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TclXML(n) TclXML(n)
Steve Ball’
______________________________________________________________________________
NAME
::xml::parser - XML parser support for Tcl
SYNOPSIS
package require xml
package require parserclass
xml2.6
::xml::sgml::xml::tclparser
::xml::parserclass option ? arg arg ... ?
::xml::parser ? name? ? -option value ... ?
parser option arg
_________________________________________________________________
DESCRIPTION
TclXML provides event-based parsing of XML documents. The application
may register callback scripts for certain document features, and when
the parser encounters those features while parsing the document the
callback is evaluated.
The parser may also perform other functions, such as normalisation,
validation and/or entity expansion. Generally, these functions are
under the control of configuration options. Whether these functions
can be performed at all depends on the parser implementation.
The TclXML package provides a generic interface for use by a Tcl appli‐
cation, along with a low-level interface for use by a parser implemen‐
tation. Each implementation provides a class of XML parser, and these
register themselves using the ::xml::parserclass create command. One
of the registered parser classes will be the default parser class.
Loading the package with the generic package require xml command allows
the package to automatically determine the default parser class. In
order to select a particular parser class as the default, that class'
package may be loaded directly, eg. package require expat. In all
cases, all available parser classes are registered with the TclXML
package, the difference is simply in which one becomes the default.
COMMANDS
::xml::parserclass
The ::xml::parserclass command is used to manage XML parser classes.
Command Options
The following command options may be used:
create create name ? -createcommand
script? ? -createentityparsercommand
script? ? -parsecommand script? ? -config‐
urecommand script? ? -getcommand script? ?
-deletecommand script?
Creates an XML parser class with the given
name.
destroy destroy name
Destroys an XML parser class.
info info names
Returns information about registered XML
parser classes.
::xml::parser
The ::xml::parser command creates an XML parser object.
The return value of the command is the name of the newly
created parser.
The parser scans an XML document's syntactical structure,
evaluating callback scripts for each feature found. At
the very least the parser will normalise the document and
check the document for well-formedness. If the document
is not well-formed then the -errorcommand option will be
evaluated. Some parser classes may perform additional
functions, such as validation. Additional features pro‐
vided by the various parser classes are described in the
section Parser Classes
Parsing is performed synchronously. The command blocks
until the entire document has been parsed. Parsing may
be terminated by an application callback, see the section
Callback Return Codes. Incremental parsing is also sup‐
ported by using the -final configuration option.
Configuration Options
The ::xml::parser command accepts the following
configuration options:
-attlistdeclcommand
-attlistdeclcommand script
Specifies the prefix of a Tcl
command to be evaluated when‐
ever an attribute list decla‐
ration is encountered in the
DTD subset of an XML docu‐
ment. The command evaluated
is: script name attrname type
default value
where:
name
Ele‐
ment
type
name
attr‐
name
Attribute
name
being
declared
type
Attribute
type
default
Attribute
default,
such
as
#IMPLIED
value
Default
attribute
value.
Empty
string
if
none
given.
-baseurl
-baseurl
URI
Speci‐
fies the
base URI
for
resolv‐
ing rel‐
ative
URIs
that may
be used
in the
XML doc‐
ument to
refer to
external
enti‐
ties.
-char‐
acter‐
datacom‐
mand
-charac‐
terdata‐
command
script
Speci‐
fies the
prefix
of a Tcl
command
to be
evalu‐
ated
whenever
charac‐
ter data
is
encoun‐
tered in
the XML
document
being
parsed.
The com‐
mand
evalu‐
ated is:
script
data
where:
data
Char‐
ac‐
ter
data
in
the
doc‐
u‐
ment
-com‐
ment‐
com‐
mand
-com‐
ment‐
com‐
mand
script
Spec‐
i‐
fies
the
pre‐
fix
of
a
Tcl
com‐
mand
to
be
eval‐
u‐
ated
when‐
ever
a
com‐
ment
is
encoun‐
tered
in
the
XML
doc‐
u‐
ment
being
parsed.
