Announcement: NPPM_GETOPENFILENAMES and related are being deprecated in v8.8.2

PeterJones

Plugin Authors:

Please note: per this commit, the
NPPM_GETOPENFILENAMES, NPPM_GETOPENFILENAMESPRIMARY & NPPM_GETOPENFILENAMESSECOND messages are being deprecated. They will still be in the codebase for some versions, but will have _DEPRECATED at the end of the constant names in Notepad_plus_msgs.h – and they will be going away eventually.

Don has updated the pluginDemo’s getFileNamesDemo() to show an alternate method to access the filenames that used to be obtained from NPPM_GETOPENFILENAMES, and I am placing those side-by-side here:

Here is the version compatible with v8.8.2-and-forward, for easy copy/paste:

void getFileNamesDemo()
{
	int nbMainViewFile = (int)::SendMessage(nppData._nppHandle, NPPM_GETNBOPENFILES, 0, PRIMARY_VIEW);
	int nbSubViewFile = (int)::SendMessage(nppData._nppHandle, NPPM_GETNBOPENFILES, 0, SECOND_VIEW);
	int nbFile = nbMainViewFile + nbSubViewFile;
	wchar_t toto[10];
	::MessageBox(nppData._nppHandle, generic_itoa(nbFile, toto, 10), L"nb opened files", MB_OK);
	
	wchar_t **fileNames = (wchar_t **)new wchar_t*[nbFile];

	int i = 0;
	for (; i < nbMainViewFile; )
	{
		LRESULT bufferId = ::SendMessage(nppData._nppHandle, NPPM_GETBUFFERIDFROMPOS, i, MAIN_VIEW);
		LRESULT len = ::SendMessage(nppData._nppHandle, NPPM_GETFULLPATHFROMBUFFERID, bufferId, (WPARAM)nullptr);
		fileNames[i] = new wchar_t[len + 1];
		::SendMessage(nppData._nppHandle, NPPM_GETFULLPATHFROMBUFFERID, bufferId, (WPARAM)fileNames[i]);
		++i;
	}

	
	for (int j = 0; j < nbSubViewFile; ++j)
	{
		LRESULT bufferId = ::SendMessage(nppData._nppHandle, NPPM_GETBUFFERIDFROMPOS, j, SUB_VIEW);
		LRESULT len = ::SendMessage(nppData._nppHandle, NPPM_GETFULLPATHFROMBUFFERID, bufferId, (WPARAM)nullptr);
		fileNames[i] = new wchar_t[len + 1];
		::SendMessage(nppData._nppHandle, NPPM_GETFULLPATHFROMBUFFERID, bufferId, (WPARAM)fileNames[i]);
		++i;
	}

	for (int k = 0 ; k < nbFile ; k++)
		::MessageBox(nppData._nppHandle, fileNames[k], L"", MB_OK);




	for (int k = 0 ; k < nbFile ; k++)
	{
		delete [] fileNames[k];
	}
	delete [] fileNames;
}

It is recommended that you make analagous changes in any plugins that use one or more of those three messages as soon as possible.

Mark Olson

@PeterJones
While I’m glad that these messages are being deprecated, I hope they’re not removed altogether! Considering that the reason I asked for the messages to be deprecated in the first place was my own misunderstanding of the interface, I don’t really think the messages are dangerous enough to warrant removal.
I’ll say the same on the GitHub issue as well.

PeterJones

@Mark-Olson said in Announcement: NPPM_GETOPENFILENAMES and related are being deprecated in v8.8.2:

While I’m glad that these messages are being deprecated, I hope they’re not removed altogether

To be “deprecated” means to be marked as “do not use, because it will be going away at some point in the future”. Generally, it’s polite to leave deprecated interfaces available for at least a few versions, but they generally do get completely removed eventually. Essentially, “it’s going away soon, but not quite yet”.

rdipardo

@Mark-Olson said in Announcement: NPPM_GETOPENFILENAMES and related are being deprecated in v8.8.2:

I don’t really think the messages are dangerous enough to warrant removal.

