[Qgis-user] [QGIS-Developer] processAlgorithm vs processFeature?

[Etienne Trimaille]

Indeed, if you can, you should use a QgsProcessingFeatureBasedAlgorithm
algorithm. It will make some shortcuts for you and the code is shorter
because you will only have a single feature to process.

Have a look to existing source code :
https://github.com/qgis/QGIS/search?q=QgsProcessingFeatureBasedAlgorithm

Le mar. 24 août 2021 à 04:55, Ujaval Gandhi <ujaval at spatialthoughts.com> a
écrit :

> If your algorithm works on each feature independently, processFeature() is
> preferred. If you need to work with layers, you need to use
> processAlgorithm(). I demonstrate this with an example at
> https://spatialthoughts.com/2019/04/05/geodesic-buffers-in-qgis/
>
> On Mon, 23 Aug 2021 at 10:25 PM, C Hamilton <adenaculture at gmail.com>
> wrote:
>
>> I discovered that it looks like there is another way to deal with
>> processing algorithms. Rather than use processAlgorithm it looks like I can
>> use prepareAlgorithm & processFeature. I have always used processAlgorithm
>> and then iterated through the features.
>>
>> Is processFeature just as quick as using processAlgorithm (iterating
>> through the features)? Is one method preferred over the other? I think for
>> some algorithms using processFeature would make the code look cleaner. Are
>> there any gotchas in using the processFeature method?
>>
>> Thanks,
>>
>> Calvin
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