Update the count field in the Patient list page based on screen data. (…

…#896) * Update the count field in the Patient list page based on the data that is showing. * Review comment changes
google · Oct 29, 2021 · 0d15fe4 · 0d15fe4
1 parent 1c4d27b
commit 0d15fe4
Showing 1 changed file with 36 additions and 12 deletions.
diff --git a/reference/src/main/java/com/google/android/fhir/reference/PatientListViewModel.kt b/reference/src/main/java/com/google/android/fhir/reference/PatientListViewModel.kt
@@ -17,12 +17,10 @@
 package com.google.android.fhir.reference
 
 import android.app.Application
-import android.util.Log
 import androidx.lifecycle.AndroidViewModel
 import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.ViewModelProvider
-import androidx.lifecycle.liveData
 import androidx.lifecycle.viewModelScope
 import com.google.android.fhir.FhirEngine
 import com.google.android.fhir.search.Order
@@ -42,36 +40,63 @@ class PatientListViewModel(application: Application, private val fhirEngine: Fhi
   AndroidViewModel(application) {
 
   val liveSearchedPatients = MutableLiveData<List<PatientItem>>()
-  val patientCount = liveData { emit(count()) }
+  val patientCount = MutableLiveData<Long>()
 
   init {
-    fetchAndPost { getSearchResults() }
+    updatePatientListAndPatientCount({ getSearchResults() }, { count() })
   }
 
   fun searchPatientsByName(nameQuery: String) {
-    fetchAndPost { getSearchResults(nameQuery) }
+    updatePatientListAndPatientCount({ getSearchResults(nameQuery) }, { count(nameQuery) })
   }
 
-  private fun fetchAndPost(search: suspend () -> List<PatientItem>) {
-    viewModelScope.launch { liveSearchedPatients.value = search() }
+  /**
+   * [updatePatientListAndPatientCount] calls the search and count lambda and updates the live data
+   * values accordingly. It is initially called when this [ViewModel] is created. Later its called
+   * by the client every time search query changes or data-sync is completed.
+   */
+  private fun updatePatientListAndPatientCount(
+    search: suspend () -> List<PatientItem>,
+    count: suspend () -> Long
+  ) {
+    viewModelScope.launch {
+      liveSearchedPatients.value = search()
+      patientCount.value = count()
+    }
   }
 
-  private suspend fun count(): Long {
-    return fhirEngine.count<Patient> { filterCity(this) }
+  /**
+   * Returns count of all the [Patient] who match the filter criteria unlike [getSearchResults]
+   * which only returns a fixed range.
+   */
+  private suspend fun count(nameQuery: String = ""): Long {
+    return fhirEngine.count<Patient> {
+      if (nameQuery.isNotEmpty()) {
+        filter(
+          Patient.NAME,
+          {
+            modifier = StringFilterModifier.CONTAINS
+            value = nameQuery
+          }
+        )
+      }
+      filterCity(this)
+    }
   }
 
   private suspend fun getSearchResults(nameQuery: String = ""): List<PatientItem> {
     val patients: MutableList<PatientItem> = mutableListOf()
     fhirEngine
       .search<Patient> {
-        if (nameQuery.isNotEmpty())
+        if (nameQuery.isNotEmpty()) {
           filter(
             Patient.NAME,
             {
               modifier = StringFilterModifier.CONTAINS
               value = nameQuery
             }
           )
+        }
         filterCity(this)
         sort(Patient.GIVEN, Order.ASCENDING)
         count = 100
@@ -83,8 +108,7 @@ class PatientListViewModel(application: Application, private val fhirEngine: Fhi
     val risks = getRiskAssessments()
     patients.forEach { patient ->
       risks["Patient/${patient.resourceId}"]?.let {
-        patient.risk = it?.prediction?.first()?.qualitativeRisk?.coding?.first()?.code
-        Log.d(TAG, "getSearchResults: ${patient.name} : ${patient.risk}")
+        patient.risk = it.prediction?.first()?.qualitativeRisk?.coding?.first()?.code
       }
     }
     return patients