IIRC, the underlying issue was that @kbilsted’s original implementation of ClikeStringArray was not Unicode-aware.

In other words, an accident waiting to happen, like much of the code in the old template project. Decisions about the API should be guided by safety, not preserving backward compatibility with really old stuff.

Coises

@Mark-Olson said in Announcement: NPPM_GETOPENFILENAMES and related are being deprecated in v8.8.2:

@PeterJones
While I’m glad that these messages are being deprecated, I hope they’re not removed altogether! Considering that the reason I asked for the messages to be deprecated in the first place was my own misunderstanding of the interface, I don’t really think the messages are dangerous enough to warrant removal.

I agree. I now regret that I wrote a message that probably helped draw attention to something which I now believe should have been ignored. Both of the concerns which motivated that message turned out to be ill-founded.

Microsoft’s documentation for lstrcpy says, “Warning Do not use.” On further examination, I believe they are being overly dramatic. It is possible to misuse that function, but it is not inherently more problematic than any function that accomplishes the same thing with C-style strings; in the context in question, it is arguably better than the alternatives. I note that despite the warning, the function is not deprecated.

My other concern was that MAX_PATH is no longer a hard limitation in Windows. This interface would be completely broken for that reason — but Notepad++ does not open file paths which exceed MAX_PATH on any version of Windows. So this only becomes a problem if that is changed someday.

If it were up to me, I wouldn’t even deprecate these functions. (Note that NPPM_GETSESSIONFILES has exactly the same weaknesses, but it is not being deprecated, because there is no alternate way to accomplish the same thing.) Deprecating them suggests that removing them in the future would be acceptable, and I see no reason to break working plugins just because they’re not constantly maintained. I would just put a note in the documentation that new code is advised to use the alternate method. These messages do not pose any unique danger if they are used correctly — which, presumably, they are in older plugins, or the errors would have been discovered.

The problem with these functions was clarity of documentation — which has been fixed — and that they are perhaps a little more error-prone than average. However, C interfaces are inherently susceptible to programmer error. C and C++ programmers are used to the pitfalls (Windows is all C interface, even in C++), but for someone trying to bridge between C# (or, I presume, most other languages) and the C interface, it’s easy to miss something.

The error-prone part of this interface is that if you supply inadequate buffers, the mistake can easily go undetected (in this case, until a file path is longer than 130 characters) and then show up in an apparently unrelated part of the program. Interface design can mitigate that sort of thing, but it’s impractical or impossible to eliminate it.

rdipardo

@Coises said in Announcement: NPPM_GETOPENFILENAMES and related are being deprecated in v8.8.2:

Note that NPPM_GETSESSIONFILES has exactly the same weaknesses, but it is not being deprecated, because there is no alternate way to accomplish the same thing.

The alternative is to parse session.xml using an XML DOM API, such as many programming languages include in their standard libraries, as was being done for nativeLang.xml before NPPM_GETNATIVELANGFILENAME existed.

The problem is that each alternative would be sui generis to the given plugin’s software ecosystem; even the canonical C++ example would have to take a dependency on TinyXML (or so I fear, since migrating to the more capable TinyXML‍2 is still a long way off).

PeterJones

@rdipardo said in Announcement: NPPM_GETOPENFILENAMES and related are being deprecated in v8.8.2:

even the canonical C++ example would have to take a dependency on TinyXML (or so I fear, since migrating to the more capable TinyXML‍2 is still a long way off ).

Correct me if I’m wrong, but the “canonical C++ example” would be able to use TinyXML2 even if N++ itself is still using TinyXML, since the two are independent codebases. Right?

But I agree in principle: making plugindemo require another library – whether tinyxml-old or tinyxml2 or whatever – seems counter to the plugindemo purpose.