This exposes some basic temporal capabilities for vector layers:
- static time range for layer (to match raster layer possibilities), this
sets a single static time range which applies to the whole layer. ALL
features from the layer will be shown whenever the canvas time
overlaps the layer time range
- "Single field with datetime": Allows selection of a single date
or datetime field from the layer. Features will be shown whenever
this field value is within the canvas time range
- "Separate Fields for Start and End Date/Time": Allows selection
of start and end date/datetime fields from the layer. Features will
be shown whenever the time interval calculated from these fields
overlaps the canvas time range
Some known limitations/inefficiencies:
- currently only date/datetime fields can be used. This was done
to simplify the format handling and avoid the need to worry about
string fields with different datetime formats. In future we should
allow selection of string fields and allow users to enter a custom
datetime format string
- unlike the Time Manager plugin approach, the approach taken here
is to rely completely on QGIS expressions and feature requests to
do the filtering (Time Manager uses layer filter strings and attempts
to set a native SQL filter syntax so that filtering is done on the
backend). This is intentional, because it provides a unified filter
approach regardless of the provider used (i.e. we don't need to worry
about the different SQL syntaxes used natively by the different
providers). The beauty of feature request expression compilation
**should** mean that the QGIS expressions are magically turned into
native backend queries, BUUUUUUUUUUUT... because we lack QGIS expression
support for date time literals, we currently rely on the "to_datetime"
expression function and coerce everything through strings. None of
the expression compilers handle this function, so currently ALL
filtering is done on the QGIS side. We need to add functions for
optimised datetime literal creation, and then ensure that the different
compilers correctly map these literals across to the backend
filter syntax to allow all the filtering work to be done on the database
side...
So currently, performance is much worse with large layers compared
to Time Manager. But, the advantage is that we can use the native
temporal framework and have vector layers animated alongside mesh
and raster layers!
in the QgsFileWidget
For example in some cases hidding filter details is useful to prevent
expanding combobox popup to the whole screen when long filter string is
used.
Also:
- enables saving/loading of layer definition files (.qlr) with vector tile layers.
- makes fields of vector tile layers sorted so they are easier to navigate
Allow load of multiple (sub-)meshes from a single file. If file contains multiple meshes (e.g. UGRID file), user needs to select the meshes to load from the dialog.
This change "dims" the results from the SAGA provider when a search
is made in the toolbox, to visually push users towards picking alternative
algorithms instead.
The Processing implementation of SAGA algorithms are a constant source
of critical bugs for users, causing incorrect analysis results. There's
zero community interest in actively maintaining this provider, so we
need to take steps to push users to stop picking these algorithms
wherever alternative (QGIS/GRASS/GDAL based) equivalents exist.
And for 4.0, seriously re-consider dropping this provider from the
out of the box install. We are causing more harm then good by offering
it to users.
These allow plugins to extend the "Open Project" dialog by adding in support
for new file filters, which appear in the formats drop down list alongside
the existing "QGS Projects" entry.
Custom project open handlers then get first chance at loading project files.
This allows plugins to extend QGIS support by adding integrated support for
opening projects from non QGS/QGZ formats, e.g. allowing users to open
ArcGIS MXD documents or MapInfo WOR Workspaces direct from the project open
dialog.
These non-native projects are also added to the recent projects list and
welcome screen, giving them a truly first-class experience within QGIS.
Sponsored by SLYR
