sgmlparser.tcl

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	# default: normal mode

	# Bug: if the attribute list has a right angle bracket then the empty
	# element marker will not be seen

	set empty [uplevel #0 $options(-emptyelement) [list $tag $param $empty]]

	switch -glob -- [string length $tag],[regexp {^\?|!.*} $tag],$close,$empty {

	    0,0,, {
		# Ignore empty tag - dealt with non-normal mode above
	    }
	    *,0,, {

		# Start tag for an element.

		# Check if the internal DTD entity is in an attribute value
		regsub -all &xml:intdtd\; $param \[$options(-internaldtd)\] param

		set code [catch {ParseEvent:ElementOpen $tag $param [array get options]} msg]
		set state(haveDocElement) 1
		switch $code {
		    0 {# OK}
		    3 {
			# break
			return {}
		    }
		    4 {
			# continue
			# Remember this tag and look for its close
			set state(continue:tag) $tag
			set state(continue:level) 1
			set state(mode) continue
			continue
		    }
		    default {
			return -code $code -errorinfo $::errorInfo $msg
		    }
		}

	    }

	    *,0,/, {

		# End tag for an element.

		set code [catch {ParseEvent:ElementClose $tag [array get options]} msg]
		switch $code {
		    0 {# OK}
		    3 {
			# break
			return {}
		    }
		    4 {
			# continue
			# skip sibling nodes
			set state(continue:tag) [lindex $state(stack) end]
			set state(continue:level) 1
			set state(mode) continue
			continue
		    }
		    default {
			return -code $code -errorinfo $::errorInfo $msg
		    }
		}

	    }

	    *,0,,/ {

		# Empty element

		# The trailing slash sneaks through into the param variable
		regsub -all /[cl $::sgml::Wsp]*\$ $param {} param

		set code [catch {ParseEvent:ElementOpen $tag $param [array get options] -empty 1} msg]
		set state(haveDocElement) 1
		switch $code {
		    0 {# OK}
		    3 {
			# break
			return {}
		    }
		    4 {
			# continue
			# Pretty useless since it closes straightaway
		    }
		    default {
			return -code $code -errorinfo $::errorInfo $msg
		    }
		}
		set code [catch {ParseEvent:ElementClose $tag [array get options] -empty 1} msg]
		switch $code {
		    0 {# OK}
		    3 {
			# break
			return {}
		    }
		    4 {
			# continue
			# skip sibling nodes
			set state(continue:tag) [lindex $state(stack) end]
			set state(continue:level) 1
			set state(mode) continue
			continue
		    }
		    default {
			return -code $code -errorinfo $::errorInfo $msg
		    }
		}

	    }

	    *,1,* {
		# Processing instructions or XML declaration
		switch -glob -- $tag {

		    {\?xml} {
			# XML Declaration
			if {$state(haveXMLDecl)} {
			    uplevel #0 $options(-errorcommand) [list illegalcharacter "unexpected characters \"<$tag\" around line $state(line)"]
			} elseif {![regexp {\?$} $param]} {
			    uplevel #0 $options(-errorcommand) [list missingcharacters "XML Declaration missing characters \"?>\" around line $state(line)"]
			} else {

			    # We can do the parsing in one step with Tcl 8.1 RE's
			    # This has the benefit of performing better WF checking

			    set adv_re [format {^[%s]*version[%s]*=[%s]*("|')(-+|[a-zA-Z0-9_.:]+)\1([%s]+encoding[%s]*=[%s]*("|')([A-Za-z][-A-Za-z0-9._]*)\4)?([%s]*standalone[%s]*=[%s]*("|')(yes|no)\7)?[%s]*\?$} $::sgml::Wsp $::sgml::Wsp $::sgml::Wsp $::sgml::Wsp $::sgml::Wsp $::sgml::Wsp $::sgml::Wsp $::sgml::Wsp $::sgml::Wsp $::sgml::Wsp]

			    if {[catch {regexp $adv_re $param discard delimiter version discard delimiter encoding discard delimiter standalone} matches]} {
				# Otherwise we must fallback to 8.0.
				# This won't detect certain well-formedness errors

