Hi Pedro,
Thanks also for your explanations.
Am 08.06.2017 um 15:14 schrieb Pedro Venâncio:
Hi Rainer,
That is not the case. The problem is that SAGA team changes very often
the sintax of the SAGA modules, even between minor updates, wich causes
problems with SAGA Processing implementation.
A big issue is the creation of models and scripts in Processing, using
SAGA algorithms. With that frequent changes, they become obsolete. For
instance, I've created a set of modules with dozens of operations, that
become unusable twice because of SAGA sintaxe changes. This prevents
much people to create Processing models and scripts, and share them.
The solution discussed and adopted was to support only a LTR version of
SAGA, and make it the default for QGIS 2.18.9+ and QGIS 3.x, so that any
user on any operation system have the same SAGA version, wich ensures
that any model created or shared is fully operational.
By other hand, is what Alexander said, there is no workforce to ensures
the check and update of descritpion files, every time SAGA releases some
minor or major version.
Hope this make sense to you.
Until here, I am with you and as I wrote in my initial mail, I am aware
of the problems with changing API etc.
My point is, that there are systems without an LTR version of SAGA GIS
and without an easy possibility for normal users to additionally install
the LTR version. The users only have a QGIS installation without any
SAGA GIS processing.
For systems like this (i.e. FreeBSD) it would be nice, if QGIS would
recognize the presence of a more recent, installed version of SAGA GIS.
In this case, QGIS could explicitely warn the user about possible API
breakage and that he/she should expect not every SAGA module to work
correctly.
The suggestion of Alexander, If I understood correctly, is that the
group of users from FreeBSD can always fork the Processig SAGA, and
support newer versions as a new Processing Plugin.
Yes, this could be possible in theory. But most likely, no one with
adequate knowledge will be found. ATM, it seems to me, that the most
realistic option for FreeBSD is to add some extra patches into the port,
which would allow us to use newer SAGA GIS version in a restricted way.
Many, many of the SAGA GIS tools will work even with newer versions.
Better than nothing ;)
So, based on some small patches, showed in my previous mail, I will
allow this behaviour for the FreeBSD port of QGIS.
Thanks again for your explanations.
Greetings from Göttingen in Germany,
Rainer Hurling
Best regards,
Pedro Venâncio
2017-06-08 11:45 GMT+01:00 Rainer Hurling <[email protected]
<mailto:[email protected]>>:
I forgot to mention, that if only FreeBSD users should have the
problem with newer SAGA GIS versions and not having an LTR version,
a local patch in the FreeBSD port is also conceivable.
Something like the following patches makes the processing tools for
SAGA GIS, newer than version 2.3.x, 'functional' again on FreeBSD:
--- python/plugins/processing/algs/saga/SagaUtils.py.orig
2017-06-06 19:35:06.000000000 +0200
+++ python/plugins/processing/algs/saga/SagaUtils.py 2017-06-08
10:49:02.387866000 +0200
@@ -26,6 +26,7 @@
__revision__ = '$Format:%H$'
import os
+import platform
import stat
import subprocess
import time
@@ -57,7 +58,7 @@
def findSagaFolder():
folder = None
- if isMac():
+ if isMac() or platform.system() == 'FreeBSD':
testfolder = os.path.join(QgsApplication.prefixPath(), 'bin')
if os.path.exists(os.path.join(testfolder, 'saga_cmd')):
folder = testfolder
@@ -82,7 +83,7 @@
def sagaPath():
- if not isWindows() and not isMac():
+ if not isWindows() and not isMac() and not platform.system() ==
'FreeBSD':
return ''
folder = findSagaFolder()
@@ -101,7 +102,7 @@
fout.write('set SAGA_MLB=' + sagaPath() + os.sep +
'modules' + '\n')
fout.write('PATH=%PATH%;%SAGA%;%SAGA_MLB%\n')
- elif isMac():
+ elif isMac() or platform.system() == 'FreeBSD':
fout.write('export SAGA_MLB=' + sagaPath() +
'/../lib/saga\n')
