Returning HTML from a REST webservice

[David H.]

Hi all,

I was wondering if there is a way that a BDL REST based webservice could return HTML back to a web browser based request? Currently the options appear to be Text, XML, Data and File. HTML sent as Text is interpreted by the browser as text which is not what I want.

If not then please could a feature request be added for this.

TIA,

David

[Frank G.]

Hi,

There are two options :
  1/ You can send the HTML page as text, and if you specify the 'text/html' mime-type as Content-Type, the browser will interpret it as HTML

  DEFINE doc xml.DomDocument
  LET doc = xml.DomDocument.Create()
  CALL doc.load("myfile.html")
  CALL req.setResponseHeader("Content-Type","text/html")
  CALL req.sendTextResponse(200,NULL, doc.saveToString())

  2/ Or you can send the HTML page in XML if you specify the "xhtml" mime-type as Content-Type header.
  DEFINE doc xml.DomDocument
  LET doc = xml.DomDocument.Create()
  CALL doc.load("myfile.html")
  CALL req.setResponseHeader("Content-Type","application/xhtml+xml")
  CALL req.sendXmlResponse(200,NULL, doc)

Regards,
Frank

[Reuben B.]

Hi David,

I have an example available at https://github.com/FourjsGenero/ex_htmlpagegenerator that illustrates the technique.  The README also has links to a site that is using this technique in production.  Note the ws/r in the following URL https://harness.hrnz.co.nz/gas/ws/r/infohorsews/wsd06x?Arg=hrnzg-Ptype&Arg=HorseDetails&Arg=hrnzg-DoSearch&Arg=TRUE&Arg=hrnzg-HorseId&Arg=27168 and the ws/r as you hover over some of the links in the resultant page.

Reuben

[David H.]

Thanks Guys. Just having one of those "do'h, of course!" moments :-)

[Reuben B.]

I should also take the opportunity to plug two additions under Genero 3.10 that help out in this area.

1. The XSLTtransformer class http://4js.com/online_documentation/fjs-fgl-manual-html/#c_gws_xmlXSLTtransformer.html enables you to generate the HTML using XSLT transformations.  Essentially use your 4gl to produce an XML document of unformatted data, and then apply an XSLT Transformation to it to produce the resultant HTML.

2. The WSHelper API http://4js.com/online_documentation/fjs-fgl-manual-html/#r_gws_wshelper_apis.html provides three methods that are useful in interpreting what the RESTful Web Services receives in the request.