The
com‐
mand
eval‐
u‐
ated
is:
script
data
where:
data
Com‐
ment
data
-default‐
com‐
mand
-default‐
com‐
mand
script
Spec‐
i‐
fies
the
pre‐
fix
of
a
Tcl
com‐
mand
to
be
eval‐
u‐
ated
when
no
other
call‐
back
has
been
defined
for
a
doc‐
u‐
ment
fea‐
ture
which
has
been
encoun‐
tered.
The
com‐
mand
eval‐
u‐
ated
is:
script
data
where:
data
Doc‐
u‐
ment
data
-defaul‐
t‐
ex‐
pand‐
in‐
ter‐
nalen‐
ti‐
ties
-defaul‐
t‐
ex‐
pand‐
in‐
ter‐
nalen‐
ti‐
ties
bool‐
ean
Spec‐
i‐
fies
whether
enti‐
ties
declared
in
the
inter‐
nal
DTD
sub‐
set
are
expanded
with
their
replace‐
ment
text.
If
enti‐
ties
are
not
expanded
then
the
entity
ref‐
er‐
ences
will
be
reported
with
no
expan‐
sion.
-doc‐
typecom‐
mand
-doc‐
typecom‐
mand
script
Spec‐
i‐
fies
the
pre‐
fix
of
a
Tcl
com‐
mand
to
be
eval‐
u‐
ated
when
the
doc‐
u‐
ment
type
dec‐
la‐
ra‐
tion
is
encoun‐
tered.
The
com‐
mand
eval‐
u‐
ated
is:
script
name
pub‐
lic
sys‐
tem
dtd
where:
name
The
name
of
the
doc‐
u‐
ment
ele‐
ment
pub‐
lic
Pub‐
lic
iden‐
ti‐
fier
for
the
exter‐
nal
DTD
sub‐
set
sys‐
tem
Sys‐
tem
iden‐
ti‐
fier
for
the
exter‐
nal
DTD
sub‐
set.
Usu‐
ally
a
URI.
dtd
The
inter‐
nal
DTD
sub‐
set
See
also
-start‐
doc‐
type‐
de‐
clcom‐
mand
and
-end‐
doc‐
type‐
de‐
clcom‐
mand.
-ele‐
ment‐
de‐
clcom‐
mand
-ele‐
ment‐
de‐
clcom‐
mand
script
Spec‐
i‐
fies
the
pre‐
fix
of
a
Tcl
com‐
mand
to
be
eval‐
u‐
ated
when
an
ele‐
ment
markup
dec‐
la‐
ra‐
tion
is
encoun‐
tered.
The
com‐
mand
eval‐
u‐
ated
is:
script
name
model
where:
name
The
ele‐
ment
type
name
model
Con‐
tent
model
spec‐
i‐
fi‐
ca‐
tion
-ele‐
mentend‐
com‐
mand
-ele‐
mentend‐
com‐
mand
script
Spec‐
i‐
fies
the
pre‐
fix
of
a
Tcl
com‐
mand
to
be
eval‐
u‐
ated
when
an
ele‐
ment
end
tag
is
encoun‐
tered.
The
com‐
mand
eval‐
u‐
ated
is:
script
name
args
where:
name
The
ele‐
ment
type
name
that
has
ended
args
Addi‐
tional
infor‐
ma‐
tion
about
this
ele‐
ment
Addi‐
tional
infor‐
ma‐
tion
about
the
ele‐
ment
takes
the
form
of
con‐
fig‐
u‐
ra‐
tion
options.
Pos‐
si‐
ble
options
are:
-empty
bool‐
ean
The
empty
ele‐
ment
syn‐
tax
was
used
for
this
ele‐
ment
-names‐
pace
uri
The
ele‐
ment
is
in
the
XML
names‐
pace
asso‐
ci‐
ated
with
the
given
URI
-ele‐
mentstart‐
com‐
mand
-ele‐
mentstart‐
com‐
mand
script
Spec‐
i‐
fies
the
pre‐
fix
of
a
Tcl
com‐
mand
to
be
eval‐
u‐
ated
when
an
ele‐
ment
start
tag
is
encoun‐
tered.
