我正在为reddit api编写一个非常简单的代理包装,因此我可以使跨域JSONP请求(reddit不允许JSONP调用我的知识)。使用HTTParty检索JSON时出现“嵌套过深”错误
我使用HTTParty gem来调出并检索响应,我立即将其显示为json。
我检索版(Subreddit)JSON完美的罚款,到目前为止这个作为我的路线:
match "r/:name" => "api#subreddit"
...这是我的控制器操作:
def subreddit
render :json => HTTParty.get("http://www.reddit.com/r/" + params[:name] + "/.json"), :callback => params[:callback]
end
作为一个例子,JSON回来是类似于这样的:http://www.reddit.com/r/pics/.json
我的问题是当我试图抓住特定线程的评论。
我的路线是这样:
match "r/:name/comments/:id" => "api#comments"
...和我的控制器操作是这样的:
def comments
render :json => HTTParty.get("http://www.reddit.com/r/" + params[:name] + "/comments/" + params[:id] + "/.json"), :callback => params[:callback]
end
,我想回到这里可以看到的JSON:http://www.reddit.com/r/pics/comments/rhzgc/.json
但是,当我将此操作称为此操作时,我收到以下错误消息:
MultiJson::DecodeError in ApiController#comments
Nesting of 20 is too deep
完整的堆栈跟踪如下:
json (1.6.6) lib/json/common.rb:148:in `parse'
json (1.6.6) lib/json/common.rb:148:in `parse'
multi_json (1.2.0) lib/multi_json/engines/json_common.rb:9:in `decode'
multi_json (1.2.0) lib/multi_json.rb:81:in `decode'
httparty (0.8.1) lib/httparty/parser.rb:116:in `json'
httparty (0.8.1) lib/httparty/parser.rb:136:in `parse_supported_format'
httparty (0.8.1) lib/httparty/parser.rb:103:in `parse'
httparty (0.8.1) lib/httparty/parser.rb:66:in `call'
httparty (0.8.1) lib/httparty/request.rb:222:in `parse_response'
httparty (0.8.1) lib/httparty/request.rb:192:in `handle_response'
httparty (0.8.1) lib/httparty/request.rb:75:in `perform'
httparty (0.8.1) lib/httparty.rb:391:in `perform_request'
httparty (0.8.1) lib/httparty.rb:343:in `get'
httparty (0.8.1) lib/httparty.rb:423:in `get'
app/controllers/api_controller.rb:12:in `comments'
actionpack (3.1.1) lib/action_controller/metal/implicit_render.rb:4:in `send_action'
actionpack (3.1.1) lib/abstract_controller/base.rb:167:in `process_action'
actionpack (3.1.1) lib/action_controller/metal/rendering.rb:10:in `process_action'
actionpack (3.1.1) lib/abstract_controller/callbacks.rb:18:in `block in process_action'
activesupport (3.1.1) lib/active_support/callbacks.rb:416:in `_run__2872109728488784816__process_action__2261783022290592822__callbacks'
activesupport (3.1.1) lib/active_support/callbacks.rb:386:in `_run_process_action_callbacks'
activesupport (3.1.1) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (3.1.1) lib/abstract_controller/callbacks.rb:17:in `process_action'
actionpack (3.1.1) lib/action_controller/metal/rescue.rb:17:in `process_action'
actionpack (3.1.1) lib/action_controller/metal/instrumentation.rb:30:in `block in process_action'
activesupport (3.1.1) lib/active_support/notifications.rb:53:in `block in instrument'
activesupport (3.1.1) lib/active_support/notifications/instrumenter.rb:21:in `instrument'
activesupport (3.1.1) lib/active_support/notifications.rb:53:in `instrument'
actionpack (3.1.1) lib/action_controller/metal/instrumentation.rb:29:in `process_action'
actionpack (3.1.1) lib/action_controller/metal/params_wrapper.rb:201:in `process_action'
activerecord (3.1.1) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
actionpack (3.1.1) lib/abstract_controller/base.rb:121:in `process'
actionpack (3.1.1) lib/abstract_controller/rendering.rb:45:in `process'
actionpack (3.1.1) lib/action_controller/metal.rb:193:in `dispatch'
actionpack (3.1.1) lib/action_controller/metal/rack_delegation.rb:14:in `dispatch'
actionpack (3.1.1) lib/action_controller/metal.rb:236:in `block in action'
actionpack (3.1.1) lib/action_dispatch/routing/route_set.rb:65:in `call'
