Typeerror: n is undefined in underscore.min.js

2019-08-16 01:51发布

问题:

The following code:

var template = _.template( $("#search_template").html() );

throws this error in the compiler when I try to run it:

Typeerror: n is undefined in underscore.min.js 5:14721

Does anyone have an idea what might be going wrong? Theoretically it should be valid code. I have also tried using the following code instead:

var template = _.template( $("#search_template").html(), variables );

Which results in exactly the same error. When I try to run with underscore.js instead get the following error:

TypeError: text is undefined in underscore.js 1429:5

Current .HTML page reads as follows:

<!DOCTYPE html>
<html lang="en">
<head>
  <title>The Order of the Mouse</title>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="icon" type="image/jpg" href="./ico/favicon.jpg">
  <meta name="description" content="Psychological horror/detective RPG; Web-Based">
  <meta name="keywords" content="RPG, Horror, Detective, Order of the Mouse, Rabbit-Cat, Dragon-Bear, Clown-Fox, Deer-Wolf">
  <link rel="stylesheet" href="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css">
  <link rel="stylesheet" href="/css/style.css">
  <script src="./vendor/jquery-1.11.3.min.js"></script>
  <script src="./vendor/bootstrap.min.js"></script>
  <script src="./vendor/underscore.js"></script>
  <script src="./vendor/backbone.min.js"></script>
  <script src="./vendor/backbone.marionette.min.js"></script>
  <script src="./react/build/react.min.js"></script>
  <script src="./react/build/react-dom.min.js"></script>
</head>
<body>
  <!-- Main Header -->
  <div class="jumbotron" id="top-bar">
    <div class="container" id="header"><h1 id="title-text1"><span class="brand">The Order of the Mouse</span></h1>
    <img id="order-ico" height="64" width="64" src="./ico/skullnoborder.png" alt="skull logo">
    <h4 id="main-sub">Rabbit-Cat, Dragon-Bear and Clown-Fox experience horror in the Castle of Cages and Revolving Walls.</h4>
    </div>
  </div> 
  <!-- Game menu starts here -->
  <nav class="navbar navbar-default">
  <div class="container-fluid">
    <div class="navbar-header">
      <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1" aria-expanded="false">
        <span class="sr-only">Toggle navigation</span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
      </button>
      <a class="navbar-brand" href="#">MENU</a>
    </div>

