Main Page » Mailing List » July 2018

<rest:response> - unclear strategy of setting header during serialization

Saturday, 14 July 2018 · 5 messages
BB
Bogdan Bogucki14 Jul 2018 11:30 #
Hello, I encountered strange behavior during HTTP response. I need to set custom header Access-Control-Allow-Origin:*. To do that I am using custom response. Following code is working and set required header: declare %rest:POST("{$json}") %rest:path("/ping") function drpg:ping(
$json as xs:string

) as element()* {

  <rest:response>

    <http:response status="200" message="OK">

      <http:header name="Access-Control-Allow-Origin" value="*"/>

      <http:header name="Content-Type" value="text/html"/>

    </http:response>

  </rest:response>,

  let $p := json:parse($json)
return ($p/json/data/_/_/_)[last()] }; Response header: Access-Control-Allow-Origin * Content-Length 11 Content-Type text/html;charset=utf-8 Date Sat, 14 Jul 2018 09:17:18 GMT Server Jetty(9.4.9.v20180320) I want to return plain text, so when I change return parameter to xs:string* and add data function header from <rest:response> is overwritten. Response header: Content-Length 6 Content-Type application/xml; charset=UTF-8 Date Sat, 14 Jul 2018 09:26:59 GMT Server Jetty(9.4.9.v20180320) Example code: declare %rest:POST("{$json}") %rest:path("/drpg/ping") function drpg:ping(
$json as xs:string

) as xs:string* {

  <rest:response>

    <http:response status="200" message="OK">

      <http:header name="Access-Control-Allow-Origin" value="*"/>

      <http:header name="Content-Type" value="text/html"/>

    </http:response>

  </rest:response>,

  let $p := json:parse($json)
return data(($p/json/data/_/_/_)[last()]) }; Why does header is overwritten ? I think if header is set explicitly it shouldn't be overwritten. Best Regards Bogdan Bogucki
CG
Christian Grün14 Jul 2018 11:44 #
Hi Bogdan, If you change the return type of an XQuery function to xs:string, your nodes will be implicitly converted to strings:
  declare function local:f() as xs:string {
    <a>X</a>
  };
  (: will result in 'X' :)
  local:f()
The string conversion of your http:response element yields an empty string, so it does not matter what you specify as attribute values. If you want to return text/plain, you’ll have to change your content type from text/html to to text/plain:
  <http:header name="Content-Type" value="text/plain"/>
Best, Christian
Quoted text · Bogdan Bogucki · 155 lines
On Sat, Jul 14, 2018 at 11:30 AM Bogdan Bogucki <bbogucki at hussar.pl> wrote: > Hello, > > > > I encountered strange behavior during HTTP response. > > > > I need to set custom header Access-Control-Allow-Origin:*. > > > > To do that I am using custom response. > > > > Following code is working and set required header: > > > > declare > > %rest:POST("{$json}") > > %rest:path("/ping") > > function drpg:ping( > > $json as xs:string > > ) as element()* { > > ​​ > <rest:response> > > <http:response status="200" message="OK"> > > <http:header name="Access-Control-Allow-Origin" value="*"/> > > ​​ > <http:header name="Content-Type" value="text/html"/> > > </http:response> > > </rest:response>, > > let $p := json:parse($json) > > return ($p/json/data/_/_/_)[last()] > > }; > > > > Response header: > > Access-Control-Allow-Origin > > * > > > > Content-Length > > 11 > > Content-Type > > text/html;charset=utf-8 > > Date > > Sat, 14 Jul 2018 09:17:18 GMT > > Server > > Jetty(9.4.9.v20180320) > > > > I want to return plain text, so when I change return parameter to > xs:string* and add data function header from <rest:response> is > overwritten. > > > > Response header: > > Content-Length > > 6 > > > > Content-Type > > application/xml; charset=UTF-8 > > Date > > Sat, 14 Jul 2018 09:26:59 GMT > > Server > > Jetty(9.4.9.v20180320) > > > > Example code: > > declare > > %rest:POST("{$json}") > > %rest:path("/drpg/ping") > > function drpg:ping( > > $json as xs:string > > ) as xs:string* { > > <rest:response> > > <http:response status="200" message="OK"> > > <http:header name="Access-Control-Allow-Origin" value="*"/> > > <http:header name="Content-Type" value="text/html"/> > > </http:response> > > </rest:response>, > > let $p := json:parse($json) > > return data(($p/json/data/_/_/_)[last()]) > > }; > > > > Why does header is overwritten ? I think if header is set explicitly it > shouldn't be overwritten. > > > > Best Regards > Bogdan Bogucki > > > > >
BB
Bogdan Bogucki14 Jul 2018 13:22 #
Hello, declare %rest:POST("{$json}") %rest:path("/drpg/ping") function drpg:ping(
$json as xs:string

