Merge pull request #236 from Samweli/fix_asset_type_v2

Resolve asset type error

src/qgis_stac/gui/asset_widget.py

@@ -13,9 +13,11 @@
 )
 from qgis.PyQt.uic import loadUiType
 
+from qgis.core import QgsNetworkAccessManager
+
 from ..api.models import AssetLayerType
 
-from ..utils import tr
+from ..utils import log, tr
 
 WidgetUi, _ = loadUiType(
     os.path.join(os.path.dirname(__file__), "../ui/asset_widget.ui")
@@ -49,29 +51,63 @@ def __init__(
     def initialize_ui(self):
         """ Populate UI inputs when loading the widget"""
 
-        layer_types = [
-            AssetLayerType.COG.value,
-            AssetLayerType.COPC.value,
-            AssetLayerType.GEOTIFF.value,
-            AssetLayerType.NETCDF.value,
-        ]
-
         self.title_la.setText(self.asset.title)
         self.type_la.setText(self.asset.type)
+        asset_load = self.asset_loadable()
 
-        self.load_box.setEnabled(self.asset.type in ''.join(layer_types))
+        self.load_box.setEnabled(asset_load)
         self.load_box.toggled.connect(self.asset_load_selected)
         self.load_box.stateChanged.connect(self.asset_load_selected)
         self.download_box.toggled.connect(self.asset_download_selected)
         self.download_box.stateChanged.connect(self.asset_download_selected)
 
-        if self.asset.type not in layer_types:
+        if asset_load:
             self.load_box.setToolTip(
                 tr("Asset contains {} media type which "
                    "cannot be loaded as a map layer in QGIS"
                    ).format(self.asset.type)
             )
 
+    def asset_loadable(self):
+        """ Returns if asset can be added into QGIS"""
+
+        layer_types = [
+            AssetLayerType.COG.value,
+            AssetLayerType.COPC.value,
+            AssetLayerType.GEOTIFF.value,
+            AssetLayerType.NETCDF.value,
+        ]
+
+        if self.asset.type is not None:
+            return self.asset.type in ''.join(layer_types)
+        else:
+            try:
+                request = QtNetwork.QNetworkRequest(
+                    QtCore.QUrl(self.asset.href)
+                )
+                response = QgsNetworkAccessManager().\
+                    instance().blockingGet(request)
+                content_type = response.rawHeader(
+                    QtCore.QByteArray(
+                        'content-type'.encode()
+                    )
+                )
+                content_type = str(content_type, 'utf-8')
+
+                for layer_type in layer_types:
+                    layer_type_values = layer_type.split(' ')
+                    for value in layer_type_values:
+                        if value in content_type:
+                            return True
+
+            except Exception as e:
+                log(f"Problem fetching asset "
+                    f"type from the asset url {self.asset.href},"
+                    f" error {e}"
+                    )
+
+            return False
+
     def asset_load_selected(self, state=None):
         """ Emits the needed signal when an asset has been selected
         for loading.