为什么我在Ruby on Rails应用程序中遇到未定义的方法错误？

Thanks for any help you can offer. I'm trying to figure out why I'm getting the undefined method error described below. I'm new to Ruby on Rails, but I thought that by creating the @waypoint, I could call methods for it (like @waypoint.waypointaddress). My models use a belongs_to and has many (Newsavedmaps can have many waypoints.) I appreciate your feedback on what I'm doing wrong.

谢谢你尽你所能的帮助。我试图找出为什么我得到下面描述的未定义方法错误。我是Ruby on Rails的新手，但我认为通过创建@waypoint，我可以为它调用方法（比如@ waypoint.waypointaddress）。我的模型使用belongs_to并且有很多（Newsavedmaps可以有很多路点。）我很感激您对我做错的反馈。

Error Refers to if !@waypoint.waypointaddress.nil?

错误是指如果！@waypoint.waypointaddress.nil？

    NoMethodError (undefined method `waypointaddress' for #<Array:NUMBERSHERE>):
    app/controllers/maptry_controller.rb:33:in `index'

maptry controller

测绘控制器

    @newsavedmap = Newsavedmap.find(:first, :conditions => {:id => params[:newsavedmap_id]})
    @waypoint = Waypoint.find(:all, :conditions => {:newsavedmap_id => params[:newsavedmap_id]})
    @newsavedmap.id = params[:newsavedmap_id]
    @newsavedmap.name = Newsavedmap.find(:first, :conditions => {:id => params[:newsavedmap_id]}).name
    @newsavedmap.optimize = Newsavedmap.find(:first, :conditions => {:id => params[:newsavedmap_id]}).optimize

    if !@newsavedmap.start_masterlocation_id.nil?       
    @start_i_name = Masterlocation.find(:first, :conditions => {:id => @newsavedmap.start_masterlocation_id}).i_name
    end
    if !@waypoint.waypointaddress.nil?  
    @waypoint_i_name = Masterlocation.find(:first, :conditions => {:id => @waypoint.waypoint_masterlocation_id}).i_name
    end
    if !@newsavedmap.end_masterlocation_id.nil?     
    @end_i_name = Masterlocation.find(:first, :conditions => {:id => @newsavedmap.end_masterlocation_id}).i_name
    end

    else
        @newsavedmap = Newsavedmap.new  
    end

EDIT 1

编辑1

Here is my updated controller using code from Mu's comment. However, I'm getting an error of "undefined method `each'" for the maptry.html.erb view included below.

这是我使用Mu评论代码更新的控制器。但是，对于下面包含的maptry.html.erb视图，我收到“undefined method` each'”的错误。

To clarify, there may be one or more waypoints that match the conditions. I'd like to return all of them and then do a for each in my maptry view.

为了澄清，可能存在一个或多个符合条件的航路点。我想返回所有这些，然后在我的maptry视图中为每个做一个。

Also, the .where(...) threw an undefined method error for where, so I used find. Maybe that's related to the problem? I'm in Rails 2.X.

此外，.where（...）在哪里抛出了未定义的方法错误，所以我使用了find。也许这与问题有关？我在Rails 2.X.

Code from maptry.html.erb

来自maptry.html.erb的代码

    <% if params[:newsavedmap_id] %>
            <% for waypoint in @waypoint %>
          <option selected value="<%= @waypoint.waypointaddress %>"><%= @waypoint_inst_name %></option>
            <% end %>
          <% end %>

updated maptry controller

更新的地图控制器

    if params[:newsavedmap_id]
    @newsavedmap = Newsavedmap.find(:first, :conditions => {:id => params[:newsavedmap_id]})
    @waypoint = Waypoint.find(:first, :conditions => {:newsavedmap_id => params[:newsavedmap_id]})
    @waypoint.waypointaddress = Waypoint.find(:first, :conditions => {:newsavedmap_id => params[:newsavedmap_id]}).waypointaddress
    @waypoint.waypoint_masterlocation_id = Waypoint.find(:first, :conditions => {:newsavedmap_id => params[:newsavedmap_id]}).waypoint_masterlocation_id
    @waypoint_inst_name = Masterlocation.find(:first, :conditions => {:id => @waypoint.waypoint_masterlocation_id}).inst_name
    @newsavedmap.id = params[:newsavedmap_id]
    @newsavedmap.name = Newsavedmap.find(:first, :conditions => {:id => params[:newsavedmap_id]}).name
    @newsavedmap.optimize = Newsavedmap.find(:first, :conditions => {:id => params[:newsavedmap_id]}).optimize

    if !@newsavedmap.start_masterlocation_id.nil?       
    @start_inst_name = Masterlocation.find(:first, :conditions => {:id => @newsavedmap.start_masterlocation_id}).inst_name
    end
    if !@newsavedmap.end_masterlocation_id.nil?     
    @end_inst_name = Masterlocation.find(:first, :conditions => {:id => @newsavedmap.end_masterlocation_id}).inst_name
    end

    else
    @newsavedmap = Newsavedmap.new  
    end

1 个解决方案

#1

You're asking ActiveRecord to find all the waypoints that match your conditions:

您要求ActiveRecord找到符合您条件的所有航路点：

@waypoint = Waypoint.find(:all, :conditions => {:newsavedmap_id => params[:newsavedmap_id]})
#-------------------------^^^^

That means that you'll get an Array in @waypoint and an Array (usually) won't have a waypointaddress method. Perhaps you meant to ask for the first one:

这意味着你将在@waypoint中获得一个数组，而一个数组（通常）将没有一个waypointaddress方法。也许你打算要求第一个：

@waypoint = Waypoint.find(:first, :conditions => {:newsavedmap_id => params[:newsavedmap_id]})

or better:

或更好：

@waypoint = Waypoint.where(:newsavedmap_id => params[:newsavedmap_id]).first

In general, you shouldn't be using find like that anymore; if you find yourself entering some :conditions in a find call, you should be saying .where(...) instead.

一般来说，你不应该再使用find了;如果你发现自己输入了一些：发现呼叫的条件，你应该说.where（...）代替。

#1