				# Get the version number
				if {[regexp [format {[%s]*version[%s]*=[%s]*"(-+|[a-zA-Z0-9_.:]+)"[%s]*} $::sgml::Wsp $::sgml::Wsp $::sgml::Wsp $::sgml::Wsp] $param discard version] || [regexp [format {[%s]*version[%s]*=[%s]*'(-+|[a-zA-Z0-9_.:]+)'[%s]*} $::sgml::Wsp $::sgml::Wsp $::sgml::Wsp $::sgml::Wsp] $param discard version]} {
				    if {[string compare $version "1.0"]} {
					# Should we support future versions?
					# At least 1.X?
					uplevel #0 $options(-errorcommand) [list versionincompatibility "document XML version \"$version\" is incompatible with XML version 1.0"]
				    }
				} else {
				    uplevel #0 $options(-errorcommand) [list missingversion "XML Declaration missing version information around line $state(line)"]
				}

				# Get the encoding declaration
				set encoding {}
				regexp [format {[%s]*encoding[%s]*=[%s]*"([A-Za-z]([A-Za-z0-9._]|-)*)"[%s]*} $::sgml::Wsp $::sgml::Wsp $::sgml::Wsp $::sgml::Wsp] $param discard encoding
				regexp [format {[%s]*encoding[%s]*=[%s]*'([A-Za-z]([A-Za-z0-9._]|-)*)'[%s]*} $::sgml::Wsp $::sgml::Wsp $::sgml::Wsp $::sgml::Wsp] $param discard encoding

				# Get the standalone declaration
				set standalone {}
				regexp [format {[%s]*standalone[%s]*=[%s]*"(yes|no)"[%s]*} $::sgml::Wsp $::sgml::Wsp $::sgml::Wsp $::sgml::Wsp] $param discard standalone
				regexp [format {[%s]*standalone[%s]*=[%s]*'(yes|no)'[%s]*} $::sgml::Wsp $::sgml::Wsp $::sgml::Wsp $::sgml::Wsp] $param discard standalone

				# Invoke the callback
				uplevel #0 $options(-xmldeclcommand) [list $version $encoding $standalone]

			    } elseif {$matches == 0} {
				uplevel #0 $options(-errorcommand) [list illformeddeclaration "XML Declaration not well-formed around line $state(line)"]
			    } else {

				# Invoke the callback
				uplevel #0 $options(-xmldeclcommand) [list $version $encoding $standalone]

			    }

			}

		    }

		    {\?*} {
			# Processing instruction
			set tag [string range $tag 1 end]
			if {[regsub {\?$} $tag {} tag]} {
			    if {[string length [string trim $param]]} {
				uplevel #0 $options(-errorcommand) [list unexpectedtext "unexpected text \"$param\" in processing instruction around line $state(line)"]
			    }
			} elseif {![regexp ^$Name\$ $tag]} {
			    uplevel #0 $options(-errorcommand) [list illegalcharacter "illegal character in processing instruction target \"$tag\""]
			} elseif {[regexp {[xX][mM][lL]} $tag]} {
			    uplevel #0 $options(-errorcommand) [list illegalcharacters "characters \"xml\" not permitted in processing instruction target \"$tag\""]
			} elseif {![regsub {\?$} $param {} param]} {
			    uplevel #0 $options(-errorcommand) [list missingquestion "PI: expected '?' character around line $state(line)"]
			}
			set code [catch {uplevel #0 $options(-processinginstructioncommand) [list $tag [string trimleft $param]]} msg]
			switch $code {
			    0 {# OK}
			    3 {
				# break
				return {}
			    }
			    4 {
				# continue
				# skip sibling nodes
				set state(continue:tag) [lindex $state(stack) end]
				set state(continue:level) 1
				set state(mode) continue
				continue
			    }
			    default {
				return -code $code -errorinfo $::errorInfo $msg
			    }
			}
		    }

