Re: [GSoC] Proposal for JavaScript for info-style navigation.

[Per Bothner]

On 04/02/2017 04:32 PM, Mathieu Lirzin wrote:

> > - The solution for handling multi-page manuals using iframe, using
> > div elements, and adjusting their visibility is implemented and
> > works great.  That is the main contribution of my prototype.
> > The only change I'd like in this area is a modest extension so any
> > page can be the start page, not just index.html.
>
> OK, IIUC that feature requires including in each sub page a reference to
> a JavaScript program that opens the different iframes accordingly.  If
> Javascript is not available in the current browser then only the basic
> page is displayed.

Right.  The idea is that the actual HTML is more-or-less the same
as what is currently created by 'makeinfo --html' (modulo some minor
cleanup of the output).  If JavaScript isn't available, navigation
will work as normal, on a static web page.  If JavaScript *is* available,
then the "onload" handler will be executed when the page has been loaded,
and that will add event handlers, add the navigation sidebar, re-write
internal links to do magic stuff (and external links to open a new
window/tab).

When a subpage is loaded in an iframe, it has its own JavaScript
execution environment (including onload handler).  In my prototype, the same
JavaScript code is loaded both the initial window, sub-pages, and navigation
table-of-contents, but it can do different actions depending on context.
For example when a sub-page has finished loading, it needs to send a message to
the main page so the main page can update its tables.

> "is not clear to me yet".  What I meant was not about how to store
> files, but how the data in memory and potentially in the DOM could take
> a lot of space compare to something like a local browser database cache.
> Obviously this was unclear.  :)

The DOM can take a lot of space, but it's nothing compared to the images
and videos that clutter the modern web ...  Maybe it will be an issue,
but it is certainly not a priority.
--
        --Per Bothner
address@hidden   http://per.bothner.com/