[QGIS-Developer] Can't find SAGA devel versions after r413c6e5
Pedro Venâncio
pedrongvenancio at gmail.com
Thu Jun 8 06:14:43 PDT 2017
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.
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.
Best regards,
Pedro Venâncio
2017-06-08 11:45 GMT+01:00 Rainer Hurling <rhurlin at gwdg.de>:
> 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('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('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 <rhurlin at gwdg.de>:
>>>
>>>> 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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