title: Displaying data from Firestore into React Native FlatList did not work
body: <p>I'm using the React Native <code>FlatList</code> module to show data that is stored in an <code>firestore</code> collection. This data should rendered into an content box with an colored background.
  Actually, when I render the corresponding <code>Screen</code>, I get as many content boxes as objects are stored into database, but no single field is rendered into the view. I also can print the data object to the console, so querying data should work.</p>
  <pre class="lang-js prettyprint-override"><code>    useEffect(() =&gt; {
          const unsubscribe = onSnapshot(query(collection(db, 'Announcement')), (querySnap) =&gt; {
              const announcements = []
              querySnap.forEach((announcement) =&gt; {
                  announcements.push({ ...announcement.data() })
                  console.log(announcement.data())
                  setContent(announcements)
                  setLoading(false)
              })
          })
          unsubscribe()
      },[])
  
  
      const renderAnnouncement = ({ item }) =&gt; {
          return(
              &lt;View style={ styles.boxItem }&gt;
                  &lt;Text style={ styles.date }&gt;{ item.date }&lt;/Text&gt;
                  &lt;Text style={ styles.title }&gt;{ item.title }&lt;/Text&gt;
                  &lt;Text style={ styles.body }&gt;{ item.body }&lt;/Text&gt;
              &lt;/View&gt;
          )
      }
  
  
      return (
          &lt;SafeAreaView style={ styles.container }&gt;
              &lt;FlatList
                  data={ content }
                  renderItem={ renderAnnouncement }
                  keyExtractor={ item =&gt; item.id }
                  ListEmptyComponent={ handleEmptyList }
              /&gt;
          &lt;/SafeAreaView&gt;
      )
  }
  </code></pre>
  <p>I have structured my data in firestore on the following way:</p>
  <pre><code>Announcements
      - Document-ID
          - message
              - title: string
              - body: string
              - date: string
              - id: number
  
      - Document-ID
          - message
              - title: string
              - body: string
              - date: string
              - id: number
  
  ... and so on
  </code></pre>
  <p>I read related topics here, but all the hints given there, did not solve my issue. Did someone of you have an hint?</p>