属性ID后缺少冒号，Firebase

Missing Colon After Property ID, Firebase

本文关键字：Firebase ID 属性      更新时间：2023-09-26

我正在编写一个程序，需要对我的服务器后端Firebase进行读写。我不知道为什么，但JS解释器说我缺少冒号，我的定义也不正确

SyntaxError: missing : after property id firebase.js:14:31
ReferenceError: refs is not defined visview.js:18:1
ReferenceError: addUser is not defined

然而，我已经清楚地定义了这些东西，并且我的函数格式正确。也许我错过了什么。

HTML:

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width">
    <title>Web of Hunger</title>
  </head>
  <body>
    <div id="visGraph" class="visNetwork">
      <canvas height="100%" width="100%" style="position: relative; -moz-user-select: none; width: 100%; height: 100%;"></canvas>
    </div>
    <link href="https://cdnjs.cloudflare.com/ajax/libs/vis/4.12.0/vis.min.css" rel="stylesheet" type="text/css" />
    <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/vis/4.12.0/vis.min.js"></script>
    <script type="text/javascript" src="https://cdn.firebase.com/js/client/2.3.2/firebase.js"></script>
    <script type="text/javascript" src="./js/firebase.js"></script>
    <script type="text/javascript" src="./js/visview.js"></script>
    <script type="text/javascript" src="./js/app.js"></script>
  </body>
</html>

firebase.js:

var refs = {
      root : new Firebase("Sorry, I am not allowed to show the URL"),
      users : new Firebase("Sorry, I am not allowed to show the URL"),
      graph : {
        graph : new Firebase("Sorry, I am not allowed to show the URL"),
        nodes : new Firebase("Sorry, I am not allowed to show the URL"),
        edges : new Firebase("Sorry, I am not allowed to show the URL")
      }
    };
    //data manipulation functions (low level to high)
    var addNode = function(node){
      refs.graph.nodes.update({node.name : "temp"});
      refs.graph.nodes.child(node.name).set({
        "id" : node.id,
        "label" : node.label
      });
    };
    var addEdge = function(edge) {
      refs.graph.edges.update({edge.name : "temp"});
      refs.graph.edges.child(edge.name).set({
        "from" : edge.from,
        "to" : edge.to,
        "arrows" : edge.arrows
      });
    };
    var addUser = function(name, edges)
    {
      if(refs.users.child(name) === null)
      {
        var time = Firebase.ServerValue.TIMESTAMP;
        if(refs.graph.nodes.child(name) === null && refs.graph.edges.child(name) === null)
        {
          refs.users.update({name : {}});
          refs.users.child(name).update({
            "id" : time,
            "edges" : {}
          });
          refs.users.child(name).child("edges").update({
            "to" : {},
            "from" : {}
          });
          addNode(new Node(name, time, name));
          for(var i = 0; i < edges.length; i++)
          {
            var nme = edges[i].name;
            refs.users.child(name).child("edges/to").update({nme : true});
            addEdge(new Edge(name, time, edges[i].to, edges[i].arrows));
            //TODO add a "from" edge so that you know who wants to eat you
          }
        }
      } else {
        alert("Username, node name, or edge name taken.");
      }
    };

visview.js:

//handy data structures
var Node = function(name, id, label) {
  this.name = name;
  this.id = id;
  this.label = label;
};
var Edge = function(name, frm, to, arrows) {
  this.name = name;
  this.from = frm;
  this.to = to;
  this.arrows = arrows;
};
//functions that allow vis to read firebase data
refs.graph.graph.on("value", function(snapshot) {
  console.log(snapshot.val());
  //main vis update section
  getGraphDataAsVis(snapshot.val());
});
var getGraphDataAsVis = function(data) {
  //var nodes = refs.graph.child("nodes").
};

app.js:

addUser("tester1", [new Edge("test1", 0, 1, 'to')]);
addNode(new Node("tester2", 400, "tester2"));

这是语法错误：

  refs.graph.nodes.update({node.name : "temp"});

在现代（ES2015）JavaScript中，这将是

  refs.graph.nodes.update({ [node.name] : "temp"});

在旧版本的JavaScript中，没有紧凑的方法可以做到这一点

  function obj() {
    var rv = {};
    for (var i = 0; i < arguments.length; ++i)
      rv[arguments[i]] = rv[arguments[i+1]];
    return rv;
  }

然后：

  refs.graph.nodes.update(obj(node.name, "temp"));

辅助函数"obj"只是将其参数视为一系列名称-值对值。第一个参数是第一个属性名称，第二个参数是一个属性值，依此类推。在ES2015之前，该语言不支持在对象初始值设定项中计算:左侧的表达式以确定属性名称的概念。只有属性值可以是作为对象初始值设定项解释的一部分计算的表达式；属性名称必须是常量。

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