export dash as pdf

[mariekers]

Allow users to export dash outputs (graphs and text) as a pdf report.

[quinn-dougherty]

so, streamlit doesn't support csv download of dataframes streamlit/streamlit#400

individual charts can be downloaded. near the upper right hand corner of each chart is a ...-looking button that offers png, svg download...

don't get your hopes up too much about exporting to pdf. but i think you can hack it by exporting to html as an intermediary? streamlit/streamlit#297 haven't read this issue too closely myself yet

[themightychris]

I maintain this NPM CLI that might be helpful https://github.com/JarvusInnovations/puppeteer-cli

[sam-writer]

If we are considering headless chrome -> PDF, it is worth mentioning that per streamlit/streamlit#566 , using the browser's print function to save a PDF works pretty well with streamlit. It's not perfect, but if you close the sidebar first, it mostly looks good

[themightychris]

is there any way to embed a custom CSS stylesheet in Streamlit? If so, we could sprinkle in some print media rules to tweak what the chromium->PDF result looks like, e.g. hide sidebar, hide interactive controls, adjust spacing, etc

[sam-writer]

is there any way to embed a custom CSS stylesheet in Streamlit? If so, we could sprinkle in some print media rules to tweak what the chromium->PDF result looks like, e.g. hide sidebar, hide interactive controls, adjust spacing, etc

AFAICT "yes*"
* very crudely, e.g.

hide_menu_style = """
        <style>
        #MainMenu {visibility: hidden;}
        </style>
        """

[selahlynch]

I'm going to attempt this one...

[selahlynch]

One approach - pure frontend javascript - however it seems to be impossible to add custom javascript to a streamlit app :/
streamlit/streamlit#969

[sam-writer]

@selahlynch reading this SO question I get the feeling that you can jam some JS in there, but it doesn't interact with streamlit. What was the JS solution you were thinking of?

Similar to how we add raw CSS here, could we add JS in a similar way? EDIT: we actually add the HTML here, the previous link defines the HTML that is added

[themightychris]

Well if we're using Puppeteer to generate the PDF, we can arbitrarily manipulate the page or inject code at that layer. So for changes we want to make only in print, we don't really need to figure out how to add them into Streamlit since we only need them present during the printing session in our backend.

To use puppeteer, we could either develop our own NodeJS app within the repo, or use the CLI wrapper I maintain which has a maybe-ready-to-merge PR open already to add an --inject-js CLI flag: JarvusInnovations/puppeteer-cli#13

[sam-writer]

@themightychris regardless of NodeJS or CLI, won't this need to be a separate process that runs on demand? Or are you thinking of calling to the CLI via python's os module?

[themightychris]

I don't know the state of Python->puppeteer(or other) bindings. But shelling out to a node process is def an option, and puppeteer (via node) offers the deepest + cleanest interaction with Chromium engine I've ever seen

FYI over in #116 I think we just tested your question @sam-qordoba about can we embed JS that way and it seems that it does not work. See also streamlit/streamlit#969

So if we need to inject JS for print, it seems like the only option may be from the client-side (i.e. via puppeteer)