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Re: HTTPAPI, RPG and COBOL
I am more and more confused. The first thing that confuses me is that it appears to me as if you still use the following procedure prototype for your end-element callback procedure:
D Callback PR extproc (p_callback)
D userdata * value
D depth 10I 0 value
D name 1024A varying, const
D path 24576A varying, const
D retval * value
D Attrs * dim (32767)
const options (* VARSIZE)
The procedure prototype above has been re-formatted from:
Callback PR extproc (p_callback)
userdata * value
10I depth value 0
1024A varying, const name
24576A path varying, const
retval * value
Attrs * dim (32767)
const options (* VARSIZE)
This prototype is not the right one to use! It is the one that Scott uses internally to either pass a string or a data structure for parameter 'retval', depending on the setting of http_XmlReturnPtr(). That is some kind of a "trick" or "hack". You definitely need to use the following prototype as long as you do not call http_XmlReturnPtr(*ON):
D Callback PI
D UserData * value
D depth 10I 0 value
D name 1024A varying const
D path 24576A varying const
D value 65535A varying const
D attrs * dim(32767)
D const options(*varsize)
Please notice the little difference between your 'retval' and my ' value'. This parameter must be defined as 'alpa-numeric', bassed by 'const'. It must not be a pointer passed by value. If you stay with the pointer passed by value your pointer will point to the character data of the field, prefixed with two length bytes. Most likely that is not what you want to get.
The second thing confusing me is your "COBOL parser (WSPARSER)". Is it really a XML parser like Expat or is it a synonym for the end element callback procedure?
I truly do not know Cobol but maybe it would help, if you posted the procedure interface (or whatever it must be called in Cobol) of your end element callback procedure. Actually error messages "Identifier does not exist." is returned when EVAL is used for displaying a non existing field, for example EVAL FOOBAA will truly return "Identifier does not exist." for your program, because most likely there is no field "FOOBAA".
Thomas.
-----Ursprüngliche Nachricht-----
Von: ftpapi-bounces@xxxxxxxxxxxxxxxxxxxxxx [mailto:ftpapi-bounces@xxxxxxxxxxxxxxxxxxxxxx] Im Auftrag von Salaheddine Zaki
Gesendet: Freitag, 29. Januar 2016 20:35
An: HTTPAPI and FTPAPI Projects
Betreff: Re: HTTPAPI, RPG and COBOL
Hello Mr. Thomas
First of all, thank your very much for your responssiveness.
Please note that this is my first confrontation with RPG400. so please excuse my ignorance. I am a beginner.
Indeed, the provided code has been copied from HTTPXMLR4 module I found that my specific COBOL parser (WSPARSER) is called after the execution of the procedure endElement, and if I understand correctly, it should return as back to my parser the following structure:
Callback PR extproc (p_callback)
userdata * value
10I depth value 0
1024A varying, const name
24576A path varying, const
retval * value
Attrs * dim (32767)
const options (* VARSIZE)
To further explain the scheme, I have a main COBOL program (titled WSCALL) that calls the RPG procedure HTTP_URL_POST_XML by passing the following
parameters:
01 WSAA-URL-POINTER POINTER.
01-WSAA STARTPROC-POINTER PROCEDURE-POINTER.
01-WSAA ENDPROC PROCEDURE-POINTER-POINTER.
01WSAA-RETURN-CODE PIC S9 (9) BINARY VALUE 0 01WSAA-SOAP-POINTER USAGE IS POINTER.
01WSAA-OUTPUT-POINTER USAGE IS POINTER.
01 WSAA-URL-SPLIT.
03 WSAA URL-LEN-PIC S9 (4) BINARY.
03 WSAA-URL-BODY PIC X (100)
VALUE "http: //xx.xx.xx.xx: yy / rest / WSNAME".
01-WSAA URL PIC X (102).
01WSAA-SOAP-SEND-ENVELOPE PIC X (2500).
01WSAA-SOAP-LEN PIC S9 (9) COMP-4.
01WSAA-TIMEOUT PIC S9 (9) COMP-4 VALUE 60.
01WSAA-USER-AGENT PIC X (64) VALUE "http-api / 1.23".
01WSAA-CONTENT-TYPE PIC X (64) VALUE "text / xml".
01WSAA-SOAP-ACTION PIC X (64)
VALUE "http: //xx.xx.xx.xx: yy / rest / WSACTION".
