Parses the XML information and builds up the DOM tree in memory
providing a Tcl object command to this DOM document object. Example:
      
dom parse $xml doc
$doc documentElement root
      parses the XML in the variable xml, creates the DOM tree in memory,
make a reference to the document object, visible in Tcl as a document object
command, and assigns this new object name to the variable doc. When doc gets
freed, the DOM tree and the associated Tcl command object (document and all
node objects) are freed automatically.
      
      
set document [dom parse $xml]
set root     [$document documentElement]
      parses the XML in the variable xml, creates the DOM tree in memory,
make a reference to the document object, visible in Tcl as a document object
command, and returns this new object name, which is then stored in
document.  To free the underlying DOM tree and the associative Tcl
object commands (document + nodes + fragment nodes) the document object command
has to be explicitly deleted by:
      
$document delete
or
rename $document ""
The valid options are:
              
                - -simple
- If -simple is
specified, a simple but fast parser is used (conforms not fully to XML
recommendation). That should double parsing and DOM generation speed. The
encoding of the data is not transformed inside the parser. The simple parser
does not respect any encoding information in the XML declaration. It skips over
the internal DTD subset and ignores any information in it. Therefore it doesn't
include defaulted attribute values into the tree, even if the according
attribute declaration is in the internal subset. It also doesn't expand
internal or external entity references other than the predefined entities and
character references.
- -html
- If -html is specified, a fast HTML parser is 
used, which tries to even parse badly formed HTML into a DOM tree.
- -html5
- This option is only available if tDOM was build
                with --enable-html5. Try the featureinfo method
                if you need to know if this feature is build in. If
                -html5 is specified, the gumbo lib html5 parser
                (https://github.com/google/gumbo-parser) is used to
                build the DOM tree. This is, as far as it goes, XML
                namespace-aware. Since this probably isn't wanted by a
                lot of users and adds only burden for no good in a lot
                of use cases -html5 can be combined with
                -ignorexmlns, in which case all nodes and
                attributes in the DOM tree are not in an XML
                namespace. All tag and attribute names in the DOM tree
                will be lower case, even for foreign elements not in
                the xhtml, svg or mathml namespace. The DOM tree may
                include nodes, that the parser inserted because they
                are implied by the context (as <head>,
                <tbody>, etc.).
- -json
- If -json is specified, the data is
                expected to be a valid JSON string (according to RFC
                7159). The command returns an ordinary DOM document
                with nesting token inside the JSON data translated
                into tree hierarchy. If a JSON array value is itself
                an object or array then container element nodes named
                (in a default build) arraycontainer or
                objectcontainer, respectively, are inserted into the
                tree. The JSON serialization of this document (with
                the domDoc method asJSON) is the same JSON
                information as the data, preserving JSON
                datatypes, allowing non-unique member names of objects
                while preserving their order and the full range of
                JSON string values. JSON datatype handling is done
                with an additional property "sticking" at the doc and
                tree nodes. This property isn't contained in an XML
                serialization of the document. If you need to store
                the JSON data represented by a document, store the
                JSON serialization and parse it back from there. Apart
                from this JSON type information the returned doc
                command or handle is an ordinary DOM doc, which may be
                investigated or modified with the full range of the
                doc and node methods. Please note that the element
                node names and the text node values within the tree
                may be outside of what the appropriate XML productions
                allow.
- -jsonroot <document element name>
- If given makes the given element name the
                document element of the resulting doc. The parsed
                content of the JSON string will be the childs of this
                document element node.
- 
-jsonmaxnesting integer
- This option only has effect if used together
                with the -json option. The current
                implementation uses a recursive descent JSON parser.
                In order to avoid using excess stack space, any JSON
                input that has more than a certain levels of nesting
                is considered invalid. The default maximum nesting is
                2000. The option -jsonmaxnesting allows the user to
                adjust that.
- --
- The option -- marks the end of options.
                While respected in general this option is only needed
                in case of parsing JSON data, which may start with a
                "-".
- -keepEmpties
- If -keepEmpties is
specified then text nodes which contain only whitespaces will be part of the
resulting DOM tree. In default case (-keepEmpties not given) those empty
text nodes are removed at parsing time.
- -keepCDATA
- If -keepCDATA is
specified then CDATA sections aren't added to the tree as text nodes
(and, if necessary, combined with sibling text nodes into one text
node) as without this option but are added as CDATA_SECTION_NODEs to
the tree. Please note that the resulting tree isn't prepared for XPath