actionpack (3.1.1) lib/action_dispatch/routing/route_set.rb:65:in `dispatch'
actionpack (3.1.1) lib/action_dispatch/routing/route_set.rb:29:in `call'
rack-mount (0.8.3) lib/rack/mount/route_set.rb:152:in `block in call'
rack-mount (0.8.3) lib/rack/mount/code_generation.rb:96:in `block in recognize'
rack-mount (0.8.3) lib/rack/mount/code_generation.rb:89:in `optimized_each'
rack-mount (0.8.3) lib/rack/mount/code_generation.rb:95:in `recognize'
rack-mount (0.8.3) lib/rack/mount/route_set.rb:141:in `call'
actionpack (3.1.1) lib/action_dispatch/routing/route_set.rb:532:in `call'
actionpack (3.1.1) lib/action_dispatch/middleware/best_standards_support.rb:17:in `call'
rack (1.3.6) lib/rack/etag.rb:23:in `call'
rack (1.3.6) lib/rack/conditionalget.rb:25:in `call'
actionpack (3.1.1) lib/action_dispatch/middleware/head.rb:14:in `call'
actionpack (3.1.1) lib/action_dispatch/middleware/params_parser.rb:21:in `call'
actionpack (3.1.1) lib/action_dispatch/middleware/flash.rb:243:in `call'
rack (1.3.6) lib/rack/session/abstract/id.rb:195:in `context'
rack (1.3.6) lib/rack/session/abstract/id.rb:190:in `call'
actionpack (3.1.1) lib/action_dispatch/middleware/cookies.rb:331:in `call'
activerecord (3.1.1) lib/active_record/query_cache.rb:62:in `call'
activerecord (3.1.1) lib/active_record/connection_adapters/abstract/connection_pool.rb:477:in `call'
actionpack (3.1.1) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
activesupport (3.1.1) lib/active_support/callbacks.rb:392:in `_run_call_callbacks'
activesupport (3.1.1) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (3.1.1) lib/action_dispatch/middleware/callbacks.rb:28:in `call'
actionpack (3.1.1) lib/action_dispatch/middleware/reloader.rb:68:in `call'
rack (1.3.6) lib/rack/sendfile.rb:101:in `call'
actionpack (3.1.1) lib/action_dispatch/middleware/remote_ip.rb:48:in `call'
actionpack (3.1.1) lib/action_dispatch/middleware/show_exceptions.rb:47:in `call'
railties (3.1.1) lib/rails/rack/logger.rb:13:in `call'
rack (1.3.6) lib/rack/methodoverride.rb:24:in `call'
rack (1.3.6) lib/rack/runtime.rb:17:in `call'
activesupport (3.1.1) lib/active_support/cache/strategy/local_cache.rb:72:in `call'
rack (1.3.6) lib/rack/lock.rb:15:in `call'
actionpack (3.1.1) lib/action_dispatch/middleware/static.rb:53:in `call'
railties (3.1.1) lib/rails/engine.rb:456:in `call'
railties (3.1.1) lib/rails/rack/content_length.rb:16:in `call'
railties (3.1.1) lib/rails/rack/log_tailer.rb:14:in `call'
rack (1.3.6) lib/rack/handler/webrick.rb:59:in `service'
/Users/emcummings/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/webrick/httpserver.rb:111:in `service'
/Users/emcummings/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/webrick/httpserver.rb:70:in `run'
/Users/emcummings/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/webrick/server.rb:183:in `block in start_thread'
什么我错在这里做什么?如果JSON太大而无法解析(我发现这种难以置信的信息!)我该怎么办?
编辑:
看起来像掉到了标准的Net :: HTTP的lib解决我的问题:
uri = URI.parse("http://www.reddit.com/r/pics/comments/rhzgc/.json")
response = Net::HTTP.get_response(uri)
render :json => response.body, :callback => params[:callback]
#OK!
...但我还是很好奇,为什么我没有这个相同的调用与HTTParty!
感谢您的帮助!
有趣的 - 我想它必须做一个JSON解析器在HTTParty内的某处 - 是否有任何限制的原因? – Evan 2012-03-29 15:26:03
我非常确定JSON gem与默认情况下使用的几乎一样,包括Rails。 HTTParty只是通过multi_json间接要求它。至于他们为什么选择19作为默认限制,我不知道。这是一个可以设置的选项,但我不确定HTTParty是否容易公开。 – jdl 2012-03-29 15:40:31
HTTParty似乎没有公开设置底层json解析器上的任何选项 - [它不会传递选项哈希(https://github.com/jnunemaker/httparty/blob/master/lib/httparty/parser.rb #L114)转换为加载或解码方法。 – jabley 2012-07-24 09:27:22