componentDidMountCache.js

componentDidMount() {
  const cachedAirtableNotes = localStorage.getItem('_cachedAirtableNotes')

  if (cachedAirtableNotes) {
    // Local data exists, now let's see if it has "expired"

    // parse data
    const parsedAirtableNotes = JSON.parse(cachedAirtableNotes)

    // Check current time against timestamp
    if (new Date().getTime() > parsedAirtableNotes.timestamp) {
      // Current time is past timestamp, therefore it's "expired"
      this.getAirtableNotes()
    }
    else {
      // Not "expired", use it
      this.setState({ airtableNotes: JSON.parse(parsedAirtableNotes.data) })
    }
  }

  else {
    this.getAirtableNotes()
  }
}