that has a lot of "stuff" (plots, code cells, etc....), sometimes syntax highlighting doesn't work at all, (even though computation still works) and closing the window and reopening, or normal refreshing does not fix the issue. However, force-refreshing, (CMD-SHIFT-R in Chrome on OSX) always fixes the issue, so I think it might have something to do with files getting fetched in a weird order and not being pulled from Chrome's cache properly? The issue is perplexing, and if this is not the same as what's being talked about here, I can go open a new issue, but it's hard to know since my problem is intermittent.

[lendle]

I am having what I think is the same issue. I found that #201 fixes this for me.

(For reasons I don't understand, Pkg.build("IJulia") didn't do anything after checking out the master branch. I made a whitespace-only change to custom.js, and after that Pkg.build("IJulia") updated custom.js in my IPython profile and syntax highlighting was fixed.)

[lendle]

Oops, please ignore my previous comment.

Looks like #201 was merged a while ago, well before the most recent tagged version of IJulia. After removing and reinstalling IJulia, this issue is not actually fixed for me. I think something screwy is going on in my .julia directory.

[null-a]

I think I'm seeing much the same thing. If I open an existing notebook in Firefox there's no syntax highlighting for Julia code.

Calling cell.code_mirror.setOption("mode", "julia") for all code cells (as suggested by @apleonhardt) from the app_initialized.NotebookApp event (in custom.js) fixes things. I've no idea how much of a hack that is though.

I see something similar in Chrome, though there it's intermittent. Sometimes existing notebooks open with syntax highlighting, other times not.

I'm on julia 0.3.3, IJulia, 0.1.16, ipython 2.3.0, Firefox 34.0.5, OS X 10.9.5.

[eldargab]

One way to workaround is to add the following to custom.js

CodeMirror.requireMode('julia', function(){
  IPython.CodeCell.options_default.cm_config.mode = "julia"
})

This will not change the mode of already created cells (in old notebooks), but will set the right mode for new ones.

The above works for ipython 2.3

[Carreau]

That's basically what this is doing, but there seem to be some timing issues.

So you should not need to add that manually to your custom.js it should be added to it by IJulia when you Pkg.build it.

With next version of IPython it should be taken care of by IPython itself.

[eldargab]

Ah, indeed, seems that I overwrote custom.js after install.

[stevengj]

Is there a change that is needed to our custom.js for IPython 1.x and 2.x?

[zmughal]

This may have been fixed in IPython 3.2. See the issue at EntropyOrg/p5-Devel-IPerl#40 for more details.

[stevengj]

@zmughal, that's good to hear. (The latest IJulia master dropped support for IPython 2.x.)