handleSubmitPost(e){
   e.preventDefault();
    const postsRef = firebase.database().ref('posts');
    var date = new Date();
    const post = {
      postContent: this.state.postContent,
      postUsername: this.state.postUsername,
      postTitle: this.state.postTitle,
      date: date.toUTCString()
    }
   postsRef.push(post);

  // CZYSZCZENIE PRZYCISKU
  this.setState({
    postContent: '',
    postUsername: '',
    postTitle: '',
    date: ''
    });
  }

handleSubmitComment(e){
    e.preventDefault(e);
      const commentRef = firebase.database().ref('comments');
      var date = new Date();
      const comment = {
        postId: this.state.post.id ????,
        commentContent: this.state.commentContent,
        commentUsername: this.state.commentUsername,
        date: date.toUTCString()
      }
    commentRef.push(comment)

    this.setState({
      commentContent: '',
      commentUsername: '',
      date: ''
      });
  }