In the Grid Writer example, if you replace the HttpProxy with a DirectProxy only the read API call works:

http://www.extjs.com/deploy/dev/exam...er/writer.html
  1. The read works fine and the grid populates
    1. Request:
      Code:
      {"action":"WriterDirect","method":"readUserInfo","data":null,"type":"rpc","tid":2}
    2. Response:
      Code:
      {"tid":2,"action":"WriterDirect","method":"readUserInfo","result":{"total":
          0,"success":true,"message":"Here is your example data...","data":[{"id":
              1,"email":"user@example.com","first":"UserFirst","last":"UserLast"}]},
        "type":"rpc"}
  2. the delete does not send an ID so that fails on the server
    1. Req:
      Code:
      {"action":"WriterDirect","method":"destroyUser","data":[],"type":"rpc","tid":3}
    2. Resp:
      Code:
      {"tid":3,"action":"WriterDirect","method":"destroyUser","message":
        "ArrayIndexOutOfBoundsException: 0","where":
        "java.lang.ArrayIndexOutOfBoundsException:...",
        "type":"exception"}
  3. the create blows up in the Ext.direct.RemotingProvider doForm method ext-all-debug.js:39939 ... The error is "form is undefined"
  4. the update blows in the same place saying "form is undefined"

ext-all-debug.js:39939 (version 3.2.0)
Code:
var isUpload = String(form.getAttribute("enctype")).toLowerCase() == 'multipart/form-data',
I'm pulling the same ext libraries as the example.