The
com‐
mand
eval‐
u‐
ated
is:
script
name
attlist
args
where:
name
The
ele‐
ment
type
name
that
has
started
attlist
A
Tcl
list
con‐
tain‐
ing
the
attributes
for
this
ele‐
ment.
The
list
of
attributes
is
for‐
mat‐
ted
as
pairs
of
attribute
names
and
their
val‐
ues.
args
Addi‐
tional
infor‐
ma‐
tion
about
this
ele‐
ment
Addi‐
tional
infor‐
ma‐
tion
about
the
ele‐
ment
takes
the
form
of
con‐
fig‐
u‐
ra‐
tion
options.
Pos‐
si‐
ble
options
are:
-empty
bool‐
ean
The
empty
ele‐
ment
syn‐
tax
was
used
for
this
ele‐
ment
-names‐
pace
uri
The
ele‐
ment
is
in
the
XML
names‐
pace
asso‐
ci‐
ated
with
the
given
URI
-names‐
pacede‐
cls
list
The
start
tag
included
one
or
more
XML
Names‐
pace
dec‐
la‐
ra‐
tions.
list
is
a
Tcl
list
giv‐
ing
the
names‐
paces
declared.
The
list
is
for‐
mat‐
ted
as
pairs
of
val‐
ues,
the
first
value
is
the
names‐
pace
URI
and
the
sec‐
ond
value
is
the
pre‐
fix
used
for
the
names‐
pace
in
this
doc‐
u‐
ment.
A
default
XML
names‐
pace
dec‐
la‐
ra‐
tion
will
have
an
empty
string
for
the
pre‐
fix.
-end‐
c‐
data‐
sec‐
tion‐
com‐
mand
-end‐
c‐
data‐
sec‐
tion‐
com‐
mand
script
Spec‐
i‐
fies
the
pre‐
fix
of
a
Tcl
com‐
mand
to
be
eval‐
u‐
ated
when
end
of
a
CDATA
sec‐
tion
is
encoun‐
tered.
The
com‐
mand
is
eval‐
u‐
ated
with
no
fur‐
ther
argu‐
ments.
-end‐
doc‐
type‐
de‐
clcom‐
mand
-end‐
doc‐
type‐
de‐
clcom‐
mand
script
Spec‐
i‐
fies
the
pre‐
fix
of
a
Tcl
com‐
mand
to
be
eval‐
u‐
ated
when
end
of
the
doc‐
u‐
ment
type
dec‐
la‐
ra‐
tion
is
encoun‐
tered.
The
com‐
mand
is
eval‐
u‐
ated
with
no
fur‐
ther
argu‐
ments.
-enti‐
ty‐
de‐
clcom‐
mand
-enti‐
ty‐
de‐
clcom‐
mand
script
Spec‐
i‐
fies
the
pre‐
fix
of
a
Tcl
com‐
mand
to
be
eval‐
u‐
ated
when
an
entity
dec‐
la‐
ra‐
tion
is
encoun‐
tered.
The
com‐
mand
eval‐
u‐
ated
is:
script
name
args
where:
name
The
name
of
the
entity
being
declared
args
Addi‐
tional
infor‐
ma‐
tion
about
the
entity
dec‐
la‐
ra‐
tion.
An
inter‐
nal
entity
shall
have
a
sin‐
gle
argu‐
ment,
the
replace‐
ment
text.
An
exter‐
nal
parsed
entity
shall
have
two
addi‐
tional
argu‐
ments,
the
pub‐
lic
and
sys‐
tem
inden‐
ti‐
fiers
of
the
exter‐
nal
resource.
