Port Find Projection alg to new API

nyalldawson · nyalldawson · commit cfb926a70de8 · 2017-08-20T18:21:03.000+10:00
Also modify alg to export a vector table of candidates instead of
a HTML list, since a vector table is more useful inside of
models and can be used for further analysis steps.
diff --git a/python/plugins/processing/algs/qgis/FindProjection.py b/python/plugins/processing/algs/qgis/FindProjection.py
@@ -26,31 +26,32 @@
 __revision__ = '$Format:%H$'
 
 import os
-import codecs
 
-from qgis.core import (QgsApplication,
-                       QgsGeometry,
+from qgis.core import (QgsGeometry,
+                       QgsFeature,
                        QgsFeatureSink,
-                       QgsRectangle,
+                       QgsField,
+                       QgsFields,
                        QgsCoordinateReferenceSystem,
                        QgsCoordinateTransform,
-                       QgsProcessingUtils)
+                       QgsWkbTypes,
+                       QgsProcessingParameterFeatureSource,
+                       QgsProcessingParameterExtent,
+                       QgsProcessingParameterCrs,
+                       QgsProcessingParameterFeatureSink)
+from qgis.PyQt.QtCore import QVariant
 
 from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
-from processing.core.parameters import ParameterVector
-from processing.core.parameters import ParameterCrs
-from processing.core.parameters import ParameterExtent
-from processing.core.outputs import OutputHTML
 
 pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
 
 
 class FindProjection(QgisAlgorithm):
 
-    INPUT_LAYER = 'INPUT_LAYER'
+    INPUT = 'INPUT'
     TARGET_AREA = 'TARGET_AREA'
     TARGET_AREA_CRS = 'TARGET_AREA_CRS'
-    OUTPUT_HTML_FILE = 'OUTPUT_HTML_FILE'
+    OUTPUT = 'OUTPUT'
 
     def tags(self):
         return self.tr('crs,srs,coordinate,reference,system,guess,estimate,finder,determine').split(',')
@@ -62,17 +63,16 @@ def __init__(self):
         super().__init__()
 
     def initAlgorithm(self, config=None):
-        self.addParameter(ParameterVector(self.INPUT_LAYER,
-                                          self.tr('Input layer')))
-        extent_parameter = ParameterExtent(self.TARGET_AREA,
-                                           self.tr('Target area for layer'),
-                                           self.INPUT_LAYER)
-        extent_parameter.skip_crs_check = True
+        self.addParameter(QgsProcessingParameterFeatureSource(self.INPUT,
+                                                              self.tr('Input layer')))
+        extent_parameter = QgsProcessingParameterExtent(self.TARGET_AREA,
+                                                        self.tr('Target area for layer'))
+        #extent_parameter.skip_crs_check = True
         self.addParameter(extent_parameter)
-        self.addParameter(ParameterCrs(self.TARGET_AREA_CRS, 'Target area CRS'))
+        self.addParameter(QgsProcessingParameterCrs(self.TARGET_AREA_CRS, 'Target area CRS'))
 
-        self.addOutput(OutputHTML(self.OUTPUT_HTML_FILE,
-                                  self.tr('Candidates')))
+        self.addParameter(QgsProcessingParameterFeatureSink(self.OUTPUT,
+                                                            self.tr('CRS candidates')))
 
     def name(self):
         return 'findprojection'
@@ -81,27 +81,34 @@ def displayName(self):
         return self.tr('Find projection')
 
     def processAlgorithm(self, parameters, context, feedback):
-        layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT_LAYER), context)
+        source = self.parameterAsSource(parameters, self.INPUT, context)
 
-        extent = self.getParameterValue(self.TARGET_AREA).split(',')
-        if not extent:
-            extent = QgsProcessingUtils.combineLayerExtents([layer])
-        target_crs = QgsCoordinateReferenceSystem(self.getParameterValue(self.TARGET_AREA_CRS))
+        extent = self.parameterAsExtent(parameters, self.TARGET_AREA, context)
+        target_crs = self.parameterAsCrs(parameters, self.TARGET_AREA_CRS, context)
 
