使用rails 3.2.2中的$ .ajax（）异步获取数据

Question

I'm trying to learn how to 'GET' data from my rails 3.2.2 project asynchronously. 我正在尝试学习如何从rails 3.2.2项目中异步“获取”数据。 I am new to both javascript and jquery but I've learned, javascript cannot GET data from a server in a different domain. 我是javascript和jquery的新手，但我已经了解到，javascript无法从不同域中的服务器获取数据。 To get around that I've read about using $.ajax(), $getJSON(), and/or $.jsonp(), so my first question is when should you use one over another? 为了解决这个问题，我已经阅读过使用$ .ajax（），$ getJSON（）和/或$ .jsonp（），所以我的第一个问题是你何时应该使用另一个？

I'm trying to get one technique to work (eg $.ajax() within my rails 3.2.2 project. I have a simple scaffold consisting of one controller => Images and one field => t.string:name. 我正在尝试使用一种技术（例如我的rails 3.2.2项目中的$ .ajax（）。我有一个简单的脚手架，由一个控制器组成=>图像和一个字段=> t.string：name。

class ImagesController < ApplicationController
  # GET /images
  # GET /images.json
  def index
    @images = Image.all

    respond_to do |format|
      format.html # index.html.erb
      format.json { render json: @images }
    end
  end

  # GET /images/1
  # GET /images/1.json 
  def show
    @image = Image.find(params[:id])

    respond_to do |format|
      format.html # show.html.erb
      format.json { render json: @image }
    end
  end

  # GET /images/new
  # GET /images/new.json
  def new
    @image = Image.new

    respond_to do |format|
      format.html # new.html.erb
      format.json { render json: @image }
    end
  end

  # GET /images/1/edit
  def edit
    @image = Image.find(params[:id])
  end

  # POST /images
  # POST /images.json
  def create
    @image = Image.new(params[:image])

    respond_to do |format|
      if @image.save
        format.html { redirect_to @image, notice: 'Image was successfully created.' }
        format.json { render json: @image, status: :created, location: @image }
      else
        format.html { render action: "new" }
        format.json { render json: @image.errors, status: :unprocessable_entity }
      end
    end
  end

  # PUT /images/1
  # PUT /images/1.json
  def update
    @image = Image.find(params[:id])

    respond_to do |format|
      if @image.update_attributes(params[:image])
        format.html { redirect_to @image, notice: 'Image was successfully updated.' }
        format.json { head :no_content }
      else
        format.html { render action: "edit" }
        format.json { render json: @image.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /images/1
  # DELETE /images/1.json
  def destroy
    @image = Image.find(params[:id])
    @image.destroy

    respond_to do |format|
      format.html { redirect_to images_url }
      format.json { head :no_content }
    end
  end
end

I first want to explore the index action and 'GET' a list of image names using an $.ajax() call in up.html: 我首先想要探索索引操作并使用up.html中的$ .ajax（）调用'GET'一个图像名称列表：

<html>
<head>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.5/jquery.min.js">    </script>
</head>
<body>
    <script>
        $(document).ready( function (){ 
            $("button").click(function(){
                    $.ajax({
                        dataType: 'jsonp',
                        url: "http://localhost:3000/images",
                        success: function(response) {
                            console.log(response);
                        }
                    });
            });
        });
    </script>

    <button id ="button" type ="button">Get names</button>

</body>
</html>

I received the following from the console: 我从控制台收到以下内容：

event.layerX and event.layerY are broken and deprecated in WebKit. They will be removed  from the engine in the near future.
jquery.min.js:16Resource interpreted as Script but transferred with MIME type text/html:  "http://localhost:3000/images?    callback=jQuery15209319186636712402_1334849479698&_=1334849481034".
images:1Uncaught SyntaxError: Unexpected token <

I'm lost here. 我迷失在这里。 I'm not sure if I should be using '?callback=?' 我不确定我是否应该使用'？callback =？' in my url or if I should have additional parameters in my controller or something else entirely? 在我的网址中，或者我应该在我的控制器中还有其他参数？

Answer 1

       $(document).ready( function (){ 
            $("button").click(function(){
                    $.ajax({
                        dataType: 'json',  // not jsonp
                        url: "http://localhost:3000/images.json",
                        success: function(response) {
                            console.log(response);
                        }
                    });
            });
        });

Answer 2

Ignore the first line in your console - that's a standard warning that appeared in recent Chrome/jquery versions. 忽略控制台中的第一行 - 这是最近Chrome / jquery版本中出现的标准警告。

The second line is telling you that your web app sent html, rather than json 第二行告诉你，你的网络应用程序发送的是html，而不是json

The third line is due to trying to parse html (presumably starting with " <html... ") as if it were a json string. 第三行是由于尝试解析html（可能以“ <html... ”开头），好像它是一个json字符串。

So, you need to tell rails to send you json, not html. 所以，你需要告诉rails给你发送json，而不是html。 Try changing your url in the json call to ""http://localhost:3000/images.json". 尝试将json调用中的url更改为“”http：// localhost：3000 / images.json“。

使用rails 3.2.2中的$ .ajax（）异步获取数据

问题描述

2 个解决方案

解决方案1
2 2012-04-19 15:55:53

解决方案2
1 2012-04-19 15:53:18

使用rails 3.2.2中的$ .ajax（）异步获取数据

问题描述

2 个解决方案

解决方案1 2 2012-04-19 15:55:53

解决方案2 1 2012-04-19 15:53:18

解决方案1
2 2012-04-19 15:55:53

解决方案2
1 2012-04-19 15:53:18