An
exter‐
nal
unparsed
entity
shall
have
three
addi‐
tional
argu‐
ments,
the
pub‐
lic
and
sys‐
tem
iden‐
ti‐
fiers
fol‐
lowed
by
the
nota‐
tion
name.
-enti‐
tyref‐
er‐
encecom‐
mand
-enti‐
tyref‐
er‐
encecom‐
mand
script
Spec‐
i‐
fies
the
pre‐
fix
of
a
Tcl
com‐
mand
to
be
eval‐
u‐
ated
when
an
entity
ref‐
er‐
ence
is
encoun‐
tered.
The
com‐
mand
eval‐
u‐
ated
is:
script
name
where:
name
The
name
of
the
entity
being
ref‐
er‐
enced
-errro‐
com‐
mand
-error‐
com‐
mand
script
Spec‐
i‐
fies
the
pre‐
fix
of
a
Tcl
com‐
mand
to
be
eval‐
u‐
ated
when
a
fatal
error
is
detected.
The
error
may
be
due
to
the
XML
doc‐
u‐
ment
not
being
well-
formed.
In
the
case
of
a
val‐
i‐
dat‐
ing
parser
class,
the
error
may
also
be
due
to
the
XML
doc‐
u‐
ment
not
obey‐
ing
valid‐
ity
con‐
straints.
By
default,
a
call‐
back
script
is
pro‐
vided
which
causes
an
error
return
code,
but
an
appli‐
ca‐
tion
may
sup‐
ply
a
script
which
attempts
to
con‐
tinue
pars‐
ing.
The
com‐
mand
eval‐
u‐
ated
is:
script
error‐
code
errormsg
where:
error‐
code
A
sin‐
gle
word
descrip‐
tion
of
the
error,
intended
for
use
by
an
appli‐
ca‐
tion
errormsg
A
human-
read‐
able
descrip‐
tion
of
the
error
-exter‐
nalen‐
ti‐
ty‐
com‐
mand
-exter‐
nalen‐
ti‐
ty‐
com‐
mand
script
Spec‐
i‐
fies
the
pre‐
fix
of
a
Tcl
com‐
mand
to
be
eval‐
u‐
ated
to
resolve
an
exter‐
nal
entity
ref‐
er‐
ence.
If
the
parser
has
been
con‐
fig‐
ured
to
val‐
i‐
date
the
XML
doc‐
u‐
ment,
a
default
script
is
sup‐
plied
that
resolves
the
URI
given
as
the
sys‐
tem
iden‐
ti‐
fier
of
the
exter‐
nal
entity
and
recur‐
sively
parses
the
entity's
data.
If
the
parser
has
been
con‐
fig‐
ured
as
a
non-
val‐
i‐
dat‐
ing
parser,
then
by
default
exter‐
nal
enti‐
ties
are
not
resolved.
This
option
can
be
used
to
over‐
ride
the
default
be‐
hav‐
iour.
The
com‐
mand
eval‐
u‐
ated
is:
script
name
baseuri
uri
id
where:
name
The
Tcl
com‐
mand
name
of
the
cur‐
rent
parser
baseuri
An
abso‐
lute
URI
for
the
cur‐
rent
entity
which
is
to
be
used
to
resolve
rel‐
a‐
tive
URIs
uri
The
sys‐
tem
iden‐
ti‐
fier
of
the
exter‐
nal
entity,
usu‐
ally
a
URI
id
The
pub‐
lic
iden‐
ti‐
fier
of
the
exter‐
nal
entity.
If
no
pub‐
lic
iden‐
ti‐
fier
was
given
in
the
entity
dec‐
la‐
ra‐
tion
then
id
will
be
an
empty
string.
-final
-final
bool‐
ean
Spec‐
i‐
fies
whether
the
XML
doc‐
u‐
ment
being
parsed
is
com‐
plete.
If
the
doc‐
u‐
ment
is
to
be
incre‐
men‐
tally
parsed
then
this
option
will
be
set
to
false,
and
when
the
last
frag‐
ment
of
doc‐
u‐
ment
is
parsed
it
is
set
to
true.
