[Proposal] Partial rendering

[schickling]

When working on big documents (with MathJax) and having lazy rendering disabled it happens that the rendering becomes kinda slow. (I know you might be arguing that I should enable lazy rendering, but the rendering process is the same).

My idea to speed up and improve this situation you could try to render just parts of the document. How you split up the document would be the biggest problem imo. Suppose you have split up the document in four parts and you currently edit the second part (realtime collaboration needs special treatment) just the second part of the document should be refreshed.

I think that could drastically speed up the document rendering while working on the document. I'd like to hear your thoughts on that.

PS: This "issue" is just an improvement idea, nothing what has to be done immediately. 🐹

[vanabel]

Just like I mentioned in #42 , also I provided another solution there.

[benweet]

@schickling @vanabel I just commited a new "partial rendering" extension that renders only modified sections (delimited by titles). Can you give me your feedback?
Note: If you modify a link definition or a footnote, it will re-render all the document.

[schickling]

Tested it a little for now and seems to work as I imagined. Great work again! 👍

[benweet]

By the way you can compare the rendering time by using this UserCustom extension:

userCustom.onPreviewFinished = function() { 
    console.log("Preview time: " + (new Date() - extensionMgr.previewStartTime));
};

You should see logs in the JavaScript console.

[benweet]

Actually this one is more interesting:

userCustom.onAsyncPreview = function(callback) {
    console.log("Conversion time: " + (new Date() - extensionMgr.previewStartTime));
    callback();
};
userCustom.onPreviewFinished = function() { 
    console.log("Preview time: " + (new Date() - extensionMgr.previewStartTime));
};

It gives you:

1. Markdown conversion time (the synchronous part)
2. Total rendering time including MathJax asynchronous typeset

[schickling]

I'll try it these days!

[vanabel]

Can't even render if you have create a new document, and type anything in it.
But if you refresh the page, it will start to render!

[vanabel]

It works for mathjax render, which will render at each section of h title, but why not only at the editing paragraph?

[benweet]

@vanabel Do you have any error logs in the JavaScript console that I can investigate?

Can you try:

1. Reset StackEdit settings
2. If it doesn't help, delete the application cache (Chome settings->Show advanced settings->Content settings->All cookies and site data->benweet.github.io->Application cache)

[vanabel]

It's normal after I delete the cookies, but you didn't tell me that will empty all my settings, including the document selector...

[benweet]

Normally, you can delete application cache (which contains StackEdit's pages) and/or local storage (which contains StackEdit's markdown documents). You probably deleted both of them.

[vanabel]

The can't render initially problem still exists!

[benweet]

Does it appear on all your documents or only on a specific one? If so, please provide an example. Can you check if you have errors in the JavaScript console?

[schickling]

The can't render initially problem still exists!

Same here if I create a new document and start to edit.

[vanabel]

For every new doc, it can't render initially. The JS console:

Document was loaded from Application Cache with manifest http://benweet.github.io/stackedit/cache.manifest benweet.github.io:1
Application Cache Checking event benweet.github.io:1
Application Cache NoUpdate event benweet.github.io:1
Port error: Could not establish connection. Receiving end does not exist. miscellaneous_bindings:236
chromeHidden.Port.dispatchOnDisconnect miscellaneous_bindings:236
Failed to load resource 

[benweet]

I just reproduced the problem. It happens when document is empty. It should be fixed now.

[schickling]

I can confirm that 👍