selects or to be the source or the stylesheet of an XSLT
transformation. If not combined with -keepEmpties only not
whitespace only CDATA sections will be added to the resulting DOM
                tree.
- 
-channel <channel-ID>
- If -channel <channel-ID> is specified, the
input to be parsed is read from the specified channel. The encoding setting of
the channel (via fconfigure -encoding) is respected, ie the data read from the
channel are converted to UTF-8 according to the encoding settings before the
data is parsed.
- 
-baseurl <baseURI>
- If -baseurl <baseURI> is specified,
                the baseURI is used as the base URI of the document.
                External entities references in the document are
                resolved relative to this base URI. This base URI is
                also stored within the DOM tree.
- 
-feedbackAfter <#bytes>
- If -feedbackAfter <#bytes> is
                specified, the tcl command given by
                -feedbackcmd is evaluated at the first element
                start within the document (or an external entity)
                after the start of the document or external entity or
                the last such call after #bytes. For backward
                compatibility if no -feedbackcmd is given but there is
                a tcl proc named ::dom::domParseFeedback this proc is
                used as -feedbackcmd. If there isn't such a proc and
                -feedbackAfter is used it is an error to not also use
                -feedbackcmd. If the called script raises error, then
                parsing will be aborted, the dom parse call
                returns error, with the script error msg as error msg.
                If the called script return -code break, the
                parsing will abort and the dom parse call will
                return the empty string.
- 
-feedbackcmd <script>
- If -feedbackcmd <script> is specified, the
script script is evaluated at the first
element start within the document (or an external entity) after the
start of the document or external entity or the last such call after
#bytes value given by the -feedbackAfter option. If
-feedbackAfter isn't given, using this option
doesn't has any effect. If the called
script raises error, then parsing will be aborted, the
dom parse call returns error, with the script
error msg as error msg. If the called script return
-code break, the parsing will abort and the dom
parse call will return the empty string.
- 
-externalentitycommand <script>
- If -externalentitycommand <script> is
specified, the specified tcl script is called to resolve any external entities
of the document. The actual evaluated command consists of this option followed
by three arguments: the base uri, the system identifier of the entity and the
public identifier of the entity. The base uri and the public identifier may be
the empty list. The script has to return a tcl list consisting of three
elements. The first element of this list signals how the external entity is
returned to the processor. Currently the two allowed types are "string"
and "channel". The second element of the list has to be the (absolute) base URI
of the external entity to be parsed.  The third element of the list are data,
either the already read data out of the external entity as string in the case
of type "string", or the name of a tcl channel, in the case of type
"channel". Note that if the script returns a tcl channel, it will not be closed
by the processor.  It must be closed separately if it is no longer
needed.
- 
-useForeignDTD <boolean>
- If <boolean> is true and the document does not have
an external subset, the parser will call the -externalentitycommand script with
empty values for the systemId and publicID arguments. Please note that if
the document also doesn't have an internal subset, the
-startdoctypedeclcommand and -enddoctypedeclcommand scripts, if set, are not
called. The -useForeignDTD respects 
- 
-paramentityparsing <always|never|notstandalone>
- The -paramentityparsing option controls,
                if the parser tries to resolve the external entities
                (including the external DTD subset) of the document
                while building the DOM tree.
                -paramentityparsing requires an argument, which
                must be either "always", "never", or "notstandalone".
                The value "always" means that the parser tries to
                resolves (recursively) all external entities of the
                XML source. This is the default in case
                -paramentityparsing is omitted. The value
                "never" means that only the given XML source is
                parsed and no external entity (including the external
                subset) will be resolved and parsed. The value
                "notstandalone" means, that all external entities will
                be resolved and parsed, with the exception of
                documents, which explicitly states standalone="yes" in
                their XML declaration.
- -ignorexmlns
- It is recommended, that you only use this option
                with the -html5 option. If this option is
                given, no node within the created DOM tree will be
                internally marked as placed into an XML Namespace,
                even if there is a default namespace in scope for
                un-prefixed elements or even if the element has a
                defined namespace prefix. One consequence is that
                XPath node expressions on such a DOM tree doesn't work
                as may be expected. Prefixed element nodes can't be
                selected naively and element nodes without prefix will
                be seen by XPath expressions as if they are not in any
                namespace (no matter if they are in fact should be in
                a default namespace). If you need to inject prefixed
                node names into an XPath expression use the '%' syntax
                described in the documentation of the of the
                domNode command method
                >selectNodes.
                