For
exam‐
ple,
set parser [::xml::parser -final 0]
$parser parse $data1
$parser parse $data2
$parser configure -final 1
$parser parse $finaldata
-ignorewhites‐
pace
-ignorewhites‐
pace
bool‐
ean
If
this
option
is
set
to
true
then
spans
of
char‐
ac‐
ter
data
in
the
XML
doc‐
u‐
ment
which
are
com‐
posed
only
of
white-
space
(CR,
LF,
space,
tab)
will
not
be
reported
to
the
appli‐
ca‐
tion.
In
other
words,
the
data
passed
to
every
invo‐
ca‐
tion
of
the
-char‐
ac‐
ter‐
dat‐
a‐
com‐
mand
script
will
con‐
tain
at
least
one
non-
white-
space
char‐
ac‐
ter.
-nota‐
tion‐
de‐
clcom‐
mand
-nota‐
tion‐
de‐
clcom‐
mand
script
Spec‐
i‐
fies
the
pre‐
fix
of
a
Tcl
com‐
mand
to
be
eval‐
u‐
ated
when
a
nota‐
tion
dec‐
la‐
ra‐
tion
is
encoun‐
tered.
The
com‐
mand
eval‐
u‐
ated
is:
script
name
uri
where:
name
The
name
of
the
nota‐
tion
uri
An
exter‐
nal
iden‐
ti‐
fier
for
the
nota‐
tion,
usu‐
ally
a
URI.
-not‐
stan‐
dalonecom‐
mand
-not‐
stan‐
dalonecom‐
mand
script
Spec‐
i‐
fies
the
pre‐
fix
of
a
Tcl
com‐
mand
to
be
eval‐
u‐
ated
when
the
parser
deter‐
mines
that
the
XML
doc‐
u‐
ment
being
parsed
is
not
a
stand‐
alone
doc‐
u‐
ment.
-para‐
men‐
ti‐
ty‐
pars‐
ing
-para‐
men‐
ti‐
ty‐
pars‐
ing
bool‐
ean
Con‐
trols
whether
exter‐
nal
param‐
e‐
ter
enti‐
ties
are
parsed.
-param‐
e‐
ter‐
en‐
ti‐
ty‐
de‐
clcom‐
mand
-param‐
e‐
ter‐
en‐
ti‐
ty‐
de‐
clcom‐
mand
script
Spec‐
i‐
fies
the
pre‐
fix
of
a
Tcl
com‐
mand
to
be
eval‐
u‐
ated
when
a
param‐
e‐
ter
entity
dec‐
la‐
ra‐
tion
is
encoun‐
tered.
The
com‐
mand
eval‐
u‐
ated
is:
script
name
args
where:
name
The
name
of
the
param‐
e‐
ter
entity
args
For
an
inter‐
nal
param‐
e‐
ter
entity
there
is
only
one
addi‐
tional
argu‐
ment,
the
replace‐
ment
text.
For
exter‐
nal
param‐
e‐
ter
enti‐
ties
there
are
two
addi‐
tional
argu‐
ments,
the
sys‐
tem
and
pub‐
lic
iden‐
ti‐
fiers
respec‐
tively.
-parser
-parser
name
The
name
of
the
parser
class
to
instan‐
ti‐
ate
for
this
parser
object.
This
option
may
only
be
spec‐
i‐
fied
when
the
parser
instance
is
cre‐
ated.
-pro‐
cessin‐
gin‐
struc‐
tion‐
com‐
mand
-pro‐
cessin‐
gin‐
struc‐
tion‐
com‐
mand
script
Spec‐
i‐
fies
the
pre‐
fix
of
a
Tcl
com‐
mand
to
be
eval‐
u‐
ated
when
a
pro‐
cess‐
ing
instruc‐
tion
is
encoun‐
tered.
