我正在跟随Michael Hartl的
here教程,并试图创建一个用户的索引.
我的代码：
class UsersController < ApplicationController
before_filter :signed_in_user,only: [:index,:edit,:update]
.
.
.
def index
@users = User.all
end
.
.
.
end
和
<%= provide(:title,'All users') %>
<h1>All users</h1>
<ul class="users">
<% @users.each do |user| %>
<li>
<%= gravatar_for user,size: 52 %>
<%= link_to user.name,user %>
</li>
<% end %>
</ul>
wrong number of arguments (2 for 1)
我究竟做错了什么？有什么想法吗？
解决方法
根据教程,gravatar_for方法被定义为
def gravatar_for(user)
gravatar_id = Digest::MD5::hexdigest(user.email.downcase)
gravatar_url = "https://secure.gravatar.com/avatar/#{gravatar_id}"
image_tag(gravatar_url,alt: user.name,class: "gravatar")
end
请注意,它只接受一个参数：用户. Later in chapter 7,练习后,本教程介绍如何添加一个size参数：
# Returns the Gravatar (http://gravatar.com/) for the given user.
def gravatar_for(user,options = { size: 50 })
gravatar_id = Digest::MD5::hexdigest(user.email.downcase)
size = options[:size]
gravatar_url = "https://secure.gravatar.com/avatar/#{gravatar_id}?s=#{size}"
image_tag(gravatar_url,class: "gravatar")
end