To call my specific PARSER WSPARSER, I affected the WSAA-ENDPROC-POINTER pointer to the parser through the following statement:
SET-WSAA ENDPROC-POINTER TO ENTRY
PROCEDURE LINKAGE "WSPARSER".
the Calling of the procedure HTTP_URL_POST_XML is as follows :
CALL PROCEDURE
"HTTP_URL_POST_XML" USING BY REFERENCE WSAA-URL
BY VALUE WSAA-SOAP-POINTER
BY VALUE WSAA-SOAP-LEN
BY VALUE WSAA-STARTPROC-POINTER
BY VALUE WSAA-ENDPROC-POINTER
BY VALUE WSAA-OUTPUT-POINTER
BY VALUE TIMEOUT-WSAA
BY REFERENCE USER-AGENT-WSAA
BY REFERENCE CONTENT-TYPE-WSAA
BY REFERENCE WSAA-SOAP-ACTION
RETURNING WSAA-RETURN-CODE.
So far everything is going well. through the debugging, I realized that my parser WSPARSER is called whenever the parser HTTPXMLR4 reaches the end of a tag, in this case, it's the endElement procedure that's called, it should return the mentioned structure in top (Callback...)
So to answer your questions, for me my programme use a single callback that's endElement.
My problem is that my PARSER WSPARSER doesn't receive the Attrs (array of pointers), as already explained an EVAL display me out that "Identifier does not exist."
My need is so simple, at the call of my parser I want to get the name of the attribute, value and an array containing the atrributs of the tag and theirs values.
Thank you for all.
Best regards.
2016-01-29 6:58 GMT+00:00 Thomas Raddatz <thomas.raddatz@xxxxxx>:
> Honestly I am not sure about what you try to accomplish. How many
> callbacks to you use? What do you use the "endElement" callback for?
> Actually it is used internally by the HTTPXMLR4 module:
>
>
> endElement B export
>
> endElement PI
>
> root likeds(elemroot)
>
> name * value
>
>
> And what is the "Callback" procedure used for? Your example code has
> been taken from the HTTPXMLR4 module. It is used to call the
> user-defined end-element callback that has been specified at the
> http_url_post_xml() statement.
>
>
> p_callback s * procptr
>
> Callback PR extproc(p_callback)
>
> userdata * value
>
> depth 10I 0 value
>
> name 1024A varying const
>
> path 24576A varying const
>
> retval * value
>
> Attrs * dim(32767)
>
> const options(*varsize)
>
>
> Usually you need to create a callback procedure with the following
> interface:
>
>
> D EndOfElement PI
>
> D UserData * value
>
> D depth 10I 0 value
>
> D name 1024A varying const
>
> D path 24576A varying const
>
> D value 65535A varying const
>
> D attrs * dim(32767)
>
> D const options(*varsize)
>
>
> In case your element values exceeds 64k, you need to call
> http_XmlReturnPtr(*ON) and use the following callback interface:
>
>
> D valDS_t ds template
>
> D p_newval * inz(*null)
>
> D len 10i 0 inz(0)
>
>
> D EndOfElement PI
>
> D UserData * value
>
> D depth 10I 0 value
>
> D name 1024A varying const
>
> D path 24576A varying const
>
> D valDS likeds(valDS_t) const
>
> D attrs * dim(32767)
>
> D const options(*varsize)
>
>
> Then you pass the procedure pointer of that procedure to the
> http_url_post_xml() procedure. The parser calls your "Callback"
> procedure whenever it encounters a closing element tag. Inside your
> callback procedure you can use http_nextXmlAttr() to spin through the
> list of attributes like this:
>
>
> D i S 10i 0
>
> D name S 1024a varying
>
> D value S 65535a varying
>
>
> i = 1;
>
> DoW (http_nextXmlAttr(attrs: i: name: value);
>
> // Do something with 'name' and 'value'.
>
> // i is increment inside http_nextXmlAttr().
>
> EndDo;
>
>
> Thomas.
>
>
> -----Ursprüngliche Nachricht-----
> Von: ftpapi-bounces@xxxxxxxxxxxxxxxxxxxxxx
> [mailto:ftpapi-bounces@xxxxxxxxxxxxxxxxxxxxxx] Im Auftrag von
> Salaheddine Zaki
> Gesendet: Donnerstag, 28. Januar 2016 13:51
> An: ftpapi@xxxxxxxxxxxxxxxxxxxxxx
> Betreff: HTTPAPI, RPG and COBOL
>
>
> Hi everybody;
>
>
>
>
>
>
> Based on HTTPAPI library of Scott Klement, and using the example of
> calling the Web service CurrencyConvertor (accessible from
> [1]http://www.webservicex.net), I developed a COBOL program (Similar to
> one provided in the example
> [2]http://scottklement.com/archives/ftpapi/200812/msg00014.html ) that
> consuming a Local Web Service, except at the level of XML PARSER I
> can't get the value of the attribute of the tag. Let me explain: the
> XML PARSER parameters are:
>
>
>
>
> LSAA-DUMMY: Pointer
>
>
> LSAA-XML-DEPTH: Pointer
>
>
> LSAA-NAME: The name of the XML tag
>
>
> LSAA-PATH: The path tag
>
>
> LSAA-VALUE: The value of the tag
>
>
> LSAA-ATTRS: A pointer that's supposed containing a pointer table of the
> attributes and values of each tag (eg <tag1 attr1 = "xxx"> "yyyy"
> </
>
> tag1) -> This is where I have problem.
