Apex_web_service.make_rest_request: Passing parameters and the content type

Question

Not sure if I am missing something, but should this API be setting the content type (to application/x-www-url-formencoded) when there are values present for the parameters p_parm_name and p_parm_value.
The example in the docs is to a yahoo API. I'm not sure about that particular one (see: http://docs.oracle.com/cd/E23903_01/doc/doc.41/e21676/apex_web_service.htm#BABEDJHJ), and I think it requires an appid (yahoo account), so i just went with the example here:
http://developer.yahoo.com/yql/guide/yql-code-examples.html#yql_php
If I run the following from a html file on my desktop it works:
<form method="POST" action="http://query.yahooapis.com/v1/public/yql">
<input type="hidden" name="q" value="select * from upcoming.events where location='San Francisco' and search_text='dance'"></input>
<input type="hidden" name="format" value="json"></input>
<input type="submit"></input>
</form>That is, it returns a JSON result.
The raw HTTP data is as follows:
POST http://query.yahooapis.com/v1/public/yql HTTP/1.1
Host: query.yahooapis.com
Connection: keep-alive
Content-Length: 110
Cache-Control: max-age=0
Origin: null
User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/536.11 (KHTML, like Gecko) Ubuntu/12.04 Chromium/20.0.1132.47 Chrome/20.0.1132.47 Safari/536.11
Content-Type: application/x-www-form-urlencoded
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Encoding: gzip,deflate,sdch
Accept-Language: en-AU,en;q=0.8,en-US;q=0.6
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3
q=select+fromupcoming.events+where+location%3D%27San+Francisco%27+and+search_text%3D%27dance%27&format=json>
However, running the following returns nothing: (nothing, as in nothing that depends on the parameters passed in)
set serveroutput on
declare
l_c CLOB;
begin
  l_c := apex_web_service.make_rest_request(
    p_url => 'http://query.yahooapis.com/v1/public/yql',
    p_http_method => 'POST',
    p_parm_name => apex_util.string_to_table('q:format'),
    p_parm_value => apex_util.string_to_table('select * from upcoming.events where location=''San Francisco'' and search_text=''dance'':json'),
    p_proxy_override => 'http://192.168.1.3:8888');
  dbms_output.put_line(substr(l_c, 1, 4000));
end;Raw HTTP data:
POST http://query.yahooapis.com/v1/public/yql HTTP/1.1
Host: query.yahooapis.com
Connection: Keep-Alive
Content-Length: 106
Connection: close
q=select+%2A+from+upcoming%2Eevents+where+location%3D'San+Francisco'+and+search_text%3D'dance'&format=json>
I do note a key difference is that content type isn't being set in the web service API.
This was just to test a public service. I do note that the above has slighty different request data (percentage encoding on some chars). However, I experienced the same behaviour on a procedure I had written (I can also provide this example test case if you like), which is where I first noticed the issue.
Using utl_http and setting the content type to application/x-www-url-formencoded, does resolve the issue. However, just thought i'd see the possibility of using the Web service API that is made available.
Is the example in the docs valid, or am I missing something obvious?
This is on ApEx 4.1 on the OTN Dev Days VM.
Thoughts?

Answer 1

Hi trent,
I too have had issues with this API , so moved forward with UTL_HTTP API.
There is something amiss.
If you change your code to the one below it works.
SET SERVEROUT ON
declare
l_c CLOB;
l_param varchar2(1000) ;
begin
l_param := 'select * from upcoming.events where location=''San Francisco'' '||
        ' and search_text=''dance'''||'&'||'format=json';
l_c := apex_web_service.make_rest_request(
    p_url => 'http://query.yahooapis.com/v1/public/yql?q='||
        utl_url.escape(l_param)
    ,p_http_method => 'POST'
  dbms_output.put_line(substr(l_c, 1, 4000));
end;
/Note the use of UTL_URL.ESCAPE. The call does not work without it.
I do not use a proxy, so that parameter does not feature in my snippet above.
Cheers,
PS: However, the below does not work. So, it appears that the p_parm_name and p_parm_value do not quite work.
SET SERVEROUT ON;
declare
l_c CLOB;
l_param varchar2(1000) ;
begin
l_param := 'select * from upcoming.events where location=''San Francisco'' and search_text=''dance''';
l_c := apex_web_service.make_rest_request(
    p_url => 'http://query.yahooapis.com/v1/public/yql'
    ,p_http_method => 'POST'
    ,p_parm_name => apex_util.string_to_table('q:format')
    ,p_parm_value => apex_util.string_to_table(utl_url.escape(l_param)||':json')
  dbms_output.put_line(substr(l_c, 1, 4000));
end;
/ Edited by: Prabodh on Oct 13, 2012 2:04 PM