The
com‐
mand
eval‐
u‐
ated
is:
script
tar‐
get
data
where:
tar‐
get
The
name
of
the
pro‐
cess‐
ing
instruc‐
tion
tar‐
get
data
Remain‐
ing
data
from
the
pro‐
cess‐
ing
instruc‐
tion
-reportempty
-reportempty
bool‐
ean
If
this
option
is
enabled
then
when
an
ele‐
ment
is
encoun‐
tered
that
uses
the
spe‐
cial
empty
ele‐
ment
syn‐
tax,
addi‐
tional
argu‐
ments
are
appended
to
the
-ele‐
mentstart‐
com‐
mand
and
-ele‐
mentend‐
com‐
mand
call‐
backs.
The
argu‐
ments
-empty
1
are
appended.
For
exam‐
ple:
script
-empty
1
-startc‐
data‐
sec‐
tion‐
com‐
mand
-startc‐
data‐
sec‐
tion‐
com‐
mand
script
Spec‐
i‐
fies
the
pre‐
fix
of
a
Tcl
com‐
mand
to
be
eval‐
u‐
ated
when
the
start
of
a
CDATA
sec‐
tion
sec‐
tion
is
encoun‐
tered.
No
argu‐
ments
are
appended
to
the
script.
-start‐
doc‐
type‐
de‐
clcom‐
mand
-start‐
doc‐
type‐
de‐
clcom‐
mand
script
Spec‐
i‐
fies
the
pre‐
fix
of
a
Tcl
com‐
mand
to
be
eval‐
u‐
ated
at
the
start
of
a
doc‐
u‐
ment
type
dec‐
la‐
ra‐
tion.
No
argu‐
ments
are
appended
to
the
script.
-unknow‐
nen‐
cod‐
ing‐
com‐
mand
-unknow‐
nen‐
cod‐
ing‐
com‐
mand
script
Spec‐
i‐
fies
the
pre‐
fix
of
a
Tcl
com‐
mand
to
be
eval‐
u‐
ated
when
a
char‐
ac‐
ter
is
encoun‐
tered
with
an
unknown
encod‐
ing.
This
option
has
not
been
imple‐
mented.
-unparseden‐
ti‐
ty‐
de‐
clcom‐
mand
-unparseden‐
ti‐
ty‐
de‐
clcom‐
mand
script
Spec‐
i‐
fies
the
pre‐
fix
of
a
Tcl
com‐
mand
to
be
eval‐
u‐
ated
when
a
dec‐
la‐
ra‐
tion
is
encoun‐
tered
for
an
unparsed
entity.
The
com‐
mand
eval‐
u‐
ated
is:
script
sys‐
tem
pub‐
lic
nota‐
tion
where:
sys‐
tem
The
sys‐
tem
iden‐
ti‐
fier
of
the
exter‐
nal
entity,
usu‐
ally
a
URI
pub‐
lic
The
pub‐
lic
iden‐
ti‐
fier
of
the
exter‐
nal
entity
nota‐
tion
The
name
of
the
nota‐
tion
for
the
exter‐
nal
entity
-val‐
i‐
date
-val‐
i‐
date
bool‐
ean
Enables
val‐
i‐
da‐
tion
of
the
XML
doc‐
u‐
ment
to
be
parsed.
Any
changes
to
this
option
are
ignored
after
an
XML
doc‐
u‐
ment
has
started
to
be
parsed,
but
the
option
may
be
changed
after
a
reset.
-warn‐
ing‐
com‐
mand
-warn‐
ing‐
com‐
mand
script
Spec‐
i‐
fies
the
pre‐
fix
of
a
Tcl
com‐
mand
to
be
eval‐
u‐
ated
when
a
warn‐
ing
con‐
di‐
tion
is
detected.
A
warn‐
ing
con‐
di‐
tion
is
where
the
XML
doc‐
u‐
ment
has
not
been
authored
cor‐
rectly,
but
is
still
well-
formed
and
may
be
valid.
For
exam‐
ple,
the
spe‐
cial
empty
ele‐
ment
syn‐
tax
may
be
used
for
an
ele‐
ment
which
has
not
been
declared
to
have
empty
con‐
tent.
By
default,
a
call‐
back
script
is
pro‐
vided
which
silently
ignores
the
warn‐
ing.
The
com‐
mand
eval‐
u‐
ated
is:
script
warn‐
ing‐
code
warn‐
ingmsg
where:
warn‐
ing‐
code
A
sin‐
gle
word
descrip‐
tion
of
the
warn‐
ing,
intended
for
use
by
an
appli‐
ca‐
tion
wan‐
ringmsg
A
human-
read‐
able
descrip‐
tion
of
the
warn‐
ing
-xmlde‐
clcom‐
mand
-xmlde‐
clcom‐
mand
script
Spec‐
i‐
fies
the
pre‐
fix
of
a
Tcl
com‐
mand
to
be
eval‐
u‐
ated
when
the
XML
dec‐
la‐
ra‐
tion
is
encoun‐
tered.
The
com‐
mand
eval‐
u‐
ated
is:
script
ver‐
sion
encod‐
ing
stand‐
alone
where:
ver‐
sion
The
ver‐
sion
num‐
ber
of
the
XML
spec‐
i‐
fi‐
ca‐
tion
to
which
this
doc‐
u‐
ment
pur‐
ports
to
con‐
form
encod‐
ing
The
char‐
ac‐
ter
encod‐
ing
of
the
doc‐
u‐
ment
stand‐
alone
A
bool‐
ean
declar‐
ing
whether
the
doc‐
u‐
ment
is
stand‐
alone
Parser
Com‐
mand
The
::xml::parser
com‐
mand
cre‐
ates
a
new
Tcl
com‐
mand
with
the
same
name
as
the
parser.
This
com‐
mand
may
be
used
to
invoke
var‐
i‐
ous
oper‐
a‐
tions
on
the
parser
object.
It
has
the
fol‐
low‐
ing
gen‐
eral
form:
name
option
arg
option
and
the
arg
deter‐
mine
the
exact
be‐
hav‐
iour
of
the
com‐
mand.
The
fol‐
low‐
ing
com‐
mands
are
pos‐
si‐
ble
for
parser
objects:
cget
cget
-option
Returns
the
cur‐
rent
value
of
the
con‐
fig‐
u‐
ra‐
tion
option
given
by
option.
Option
may
have
any
of
the
val‐
ues
accepted
by
the
parser
object.
con‐
fig‐
ure
con‐
fig‐
ure
?
-option
value
...
?
Mod‐
ify
the
con‐
fig‐
u‐
ra‐
tion
options
of
the
parser
object.
Option
may
have
any
of
the
val‐
ues
accepted
by
the
parser
object.
enti‐
ty‐
parser
enti‐
ty‐
parser
?
option
value
...
?
Cre‐
ates
a
new
parser
object.
The
new
object
inher‐
its
the
same
con‐
fig‐
u‐
ra‐
tion
options
as
the
par‐
ent
parser
object,
but
is
able
to
parse
XML
data
in
a
parsed
entity.
The
option
-dtd‐
sub‐
set
allows
markup
dec‐
la‐
ra‐
tions
to
be
treated
as
being
in
the
inter‐
nal
or
exter‐
nal
DTD
sub‐
set.
free
free
name
Frees
all
resources
asso‐
ci‐
ated
with
the
parser
object.
The
object
is
not
usable
after
this
com‐
mand
has
been
invoked.
get
get
name
args
Returns
infor‐
ma‐
tion
about
the
XML
doc‐
u‐
ment
being
parsed.
Each
parser
class
pro‐
vides
dif‐
fer‐
ent
infor‐
ma‐
tion,
see
the
doc‐
u‐
men‐
ta‐
tion
for
the
parser
class.
parse
parse
xml
args
Parses
the
XML
doc‐
u‐
ment.
