Hfrhyu

With PyQGIS, I want to set project layer properties (Project Menu > Properties > DataSource) such as Identifiable, Searchable and Required (for Read Only, the method is QgsVectorLayer.setReadOnly() (link)).

In the API doc, for the method QgsProject.nonIdentifiableLayers(), it says:

Deprecated since version since: QGIS 3.4 use QgsMapLayer.setFlags() instead

But there is no clear documentation (for me) or example for how to use this new method QgsMapLayer.setFlags().

I would like to understand how to use this method.

I tried to understand the behavior of the setFlags method by see on a vector layer the results of :

vl = iface.activeLayer()
flags = 1
vl.setFlags(QgsMapLayer.LayerFlag(flags))
# result : the layer is identifiable and required

I looked at the Python API doc for QgsMapLayer, in these attributes and :

• Identifiable = 1 (= 2 power 0)


• Removable = 2 (= 2 power 1)


• Searchable = 4 (= 2 power 2)

If we draw a binary table :

Num2 power 22 power 12 power 0
   0   
      0      
      0      
      0      

   1   
      0      
      0      
      1      

   2   
      0      
      1      
      0      

   3   
      0      
      1      
      1      

   4   
      1      
      0      
      0      

   5   
      1      
      0      
      1      

   6   
      1      
      1      
      0      

   7   
      1      
      1      
      1      

and a table of project layer settings (DataSource tab) with the result of vl.setFlags(QgsMapLayer.LayerFlag(Num)), 1 as True and 0 as False :

NumSearchable Required Identifiable
   0   
       0       
       1       
       0       

   1   
       0       
       1       
       1       

   2   
       0       
       0       
       0       

   3   
       0       
       0       
       1       

   4   
       1       
       1       
       0       

   5   
       1       
       1       
       1       

   6   
       1       
       0       
       0       

   7   
       1       
       0       
       1       

• Identifiable behavior equals 2 power 0


• Searchage behavior equals 2 power 2


• but Removable behavior is the inverse of 2 power 1.

... and wait ! Required is the inverse of Removable.

For set these settings for a layer in a project, the code is :

vl = activeLayer()
identifiable = QgsMapLayer.Identifiable
searchable = QgsMapLayer.Searchable
removable = QgsMapLayer.Removable

# for a non-required and identifiable layer
vl.setFlags(QgsMapLayer.LayerFlag(identifiable + removable))

# for a searchable only layer
vl.setFlags(QgsMapLayer.LayerFlag(searchable + removable))

# for a searchable and required layer
vl.setFlags(QgsMapLayer.LayerFlag(searchable))

Or a function :

def layer_settings(vectorLayer, isIdentifiable=True,
 isSearchable=True, isRequired=False):

 flags = 0
 if isIdentifiable:
 flags += QgsMapLayer.Identifiable

 if isSearchable:
 flags += QgsMapLayer.Searchable

 if not isRequired:
 flags += QgsMapLayer.Removable

 vectorLayer.setFlags(QgsMapLayer.LayerFlag(flags))

vl = iface.activeLayer()
# for an identifiable and required layer
layer_settings(vl, True, False, True)