) as xs:string* {

  <rest:response>

    <http:response status="200" message="OK">

      <http:header name="Access-Control-Allow-Origin" value="*"/>

      <http:header name="Content-Type" value="text/plain"/>

    </http:response>

  </rest:response>,

  let $p := json:parse($json)
return ($p/json/data/_/_/_)[last()] }; Element was converted to string but header is overwritten. Response header: Content-Length: 6 Content-Type: application/xml; charset=UTF-8 Date: Sat, 14 Jul 2018 11:14:32 GMT Server: Jetty(9.4.9.v20180320) How can I set <http:header name="Access-Control-Allow-Origin" value="*"/> ? Why when return type is element() header is set correctly ? Access-Control-Allow-Origin : * Content-Length : 11 Content-Type: text/plain;charset=utf-8 Date: Sat, 14 Jul 2018 11:18:43 GMT Server: Jetty(9.4.9.v20180320) Pozdrawiam Bogdan Bogucki HUSSAR SYSTEMS NIP: 532-170-12-00 Regon: 142624070 e-mail: <mailto:bbogucki at hussar.pl> bbogucki at hussar.pl tel. kom.: +48 607 409 301 www: <http://www.hussar.pl/> www.hussar.pl Od: Christian Grün [mailto:christian.gruen at gmail.com] Wysłano: 14 lipca 2018 11:45 Do: Bogdan Bogucki DW: BaseX Temat: Re: [basex-talk] <rest:response> - unclear strategy of setting header during serialization Hi Bogdan, If you change the return type of an XQuery function to xs:string, your nodes will be implicitly converted to strings:
  declare function local:f() as xs:string {

    <a>X</a>
}; (: will result in 'X' :)
  local:f()
The string conversion of your http:response element yields an empty string, so it does not matter what you specify as attribute values. If you want to return text/plain, you’ll have to change your content type from text/html to to text/plain:
  <http:header name="Content-Type" value="text/plain"/>
Best, Christian
Quoted text · Bogdan Bogucki · 1 line
On Sat, Jul 14, 2018 at 11:30 AM Bogdan Bogucki <bbogucki at hussar.pl> wrote:
Hello, I encountered strange behavior during HTTP response. I need to set custom header Access-Control-Allow-Origin:*. To do that I am using custom response. Following code is working and set required header: declare %rest:POST("{$json}") %rest:path("/ping") function drpg:ping(
$json as xs:string

) as element()* {
​​
  <rest:response>

    <http:response status="200" message="OK">

      <http:header name="Access-Control-Allow-Origin" value="*"/>
​​
      <http:header name="Content-Type" value="text/html"/>

    </http:response>

  </rest:response>,

  let $p := json:parse($json)
return ($p/json/data/_/_/_)[last()] }; Response header: Access-Control-Allow-Origin * Content-Length 11 Content-Type text/html;charset=utf-8 Date Sat, 14 Jul 2018 09:17:18 GMT Server Jetty(9.4.9.v20180320) I want to return plain text, so when I change return parameter to xs:string* and add data function header from <rest:response> is overwritten. Response header: Content-Length 6 Content-Type application/xml; charset=UTF-8 Date Sat, 14 Jul 2018 09:26:59 GMT Server Jetty(9.4.9.v20180320) Example code: declare %rest:POST("{$json}") %rest:path("/drpg/ping") function drpg:ping(
$json as xs:string

) as xs:string* {

  <rest:response>

    <http:response status="200" message="OK">

      <http:header name="Access-Control-Allow-Origin" value="*"/>

      <http:header name="Content-Type" value="text/html"/>

    </http:response>

  </rest:response>,

  let $p := json:parse($json)
return data(($p/json/data/_/_/_)[last()]) }; Why does header is overwritten ? I think if header is set explicitly it shouldn't be overwritten. Best Regards Bogdan Bogucki
CG
Christian Grün14 Jul 2018 13:25 #
Quoted text · Bogdan Bogucki · 4 lines
> > If you change the return type of an XQuery function to xs:string, your > nodes will be implicitly converted to strings. >
This is the standard behavior of XQuery and no particular feature of RESTXQ. Play around with the query that I presented in my previous answer. You need to remove the xs:string* return typeb you can replace it with item()*.
BB
Bogdan Bogucki14 Jul 2018 20:47 #
Hello CHristian, Thank you for help. Understood. Structure <rest:response> was serialized to empty string. Now It is clear for me why data is lost. Best Regards Bogdan Bogucki Od: Christian Grün [mailto:christian.gruen at gmail.com] Wysłano: 14 lipca 2018 13:25 Do: Bogdan Bogucki DW: BaseX Temat: Re: [basex-talk] <rest:response> - unclear strategy of setting header during serialization If you change the return type of an XQuery function to xs:string, your nodes will be implicitly converted to strings. This is the standard behavior of XQuery and no particular feature of RESTXQ. Play around with the query that I presented in my previous answer. You need to remove the xs:string* return typeb you can replace it with item()*.

Written for BaseX 9.0. BaseX may have changed since: please check the current documentation.

« Number of Databases in BaseXRe Re Add line-number function »
⚡Generated with XQuery