feat: filter layers with selected plan (WIP)

Author: nmaarnio

src/arho_feature_template/core/update_plan.py

@@ -0,0 +1,56 @@
+from dataclasses import dataclass
+
+from typing import List
+
+from qgis.core import QgsProject, QgsVectorLayer, QgsMapLayer
+
+
+@dataclass
+class LandUsePlan:
+    id: str
+    name: str
+
+
+LAYER_PLAN_ID_MAP = {
+    "Kaava": "id",
+    "Aluevaraus": "plan_id",
+    "Osa-alue": "plan_id",
+}
+
+
+def update_selected_plan(new_plan: LandUsePlan):
+    id = new_plan.id
+    for layer_name, field_name in LAYER_PLAN_ID_MAP.items():
+        set_filter_for_layer(layer_name, field_name, id)
+
+
+def set_filter_for_layer(layer_name: str, field_name: str, field_value: str):
+    # Get layer and perform checks
+    layers = QgsProject.instance().mapLayersByName(layer_name)
+    if not _check_layer_count(layers):
+        return
+    layer = layers[0]
+    if not _check_vector_layer(layer):
+        return
+
+    # Perform the filtering
+    query = f"{field_name} = {field_value}"
+    if not layer.setSubsetString(query):
+        # TODO: Convert to log msg?
+        print(f"ERROR: Failed to filter layer {layer_name} with query {query}")
+
+
+def _check_layer_count(layers: List[QgsMapLayer]) -> bool:
+    if len(layers) > 1:
+        # TODO: Convert to log msg?
+        print(f"ERROR: Found multiple layers ({len(layers)}) with same name ({layers[0].name()}).")
+        return False
+    return True
+
+
+def _check_vector_layer(layer: QgsMapLayer) -> bool:
+    if not isinstance(layer, QgsVectorLayer):
+        # TODO: Convert to log msg?
+        print(f"ERROR: Layer {layer.name()} is not a vector layer: f{type(layer)}")
+        return False
+    return True