-        target_geom = QgsGeometry.fromRect(QgsRectangle(float(extent[0]), float(extent[2]),
-                                                        float(extent[1]), float(extent[3])))
+        target_geom = QgsGeometry.fromRect(extent)
 
-        output_file = self.getOutputValue(self.OUTPUT_HTML_FILE)
+        fields = QgsFields()
+        fields.append(QgsField('auth_id', QVariant.String, '', 20))
+
+        (sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
+                                               fields, QgsWkbTypes.NoGeometry, QgsCoordinateReferenceSystem())
 
         # make intersection tests nice and fast
         engine = QgsGeometry.createGeometryEngine(target_geom.geometry())
         engine.prepareGeometry()
 
-        layer_bounds = QgsGeometry.fromRect(layer.extent())
+        layer_bounds = QgsGeometry.fromRect(source.sourceExtent())
+
+        crses_to_check = QgsCoordinateReferenceSystem.validSrsIds()
+        total = 100.0 / len(crses_to_check)
+
+        found_results = 0
 
-        results = []
+        for current, srs_id in enumerate(crses_to_check):
+            if feedback.isCanceled():
+                break
 
-        for srs_id in QgsCoordinateReferenceSystem.validSrsIds():
             candidate_crs = QgsCoordinateReferenceSystem.fromSrsId(srs_id)
             if not candidate_crs.isValid():
                 continue
@@ -115,15 +122,15 @@ def processAlgorithm(self, parameters, context, feedback):
                 continue
 
             if engine.intersects(transformed_bounds.geometry()):
-                results.append(candidate_crs.authid())
-
-        self.createHTML(output_file, results)
-
-    def createHTML(self, outputFile, candidates):
-        with codecs.open(outputFile, 'w', encoding='utf-8') as f:
-            f.write('<html><head>\n')
-            f.write('<meta http-equiv="Content-Type" content="text/html; \
-                    charset=utf-8" /></head><body>\n')
-            for c in candidates:
-                f.write('<p>' + c + '</p>\n')
-            f.write('</body></html>\n')
+                feedback.pushInfo(self.tr('Found candidate CRS: {}').format(candidate_crs.authid()))
+                f = QgsFeature(fields)
+                f.setAttributes([candidate_crs.authid()])
+                sink.addFeature(f, QgsFeatureSink.FastInsert)
+                found_results += 1
+
+            feedback.setProgress(int(current * total))
+
+        if found_results == 0:
+            feedback.reportError(self.tr('No matching projections found'))
+
+        return {self.OUTPUT: dest_id}
diff --git a/python/plugins/processing/algs/qgis/QGISAlgorithmProvider.py b/python/plugins/processing/algs/qgis/QGISAlgorithmProvider.py
@@ -73,6 +73,7 @@
 from .FieldPyculator import FieldsPyculator
 from .FieldsCalculator import FieldsCalculator
 from .FieldsMapper import FieldsMapper
+from .FindProjection import FindProjection
 from .FixedDistanceBuffer import FixedDistanceBuffer
 from .FixGeometry import FixGeometry
 from .GeometryByExpression import GeometryByExpression
@@ -172,7 +173,6 @@
 # from .DefineProjection import DefineProjection
 # from .RasterCalculator import RasterCalculator
 # from .ExecuteSQL import ExecuteSQL
-# from .FindProjection import FindProjection
 
