[QGIS-Developer] QGIS3 - processing python script. Read features from output layer

[kimaidou]

Found id !
I have to use mapLayerFromString :

blayer = QgsProcessingUtils.mapLayerFromString(area_result['OUTPUT'],
context)

\o/

2018-02-16 7:11 GMT+01:00 kimaidou <kimaidou at gmail.com>:

> Hi Salvatore,
>
> I already tried to use
>
> blayer = area_result['OUTPUT']
> for feat in blayer.getFeatures():
>     ....
>
> with no success . If I do so I get
>
> AttributeError: 'str' object has no attribute 'getFeatures'
>
> There must be a way to transforme this string representing the layer as a
> processing layer object....
> I use this code inside the processAlgorithm method of my
> QgsProcessingAlgorithm class.
>
>
> Michaël
>
> 2018-02-15 22:39 GMT+01:00 Salvatore Larosa <lrssvtml at gmail.com>:
>
>> Hi Michaël,
>>
>> On Thu, Feb 15, 2018 at 6:36 PM, kimaidou <kimaidou at gmail.com> wrote:
>>
>>> Hi all,
>>>
>>> I have a simple processing python alg which
>>> * generates a buffer with qgis:buffer
>>> * use qgis:fieldcalculator to add an buf_area field -> the output vector
>>> of my alg is this buffer+new field.
>>>
>>> I would like to parse the features of the output vector in order to
>>> gather some information and put it in a new string output. I have not been
>>> able to get the layer object to perform a getFeatures on it.
>>>
>>> See the code
>>> http://paste.debian.net/1010463/
>>>
>>> In line 32, my blayer is None
>>> I think I am not using the good way to get the output vector layer
>>> features? I tried to use the same way as for reading an input layer, but
>>> oviously it is different.
>>>
>>
>> What does happen if you put area_result['OUTPUT'] directly instead of
>> self.parameterAsSource?
>> parameterAsSource() accept a parameter as first argument and area_result
>> should be already un QgsVectorLayer.
>>
>> Where you are trying to execute it from?
>>
>>
>> --
>> Salvatore Larosa
>> linkedIn: http://linkedin.com/in/larosasalvatore
>> twitter: @lrssvt
>> skype: s.larosa
>> IRC: lrssvt on freenode
>>
>
>
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