    <!-- Collect the nav links, forms, and other content for toggling -->
    <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
      <ul class="nav navbar-nav">
      <li class="active"><a href="#">Main Screen<span class="sr-only">(current)</span></a></li>
      <li><a href="#">Help</a></li>
      <li class="dropdown">
          <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Party<span class="caret"></span></a>
      <ul class="dropdown-menu">
          <li id="Dragon-Bear"><a href="#">Dragon-Bear</a></li>
          <li id="Deer-Wolf"><a href="#">Deer-Wolf</a></li>
          <li id="Clown-Fox"><a href="#">Clown-Fox</a></li>
          <li id="Rabbit-Cat"><a href="#">Rabbit-Cat</a></li>
          <li role="separator" class="divider"></li>
          <li id="ChangeFormation"><a href="#">Change Formation</a></li>
        </ul>
      </li>
      <li class="dropdown">
          <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Skills<span class="caret"></span></a>
      <ul class="dropdown-menu">
        <li id="BattleSkills"><a href="#">Battle Skills</a></li>
        <li id="AdentureSkills"><a href="#">Adventure Skills</a></li>
        <li id="MiscSkills"><a href="#">Misc Skills</a></li>
        <li role="separator" class="divider"></li>
        <li id="Learn"><a href="#">Learn</a></li>
        <li id="Combine"><a href="#">Combine</a></li>
        <li id="Aquire"><a href="#">Aquire</a></li>
      </ul>
    </li>
    <li class="dropdown">
        <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Inventory<span class="caret"></span></a>
        <ul class="dropdown-menu">
        <li id="EquipCharacters"><a href="#">Equip Characters</a></li>
        <li id="ManageQuickslots"><a href="#">Manage Quickslots</a></li>
      </ul>
    </li>
    <li class="dropdown">
        <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Relationships<span class="caret"></span></a>
        <ul class="dropdown-menu">
        <li id="Friendships"><a href="#">Friendships</a></li>
        <li id="Romances"><a href="#">Romances</a></li>
        <li id="Enemies"><a href="#">Enemies</a></li>
      </ul>
    </li>
    <li class="dropdown">
        <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Magic<span class="caret"></span></a>
        <ul class="dropdown-menu">
            <li id="Memes"><a href="#">Memes</a></li>
            <li id="Resonances"><a href="#">Resonances</a></li>
            <li id="Auras"><a href="#">Auras</a></li>
            <li id="Mantra"><a href="#">Mantra</a></li>
      </ul>
    </li>
  </ul>
  <ul class="nav navbar-nav navbar-right">
      <li class="dropdown">
          <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Account<span class="caret"></span></a>
          <ul class="dropdown-menu">
            <li id="Profile"><a href="#">Profile</a></li>
            <li role="separator" class="divider"></li>
          <li id="Logout"><a href="#">Logout</a></li>
        </ul>
      </li>
    </ul>
  </div><!-- /.navbar-collapse -->
  </div><!-- /.container-fluid -->
</nav>
<!-- Game menu ends here -->
<!-- MVC starts here-->
<div id="app-container">
  <div id="main-region" class="container">
    </div>
  </div>
  <div id="search_container"></div>
  <script type="text/template" id="no-template">
  <p>You try to fall asleep in your bed but you cannot. Your heart is     beating so fast you feel like it will fail. All night you are plagued by images of your still conscious body being cut open at autopsy. You wake up often. During the days you are afraid to be left alone. The only solace you have is a lady
who calls herself Deer-Wolf, who texts you often and calls you on occasion. You find her voice comforting but you are still afraid, and feel that you will never be fully safe until you solve the case. You ask your friends for help, even offer to pay them to investigate but they etiher ignore you, decline, or tell you to go away. You are not sure if they believe you and are too scared, or if they think you are crazy. Either way, they won't help.</p>
  </script>
  <script type="text/template" id="static-template">
    <p><em>You are Drogon Barre, aka Dragon-Bear.</em></p>
    <p>The date is October 3rd. You are sitting quietly at your father's house when a letter arrives through the door with details of a rape and murder. The letter says that the murder was committed by a member of the infamous cult <strong>The Order of the Mouse</strong>. The writer claims the victim was her sister and that she looked on powerless as the assailant took her sister's life. She claims that the perpetrator currently resides in a hotel just outside Plymouth. The letter gives the address but no further details.</p><p>Do you choose to investigate?</p><button type="button" class="btn btn-success" id="yesbtn">Yes</button><button type="button" class="btn btn-danger" id="nobtn">No</button>
  </script>
  <script type="text/template" id="yes-template">
       <p>When you arrive at the Plymouth station a woman named Deer-Wolf is there to meet you. Initially she fails to notice you
and looks into the distance with a kind of dazed confusion that seems to suggest she has considered the exact point at
which the universe might have ended, present within a kind of altered dimensionality that placed her materially at a similar point
of existence to you, while leaving her utterly absent from it in some other, more absolute sense. Two nuns scurry past
her, heading towards a small, fluffy dog, who they pet while making cooing sounds, as a stern man in an ill-fitting police officer's
uniform eyes them suspiciously. This specticle seems to rouse her from her trance, and she looks quizzically at them, tilting her 
head to one side, before spotting you out of the corner her eye and waving you over.</p>
    <p>When you arrive at the hotel it is empty but for two bleary eyed reception staff who stare as you walk past.
Deer-Wolf tells you this is the place where the murderer lives. He rents a different room each week, always under different
assumed names. He tells people this is because he is married, and likes to take women back un-noticed. The staff have never seen one leave,
but the room is always impecably kept, so the uneasy feeling the hotel staff have about him has never yet been officially corroborated. </p>
  </script>

  <script type="text/javascript">
    var TheOrder = new Marionette.Application();
    TheOrder.StaticView = Marionette.ItemView.extend({
    el: "#main-region",
    template: "#static-template",
    events : {
    "click input[type=button]" : "yesPage"
  },
  yesPage: function(event){
  // Button clicked
  alert("test");
    },
  });
  TheOrder.on("start", function(){
  var staticView = new TheOrder.StaticView();
  console.log("Order of the Mouse has started!");
  staticView.render();
  });
  TheOrder.start();
</script>

<script type="text/javascript">
  SearchView = Backbone.View.extend({
    initialize: function(){
      this.render();
    },
    render: function(){
        alert("starting to understand marionette");
        var template = _.template( $("#search_template").html() );
        this.$el.html( template(variables) );
    }
  });

  var search_view = new SearchView({ el: $("#search_container") }); 
</script>
<script type="text/javascript">
var character = Backbone.Model.extend({
  initialize: function(){

