Where can I see output of the code executed?

[holyjak]

Hello, I am not able to figure out where I can see the output of the code that I execute, f.ex. this JS snippet:

console.log("Hello, Jupyter!");

Where can I see the Hello, Jupyter! output? Or is it impossible?

Thank you!

[willwhitney]

This is an issue with some kernels which are janky and don't put the output in the right place. Which Javascript kernel are you using?

[rgbkrk]

It's the IJavascript kernel I assume (I just read n-riesco/ijavascript#31).

[holyjak]

Indeed

Forget software. Strive to make an impact, deliver a valuable change.

(Vær så snill og hjelp meg med å forbedre norsken min – skriftlig og
muntlig. Takk!)

Jakub Holy
Solutions Engineer | +47 966 23 666
Iterate AS | www.iterate.no
The Lean Software Development Consultancy

• http://theholyjava.wordpress.com/ -
• juni 2015 17:28 skrev "Kyle Kelley" notifications@github.com:

It's the IJavascript kernel I assume (I just read n-riesco/ijavascript#31
n-riesco/ijavascript#31).

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#52 (comment)
.

[n-riesco]

Hi everyone,

I've tried to reproduce this issue and I've noticed that:

• if I don't save the document before pressing ctrl-alt-enter, no output is shown (only a looping icon).
• if I save the document, then I get the result of calling console.log("Hello, Jupyter"), which is undefined, but I don't see the text written to process.stdout.

[n-riesco]

I've quickly skimmed through Hydrogen's code. If I understood correctly this, when a kernel returns a result, Hydrogen doesn't show what was written to stdout.

I'm planning to add a flag to IJavascript to let the user silence undefined results (so that it plays nicely with Hydrogen). Most likely, I will make this the default behaviour.

[holyjak]

I like the way Light Table works: returning the result of the statement
(even if being undefined) and having a separate output view where I can go
check for side effects. Though anything is much better than nothing :)

Forget software. Strive to make an impact, deliver a valuable change.

(Vær så snill og hjelp meg med å forbedre norsken min – skriftlig og
muntlig. Takk!)

Jakub Holy
Solutions Engineer | +47 966 23 666
Iterate AS | www.iterate.no
The Lean Software Development Consultancy

• http://theholyjava.wordpress.com/ -
• juni 2015 19:36 skrev "Nicolas Riesco" notifications@github.com:

I've quickly skimmed through Hydrogen's code. If I understood correctly this
https://github.com/willwhitney/hydrogen/blob/2d2ae6e49e556a45c39231c758dd57afda56202d/lib/result-view.coffee#L78,
when a kernel returns a result, Hydrogen doesn't show what was written to
stdout.

I'm planning to add a flag to IJavascript to let the user silence undefined
results (so that it plays nicely with Hydrogen). Most likely, I will make
this the default behaviour.

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#52 (comment).

[willwhitney]

@n-riesco That's not where that logic is, but you're basically right. My reading is that kernels are supposed to put their stdout in the io stream: http://ipython.org/ipython-doc/stable/development/messaging.html#streams-stdout-stderr-etc

I'll look into the issue with not getting results until the file is saved.

@jakubholynet I agree in principle with separating those concerns, but due to kernel variability this is not feasible. Some kernels put all their results in the io stream, some put them into an execute_reply, etc. Right now my strategy is to just copy Jupyter's behavior of showing all the results.

[n-riesco]

@willwhitney IJavascript does send stdout to the IOSocket (as IPython and IJulia do). The difference is that whereas IJavascript returns undefined results, IPython drops Nones and IJulia drops nothings.

[n-riesco]

@jakubholynet This is issue is solved in IJavascript v5.0.3 (now available from npm)

@willwhitney This issue turned out to be solved by the PR you sent me last time. Unfortunately, I hadn't made it available on npm.

I'm sorry for all the inconvenience.