Add No Attestations when attestations DB is empty

app/src/main/java/fr/sanchezm/attestationsCovid19/ui/attestations/AttestationsViewModel.kt

@@ -1,5 +1,6 @@
 package fr.sanchezm.attestationsCovid19.ui.attestations
 
+import android.view.View
 import androidx.lifecycle.LiveData
 import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.ViewModel
@@ -13,13 +14,23 @@ class AttestationsViewModel(attestationRepository: AttestationRepository) : View
 
     private var _attestations = attestationRepository.getAttestations() as MutableLiveData<ArrayList<Attestation>>
 
+    private var _displayNoAttestation = MutableLiveData<Int>()
+
     val attestations: LiveData<ArrayList<Attestation>> =
         _attestations
 
     val startActivity: LiveData<Event<Long>> =
         _startActivity
 
+    val displayNoAttestation: LiveData<Int> =
+        _displayNoAttestation
+
     init {
-        _attestations = attestationRepository.getAttestations() as MutableLiveData<ArrayList<Attestation>>
+        if (_attestations.value == null || _attestations.value?.size == 0) {
+            _displayNoAttestation.value = View.VISIBLE
+        } else {
+            _displayNoAttestation.value = View.GONE
+        }
     }
+
 }

app/src/main/res/layout/fragment_attestations.xml

@@ -29,6 +29,16 @@
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toTopOf="parent" />
 
+        <TextView
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="20dp"
+            android:text="@string/no_attestation"
+            android:visibility="@{viewModel.displayNoAttestation}"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toBottomOf="@id/title" />
+
         <androidx.recyclerview.widget.RecyclerView
             android:id="@+id/attestation_recycler_view"
             android:layout_width="match_parent"

app/src/main/res/values/strings.xml

@@ -9,6 +9,7 @@
     <string name="attestation_subtitle">#RestonsChezNous</string>
     <string name="error_cannot_create_attestation">Erreur lors de la génération de l\'attestation, tout les champs ne sont pas compléter</string>
     <string name="attestation_generated">Attestation générer</string>
+    <string name="no_attestation">Aucune attestation, veuillez en générer une.</string>
 
     <!-- Field for attestation -->
     <string name="first_name">Prénom</string>