Re: Bring up a screen giving option to open a series of orgmode files

[Maxim Nikulin]

2020-29-11 Jean Louis wrote:
> * Maxim Nikulin [2020-11-28 18:52]:
>
> Any viewer should have option to quickly construct a hyperlink and
> store it somewhere with its annotation and other meta data so that
> such can be reused by any other program.

Xpdf do not have option to construct hyperlink, it allows to execute 
arbitrary command (if context matches) and pass some parameters using 
substitutions. It is enough e.g. to copy target of the link, to do 
something with page number (construct hyperlink to this page). Maybe 
selection region could be passed to pdftotext to extract selection text 
that could be inserted to a note.

Surprisingly PDF viewers built in into browser have fences preventing 
access of browser extensions to the text content. I did not expect such 
limitations. There are extensions that offer translation of text 
selected in PDF files however. It seems they use bundled pdf.js to 
replace built-in viewer. Unsure that JS working with PDF file runs in 
proper security context. I expected a robust way for integration with 
note taking applications.

> > De facto, extensions should communicate with HTTP servers, to
> > protect users, access to filesystem is not allowed any more.
>
> Alright, only if it would be that secure, then this type of advise
> would not be there:
>
> How to Run a More Secure Browser
> https://www.dragonflybsd.org/docs/handbook/RunSecureBrowser/

Just one problem, if one uses a browser extension that works with local 
files then he have content accessible by extensions. Another extension 
could do something bad with such files. Mozilla XUL extensions were very 
powerful and had access to file system. It is impossible to ensure that 
there is no malicious extensions in the add-on catalog. XUL was dropped, 
chrome extension API has been adopted. File system is protected against 
bad extensions, extensions have to keep user data on some server. Only 
local files are protected, security model for requests to remote servers 
is quite poor. It is funny, that attempts to allow web applications to 
work with local files are not stopped, unsure if I have heard about this 
particular proposal earlier or it is another one: 
https://web.dev/file-system-access/

In the previous message I was writing about very specific problem: 
extension author could put code that steal files or ruin them. To solve 
it, extension developers were force to store user content on a remote 
server instead of local files. I do not think it is significantly safer.

And finally, running browser under a different user is likely not 
enough. Browser for working with "external" resources should be isolated 
from home or office network (network namespace, container, virtual 
machine). There are enough web sites that checks which ports are open at 
least on the localhost. Local network could be scanned through browser 
as well.

> > In principle, any paragraph could be addressed using
> > XPath
> > https://developer.mozilla.org/en-US/docs/Web/XPath/Introduction_to_using_XPath_in_JavaScript
> > but it is extremely fragile since link will be likely invalid after
> > web site redesign or modification of the text.
>
> ...
>  From the above link on XPath I have not figured out yet how to
> generate a hyperlink to specific paragraph. I may spend days until I
> figure it out.

Page inspector in developer tools has a context menu entry to copy XPath 
to particular element. Likely you will prefer to generate link in a more 
smart and stable way, e,g, by looking for an element with id attribute 
nearby and construct a link relative to it. Maybe it is possible to 
implement protocol handler for custom scheme with XPath references
https://developer.mozilla.org/en-US/docs/Web/API/Navigator/registerProtocolHandler

> My surprise was
> big when I realized that Org is there with features to manage tasks
> but does not offer feature to "send the task".

In my opinion, you have demonstrated that emacs and org mode are 
powerful enough to allow users to implement rather specific workflow 
with a quite small piece of code. It may be a dedicated package but I do 
not think it worth including such features to the base set. Docs will be 
longer than the code. Personally, I would expect export-based solution 
that strips comments, takes email addresses from some properties and 
saves messages to the draft folder for review before sending them.