 pluginPath = os.path.normpath(os.path.join(
     os.path.split(os.path.dirname(__file__))[0], os.pardir))
@@ -194,7 +194,7 @@ def getAlgs(self):
         #         SelectByAttributeSum()
         #         DefineProjection(),
         #         RasterCalculator(),
-        #          ExecuteSQL(), FindProjection(),
+        #          ExecuteSQL(),
         #         ]
         algs = [AddTableField(),
                 Aggregate(),
@@ -229,6 +229,7 @@ def getAlgs(self):
                 FieldsCalculator(),
                 FieldsMapper(),
                 FieldsPyculator(),
+                FindProjection(),
                 FixedDistanceBuffer(),
                 FixGeometry(),
                 GeometryByExpression(),
diff --git a/python/plugins/processing/tests/testdata/expected/projection_candidates.gfs b/python/plugins/processing/tests/testdata/expected/projection_candidates.gfs
@@ -0,0 +1,16 @@
+<GMLFeatureClassList>
+  <GMLFeatureClass>
+    <Name>projection_candidates</Name>
+    <ElementPath>projection_candidates</ElementPath>
+    <GeometryType>100</GeometryType>
+    <DatasetSpecificInfo>
+      <FeatureCount>8</FeatureCount>
+    </DatasetSpecificInfo>
+    <PropertyDefn>
+      <Name>auth_id</Name>
+      <ElementPath>auth_id</ElementPath>
+      <Type>String</Type>
+      <Width>14</Width>
+    </PropertyDefn>
+  </GMLFeatureClass>
+</GMLFeatureClassList>
diff --git a/python/plugins/processing/tests/testdata/expected/projection_candidates.gml b/python/plugins/processing/tests/testdata/expected/projection_candidates.gml
@@ -0,0 +1,49 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ogr:FeatureCollection
+     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+     xsi:schemaLocation=""
+     xmlns:ogr="http://ogr.maptools.org/"
+     xmlns:gml="http://www.opengis.net/gml">
+  <gml:boundedBy><gml:null>missing</gml:null></gml:boundedBy>
+                                                                                                                                                                                                                                                                                                
+  <gml:featureMember>
+    <ogr:projection_candidates fid="projection_candidates.0">
+      <ogr:auth_id>EPSG:20256</ogr:auth_id>
+    </ogr:projection_candidates>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:projection_candidates fid="projection_candidates.1">
+      <ogr:auth_id>EPSG:20356</ogr:auth_id>
+    </ogr:projection_candidates>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:projection_candidates fid="projection_candidates.2">
+      <ogr:auth_id>EPSG:28356</ogr:auth_id>
+    </ogr:projection_candidates>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:projection_candidates fid="projection_candidates.3">
+      <ogr:auth_id>EPSG:32356</ogr:auth_id>
+    </ogr:projection_candidates>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:projection_candidates fid="projection_candidates.4">
+      <ogr:auth_id>EPSG:32556</ogr:auth_id>
+    </ogr:projection_candidates>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:projection_candidates fid="projection_candidates.5">
+      <ogr:auth_id>EPSG:32756</ogr:auth_id>
+    </ogr:projection_candidates>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:projection_candidates fid="projection_candidates.6">
+      <ogr:auth_id>IGNF:UTM56SW84</ogr:auth_id>
+    </ogr:projection_candidates>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:projection_candidates fid="projection_candidates.7">
+      <ogr:auth_id>EPSG:5552</ogr:auth_id>
+    </ogr:projection_candidates>
+  </gml:featureMember>
+</ogr:FeatureCollection>
diff --git a/python/plugins/processing/tests/testdata/qgis_algorithm_tests.yaml b/python/plugins/processing/tests/testdata/qgis_algorithm_tests.yaml
@@ -2827,19 +2827,19 @@ tests:
           fields:
             fid: skip
 
-#  - algorithm: qgis:findprojection
-#    name: Find projection
-#    params:
-#      INPUT_LAYER:
-#        name: custom/find_projection.gml
-#        type: vector
-#      TARGET_AREA: 151.1198,151.1368,-33.9118,-33.9003
-#      TARGET_AREA_CRS: EPSG:4326
-#    results:
-#      OUTPUT_HTML_FILE:
-#        name: expected/find_projection.html
-#        type: file
-#
+  - algorithm: qgis:findprojection
+    name: Find projection
+    params:
+      INPUT:
+        name: custom/find_projection.gml
+        type: vector
+      TARGET_AREA: 151.1198,151.1368,-33.9118,-33.9003
+      TARGET_AREA_CRS: EPSG:4326
+    results:
+      OUTPUT:
+        name: expected/projection_candidates.gml
+        type: vector
+
   - algorithm: qgis:polygonfromlayerextent
     name: Standard polygon from layer extent
     params:
