Re: [Tclxml-users] How to parse a particular tag in an XML document using TCLXML

[Kala V. <kv...@ci...>]

Hi,

         Thanks a lot for your time.
         I have some more doubts. In the script using TCLXML, variable $xml 
is parsed to the parser object. Can this $xml be an xml file name? Or 
should it be a string. I tried to run the script by defining the $xml 
variable with different options,

         set xml "<Outer><Inner> Testing </Inner></Outer>"

         I am able to retrieve the Inner tag value without any problem, but 
if i add another tag to the same string, say,

         set xml "<Outer><Inner> Testing 
</Inner></Outer><Another>AnotherTag</Another>"

         then, i am getting an error as follows :

emch-sp22-ultra# tclsh8.3 test2.tcl
error "junk after document element" at line 1 character 91
     while executing
"$p parse $xml"
     (file "test2.tcl" line 35)
emch-sp22-ultra#

         Similarly, can i write into an XML file using TCLXML?

Thanks in Advance
Kala

At 07:08 AM 3/5/2002 +1100, Steve Ball wrote:
>Kala Veda wrote:
>>     I need to parse the xml document using a TCL Function, by passing a 
>> tag name to retrieve the value of the tag. Something similar to 
>> "Simple.pm" in perl.  For example i have an example xml document :
>><Outer>
>>     <Inner>
>>         Testing
>>     </Inner>
>></Outer>
>><Another>
>>     AnotherTag
>></Another>
>>     Say to retrive the value contained in the tag "Another", i should 
>> pass "Another" to a TCL function, which should retreive me "AnotherTag". 
>> How can i use TCLXML to implement this?
>
>There are two ways to do this, using TclXML or by using TclDOM.
>
>If all you want to do is extract the value from that one element
>then TclXML can do that by using an element handler.  You need to
>know about the start of the desired tag, capture its content
>and then stop capturing when the end tag occurs.  For example:
>
>package require xml
>set p [xml::parser -elementstartcommand EStart \
>         -elementendcommand EEnd \
>         -characterdatacommand Data]
>
>proc EStart {tag attrs args} {
>   global capture
>
>   if {[string equal $tag "Another"]} {
>     set capture 1
>   }
>}
>proc EEnd {tag args} {
>   global capture
>
>   if {[string equal $tag "Another"]} {
>     set capture 0
>   }
>}
>proc Data data {
>   global capture pcdata
>
>   if {$capture} {
>     append pcdata $data
>   }
>}
>
>set pcdata {}
>set capture 0
>$p parse $xml
>
>puts "captured data is \"$pcdata\""
>
>-------
>
>Now, using TclDOM v2.0 with its XPath support is a little
>easier:
>
>package require dom 2.0
>
>set doc [dom::DOMImplementation parse $xml]
>
># First get the desired element.
># This will return a list (nodeset) of all elements
># that match the expression.
>set element_list [dom::document selectNode $doc //Another]
>set one_element [lindex $element_list 0]
>
># Now get its string value (the textual content).
>
>puts "element content is \"[dom::node stringValue $one_element]\""
>
>>     Moreover, i tried to run the flatten.tcl with the sample xml file 
>> given in the examples, it is giving an error. The error is as follows :
>
>Please submit a SF bug report.
>
>>     Can you let me know what the problem is? Is there any detailed 
>> documentation for TCLXML implementation?
>
>There is the reference documentation (ie. the man page) on the
>website.  I should probably write up a "roadmap" for the
>Tcl parser implementation.  Why don't you submit a tracker
>item on SF for that too?
>
>Cheers,
>Steve Ball
>
>--
>Steve Ball            |   XSLT Standard Library   | Training & Seminars
>Zveno Pty Ltd         |     Web Tcl Complete      |   XML XSL Schemas
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>