如何在Firebase中以随机播放模式排序帖子,而无需重复?

时间:2019-07-17 23:38:08

标签: javascript firebase loops shuffle

我想在列表之后显示来自用户的帖子列表。 我可以按默认顺序显示它,但我想按随机顺序显示它。 我使用的是称为shuffle的函数,该函数可以正常工作,但是在我的代码中无法正常工作,因为重复了很多帖子。 我的代码是这样的:

function feed(){
var postList = document.getElementById('postList');
var userId = "a";

let rangeNumbers=[];

var keys = firebase.database().ref('users/'+userId).child("following").once('value').then(function(datakey){

        let usersPost = [];
    let usersPostProfile = [];
        var contador = 0;
    let htmlPost = "";
        var i = 0;

        datakey.forEach(function(data){

            let userDB = data.val();
            let userIdFollowing = userDB.id;

            firebase.database().ref('posts/').orderByChild("id").equalTo(userIdFollowing).once('value').then(function(postdatakey){

              let cantidad = postdatakey.numChildren();


         postdatakey.forEach(function(postdata){

            //Detecta todos los datos de la publicacion
            let postDB = postdata.val();
            let postId = postDB.id;



      firebase.database().ref('/users/' + postId).once('value').then(function(snapshot) {
  let username = (snapshot.val() && snapshot.val().username);
  let name = (snapshot.val() && snapshot.val().name);
  let image = (snapshot.val() && snapshot.val().image);

  // ...
let newArray = {
            text: postDB.text,
            image: postDB.image,
            imageProfile: image,
            username: username,
            name: name,
            timestamp: postDB.timestamp
      };

 usersPost.push(newArray);

 htmlPost += 
      '<div class="postItem">'
      +'<br>'
    +'<img class="post-img-profile" src="'+usersPost[i].imageProfile+'">'
    +'<div class="userData">'

      +'<a><b>'+usersPost[i].name+'</b></a><br>'
      +'<a>'+usersPost[i].username+'</a>'
      +'</div>'
      +'<br><br><Br><br>'
      +'<div class="post">'
      +'<p>'+usersPost[i].text+'</p>'

      +'<div class="center-content">'
        +'<img class="imagePostBig" src="'+usersPost[i].image+'">'
      +'</div>'

    +'</div>'

    +'<div class="optionPost">'
      +'<img class="post-icon" src="https://img.icons8.com/ios/50/000000/like.png">'
    +'<img class="post-icon" src="https://img.icons8.com/ios/50/000000/comments.png">'
    +'<div class="line"></div>'
    +'</div>'



  +'</div>';

        //console.log(htmlPost);

        postList.innerHTML = htmlPost;

i++
      });


         });



            });  



                            });



    });  



}

function shuffle(array) {
  var currentIndex = array.length, temporaryValue, randomIndex;

  // While there remain elements to shuffle...
  while (0 !== currentIndex) {

    // Pick a remaining element...
    randomIndex = Math.floor(Math.random() * currentIndex);
    currentIndex -= 1;

    // And swap it with the current element.
    temporaryValue = array[currentIndex];
    array[currentIndex] = array[randomIndex];
    array[randomIndex] = temporaryValue;
  }

  return array;
}



feed();

我正在使用随机播放功能,但是它重复了帖子。你能帮我吗?如何以随机顺序显示此帖子?

1 个答案:

答案 0 :(得分:0)

很难说,因为我无法运行它,并且您从未在发布的代码中实际调用shuffle,但在我看来,您只需要在正确的位置调用shuffle。

在前一行

postdatakey.forEach(function(postdata){

添加

shuffle(postdatakey);

随机排列帖子的顺序。