The
usual
desired
effect
is
for
var‐
i‐
ous
appli‐
ca‐
tion
call‐
backs
to
be
eval‐
u‐
ated.
Other
func‐
tions
will
also
be
per‐
formed
by
the
parser
class,
at
the
very
least
this
includes
check‐
ing
the
XML
doc‐
u‐
ment
for
well-
formed‐
ness.
reset
reset
Ini‐
tialises
the
parser
object
in
prepa‐
ra‐
tion
for
pars‐
ing
a
new
XML
doc‐
u‐
ment.
CALL‐
BACK
RETURN
CODES
Every
call‐
back
script
eval‐
u‐
ated
by
a
parser
may
return
a
return
code
other
than
TCL_OK.
Return
codes
are
inter‐
preted
as
fol‐
lows:
break
Sup‐
presses
invo‐
ca‐
tion
of
all
fur‐
ther
call‐
back
scripts.
The
parse
method
returns
the
TCL_OK
return
code.
con‐
tinue
Sup‐
presses
invo‐
ca‐
tion
of
fur‐
ther
call‐
back
scripts
until
the
cur‐
rent
ele‐
ment
has
fin‐
ished.
error
Sup‐
presses
invo‐
ca‐
tion
of
all
fur‐
ther
call‐
back
scripts.
The
parse
method
also
returns
the
TCL_ERROR
return
code.
default
Any
other
return
code
sup‐
presses
invo‐
ca‐
tion
of
all
fur‐
ther
call‐
back
scripts.
The
parse
method
returns
the
same
return
code.
APPLI‐
CA‐
TION
EXAM‐
PLES
This
script
out‐
puts
the
char‐
ac‐
ter
data
of
an
XML
doc‐
u‐
ment
read
from
stdin.
package require xml
proc cdata {data args} {
puts -nonewline $data
}
set parser [::xml::parser -characterdatacommand cdata]
$parser parse [read stdin]
This
script
counts
the
num‐
ber
of
ele‐
ments
in
an
XML
doc‐
u‐
ment
read
from
stdin.
package require xml
proc EStart {varName name attlist args} {
upvar #0 $varName var
incr var
}
set count 0
set parser [::xml::parser -elementstartcommand [list EStart count]]
$parser parse [read stdin]
puts "The XML document contains $count elements"
PARSER
CLASSES
This
sec‐
tion
will
dis‐
cuss
how
a
parser
class
is
imple‐
mented.
Tcl
Parser
Class
The
pure-
Tcl
parser
class
requires
no
com‐
pi‐
la‐
tion
-
it
is
a
col‐
lec‐
tion
of
Tcl
scripts.
This
parser
imple‐
men‐
ta‐
tion
is
non-
val‐
i‐
dat‐
ing,
ie.
it
can
only
check
well-
formed‐
ness
in
a
doc‐
u‐
ment.
How‐
ever,
by
enabling
the
-val‐
i‐
date
option
it
will
read
the
doc‐
u‐
ment's
DTD
and
resolve
exter‐
nal
enti‐
ties.
This
parser
imple‐
men‐
ta‐
tion
aims
to
imple‐
ment
XML
v1.0
and
sup‐
ports
XML
Names‐
paces.
Gen‐
er‐
ally
the
parser
pro‐
duces
XML
Infoset
infor‐
ma‐
tion
items.
That
is,
it
gives
the
appli‐
ca‐
tion
a
slightly
higher-
level
view
than
the
raw
XML
syn‐
tax.
For
exam‐
ple,
it
does
not
report
CDATA
Sec‐
tions.
Expat
Parser
Class
This
sec‐
tion
will
dis‐
cuss
the
Expat
parser
class.
SEE
ALSO
TclDOM,
a
Tcl
inter‐
face
for
the
W3C
Doc‐
u‐
ment
Object
Model.
KEY‐
WORDS
Tcl Built-In Commands Tcl TclXML(n)
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