I have made some changes to my jhs installation to allow the retrieval
from the server of xml files and xml-tagged J nouns (to a xul app). The
diff output is below. Using these facilities allows me to serve more
data than jijx will output to the screen; use XPath facilities in
javascript to extract data from the J result; and, when I get to it, tag
a J noun with structure information to allow boxed nouns to be passed
between J and javascript code. I apologize for the length of what follows.
To retrieve an existing .xml file
http://127.0.0.1:50000/theXMLFILENAME
To execute a jsentence that returns an xml-tagged noun,
http://127.0.0.1:50000/jxmlout
An illustration:
var url="http://127.0.0.1:50000/jxmlout";;
var req = new XMLHttpRequest();
req.open('POST', url, true);
.
.
.
req.send("jsentence="+myEncodeURIComponent(sentence)+"&jajax=");
In the "onreadystatechange" function I call req.responseXML which
returns a "dom." In my (very limited experience) this dom is either: 1)
what I want; or, 2) an error structure the J code creates; or 3) a
"parse error" from XMLHttpRequest. An example of handling the response is:
var dom=this.jhsResponseXML;
var sMsg="";
if (dom.documentElement.nodeName == "parsererror")
sMsg="error while parsing replay";
else if(dom.documentElement.nodeName == "error") {
sMsg=dom.firstChild.textContent+"\n";
sMsg+=dom.documentElement.lastChild.textContent;
} else if(1) {
var results = this.evaluateXPath(dom, this.xpath.value);
sMsg="Car#\tid\n";
for (let i in results) {
sMsg+=i + " \t" + results[i].value+"\n";
}
}
alert(sMsg);
References: google for: mdc "parsing xml" and mdc evaluateXPath
===========================================
The diff file:
===========================================
diff -a -c -N jhs.org/core.ijs jhs/core.ijs
*** jhs.org/core.ijs 2010-05-03 12:54:16.000000000 -0500
--- jhs/core.ijs 2010-05-03 14:30:55.000000000 -0500
***************
*** 110,115 ****
--- 110,116 ----
if. 1=NVDEBUG do. smoutput NV end. NB. HNV,NV
DISPLAY=: 0
if. 0~:$ r=. getvqq'jbutton' do.
+ elseif. +./'jxmlout' E. URL [XMLS=:getv'jsentence'
[r=.'url',METHOD,'_',URL,'_ XMLS_jfe_' do.
elseif. -.0-: r=. getv'jsentence' do. DISPLAY=: 1
elseif. -.'.' e. URL [r=.'url',METHOD,'_',URL,'_ 0' do.
elseif. 1 [r=. 'getsrcfile_jfile_ URL_jfe_' do.
***************
*** 684,687 ****
load__ '~system\extras\util\jhs\jijxmin.ijs'
load__ '~system\extras\util\jhs\jal.ijs'
load__ '~system\extras\util\jhs\jdemo.ijs'
!
--- 685,688 ----
load__ '~system\extras\util\jhs\jijxmin.ijs'
load__ '~system\extras\util\jhs\jal.ijs'
load__ '~system\extras\util\jhs\jdemo.ijs'
! load__ '~system\extras\util\jhs\jxmlout.ijs'
diff -a -c -N jhs.org/jfile.ijs jhs/jfile.ijs
*** jhs.org/jfile.ijs 2010-05-01 14:44:00.000000000 -0500
--- jhs/jfile.ijs 2010-05-01 23:16:51.000000000 -0500
***************
*** 432,442 ****
--- 432,469 ----
'text/x-component'gsrcf y
elseif. '.swf'-:_4{.y do.
'application/x-shockwave-flash'gsrcf y
+ elseif. +./'.xml' E. y do.
+ xmlget y
elseif. 1 do.
smoutput 'do not get files of type: ',y
end.
)
+ xmlhead=: 0 : 0
+ HTTP/1.1 200 OK
+ Accept-Ranges: bytes
+ Content-Type: application/xml
+ Content-Length: LENGTH
+
+ )
+
+ xml404=: 0 : 0
+ <?xml version="1.0" encoding="iso-8859-1"?>
+ <error><msg>MSG</msg><txt>TXT</txt></error>
+ )
+
+ NB. return xml file
+ xmlget=: 3 : 0
+ try.
+ d=. 1!:1 <jpath LF -.~ y NB. javascript strings LF terminated?
+ catch.
+ et=. ><;._1 ('<';'<';'>';'>';LF;'') rplc~ [13!:12 ''
+ msg=. {.et [txt=. {:et
+ d=. deb xml404 rplc ('MSG';msg;'TXT';txt)
+ end.
+ htmlresponse d,~xmlhead rplc 'LENGTH';":#d
+ )
+
favicon=: 3 : 0
htmlresponse htmlfav,1!:1 <jpath'~bin\icons\favicon.ico'
)
diff -a -c -N jhs.org/jxmlout.ijs jhs/jxmlout.ijs
*** jhs.org/jxmlout.ijs 1969-12-31 18:00:00.000000000 -0600
--- jhs/jxmlout.ijs 2010-05-03 15:30:24.000000000 -0500
***************
*** 0 ****
--- 1,38 ----
+ NB. J HTTP Server - jxmlout service
+
+ coclass'jxmlout'
+ coinsert'jfe'
+
+ urlget=: mtv
+ NB. urlpost=: mtv
+
+ urlpost=: 3 : 0
+ xmlget y
+ )
+
+ xmlhead=: 0 : 0
+ HTTP/1.1 200 OK
+ Accept-Ranges: bytes
+ Content-Type: application/xml
+ Content-Length: LENGTH
+
+ )
+
+ xml404=: 0 : 0
+ <?xml version="1.0" encoding="iso-8859-1"?>
+ <error><msg>MSG</msg><txt>TXT</txt></error>
+ )
+
+ NB. return xml response
+ NB. y is a jsentence
+ xmlget=: 3 : 0
+ try.
+ d=. ". y
+ catch.
+ et=. ><;._1 ('<';'<';'>';'>';LF;'') rplc~ [13!:12 ''
+ msg=. {.et [txt=. {:et
+ d=. deb xml404 rplc ('MSG';msg;'TXT';txt)
+ end.
+ htmlresponse d,~xmlhead rplc 'LENGTH';":#d
+ )
+
Common subdirectories: jhs.org/src and jhs/src
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