		    !DOCTYPE {
			# External entity reference
			# This should move into xml.tcl
			# Parse the params supplied.  Looking for Name, ExternalID and MarkupDecl
			set matched [regexp ^[cl $Wsp]*($Name)[cl $Wsp]*(.*) $param x state(doc_name) param]
			set state(doc_name) [Normalize $state(doc_name) $options(-normalize)]
			set externalID {}
			set pubidlit {}
			set systemlit {}
			set externalID {}
			if {[regexp -nocase ^[cl $Wsp]*(SYSTEM|PUBLIC)(.*) $param x id param]} {
			    switch [string toupper $id] {
				SYSTEM {
				    if {[regexp ^[cl $Wsp]+"([cl ^"]*)"(.*) $param x systemlit param] || [regexp ^[cl $Wsp]+'([cl ^']*)'(.*) $param x systemlit param]} {
					set externalID [list SYSTEM $systemlit] ;# "
				    } else {
					uplevel #0 $options(-errorcommand) {syntaxerror {syntax error: SYSTEM identifier not followed by literal}}
				    }
				}
				PUBLIC {
				    if {[regexp ^[cl $Wsp]+"([cl ^"]*)"(.*) $param x pubidlit param] || [regexp ^[cl $Wsp]+'([cl ^']*)'(.*) $param x pubidlit param]} {
					if {[regexp ^[cl $Wsp]+"([cl ^"]*)"(.*) $param x systemlit param] || [regexp ^[cl $Wsp]+'([cl ^']*)'(.*) $param x systemlit param]} {
					    set externalID [list PUBLIC $pubidlit $systemlit]
					} else {
					    uplevel #0 $options(-errorcommand) [list syntaxerror "syntax error: PUBLIC identifier not followed by system literal around line $state(line)"]
					}
				    } else {
					uplevel #0 $options(-errorcommand) [list syntaxerror "syntax error: PUBLIC identifier not followed by literal around line $state(line)"]
				    }
				}
			    }
			    if {[regexp -nocase ^[cl $Wsp]+NDATA[cl $Wsp]+($Name)(.*) $param x notation param]} {
				lappend externalID $notation
			    }
			}

			set state(inDTD) 1

			ParseEvent:DocTypeDecl [array get options] $state(doc_name) $pubidlit $systemlit $options(-internaldtd)

			set state(inDTD) 0

		    }

		    !--* {

			# Start of a comment
			# See if it ends in the same tag, otherwise change the
			# parsing mode

			regexp {!--(.*)} $tag discard comm1
			if {[regexp ([cl ^-]*)--[cl $Wsp]*\$ $comm1 discard comm1_1]} {
			    # processed comment (end in tag)
			    uplevel #0 $options(-commentcommand) [list $comm1_1]
			} elseif {[regexp ([cl ^-]*)--[cl $Wsp]*\$ $param discard comm2]} {
			    # processed comment (end in attributes)
			    uplevel #0 $options(-commentcommand) [list $comm1$comm2]
			} elseif {[regexp ([cl ^-]*)-->(.*) $text discard comm2 text]} {
			    # processed comment (end in text)
			    uplevel #0 $options(-commentcommand) [list $comm1$param$empty>$comm2]
			} else {
			    # start of comment
			    set state(mode) comment
			    set state(commentdata) "$comm1$param$empty>$text"
			    continue
			}
		    }

		    {!\[CDATA\[*} {

			regexp {!\[CDATA\[(.*)} $tag discard cdata1
			if {[regexp {(.*)]]$} $cdata1 discard cdata2]} {
			    # processed CDATA (end in tag)
			    PCDATA [array get options] [subst -novariable -nocommand $cdata2]
			    set text [subst -novariable -nocommand $text]
			} elseif {[regexp {(.*)]]$} $param discard cdata2]} {
			    # processed CDATA (end in attribute)
			    # Backslashes in param are quoted at this stage
			    PCDATA [array get options] $cdata1[subst -novariable -nocommand $cdata2]
			    set text [subst -novariable -nocommand $text]
			} elseif {[regexp {(.*)]]>(.*)} $text discard cdata2 text]} {
			    # processed CDATA (end in text)
			    # Backslashes in param and text are quoted at this stage
			    PCDATA [array get options] $cdata1[subst -novariable -nocommand $param]$empty>[subst -novariable -nocommand $cdata2]
			    set text [subst -novariable -nocommand $text]
			} else {
			    # start CDATA
			    set state(cdata) "$cdata1$param>$text"
			    set state(mode) cdata
			    continue
			}

