This allows creation of models with child algorithms which do
things like merge a selected layer with a predefined static
layer, or create a vrt with a mix of static and user selected
layers.
parameters which accept lists of multiple layers
E.g. build vrt alg, merge vector layers alg
Otherwise you may need to load 100's of layers temporarily into
a project to perform algs on them
parameters in models
There's not a 1:1 correlation here - vector layers can be used
as inputs for sources, but sources cannot be used when a
full vector layer is required.
to control whether selected features only are to be used
Replaces the old global setting and makes it immediately obvious
to users when the selection will be respected
Algorithms and other processing code should use this method
(instead of dataobjects.getLayerFromString) to
retrieve layers from a string, as it considers the processing
context and allows resolving strings to temporarily stored layers.
This permits processing models to function correctly when
intermediate results are stored as memory layers. Subsequent
model algorithms can then access these temporary layers as inputs.
All temporary layers will be removed when the context object
is destroyed after the model algorithm is run.
Also
- simplify and add tests
- remove large memory leak (persistant store of all non-project layers)
- remove broken support for direct loading postgres/virtual layers
by string (Python version was very broken and would never match
a postgres/virtual layer)
* [processing] qgis regular points test
* [processing] qgis shape buffer variable tests
* [processing] qgis create grid lines test
* [processing] qgis convert geometry test
* [processing] qgis extract by location test
* [processing] qgis add field test
* [processing] trying to fix travis failing
* [processing] trying to fix travis failing/2
* trying to fix travis failing/3
* [processing] Add new default option "ProjectCrs" to ParameterCrs
* [processing] RegularPoints tests shouldn't rely on iface
* [processing] Fix regular points test
* [processing] RandmPointsExtent new CRS parameter
* [processing] qgis random point in extent test
* [processing] qgis random point in extent test/2
* [processing] remove qgis random point in extent test
* no output random points in extent test
* remove useless output
