This is an interface to James
Clark's expat library for parsing XML documents.
Module Processor.ozf exports a class that implements a
SAX-like processor which can be used e.g. as shown below.
SAX events are invoked as methods. Each application should specialize
these methods to do something useful.
functor
import Processor at 'x-ozlib://duchier/xml/expat/Processor.ozf'
define
...
class MyProcessor from Processor.'class'
...
meth startElement(Tag Attribs) ... end
...
end
...
end
In order to build this package you first also need an installation of
James Clark's expat library that provides header file
The distribution include an example.oz
application. It can be invoked in the following way:
example URL1 ... URLn
where input is obtained from the given URLs (or files) as if they had
been concatenated. If no url is given, standard input is used. The
input is assumed to contain an XML document. The structure of this
document is printed on standard output. The amount of indentation
used for this purpose can be changed with the --index
option:
example --index=3 ...
uses 3 additional indentation spaces for each level of XML nesting.
The default is 2. For example, after this package has been installed,
you can execute:
ozengine x-ozlib://duchier/xml/expat/{example,testa.xml,testb.xml}
which results in the following printout:
/NONE one
/NONE two
/FOO/BAR two
/OTHER three
/OTHER three
/OTHER three
/OTHER four
/OTHER four
/NONE two
/NONE three
The argument files are
testa.xml and
testb.xml.
See API
Module Processor.ozf exports, on feature
class, a class definition for a SAX-like XML processor.
SAX events are invoked as methods. It is up to each application to
specialize the methods to do something useful (by default they do
nothing). See above the definition of class
MyProcessor. It can be instantiated as follows:
P={New MyProcessor initFromFile(Path)}
More generally, the init method takes one argument which
is either an InputSource object or a list of specs for
creating an InputSource object.
The processor object P can be used to obtain SAX
events one by one using method getEvent($), or method
parse can be invoked to process all SAX events in a
loop until the end. See the API for a
detailed list of the methods corresponding to SAX events, and see
example.oz for illustrative code.
This package also contains a XML parser that is implemented by
subclassing the previous processor. What this parser does is to build
a representation of the XML document as a term. This representation
is made available on feature root of the parser object.