Rails 3.1:使用动态jQuery添加和重新设置字段(Railscasts#197)

Question

这里是Rails noob。

我一直在谷歌和StackOverflow上搜索信息，以使铁路#197中使用的示例能够正常工作，但是我访问过的链接都没有使用Rails 3.1！

当我单击“删除”或“添加新字段”按钮时，绝对不会发生任何事情。这真是令人沮丧

谁知道我下面提供的代码为什么不像RailsCasts节目那样动态地添加字段或删除字段呢？

application_helper.rb

def link_to_remove_fields(name, f)
f.hidden_field(:_destroy) + link_to_function(name, "remove_fields(this)")
end 

def link_to_add_fields(name, f, association)
new_object = f.object.class.reflect_on_association(association).klass.new
fields = f.fields_for(association, new_object, :child_index => "new_#{association}") do    |builder|
    render(association.to_s.singularize + "_fields", :f => builder)
 end 
    link_to_function(name, "add_fields(this, '#{association}', '#    {escape_javascript(fields)}')", :remote => true)
 end

app.js

// delete characters on users#edit and users#new
function remove_fields(link) {
$(link).prev("input[type=hidden]").val("1");
$(link).closest("#character").hide();
}

// add character fields on users#edit and users#new
function add_fields(link, association, content) {  
    var new_id = new Date().getTime();  
    var regexp = new RegExp("new_" + association, "g");  
    $(link).parent().before(content.replace(regexp, new_id));  
}

html

<div id="account">
<div class="field">
    <%= f.label :account_name %><br />
    <%= f.text_field :account_name %>
</div>
<div class="field">
    <%= f.radio_button(:realm, "USWest") %>
    <%= f.label(:realm, "USWest") %>

    <%= f.radio_button(:realm, "USEast") %>
    <%= f.label(:realm, "USEast") %>

    <%= f.radio_button(:realm, "Europe") %>
    <%= f.label(:realm, "Europe") %>

    <%= f.radio_button(:realm, "Asia") %>
    <%= f.label(:realm, "Asia") %>
</div>      
<div class="field">
    <%= link_to_add_fields "Add new account", f, :characters %>
</div>

<div class="field"> 
    <%= f.hidden_field :_destroy %>
     <%= link_to_remove_fields "remove", f %>
</div>
<%= f.fields_for :characters do |builder| %>
<%= render "characters/char_fields", :f => builder %>
<% end %>
</div>

Answer 1

我看不出必要的部分是：

render(association.to_s.singularize + "_fields", :f => builder)

Answer 2

好的，首先您需要确保您在application.js文件的头上使用了正确的rails 3.1include标记。在银幕上，他用的是旧的方式：

<%= javascript_include_tag :defaults, :cache => true %>

新的方法是：

<%= javascript_include_tag "application" %>

现在，在上述application.js文件中，您将看到下面的代码，不要删除这个，在资产管道中使用这些注释来包含jquery，它现在与rails捆绑在一起，而不是prototype.js。

// This is a manifest file that'll be compiled into including all the files listed below.
// Add new JavaScript/Coffee code in separate files in this directory and they'll automatically
// be included in the compiled file accessible from http://example.com/assets/application.js
// It's not advisable to add code directly here, but if you do, it'll appear at the bottom of the
// the compiled file.
//
//= require jquery
//= require jquery_ujs
//= require_tree .

看起来您的代码已经为jquery设置好了，因此，如果您想简化，只需将代码附加到注释下面的application.js文件底部，您就应该设置好了。