如何显示Vue.js和Firebase未过时的元素？

Question

Here is how I fetch data from Firebase. I can print all my list of events and i'm quite happy for that but now i would like to only load "Events" that are not outdated ? I'm stuck.

Huge thanks for your help :) Max,

    loadEvents ({commit}) {
  commit('setLoading', true)
  firebase.database().ref('events').once('value')
    .then((data) => {
      const events = []
      const obj = data.val()
      for (let key in obj) {
        events.push({
          id: key,
          title: obj[key].title,
          day: obj[key].day,
          description: obj[key].description,
          imageUrl: obj[key].imageUrl,
          date: obj[key].date,
          location: obj[key].location,
          creatorId: obj[key].creatorId
        })

      }
      commit('setLoadedEvents', events)
      commit('setLoading', false)
    })
    .catch(
      (error) => {
        console.log(error)
        commit('setLoading', false)
      }
    )
},

EDIT : thanks to Frank now i can selected only the nodes who have something correct in the field "expires". If there is something wrong like text in this field, the nodes is not displayed. How can I get only the nodes where the date (timestamp) in the field "expires" is upper than the date of yesterday ?

     loadMeetups ({commit}) {
  commit('setLoading', true)
  firebase.database().ref('Meetups').orderByChild('expires').startAt(Date.now()).once('value')
    .then((data) => {
      const Meetups = []
      const obj = data.val()
      for (let key in obj) {
        Meetups.push({
          id: key,
          title: obj[key].title,
          day: obj[key].day,
          expires: obj[key].expires,
          description: obj[key].description,
          imageUrl: obj[key].imageUrl,
          date: obj[key].date,
          location: obj[key].location,
          creatorId: obj[key].creatorId
        })
      }

Here is how i push my data on Firebase :

  methods: {
  onCreateMeetup () {
    if (!this.formIsValid) {
      return
    }
    const MeetupData = {
      title: this.title,
      day: this.day,
      expires: this.expires,
      location: this.location,
      imageUrl: this.imageUrl,
      description: this.description,
      date: this.submittableDateTime
    }
    this.$store.dispatch('createMeetup', MeetupData)
    this.$router.push('/Meetups')
  }
}

And here are a sample of my data

Best,

Answer 1

This depends a bit on the definition of when a node expires. If you store the timestamp of when a child node becomes outdated, eg

child.expires = Date.now();

Then you can query for nodes that haven't expired with:

firebase.database().ref('events').orderByChild('expires').startAt(Date.now()).once('value')
  .then((data) => {
    ...