fout.write('export PATH=' + sagaPath() + ':$PATH\n')
@@ -130,7 +131,7 @@
if isWindows():
commands = [os.path.join(sagaPath(), "saga_cmd.exe"), "-v"]
- elif isMac():
+ elif isMac() or platform.system() == 'FreeBSD':
commands = [os.path.join(sagaPath(), "saga_cmd -v")]
else:
# for Linux use just one string instead of separated
parameters as the list
@@ -146,7 +147,7 @@
stderr=subprocess.STDOUT,
universal_newlines=True,
).stdout
- if isMac(): # This trick avoids having an uninterrupted
system call exception if SAGA is not installed
+ if isMac() or platform.system() == 'FreeBSD': # This trick
avoids having an uninterrupted system call exception if SAGA is not
installed
time.sleep(1)
try:
lines = proc.readlines()
---
python/plugins/processing/algs/saga/SagaAlgorithmProvider.py.orig
2017-06-08 02:16:08.000000000 +0200
+++ python/plugins/processing/algs/saga/SagaAlgorithmProvider.py
2017-06-08 11:15:09.732518000 +0200
@@ -73,7 +73,7 @@
self.tr <http://self.tr>('Problem with SAGA installation: SAGA was
not found or is not correctly installed'))
return
- if not version.startswith('2.3.'):
+ if version < '2.3.':
ProcessingLog.addToLog(ProcessingLog.LOG_ERROR,
self.tr <http://self.tr>('Problem with SAGA installation:
unsupported SAGA version found.'))
return
Am 08.06.2017 um 11:42 schrieb Rainer Hurling:
Hi Alex,
Thanks for the quick and detailed answer.
Am 08.06.2017 um 11:29 schrieb Alexander Bruy:
Hi Rainer,
2017-06-08 10:24 GMT+03:00 Rainer Hurling <[email protected]
<mailto:[email protected]>>:
For some reasons, we don't package our system with
different versions of
SAGA GIS. Recent FreeBSD comes with SAGA GIS version
3.0.0, I am working on
an update to version 4.1.0.
With your latest updates to QGIS (r413c6e5), newer
versions of SAGA GIS than
2.3.x are not recognized any more :(
I am familiar with the background, that QGIS processing
only garantees to
work well with the SAGA GIS LTR version. But there was a
kind of tacit
agreement for several years now, that QGIS processing
tools also accepted to
display (and somewhat work with) newer SAGA GIS versions.
Previously QGIS Processing supported multiple SAGA versions,
but as SAGA
devs often changed API even between minor versions it was a
real pain to
maintain compatibility and provide users with robust and
working SAGA inteface.
Because for each change in SAGA API we need not only update
algorithms
descriptions but also add some workaronds in the Processing
source code.
After release of SAGA LTR we had several long discussions
and finally decided
that better to have good support for single SAGA version
that multiple partially
broken version. That's why support for all other versions
was removed. We also
removed option to choose another SAGA installation, as this
makes no sense
now and can lead to confusion in case when user select
unsupported SAGA
version.
In principle I understand this point of view, but it makes it
relatively difficult to identify the necessary changes for newer
SAGA GIS versions.
And as I outlined before, there are constraints on some OS for
the presence of newer SAGA GIS versions. In the past, the QGIS
user was able to use most of the SAGA GIS functions, as only
some of the functions had bigger API changes.
Now my request: It would be fine and at least important
for FreeBSD users,
to have the possibility to use SAGA GIS > 2.3.x with
QGIS 2.18.9 again.
I'm afrad this is not possible, as we have no resources to
keep algorithms
descriptions and, more importantly, source code updated with
numerous SAGA
API breaks in every SAGA release.
As an option I can suggest to create altenate SAGA provider
plugin which will
support non-LTR SAGA versions.
This would be a very nice option to have such an additional
support. A provider plugin for (newer) non-LTR SAGA versions
could throw a warnings, that this SAGA GIS version is not fully
supported and the user has to expect problems ...
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