Only use db functions when components are actually mounted

components/chart/chart.js

@@ -5,7 +5,7 @@ import { LocalDate } from 'js-joda'
 import { makeYAxisLabels, normalizeToScale, makeHorizontalGrid } from './y-axis'
 import nfpLines from './nfp-lines'
 import DayColumn from './day-column'
-import { getCycleDay, cycleDaysSortedByDate, getAmountOfCycleDays } from '../../db'
+import { getCycleDay, getCycleDaysSortedByDate, getAmountOfCycleDays } from '../../db'
 import styles from './styles'
 import { scaleObservable } from '../../local-storage'
 import config from '../../config'
@@ -25,6 +25,7 @@ export default class CycleChart extends Component {
         />
       )
     }
+    this.cycleDaysSortedByDate = getCycleDaysSortedByDate()
   }
 
   onLayout = ({ nativeEvent }) => {
@@ -35,12 +36,12 @@ export default class CycleChart extends Component {
       this.setState({ columns: this.makeColumnInfo(nfpLines(height)) })
     }
 
-    cycleDaysSortedByDate.addListener(this.reCalculateChartInfo)
+    this.cycleDaysSortedByDate.addListener(this.reCalculateChartInfo)
     this.removeObvListener = scaleObservable(this.reCalculateChartInfo, false)
   }
 
   componentWillUnmount() {
-    cycleDaysSortedByDate.removeListener(this.reCalculateChartInfo)
+    this.cycleDaysSortedByDate.removeListener(this.reCalculateChartInfo)
     this.removeObvListener()
   }
 

components/chart/day-column.js

@@ -9,10 +9,13 @@ import { getOrCreateCycleDay } from '../../db'
 import cycleModule from '../../lib/cycle'
 import DotAndLine from './dot-and-line'
 
-const getCycleDayNumber = cycleModule().getCycleDayNumber
 const label = styles.column.label
 
 export default class DayColumn extends Component {
+  constructor() {
+    super()
+    this.getCycleDayNumber = cycleModule().getCycleDayNumber
+  }
   passDateToDayView(dateString) {
     const cycleDay = getOrCreateCycleDay(dateString)
     this.props.navigate('CycleDay', { cycleDay })
@@ -68,7 +71,7 @@ export default class DayColumn extends Component {
       )
     }
 
-    const cycleDayNumber = getCycleDayNumber(dateString)
+    const cycleDayNumber = this.getCycleDayNumber(dateString)
     const shortDate = dateString.split('-').slice(1).join('-')
     const cycleDayLabel = (
       <Text style = {label.number}>