form_for 没有 ActiveRecord，表单操作不更新

Question

我使用的是 API 而不是数据库，所以我使用的不是 ActiveRecord 而是 ActiveModel（我主要喜欢这里：railscasts.com/episodes/219-active-model）

问题是，当我尝试编辑一个项目（在我的例子中是一个停车）时，表单的动作仍然是创建动作而不是更新。

所以当我继续 /parkings/2/edit 编辑停车场时，表格仍然是：

<form accept-charset="UTF-8" action="/parkings" class="form-horizontal" id="new_parking" method="post">

当它应该更像是 put hidden field 和 parks/2 作为动作时：

<form accept-charset="UTF-8" action="/parkings/2" class="form-horizontal" id="edit_parking" method="post"><div style="margin:0;padding:0;display:inline"><input name="utf8" type="hidden" value="&#x2713;" /><input name="_method" type="hidden" value="put" />

有人知道form_for的方法&动作是根据路由设置在哪里的吗？我正在尝试做的就像我在数据库中使用 ActiveRecord 一样接近。

这是一些代码：

_form.html.erb

<%= form_for(@parking, :html => { :class => "form-horizontal" }) do |f| %>
...
<% end %>

edit.html.erb & new.html.erb，简直有

<%= render 'form' %>

控制器

class ParkingsController < ApplicationController
  def index    
    @parkings = Parse.get("Parking")

    respond_to do |format|
      format.html
      format.json { render :json => @parking }
    end
  end

  def new
    @parking = Parking.new

    respond_to do |format|
      format.html
      format.json { render :json => @parking }
    end
  end

  def edit
    @parking = Parking.find(params[:id])

    respond_to do |format|
      format.html
      format.json { render :json => @parking }
    end
  end

  def create
    @parking = Parking.new(params[:parking])
    if (@parking.save)
       flash[:success] = "Parking was just added!"
       redirect_to :action => "new"
    else
      render :action => "new"
    end
  end

  def update
   # Testing
   parking = Parse.get("Parking", params[:id])
   parking.delete("updatedAt")
   parking["name"] = params[:parking][:name]
   parking.save

   redirect_to :action => "index"
  end

型号

class Parking
  include ActiveModel::Validations
  include ActiveModel::Conversion
  extend  ActiveModel::Naming

  attr_accessor :name, :address, :city, :longitude, :latitude, :contributor_name, :contributor_email
  validates_presence_of :name, :address, :city, :longitude, :latitude

  @id = nil

  def initialize(attributes = {})
    attributes.each do |name, value|
      send("#{name}=", value)
    end
  end

  def self.find(id)
    @id = id
    raw                       = Parse.get("Parking", @id.to_s)

    parking = Parking.new
    parking.name              = raw["name"]
    parking.address           = raw["address"]
    parking.city              = raw["city"]
    parking.longitude         = raw["location"]["longitude"]
    parking.latitude          = raw["location"]["latitude"]
    parking.contributor_name  = raw["contributorName"]
    parking.contributor_email = raw["contributorEmail"]

    return parking
  end

  def save
    if (!valid?)
      return false
    else
      parking = Parse::Object.new("Parking")

      data =
      {
        :longitude => longitude.to_f,
        :latitude  => latitude.to_f
      }

      point = Parse::GeoPoint.new(data)

      parking["location"]         = point
      parking["name"]             = name
      parking["address"]          = address
      parking["city"]             = city
      parking["contributorName"]  = contributor_name
      parking["contributorEmail"] = contributor_email

      if (parking.save)
        return true
      end
    end
  end

  def persisted?
    false
  end
end

请注意，创建正在工作，如果我使用 Web Inspector 或 Firebug 在表单 action="" 中添加我的停车 ID，并在我的 form_for 中添加 :method => "put"，我的记录成功更新.

这里真正的问题是 form_for 操作和方法在我编辑停车场时没有得到更新，并且就像我添加新停车场一样。

我还在学习 Rails，如果有些信息不清楚，请见谅！

谢谢！

--- 解决方案 ---

坚持？不应该只返回 false，而且我的模型需要定义一个返回对象 id 的方法（以便他们可以更新 action=""）所以这是我更新的模型：

class Parking
  include ActiveModel::Validations
  include ActiveModel::Conversion
  extend  ActiveModel::Naming

  attr_accessor :objectId, :name, :address, :city, :longitude, :latitude, :contributor_name, :contributor_email
  validates_presence_of :name, :address, :city, :longitude, :latitude

  @id = nil

  def initialize(attributes = {})
    attributes.each do |name, value|
      send("#{name}=", value)
    end
  end

  def self.find(id)
    raw                       = Parse.get("Parking", id.to_s)

    parking = Parking.new
    parking.objectId          = id
    parking.name              = raw["name"]
    parking.address           = raw["address"]
    parking.city              = raw["city"]
    parking.longitude         = raw["location"]["longitude"]
    parking.latitude          = raw["location"]["latitude"]
    parking.contributor_name  = raw["contributorName"]
    parking.contributor_email = raw["contributorEmail"]

    return parking
  end

  def save
    if (!valid?)
      return false
    else
      parking = Parse::Object.new("Parking")

      data =
      {
        :longitude => longitude.to_f,
        :latitude  => latitude.to_f
      }

      point = Parse::GeoPoint.new(data)

      parking["location"]         = point
      parking["name"]             = name
      parking["address"]          = address
      parking["city"]             = city
      parking["contributorName"]  = contributor_name
      parking["contributorEmail"] = contributor_email

      if (parking.save)
        return true
      end
    end
  end

  def update_attributes(aParking)
    parking = Parse.get("Parking", @id.to_s)
    parking.delete("updatedAt")

    parking["name"] = aParking["name"]
    parking.save

    return true
  end

  def destroy
    parking = Parse.get("Parking", @id)
    #parking.parse_delete
  end

  def id
    return self.objectId
  end

  def persisted?
    !(self.id.nil?)
  end
end

Answer 1

我认为您的问题出在模型的 persisted? 方法中。由于它总是返回 false，Rails 总是认为它正在为新创建的记录构建表单，因此它使用 POST 并提交到集合 URL。

您需要在该方法中使用某种逻辑，以便现有记录返回 true 而新记录返回 false。

Answer 2

你好朋友，你可以告诉表单生成器使用哪种方法。所以试试

<%= form_for(@parking, :method => ["new", "create"].include?(action_name) ? :post : :put,
    :html => { :class => "form-horizontal" }) do |f| %>
  ...
 <% end %>

Answer 3

如果你没有使用 ActiveRecord，你应该使用 'form_tag' 而不是 'form_for'