[QGIS-Developer] QgsProcessingAlgorithm: no output layer when cancelled

[Nyall Dawson]

On Mon, 22 Jul 2019 at 17:41, Nils Nolde <nilsnolde at gmail.com> wrote:
>
> Hola,
>
> running into 2 notorious problems with the ORS Tools plugin:
>
> 1. QgsProcessingAlgorithm, where it doesn't return the features which
> were processed until the user presses Cancel. More elaborate on SE:
>
> https://gis.stackexchange.com/questions/328913/pyqgis-qgsprocessingalgorithm-no-output-layer-when-cancelled

That's by design, intended to avoid users getting misleading partial
results from a canceled algorithm.

> 2. Another, more subtle, behavior when someone uses the batch processing
> algorithms for ORS Tools plugin like so:
>
> - save result as .shp or .gpkg instead of memory layer
>
> - user exceeds our minutely query limit (usually 40 queries/minute),
> i.e. errors are printed, but internally NetworkAccessManager is just
> sleeping until the minute is over and the limit is lifted
>
> - when all is done, the resulting layer is empty. However, when using
> memory layers instead, the results are available.

Sorry, no clues as to why this is the case...

Nyall