Markdown rendering empty about jupyterlab-markup HOT 11 CLOSED

I just tried this on Jupyter Lab 1.0.2, and still, my markdown cells show nothing. This is for regular markdown cells -- I haven't even gotten to the point of testing the mermaid/etc additional features this extension is supposed to provide. When I disable the extension and reload the page, these markdown cells go back to being displayed.

And, no worries about not having time! At this stage, this is more of a nice-to-have/novelty feature than something that I daily depend on.

from jupyterlab-markup.

@RobertoMaurizzi Thanks for all the troubleshooting work!

@Memento1990 @kenjioman this issue makes more sense to me now, as I had to reinstall the extension on a fresh system.

The way in which webpack bundles the wasm code for this extension means that the system needs to understand the mimetype of the file when serving it to the browser. By default, most systems do not provide this mimetype. In the install instructions I provide a small bash script to register this mimetype on Linux (in /etc/mime.types). Other systems may have different mechanisms for doing this.

from jupyterlab-markup.

Addition on what to do exactly since every time Apple releases an update for their OS I fumble half an hour to get this working:

1. add wasm to /etc/mime.types (I'm using a link to /etc/apache/mime.types, it might be it's better to copy the file but it's risky: what if they use it for something else and they change/add types?)
2. restart JupyterLab
3. clear your browser cache (I open the devtools, go to network, filter for wasm, get the only wasm request, check it's binary/octet-stream then use the menu to "clear browser cache" for that request.
4. force-reload the page and it works

from jupyterlab-markup.

I've noticed that markdown cells sometimes need to be re-rendered (by editing and hitting CTRL+ENTER), have you tried this?

from jupyterlab-markup.

CTRL+ENTER didn't do anything for me -- the cells still show nothing (with a small blue bar on the left to indicate I have this cell selected). Running Jupyter Lab Version 0.35.3

from jupyterlab-markup.

I don't have time to look at this at the moment. I can't seem to reproduce the issue my end unfortunately. I used to use JupyterLab 0.35.6, and now use 1.0.2. Could you try either the latest JupyterLab, or 0.35.6, and see if it works there?

from jupyterlab-markup.

I got the error on JupyterLab 0.35.4, and recently have no plan to update JupyterLab. Agree on the upstairs's option, and no worries about this. 😄

from jupyterlab-markup.

I'm still seeing this on Jupyterlab 1.1.2. I'm on OSX and there's no mime.types file I can find to add wasm to.
In the browser (Chrome 76.0.3809.132) console I get a

Uncaught (in promise) TypeError: Failed to execute 'compile' on 'WebAssembly': Incorrect response MIME type. Expected 'application/wasm'.

while Firefox has a more generic but similar TypeError: Response has unsupported MIME type.

From a cursory investigation it looks like there's no way to specify mime types on OSX (or at least not anymore: the recommended solution of using RCDefaultApp doesn't show me a panel for mime types anymore. I tried to investigate what Jupyter and Python are doing with regard to recognizing mime types and apparently application/wasm was added (to lib/mimetypes.py, see https://bugs.python.org/issue34758) a while ago but I'm not sure which specific releases included it right now (my 3.6.5 surely doesn't).

UPDATE: I installed JupyterLab and the rest in a virtualenv based on Python 3.7.4 and it's still the same, mimetypes can't understand what to do with .wasm. Currently Trying 3.8-dev (using pyenv)

from jupyterlab-markup.

So, with 3.7.4:

>>> import mimetypes
>>> mimetypes.guess_type('file://home/roberto/testfile.wasm')
(None, None)

while on 3.8.0b4+

>>> import mimetypes
>>> mimetypes.guess_type('file://home/roberto/testfile.wasm')
('application/wasm', None)

from jupyterlab-markup.

I ended up linking apache's mime.types file in /etc/mime.types and adding wasm as per instructions: python's mimetypes picks it up and the above test now prints the correct result also with Python 3.7.4.
Now I need to hope this won't kill OSX's UI at the next login... 😅

Jupyter still didn't render markdown cells, but it turned out that it had the wasm code request cached with the wrong (actually, missing) mime-type: after a cache clear now I can see Markdown cells again and they can render both bob and mermaid graphics :-)

Thank you for this extension, it makes writing process documentation in Jupyterlab so much easier! :-)

from jupyterlab-markup.

Closed due to above reason :)

from jupyterlab-markup.