NPPExec: is it possible to detect if text is selected or not?

pbarney

I’m just beginning to dip my foot into NPPExec, but I want to make sure my expectations match reality.

My Goal:

I want to convert html to markdown.

My Approach:

I’m using the external program Pandoc to do the conversion, and NPPExec to call the program. [I tried to post a link to Pandoc, but Akismet is flagging this post as spam, so you’ll have to look it up if you’re interested.]

I’ve copied an example program by @PeterJones from a post here on the forum (Thank you, PeterJones!). It takes the current document, selects all, hands it over to Pandoc and pastes it back into the original document:

cls
cmd.exe /c exit %RANDOM%                                                // get a random number for the temporary filenames
set tempfile = $(SYS.TEMP)\NppMdFile_$(EXITCODE).tmp                    // create a random tempfile name
set mdfile = $(SYS.TEMP)\NppMdFile_$(EXITCODE).md                       // create an associated markdown name
sci_sendmsg SCI_SELECTALL                                               // select all
sel_saveto $(tempfile) :a                                               // save selection to the tempfile (use :a to save as ansi, to prevent unicode prefix ÿþ getting embedded)
c:\utils\pandoc\pandoc -f html -t markdown -o "$(mdfile)" "$(tempfile)" // convert
sel_loadfrom $(mdfile)                                                  // replace selection with results
sci_sendmsg SCI_DOCUMENTSTART                                           // deselect
rm -rf "$(tempfile)" "$(mdfile)"                                        // clean up temp files

What I’d like to have happen:

If nothing is selected: run all of the text through Pandoc (this is the current state of the script).
If text is selected: run only the selected text through Pandoc.

My questions are:

Can NPPExec determine if text is currently selected? And if so,
is NPPExec capable of branching based on that determination?

Thank you for any help.

pbarney

I may have asked too fast because I think I solved my own problem. Here is the script as updated:

cls
cmd.exe /c exit %RANDOM%                                                // get a random number for the temporary filenames
set tempfile = $(SYS.TEMP)\NppMdFile_$(EXITCODE).tmp                    // create a random tempfile name
set mdfile = $(SYS.TEMP)\NppMdFile_$(EXITCODE).md                       // create an associated markdown name

sci_sendmsg SCI_GETSELTEXT                                              // Check if text is selected
set len = $(MSG_RESULT)                                                 // get result

if $(len) == 0 then                                                     // If no text is selected, select all
    sci_sendmsg SCI_SELECTALL                                           // select all
endif

sel_saveto $(tempfile) :a                                               // save selection to the tempfile (use :a to save as ansi)
c:\utils\pandoc\pandoc -f html -t markdown -o "$(mdfile)" "$(tempfile)" // convert using pandoc
sel_loadfrom $(mdfile)                                                  // replace selection with results
sci_sendmsg SCI_DOCUMENTSTART                                           // deselect
rm -rf "$(tempfile)" "$(mdfile)"                                        // clean up temp files

Would this the the best way to approach this problem? I’m open to alternative approaches, including ones that don’t require the use of NPPExec.

Mark Olson

@pbarney

If you want to detect if there is exactly one selection of nonzero length, do the following:

Call SCI_GETSELECTIONS. If the result is greater than 1, there are multiple selections.
Call SCI_GETSELECTIONSTART and SCI_GETSELECTIONEND to get the start and end of the selection. If the end is greater than the start, the user has a single nonzero-length selection.
As you correctly identified, you can then use SCI_GETSELTEXT to get the selected text, although in this script it doesn’t look like that’s really necessary.

Based on a recent issue I saw with the JSON-Viewer plugin where incorrectly assuming that the user always had a single selection caused NPP to crash, I think that validating that there is a single selection is generally good practice,