Auto save whenever symptom view updates

components/cycle-day/symptoms/symptom-view.js

@@ -1,6 +1,6 @@
 import React, { Component } from 'react'
 import {
-  BackHandler, View, Alert, TouchableOpacity
+  View, Alert, TouchableOpacity
 } from 'react-native'
 import { saveSymptom } from '../../../db'
 import InfoPopUp from './info-symptom'
@@ -13,11 +13,6 @@ import styles, { iconStyles } from '../../../styles'
 export default class SymptomView extends Component {
   constructor(props) {
     super()
-    this.backHandler = BackHandler.addEventListener(
-      'hardwareBackPress',
-      this.handleBackButtonPressOnSymptomView.bind(this)
-    )
-    this.globalBackhandler = props.handleBackButtonPress
     this.date = props.date
     this.navigate = props.navigate
     this.state = {
@@ -25,6 +20,11 @@ export default class SymptomView extends Component {
     }
   }
 
+  componentDidUpdate() {
+    this.autoSave()
+  }
+
+  // TODO where is this needed now?
   async handleBackButtonPressOnSymptomView() {
     // every specific symptom view provides their own onBackButtonPress method
     const stopHere = await this.onBackButtonPress()
@@ -39,10 +39,6 @@ export default class SymptomView extends Component {
     saveSymptom(this.symptomName, this.date)
   }
 
-  componentWillUnmount() {
-    this.backHandler.remove()
-  }
-
   isDeleteIconActive() {
     const symptomValueHasBeenFilledOut = key => {
       // the state tracks whether the symptom info should be shown,
@@ -63,6 +59,7 @@ export default class SymptomView extends Component {
         <Header
           title={headerTitles[this.symptomName].toLowerCase()}
           date={this.date}
+          // TODO what to put here instead?
           goBack={this.handleBackButtonPressOnSymptomView.bind(this)}
           deleteIconActive={this.isDeleteIconActive()}
           deleteEntry={() => {