Issues with JS and TextDocumentContentProvider

[dfinke]

TextDocumentContentProvider works. I used this as a starting point https://github.com/Microsoft/vscode-extension-samples/tree/master/textdocumentprovider-sample

This works if you save it as an html file and open it in a browser, but not if I return it in provideTextDocumentContent:
https://gist.github.com/dfinke/f51f8cba643b1b153ef8

Is there a way to make it work or debug?

[alexdima]

I didn't implement this, but I think we use an <iframe> to render the preview and we disable all <scripts> because they would run in the UI thread.

fyi @jrieken

[egamma]

@alexandrudima correct, but we do not disable JS execution and I don't think we strip scripts. This was the state when we last discussed it and the intent is to switch from an <iframe> to a <webview>.

@dfinke the code is here:
vscode\src\vs\workbench\parts\html\browser\htmlPreviewPart.ts

To debug this pls see https://github.com/Microsoft/vscode/wiki/How-to-Contribute#development-workflow in the Debugging section. The htmlPreview code runs into the renderer process.

I'll look into this later, I see where you are going with your scenario and this is a interesting scenario.

[egamma]

@dfinke @alexandrudima
In the markdown preview the JavaScript from the above gist is executed as shown below. I was assuming that the html preview mostly mimics the mark down preview, but this is not the case and I did not succeed to execute scripts in the html preview.

[dfinke]

Very cool. So a few tweaks to the html preview and vs code can be an interactive d3 pad.

I was looking at the htmlPreviewPart.ts to see if I could swap the iframe out, but I don't know if that would be enough. Maybe cloning the markdown preview is the place to start.

[egamma]

Maybe cloning the markdown preview is the place to start.

well this is where it started 😄, need to understand the differences with regard to JS handling in the two implementations.

As a workaround you could already do the d3 things using the markdown preview as is done in the twitter extension, but we should really get this to work.

[dfinke]

The short Tweet on this drove questions in my direction. The snippet does not work in the 0.10.8 release. I know the Build conference is coming. Hopefully this can make it into the editor no too long after. It'd be a great feature.

[jrieken]

I'll take a look - things are rendered in an iframe and script aren't blocked in anyway.