   this.on("change:name", function(model){
      var name = model.get("name"); 
      var nickname = model.get("nickname"); 
      var age = model.get("age");
      var funny = model.get("funny");
      var kind = model.get("kind"); 
      var credible = model.get("credible"); 
      var strong = model.get("strong"); 
      var quick = model.get("quick"); 
      var intellegent = model.get("intellegent"); 
      alert("Created " + name + " Changed Nickname to " + nickname + " Changed Age to " + age + " Changed Funny attribute to " + funny + " Changed Kind attribute to " + kind + " Changed Credible attribute to " + credible + " Changed Strong attribute to " + strong + " Changed Quick attribute to " + quick + " Changed Intellegent attribute to " + intellegent + ".");
    });
  }
});
var DragonBear = new character;
DragonBear.set({ name: "Dragon-Bear", nickname: "Drogon Barre", age: 33, funny: 138, kind: 145, credible: 378, cool: 167, strong: 143, quick: 176, intellegent: 176});
var DeerWolf = new character;
DeerWolf.set({ name: "Deer-Wolf", nickname: "EDI CAM", age: 22, funny: 134, kind: 156, credible: 495, strong: 83, cool: 198, quick: 123, intellegent: 114 });
var RabbitCat = new character({ name: "Rabbit-Cat", age: 25, funny: 124, kind: 43, credible: 78, strong: 34, quick: 156, intellegent: 202 });
var ClownFox = new character({ name: "Clown-Fox", age: 24, funny: 154, kind: 156, credible: 145, strong:380, quick: 166, intellegent: 475 });
var FireStoat = new character({ name: "Fire-Stoat", age: 54, funny: 87, kind: 298, credible: 134, strong: 143, quick: 176, intellegent: 198 });
</script>
<script type="text/template" id="search_template">      
  <label>Search</label> 
  <input type="text" id="search_input" /> 
  <input type="button" id="search_button" value="Search" />
</script>
<div id="search_container"> </div>

回答1:

You have two problems there.


First one is critical and is not about the code itself. Suppose you've defined a SearchView class and it is fine. I'm following your code and the next thing you do is create an instance of that class with new SearchView. initalize gets called. render gets called.

Now let's see what's happening in the render. There's a template call, and it accepts an actual html by looking up an element with $("#search_template").html(). And here's where the catch is. The browser is reading this html and javascript from top to bottom. It doen't just read all html and then goes back to run the script. It defines html elements when he sees those, then runs javascript when he stumbles on a script tag. And the problem is that, if you look all the way up from the new SearchView line, there no #search_template element anywhere. So your template is created from nothing.

Then of course there's that element at the end of your html page, but the script interpreter (the browser) doesn't care to go back and update your template.


The other problem is less critical, it's where you say this.$el.html( template(variables) ); and there's no variables variable defined anywhere before that. Since you don't have any variables in that view anyway, it's absolutely fine to just call that as this.$el.html( template() );.


Let's make it run after all.

<script src='http://code.jquery.com/jquery.js'></script>
<script src='http://underscorejs.org/underscore.js'></script>
<script src='http://backbonejs.org/backbone.js'></script>
  
<script type="text/template" id="search_template">      
  <label>Search</label> 
  <input type="text" id="search_input" /> 
  <input type="button" id="search_button" value="Search" />
</script>

<div id="search_container"></div>
  
<script type="text/javascript">
  var SearchView = Backbone.View.extend({
    initialize: function(){
      this.render();
    },
    render: function(){
        var template = _.template( $("#search_template").html() );
        this.$el.html( template() );
    }
  });

  var search_view = new SearchView({ el: $("#search_container") }); 
</script>


And here's a twist. I have defined the SearchView before the template it requires. But I make sure that by the moment when I create an instance with new SearchView, the template should be available already. And it still works of course.

The lesson here is that you can put all your classes together and just start the application at the end.

<script src='http://code.jquery.com/jquery.js'></script>
<script src='http://underscorejs.org/underscore.js'></script>
<script src='http://backbonejs.org/backbone.js'></script>

<script type="text/javascript">
  var SearchView = Backbone.View.extend({
    initialize: function(){
      this.render();
    },
    render: function(){
        var template = _.template( $("#search_template").html() );
        this.$el.html( template() );
    }
  });
</script>

<script type="text/template" id="search_template">      
  <label>Search</label> 
  <input type="text" id="search_input" /> 
  <input type="button" id="search_button" value="Search" />
</script>

<div id="search_container"></div>
  
<script type="text/javascript">
  var search_view = new SearchView({ el: $("#search_container") }); 
</script>



回答2:

You should call _.template function like in my example, because second parameter in _.template is [settings] not object with variables for template

var variables = {
    variable: 100
};
var template = _.template( $("#search_template").html() );
template = template(variables);

$('#content').html(template);
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.0/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore.js"></script>

<script type="text/template" id="search_template">
    <p><b><%= variable %></b></p>
</script>
<div id="content"></div>