This method creates Tcl commands, which in turn create
          tDOM nodes. Tcl commands created by this command are only
          available inside a script given to the domNode methods
          appendFromScript or insertBeforeFromScript. If
          a command created with createNodeCmd is invoked in
          any other context, it will return error. The created command
          commandName replaces any existing command or
          procedure with that name. If the commandName includes
          any namespace qualifiers, it is created in the specified
          namespace. The -tagName option is only allowed for
          the elementNode type. The -jsonType option is only
          allowed for elementNode and textNode types.If such command is invoked inside a script given as argument to the
domNode method appendFromScript or
insertBeforeFromScript it creates a new node and appends this
node at the end of the child list of the invoking element node. If the
option -returnNodeCmd was given, the command returns the
created node as Tcl command. If this option was omitted, the command
returns nothing. Each command creates always the same type of node.
Which type of node is created by the command is determined by the
first argument to the createNodeCmd. The syntax of the created
command depends on the type of the node it creates.
If the command type to create is elementNode, the created
command will create an element node, if called. Without the
-tagName option the tag name of the created node is
commandName without namespace qualifiers. If the
-tagName option was given then the created command the created
elements will have this tag name. If the -jsonType option was
given then the created node elements will have the given JSON type. If
the -namespace option is given the created element node will be
XML namespaced and in the namespace given by the option. The element
name will be literal as given either by the command name or the
-tagname option, if that was given. An appropriate XML
namespace declaration will be automatically added, to bind the prefix
(if the element name has one) or the default namespace (if the element
name hasn't a prefix) to the namespace if such a binding isn't in
scope.
The syntax of the created command is:
elementNodeCmd ?attributeName attributeValue ...? ?script?
elementNodeCmd ?-attributeName attributeValue ...? ?script?
elementNodeCmd name_value_list script
The command syntax allows three different ways to specify the attributes of
the resulting element. These could be specified with attributeName
attributeValue argument pairs, in an "option style" way with
-attriubteName attributeValue argument pairs (the '-' character is only
syntactical sugar and will be stripped off) or as a Tcl list with elements
interpreted as attribute name and the corresponding attribute value.
The attribute name elements in the list may have a leading '-' character, which
will be stripped off.
Every elementNodeCmd accepts an optional Tcl script as last
argument. This script is evaluated as recursive appendFromScript script
with the node created by the elementNodeCmd as parent of all nodes
created by the script.
If the first argument of the method is textNode, the command
will create a text node. If the -jsonType option was given then
the created text node will have that JSON type. The syntax of the
created command is:
textNodeCmd ?-disableOutputEscaping? data
If the optional flag -disableOutputEscaping is given, the
escaping of the ampersand character (&) and the left angle bracket (<)
inside the data is disabled. You should use this flag carefully.
If the first argument of the method is commentNode or 
cdataNode the command will create an comment node or CDATA section 
node. The syntax of the created command is:
nodeCmd data
If the first argument of the method is piNode, the command will
create a processing instruction node. The syntax of the created
command is:
piNodeCmd target data