>
>
>
>
> The XML PARSER is called after each callback of the RPG procedure. And
> it's receives the expected parameters, except in case of a tag with
> attribute (eg. attr1) the PARSER receives a null pointer (Eval pointer
> gives "Identifier does not exist").
>
>
>
>
> I think that the problem is at the passing/crossing of parameters
> between programs.
>
>
>
>
> Are Did anyone have already encountered this problem ?
>
>
>
>
> For full clarification, here are the details of the problem :
>
>
> 1- The COBOL program "WSCALL" calls an RPG HTTP_URL_POST_XML
>
> procedure, by passing some parameters like: the URL of the WS, the
> TIMEOUT, CONTENT-TYPE, ACTION ... etc (see code).
>
>
>
> CALL PROCEDURE
>
> "HTTP_URL_POST_XML" USING BY REFERENCE WSAA-URL
>
> BY VALUE WSAA-SOAP-POINTER
>
> BY VALUE WSAA-SOAP-LEN
>
> BY VALUE WSAA-STARTPROC-POINTER
>
> BY VALUE WSAA-ENDPROC-POINTER
>
> BY VALUE WSAA-OUTPUT-POINTER
>
> BY VALUE WSAA-TIMEOUT
>
> BY REFERENCE WSAA-USER-AGENT
>
> BY REFERENCE WSAA-CONTENT-TYPE
>
> BY REFERENCE WSAA-SOAP-ACTION
>
> RETURNING WSAA-RETURN-CODE.
>
>
> 2- 2- After running and receiving / reading the XML response, and when
> closing a tag (</ tag>) EXPORT RPG procedure is called, it makes a
> callback by completing a structure:
>
>
>
> Callback( root.userdata
>
> : rootDepth(root)
>
> : element.name
>
> : elemPath(root: element)
>
> : p_retval
>
> : wwAttrAry
>
> );
>
>
>
> The structure is defined as follows:
>
>
>
> endElement B export
>
> endElement PI
>
> root likeds(elemroot)
>
> name * value
>
>
> p_callback s * procptr
>
> Callback PR extproc(p_callback)
>
> userdata * value
>
> depth 10I 0 value
>
> name 1024A varying const
>
> path 24576A varying const
>
> retval * value
>
> Attrs * dim(32767)
>
> const options(*varsize)
>
>
>
> qqq
>
>
>
>
> 3- Evaluating the wwAttrAry, the result is:
>
>
> > EVAL wwAttrAry
>
> WWATTRARY (1) = SPP: E9AC54183F05AF70
>
> WWATTRARY (2) = SPP: E9AC54183F05AF90
>
> WWATTRARY (3) = SPP: * NULL
>
> WWATTRARY (4) = SPP: * NULL
>
> WWATTRARY (5) = SPP: * NULL
>
> .... etc.
>
> WWATTRARY (500) = SPP: * NULL
>
>
> Here is the result of a first table case: EVAL on the table :
>
> wwAttrAry(1):C 100 ==> "v ® ZÐ}y GREEN"
>
> the "v" is the name of the attribute, "GREEN" is its value.
>
>
>
>
> 4- Continuing the execution, the PARSER is called, only the LSAA-NAME,
> LSAA-PATH and LSAA VALUE parameters are set.
>
>
>
>
> Question :
>
>
>
> 1 - How i can get the right parameters return in my COBOL program (Get
> all parameters, not only LSAA-NAME, LSAA-PATH and LSAA VALUE).
>
>
> 2 - How can i read the content of the table wwAttrAry case by case (get
> the values not the pointers adresses)
>
>
>
> Thank you so much for your potential returns.
>
>
>
> Best regards.
>
> --
> IMPORTANT NOTICE:
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>
> References
>
> 1. http://www.webservicex.net/
> 2. http://scottklement.com/archives/ftpapi/200812/msg00014.html
>
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