		    }

		    !ELEMENT -
		    !ATTLIST -
		    !ENTITY -
		    !NOTATION {
			uplevel #0 $options(-errorcommand) [list illegaldeclaration "[string range $tag 1 end] declaration not expected in document instance around line $state(line)"]
		    }

		    default {
			uplevel #0 $options(-errorcommand) [list unknowninstruction "unknown processing instruction \"<$tag>\" around line $state(line)"]
		    }
		}
	    }
	    *,1,* -
	    *,0,/,/ {
		# Syntax error
	    	uplevel #0 $options(-errorcommand) [list syntaxerror "syntax error: closed/empty tag: tag $tag param $param empty $empty close $close around line $state(line)"]
	    }
	}

	# Process character data

	if {$state(haveDocElement) && [llength $state(stack)]} {

	    # Check if the internal DTD entity is in the text
	    regsub -all &xml:intdtd\; $text \[$options(-internaldtd)\] text

	    # Look for entity references
	    if {([array size entities] || \
		    [string length $options(-entityreferencecommand)]) && \
		    $options(-defaultexpandinternalentities) && \
		    [regexp {&[^;]+;} $text]} {

		# protect Tcl specials
		# NB. braces and backslashes may already be protected
		regsub -all {\\({|}|\\)} $text {\1} text
		regsub -all {([][$\\{}])} $text {\\\1} text

		# Mark entity references
		regsub -all {&([^;]+);} $text [format {%s; %s {\1} ; %s %s} \}\} [namespace code [list Entity [array get options] $options(-entityreferencecommand) [namespace code [list PCDATA [array get options]]] $options(entities)]] [namespace code [list DeProtect [namespace code [list PCDATA [array get options]]]]] \{\{] text
		set text "uplevel #0 [namespace code [list DeProtect1 [namespace code [list PCDATA [array get options]]]]] {{$text}}"
		eval $text
	    } else {

		# Restore protected special characters
		regsub -all {\\([][{}\\])} $text {\1} text
		PCDATA [array get options] $text
	    }
	} elseif {[string length [string trim $text]]} {
	    uplevel #0 $options(-errorcommand) [list unexpectedtext "unexpected text \"$text\" in document prolog around line $state(line)"]
	}

    }

    # If this is the end of the document, close all open containers
    if {$options(-final) && [llength $state(stack)]} {
	eval $options(-errorcommand) [list unclosedelement "element [lindex $state(stack) end] remains unclosed around line $state(line)"]
    }

    return {}
}

# sgml::DeProtect --
#
#	Invoke given command after removing protecting backslashes
#	from given text.
#
# Arguments:
#	cmd	Command to invoke
#	text	Text to deprotect
#
# Results:
#	Depends on command

proc sgml::DeProtect1 {cmd text} {
    if {[string compare {} $text]} {
	regsub -all {\\([]$[{}\\])} $text {\1} text
	uplevel #0 $cmd [list $text]
    }
}
proc sgml::DeProtect {cmd text} {
    set text [lindex $text 0]
    if {[string compare {} $text]} {
	regsub -all {\\([]$[{}\\])} $text {\1} text
	uplevel #0 $cmd [list $text]
    }
}

# sgml::ParserDelete --
#
#	Free all memory associated with parser
#
# Arguments:
#	var	global state array
#
# Results:
#	Variables unset

proc sgml::ParserDelete var {
    upvar #0 $var state

    if {![info exists state]} {
	return -code error "unknown parser"
    }

    catch {unset $state(entities)}
    catch {unset $state(parameterentities)}
    catch {unset $state(elementdecls)}
    catch {unset $state(attlistdecls)}
    catch {unset $state(notationdecls)}
    catch {unset $state(namespaces)}

    unset state

    return {}
}

# sgml::ParseEvent:ElementOpen --
#
#	Start of an element.
#
# Arguments:
#	tag	Element name
#	attr	Attribute list
#	opts	Options
#	args	further configuration options
#