Question

我正在尝试使用Handlebars帮助程序，但帮助程序视图不会更新。

观点，

<script type="text/x-handlebars">
  {{#view App.NumberView}}
    <button {{action changeNumber}}>Change number</button><br>
    {{formatNumber view.number}} <br>
    {{view.number}}
  {{/view}}
</script>

代码，

App = Ember.Application.create({});

App.NumberView = Ember.View.extend({
  number: 5,
  changeNumber: function(e) {
    this.set('number', this.get('number') + 1);
  }    
});

Em.Handlebars.registerHelper('formatNumber', function(timePath, options) {
  var number = Em.Handlebars.getPath(this, timePath, options);
  return new Handlebars.SafeString("Formated number: " + number);
});

jsfiddle http://jsfiddle.net/LP7Hz/1/

中的实例

那有什么不对？

Answer 1

因为Handlebars在Ember中帮助没有绑定帮助者。所以你可以实例化一个辅助视图，就像这个小提琴一样：

http://jsfiddle.net/secretlm/qfNJw/2/

HTML：

<script type="text/x-handlebars">
    {{#view App.NumberView}}
        <button {{action changeNumber}}>Change number</button><br>
        {{formatNumber view.number}} <br>
        {{view.number}}
    {{/view}}
</script>

使用Javascript：

App = Ember.Application.create({});

App.NumberView = Ember.View.extend({
    number: 5,
    changeNumber: function(e) {
        this.set('number', this.get('number') + 1);
    }    
});


App.registerViewHelper = function(name, view) {
  Ember.Handlebars.registerHelper(name, function(property, options) {
    options.hash.contentBinding = property;
    return Ember.Handlebars.helpers.view.call(this, view, options);
  });
};


inlineFormatter = function(fn) {
  return Ember.View.extend({
    tagName: 'span',

    template: Ember.Handlebars.compile('{{view.formattedContent}}'),

    formattedContent: (function() {
      if (this.get('content') != null) {
        return fn(this.get('content'));
      }
    }).property('content')
  });
};


App.registerViewHelper('formatNumber', inlineFormatter(function(content) {

    return new Handlebars.SafeString("Formated number: " + content);
}));

此链接很有用：来自@Jo Liss的http://techblog.fundinggates.com/blog/2012/08/ember-handlebars-helpers-bound-and-unbound/

Answer 2

你正在寻找一个尚未存在的绑定帮助器。有一个Pull Request和相关的讨论。

Answer 3

我认为stackoverflow上存在类似的问题，与绑定帮助器相关检查此链接Writing a helper that produces bound results?

Ember Handlebars助手视图未更新

3 个答案: