xml(3)

NAME
xml - standard xml module

XML PARSING
This chapter is dedicated to the AFNIX XML parsing, a subpart of the standard xml processing module. XML parsing refers to the ability to read valid xml constructs from an input stream and build an internal representation that is suitable for later processing. This chapter is designed for handling basic XML representation and does not cover the operations performed by a XML processor, such like entity expansion or DTD validation. All AFNIX xml processing objects are located in the afnix-xml module. This module must be loaded prior any operation. Multiple calls to the module initialization routine are harmless. The interpreter method library loads a specific module by name. When the module has been loaded, the object are available in the afnix:xml nameset.

interp:library "afnix-xml"

XML tree representation
A xml document is represented with a tree. At the top of the tree is the XmlRoot object. The root object is not part of the document, but acts as the primary container for other objects. Inside AFNIX , a xml document starts with a root node and all other child elements are XmlNode objects.

Node base object
The xml tree is built with the XmlNode object. The node object has different derivation depending on the required representation. For example, the XmlRoot object is derived from the XmlNode object. A node object can have child object unless the node is marked as an empty node. Trying to add node to an empty node results in an exception. A node can also be marked empty by the user. This situation typically arises with tag node which are used alone such like the <br/> xhtml empty tag or an empty paragraph <p/>. Although a xml node cannot be constructed directly, there is a predicate node-p that can be used to assert the node type.

# check a node
assert true (afnix:xml:node-p node)

The add-child method adds a child node to the calling node. If the calling node is marked empty, an exception is raised when attempting to add the node. There is no limit for the number of nodes to add. In particular, when a text is to be added, care should be taken that there is no markup within that text. In doubt, the parse method should be used.

# parse a text and add 3 child nodes
p:parse "The quick brown <b>fox</b> jumps over the lazy dog"

In the previous example, the first child node is a XmlText node with the value The quick brown . The second node is a XmlTag node with name b. Finally, the third node is also a XmlText node with the value jumps over the lazy dog. It should be noted that the tag node has a child XmlText node with the value fox. This example also illustrates the power of the parse method which considerably simplify the creation of a xml tree. Finally, there is a subtle subject to be treated later which concerns the use of character reference with the parse method. Like any other xml parser, character references are evaluated during the parsing phase, thus providing no mechanism to create such reference. For this reason, a special class called XmlCref is provided in the module.

Tag object
The XmlTag class is one of the most important class as it holds most of the xml constructs. A tag is defined by a name, a set of attributes and eventually a content. In its simplest form, a tag is created by name. With an additional boolean parameter, the tag can be marked as an empty node.

# create an empty paragraph tag
const p (afnix:xml:XmlTag "p" true)

Adding attributes to a tag is imply a matter of method call. The add-attribute method operates with a Property object while the set-attribute operates with a name and a literal value. As a matter of fact, the attributes are stored internally as a property list.

# <p class="text">
# create a paragraph tag
const p (afnix:xml:XmlTag "p")
# set the class attribute
p:set-attribute "class" "text"

The node empty flag determines whether or not there is a end tag associated with a tag. If the empty flag is false, the node can have children nodes and is associated with a end tag. With the empty flag set, there is no child nodes. Such situation corresponds to the xml /> notation.

# <br/>
# create a br empty tag
const br (afnix:xml:XmlTag "br" true)

Text objects
The xml module provides two types of xml text node. The basic object is the XmlText node which is designed to hold some text without markup. It is this kind of nodes which is automatically instantiated by the parse method, as described earlier. The other object is the XmlData which corresponds to the xml CDATA special markup. With a character data node, the characters are not interpreted, including those that indicate markup starts like < or end like >. The XmlData is particularly used to store scripts or other program text inside a xml description. As an example, it is recommended to use a character data node inside a script tag with xhtml.

Document reading
A xml document is read by scanning an input stream an building a representation of the xml tree.

The document object
The XmlDocument object is a special object is designed to ease the reading process of an xml document. The process of creating a xml document consists of creating a document object, then binding a xml reader, parsing the input stream and finally storing the root node. When the operation is completed, the root node is available in the document object.

# create a xml document
const xdoc (afnix:xml:XmlDocument "example.xml")
# get the root node
const rppt (xdoc:get-root)

The root node content
When a document is parsed, the root node holds all the elements and markup sequentially. At this stage, it shall be noted that the element data are not expanded. Unlike a normal XML reader, the parameter entity are kept in the node data, are expended later by the XML processor.

XML NODE ENGINE
This chapter is dedicated to the AFNIX XML node engine (xne), a subpart of the standard xml processing module. The XML node engine is designed to manipulate the node tree as well as searching for nodes.

Node tree operations
The class XneTree provides a single framework to operate on a node and its associated tree. Since a node always carries a subtree, this chapter will refer to it as the node tree.

Creating a node tree
A node tree is created either from a node at construction or with the help of the set-node method.

# create a node tree at construction
const tree (afnix:xml:XneTree root)
# change the node tree
tree:set-node node

Once a tree is created, various methods are provided to operate on the whole tree. The depth method returns the depth of the node tree. The get-node methods returns the the node associated with the tree.

# get the tree depth
println (tree:depth)

Namespace operations
The concept of namespace is an extension to the xml standard. Unlike other programming language, the concept of namespace is designed to establish a binding between a name and an uri. Such binding permits to establish a scope for tags without too much burden. In the xml namespace terminology, an expanded name is composed of a prefix and a local name. The basic operations provided at the tree level is the prefix cancellation and the tree prefix setting.

# clear the prefix for the whole tree
tree:clear-prefix
# set a prefix for the whole tree
tree:set-prefix "afnix"

The set-prefix changes the prefix for the whole tree. It is not necessary to clear first the prefix.

Attribute operations
Each node in the node tree can have its attribute list modified in a single operation. The first operation is to clear all attributes for all nodes. Although this operation might be useful, it should be carried with caution. The attributes can also cleared more selectively by using the tag name as a filter. For more complex operation, the clear-attribute method of the XmlTag is the definitive answer.

# clear all attributes
tree:clear-attribute
# clear all attributes by tag name
tree:clear-attribute "p"

The set-attribute method sets an attribute to the whole tree. The first argument is the attribute name and the second is a literal value. For more selective operations, the set-attribute method can be also called at the tag level.

# clear all attributes
tree:set-attribute "class" "text"

When it comes to set attributes, there is a special operation related to the "id" attribute. Such attribute is supposed to be unique for the whole tree. For this reason, the generate-id generates a unique id for each node and assign the id attribute. The attribute is unique at the time of the call. If the tree is modified, and in particular, if new node are added, the method must be called again to regenerate the node id.

# set a unique id for all nodes
tree:generate-id

Node location and searching
The node location is the ability to locate one or several nodes in a xml tree. A node is generally located by name, path or id. Once a node has been located, it can be processed. Note that the node locator operates operates almost exclusively with XmlTag node, although it might not be always the case.

Node selection
The process of finding a child node is obtained with the help of the XneCond class combined with the select method of the XneTree Object. The select method traverses the whole tree and attempts to match a condition for each node. If the condition is evaluated successfully for a node, the node is added in the result vector. Note that the tree can be traversed entirely or with only the filar layer of children.

# creating a condition node
const xcnd (afnix:xml:XneCond)
# create a tree with a root node
const tree (afnix:xml:XneTree root)
# select all nodes for that condition
trans result (tree:select xcnd)

In the previous example, the condition object is empty. This means that there is no condition, and thus wowrks for all nodes. This previous example will return all nodes in the tree.

Node condition
The XmlCond class provides several method to add a conditions. The add method is the method of choice to add a condition. The method operates with a condition type and a literal. Note that the object can contain several conditions.

# creating a condition node
const xcnd (afnix:xml:XneCond)
# add a condition by name
xcnd:add afnix:xml:xne:NAME "p"

In the previous example, a condition is designed to operate with a tag name. Upon a call to the select method with this condition, all nodes in the tree that have the tag name p will be selected.

# creating a condition node
const xcnd (afnix:xml:XneCond)
# add a condition by name
xcnd:add afnix:xml:xne:NAME "p"
# add an index condition
xcnd:add afnix:xml:xne:INDEX 0

In the previous example, a condition is designed to operate with a tag name and index. Upon a call to the select method with this condition, all nodes in the tree that have the tag name p and those child index is 0 will be selected.

Selection result
The node selection operates by default on the whole tree. The select method, when called with a second boolean argument can rstrict the search to the child nodes.

# creating a condition node
const xcnd (afnix:xml:XneCond)
# create a tree with a root node
const tree (afnix:xml:XneTree root)
# select all nodes for that condition
trans result (tree:select xcnd false)

The selection results is stored in a vector object. The node order corresponds to the tree order obtained with a depth first search approach.

XML NODE ENGINE
This chapter is dedicated to the AFNIX XML simple model (xsm), a subpart of the standard xml processing module. The XML simple model is designed to simplify the interpretation of a general sgml document such like, html or xhtml document. In the simple model approach, there is no tree. Instead, a vector of simple nodes is built, and a document interface can be used to access the nodes. Therefore, this simple model should be considered as a mean to quickly parse document, but should not be used when tree operations come into play. In such case, the xml model is by far more appropriate. The simple model can be used to parse a html document for instance. Nore also that the simple model is a relaxed model in terms of parsing rules. For example, the tag start/end consistency is not checked and the attribute parsing is not aggressive as it can be found generaly in poorly written html document.

Simple model node
In the simple model, a XsmNode is just a text place holder. The node transports its type which can be either text, tag, reference of end node. For the tag node, a subtype that identifies reserved nodes versus normal type is also available.

Creating a node
A xsm node is created by name or byte and name. In the first case, the node is a text node. In the second case, the node subtype is automatically detected for tag node.

# create a xsm text node
const ntxt (afnix:xml:XsmNode "afnix">
  # create a xsm tag node
  const ntag (afnix:xml:XsmNode afnix:xml:XsmNode:TAG "afnix">

Note that the text corresponds to the node content. For example, the string "!-- example --" might corresponds to a comment in html which is to say a reserved tag when the type is tag or a simple text if the type is a text node. A reserved tag is defined by a string which start either with the '!' character or the '[' character.

# create a reserved tag
const rtag (afnix:xml:XsmNode afnix:xml:XsmNode:TAG "!-- example --")

Node representation
The xsm node is a literal node. This means that the to-string and to-literal methods are available. When the to-literal method is called, the node text is automatically formatted to reflect the node type.

# create a reserved tag
const rtag (afnix:xml:XsmNode afnix:xml:XsmNode:TAG "!-- example --")
# print the node literal
rtag:to-literal # <!-- example -->

If the node is a reference node, the node literal is represented with the original definition while the to-string method will produce the corresponding character if it knowm.

Node information
With a xsm node, the operation are a limited number of node information operations. The get-name method returns the first name found in a node. If the node is a normal tag, the get-name will return the tag name. For the other node, the method will return the first available string. This also means, that the method will behave correctly with end tag node.

# create a tag node
const ntag (afnix:xml:XsmNode afnix:xml:XsmNode:TAG "afnix">
  # get the tag name
  ntag:get-name

There is a predicate for all types. For example, the text-p predicate returns true if the node is a text node. The tag-p predicate returns true if the node is a normal or reserved tag.

Document reading
A document is read in a way similar to the XmlDocument with the help of the XsmDocument object. Once created, the document holds a vector of nodes.

The document object
The XsmDocument object is a special xsm object designed to ease the reading process of a document. The process of creating a document consists of creating a document object, then binding a xsm reader, parsing the input stream and storing the nodes in a vector. When the operation is completed, the vector can be accessed by index.

# create a xms document
const xdoc (afnix:xml:XsmDocument "example.htm")
# get the document length
xdoc:length

Node information object
The XsoInfo object is a node information object designed to hold a node name, an attributes list and eventually a text associated with the node. For example, if a html document contains a anchor node, the associated information node, will have the anchoring text stored as the node information text.

# create a xso node by name and text
const info (afnix:xml:XsoInfo "a" "click here")

Simple model operations
The XsmDocument is designed to perform simple operations such like searching all nodes that matches a particular name. While this operation can be done easily, it is done in such a way that a vector of node information is returned instead of a vector of nodes which can always be constructed with a simple loop.

# create a xsm document
const xdoc (afnix:xml:XsmDocument "example.htm")
# get all node named "a" - forcing lower case
xdoc:get-info-vector "a" true

STANDARD XML REFERENCE
This appendix is a reference of the AFNIX standard xml module.
Symbol | Description
afnix-xml | module
afnix:xml | nameset

XmlNode
The XmlNode class is the base class used to represent the xml tree. The tree is built as a vector of nodes. Each node owns as well its parent node. Walking in the tree is achieved by taking the child node and then moving to the child and/or next node. The node also manages an empty flags. It the empty flag is set, it is an error to add child nodes.

Predicate

    node-p

Inheritance

    Object

Methods

    to-text -> String (none)
    The to-text method returns a text representation of the tree content. Unlike the write method, the tag are not generated, but rather the text content is accumulated. This method is useful tor read the node content. If a node does n;ot have text, the nil string is returned.

    write -> none (none|Stream|Buffer)
    The write method write the node contents as well as the child nodes to an output stream argument or a buffer. When node is written, the method attempts to use the stream encoding in such way that the contents fits into the requested output encoding. Without argument, the node is written to the interpreter output stream. with one argument, the node is written to the specified stream or buffer.

    name-p -> Boolean (String)
    The name-p predicate checks if the name matches the node name. Care should be taken that not all node have a name, and in such case, the false value is returned. This method is useful when the node is a tag.

    attribute-p -> Boolean (String| String String)
    The attribute-p predicate checks if there is a node attribute that matches the string argument name. In the first form, the predicate returns true is an attribute exists with the name argument. In the second form, the predicate returns true if the attribute name and value matches the arguments. The first argument is the attribute name. The second argument is the attribute value. Not all nodes have attributes. In such case, the predicate always returns false.

    parse -> none (String)
    The parse method parses the string argument and adds the results as a set of child node to the calling node. If the node is an empty node, the method will almost fail. This method should be used when an attempt is made to add some text that may contain some xml tags.

    get-parent -> XmlNode (none)
    The get-parent method returns the parent node. If the node is the root node, nil is returned.

    set-parent -> none (XmlNode)
    The set-parent method sets the parent node.

    copy -> XmlNode (none)
    The copy method copy the node tree by regenerating a new tree.

    clear-child -> none (none)
    The clear-child method clear the child node list, leaving the node without child node.

    add-child -> none (XmlNode|XmlNode Integer)
    The add-child method adds a node argument as a child node to the calling node. In the first form, the node is added at the end of the node list. In the second form, the node is added by index and all subsequent nodes are shifted by one position.

    get-child -> XmlNode (Integer String)
    The get-child method returns a child node by index or by name. If the calling argument is an integer, the node is returned by index. If the calling argument is a string, the node is returned by name. If the node cannot be found, nil is returned raised.

    get-index -> Integer (XmlNode)
    The gett-index method returns a child node index. The node argument is the node to find as a child node. If the node is not found, an exception is raised.

    merge -> none (XmlNode Integer)
    The merge method merge an existing node with another one. The first argument is the source node used for merging. The second argument the child node index to merge. The method operates by rst removing the child node at the specified index and then add in position, the child nodes of the source node.

    nil-child-p -> Boolean (none)
    The nil-child-p predicate returns true if the node does not have a child node.

    lookup-child -> XmlNode (String)
    The lookup-child method returns a child node by name. Unlike the get-child method, the method raises an exception if the node cannot be found.

    child-length -> Integer (none)
    The child-length method returns the number of children nodes.

    get-source-line -> Integer (none)
    The get-source-line method returns the node source line number if any.

    set-source-line -> none (Integer)
    The set-source-line method sets the node source line number.

    get-source-name -> String (none)
    The get-source-name method returns the node source name if any.

    set-source-name -> none (String)
    The set-source-name method sets the node source name.

XmlTag
The XmlTag class is the base class used to represent a xml tag. A tag is defined with a name and an attribute list. The tag is derived from the xml node class and is not marked empty by default.

Predicate

    tag-p

Inheritance

    XmlNode

Constructors

    XmlTag (String)
    The XmlTag constructor creates a tag node. The node is not marked empty.

    XmlTag (String Boolean)
    The XmlTag constructor creates a tag node. The first argument is the tag name. The second argument is the empty flag.

Methods

    set-name -> none (String)
    The set-name method sets the tag name.

    get-name -> String (none)
    The get-name method returns the tag name.

    clear-attribute -> none (node)
    The clear-attribute method clear the node attribute list.

    add-attribute -> none (Property)
    The add-attribute method adds a new attribute to the tag. The attribute must be new for this method to succeed. In doubt, the set-attribute is preferable.

    set-attribute -> none (String Literal)
    The set-attribute method sets an attribute to the tag. The first argument is the attribute name. The second argument is the attribute value. If the attribute already exists, the old value is replaced with the new one.

    get-attribute -> Property (Integer|String)
    The get-attribute method returns a tag attribute in the form o a property object. With an integer object, the attribute is returned by index. With a string object, the property is return by name. If the property is not found, nil is returned.

    get-attribute-value -> String (String)
    The get-attribute-value method returns a tag attribute value by name. The string argument is the attribute name. If the property is not found, an exception is raised.

    lookup-attribute -> Property (String)
    The lookup-attribute method returns a tag attribute by name in the form of a property. The string argument is the attribute name. If the property is not found, an exception is raised.

    attribut-length -> Integer (none)
    The attribute-length method returns the number of attributes.

XmlText
The XmlText class is the xml text node. A text node is directly built by the xml reader and the content placed into a string. By definition, a text node is an empty node.

Predicate

    text-p

Inheritance

    XmlNode

Constructors

    XmlText (none)
    The XmlText constructor creates a default text node. By definition, a text node is an empty node.

    XmlText (String)
    The XmlText constructor creates a text node with the string argument.

Methods

    set-xval -> none (String)
    The set-xval method sets the text node value.

    get-xval -> String (none)
    The get-xval method returns the text node value.

    to-normal -> String (none)
    The to-normal method returns the normalized text node value.

XmlData
The XmlData class is the xml cdata node. A data node differs from the text node in the sense that the data node contains characters that could be reserved characters such like markup delimiters. The data node is most of the time used to hold text used for scripting. The data node is an empty node.

Predicate

    data-p

Inheritance

    XmlNode

Constructors

    XmlData (none)
    The XmlData constructor creates a default data node. By definition, a data node is an empty node.

    XmlData (String)
    The XmlData constructor creates a data node with the string argument.

Methods

    set-xval -> none (String)
    The set-xval method sets the data node value.

    get-xval -> String (none)
    The get-xval method returns the data node value.

XmlComment
The XmlComment class is the xml comment node. The comment node is a special node that holds the comment text. The comment node is an empty node.

Predicate

    comment-p

Inheritance

    XmlNode

Constructors

    XmlComment (none)
    The XmlComment constructor creates a default comment node. By definition, a comment node is an empty node.

    XmlComment (String)
    The XmlComment constructor creates a comment node with the string argument.

Methods

    set-xval -> none (String)
    The set-xval method sets the comment node value.

    get-xval -> String (none)
    The get-xval method returns the comment node value.

XmlDoctype
The XmlDoctype class is the xml document type node. In its simplest form, the document type has just a name which acts the starting tag for the document. The document type can also be associated with a system or a public identifier. Note also that a local root node can be attached to this node.

Predicate

    doctype-p

Inheritance

    XmlNode

Constructors

    XmlDoctype (String)
    The XmlDoctype constructor creates a document type with a starting tag name as the string argument. This is the simplest form of a document type definition.

    XmlDoctype (String String)
    The XmlDoctype constructor creates a document type with a starting tag name and a system identifier. The first string argument is the tag name. The second argument is the system identifier.

    XmlDoctype (String String String)
    The XmlDoctype constructor creates a document type with a starting tag name, a public and a system identifier. The first string argument is the tag name. The second argument is the public identifier. The third argument is the system identifier.

Methods

    get-xval -> String (none)
    The get-xval method returns the document type starting tag name.

    get-public-id -> String (none)
    The get-public-id method returns the document type public identifier.

    get-system-id -> String (none)
    The get-system-id method returns the document type system identifier.

XmlPi
The XmlPi class is the xml processing node. The processing node is a tag node. Although a processing node is seen as tag with attributes, the specification describes the processing node as a special tag with a string value. The processing node is an empty node.

Predicate

    pi-p

Inheritance

    XmlNode

Constructors

    XmlPi (String)
    The XmlPi constructor creates a processing node with the name string argument.

    XmlPi (String String)
    The XmlPi constructor creates a processing node with the name string argument and the string value. The first argument is the tag name. The second argument is the processing node value.

Methods

    set-name -> none (String)
    The set-name method sets the xml pi node name.

    get-name -> String (none)
    The get-name method returns the pi node name.

    set-xval -> none (String)
    The set-xval method sets the processing node value.

    get-xval -> String (none)
    The get-xval method returns the processing node value.

XmlDecl
The XmlDecl class is the xml declaration node. The declaration node is a processing node. A declaration node is defined with a version id, an encoding string and a standalone flag. Each value is represented by an attribute at the tag level.

Predicate

    decl-p

Inheritance

    XmlPi

Constructors

    XmlDecl (none)
    The XmlDecl constructor creates a default declaration node. By default, the declaration node is set with the xml version 1.0, the UTF-8 encoding and the standalone flag is not set.

    XmlDecl (String)
    The XmlDecl constructor creates a declaration node with a version. The string argument is the xml version version which must be a supported one.

    XmlDecl (String String)
    The XmlDecl constructor creates a declaration node with a version and an encoding. The string argument is the xml version version which must be a supported one. The second argument is the xml encoding.

    XmlDecl (String String String)
    The XmlDecl constructor creates a declaration node with a version, an encoding and a standalone flag. The string argument is the xml version version which must be a supported one. The second argument is the xml encoding. The third argument is the standalone flag.

XmlRef
The XmlRef class is the xml reference node class. This class is a base class which cannot be instantiated directly. The class is designed to hold reference, the only element which is in common is the string representation.

Predicate

    ref-p

Inheritance

    XmlNode

Methods

    set-xref -> none (String)
    The set-xref method sets the node reference name.

    get-xref -> String (none)
    The get-xref method returns the node reference name.

XmlCref
The XmlCref class is the xml character reference node class. Normally this class should only be used when building a xml tree manually. During a parsing process, the character reference is automatically expanded.

Predicate

    cref-p

Inheritance

    XmlRef

Constructors

    XmlCref (none)
    The XmlCref constructor creates a default character reference those value is the null character.

    XmlCref (Character|Integer)
    The XmlCref constructor creates a character reference those value is the character or integer argument.

Methods

    set-value -> none (Character|Integer)
    The set-value method sets the character reference value by character or integer.

    get-value -> Character (none)
    The get-value method returns the character reference value.

XmlEref
The XmlEref class is the xml entity reference node class. The entity reference is defined with a reference name.

Predicate

    eref-p

Inheritance

    XmlRef

Constructors

    XmlEref (none)
    The XmlCref constructor creates an empty entity reference.

    XmlCref (String)
    The XmlEref constructor creates an entity reference those value is the string argument.

XmlSection
The XmlSection class is the xml section type node. A section node is used to model conditional section that are part of a dtd. The section value is a string that is evaluated by the xml processor. Most of the time, it is a parameter entity reference which corresponds to the keyword INCLUDE or IGNORE , but it could be anything else. A node is also attached to this section.

Predicate

    section-p

Inheritance

    xmlNode

Constructors

    XmlSection (String)
    The XmlSection constructor creates a xml section node by value.

Methods

    get-xval -> String (none)
    The get-xval method returns the section node value.

XmlAttlist
The XmlAttlist class is the xml attribute list node class. A xml attribute list is primarily defined with two names. The first name is the element and the second name is the attribute name. There are 3 types of attribute list. The string type, the token type and the enumeration type. The class manages each type by associating a type descriptor which is detected at construction.

Predicate

    attlist-p

Inheritance

    XmlNode

Constructors

    XmlAttlist (String String)
    The XmlAttlist constructor creates an attribute list by element name and attribute name. The first argument is the element name. The second argument is the attribute name.

Methods

    set-element-name -> none (String)
    The set-element-name method sets the attribute list element name.

    get-element-name -> String (none)
    The get-element-name method returns the attribute list element name.

    set-attribute-name -> none (String)
    The set-attribute-name method sets the attribute list name.

    get-attribute-name -> String (none)
    The get-attribute-name method returns the attribute list name.

    set-type -> none (String | Vector Boolean)
    The set-type method set the attribute type by string or enumeration vector. In its first form, the attribute type is defined by a string. The type can be either, "CDATA", "ID", "IDREF", "IDREFS", "ENTITY", "ENTITIES", "NMTOKEN" or "NMTOKENS". In the second form, the attribute type is an enumeration those values are defined in the argument vector. The boolean argument controls the notation flag for that enumeration.

    set-default -> none (String)
    The set-default method set the attribute value by string. The string can be any value or the special value "#IMPLIED" and "#REQUIRED". If the default value is fixed, the set-fixed is the preferred method.

    set-fixed -> none (String)
    The set-fixed method set the fixed attribute default value by string.

XmlRoot
The XmlRoot class is the top level root instantiated by the xml reader when starting to parse a stream. There should be only one root node in a tree. The root node does not have a parent node.

Predicate

    root-p

Inheritance

    XmlNode

Constructors

    XmlRoot (none)
    The XmlRoot constructor creates a default xml root node which is empty.

Methods

    get-declaration -> XmlDecl (none)
    The get-declaration method returns the declaration node associated with the root node. Normally, the declaration node is the first child node.

    del-declaration -> none (none)
    The del-declaration method removes the declaration node associated with the root node. Normally, the declaration node is the first child node.

XmlDocument
The XmlDocument class is the xml document class. The document class is the root document class that maintains a xml document along with its associated tree and other useful information. Generally the class is constructed with a file name or a name and an input stream that is used for parsing the input data. The document can also be designed by constructing manually the document tree. In that case, the document name must be set explicitly.

Predicate

    document-p

Inheritance

    Nameable

Constructors

    XmlDocument (none)
    The XmlDocument constructor creates a default xml document.

    XmlDocument (String)
    The XmlDocument constructor creates a xml document by parsing the file. The file name is the string argument.

    XmlDocument (String Input)
    The XmlDocument constructor creates a xml document by name and by parsing the input stream. The first argument is the xml document name. The second argument is the input stream to parse.

    XmlDocument (String XmlRoot)
    The XmlDocument constructor creates a xml document by name and root node. The first argument is the xml document name. The second argument is the xml root node.

Methods

    set-name -> none (String)
    The set-name method sets the xml document name. The get-name method is available from the nameable base class.

    get-root -> none (XmlRoot)
    The get-root method returns the document xml root node.

XmlElement
The XmlElement class is the xml element class node. A xml element is represented with a name and a value. It is during the processing phase that the element value is interpreted. An element is built with a name and a value.

Predicate

    element-p

Inheritance

    XmlNode

Constructors

    XmlElement (String String)
    The XmlElement constructor creates a xml element by name and value. The first argument is the element name. The second argument is the argument value.

Methods

    set-name -> none (String)
    The set-name method sets the xml element name.

    get-name -> String (none)
    The get-name method returns the element name.

    set-xval -> none (String)
    The set-xval method sets the xml element value.

    get-xval -> String (none)
    The get-xval method returns the element value.

XmlEntity
The XmlEntity class is the base class for the xml entity representation. A xml entity can be either a general entity or a parameter entity. They differ initially with the presence of the '%' character. Both entity model have a name which is path of the base class.

Predicate

    entity-p

Inheritance

    XmlNode

Methods

    set-name -> none (String)
    The set-name method sets the entity name.

    get-name -> String (none)
    The get-name method returns the entity name.

XmlGe
The XmlGe class is the xml general entity node. In its simplest form, the general entity has a name and a value. The entity type can also be associated with a system or a public identifier with or without an extra type name.

Predicate

    ge-p

Inheritance

    XmlEntity

Constructors

    XmlGe (String String)
    The XmlGe constructor creates a xml entity by name and value. The first argument is the entity name. The second argument is the entity value. Most of the time, the entity value is a parameter entity.

    XmlGe (String String String)
    The XmlGe constructor creates a xml entity by name and identifier. The first argument is the entity name. The second argument is the entity public identifier. The third argument is the entity system identifier.

    XmlGe (String String String String)
    The XmlGe constructor creates a xml entity by name, identifier and data type. The first argument is the entity name. The second argument is the entity public identifier. the third argument is the entity system identifier. The fourth argument is the entity type name.

Methods

    get-xval -> String (none)
    The get-xval method returns the entity value.

    get-data -> String (none)
    The get-data method returns the entity data type.

    get-public-id -> String (none)
    The get-public-id method returns the entity public identifier.

    get-system-id -> String (none)
    The get-system-id method returns the entity system identifier.

XmlPe
The XmlPe class is the xml parameter entity node. In its simplest form, the parameter entity has a name and a value. The entity type can also be associated with a system or a public identifier.

Predicate

    ge-p

Inheritance

    XmlEntity

Constructors

    XmlPe (String String)
    The XmlGe constructor creates a xml entity by name and value. The first argument is the entity name. The second argument is the entity value.

    XmlPe (String String String)
    The XmlGe constructor creates a xml entity by name and identifier. The first argument is the entity name. The second argument is the entity public identifier. The third argument is the entity system identifier.

Methods

    get-xval -> String (none)
    The get-xval method returns the entity value.

    get-public-id -> String (none)
    The get-public-id method returns the entity public identifier.

    get-system-id -> String (none)
    The get-system-id method returns the entity system identifier.

XmlReader
The XmlReader class is the xml parser that operates on an input stream. The reader creates a tree of nodes by reading the input stream and returns the root node when an end-of-stream is reached. Multiple read can be done sequentially. If the reset method is not called between multiple read passes, the reader will accumulate the nodes in the current tree.

Predicate

    reader-p

Inheritance

    Object

Constructors

    XmlReader (none)
    The XmlReader constructor creates a default xml reader.

Methods

    reset -> none (none)
    The reset method resets the xml reader. In particular, the root node is restored to the nil node.

    parse -> none (Input|String)
    The parse method parses an input stream or a file. During the parsing process, the root node is filled with the parsed nodes.

    get-root -> XmlRoot (none)
    The get-root method returns the parsed root node.

    get-node -> XmlNode (String)
    The get-node method parse a string and returns a node.

STANDARD XNE REFERENCE

Xne
The Xne is a nameset that binds constants used by the xne system.

Constants

    ID
    The ID constant defines a node access by id.

    NAME
    The NAME constant defines a node access by name.

    INDEX
    The INDEX constant defines a node access by child index. The child index is node index seen from the parent.

XneTree
The XneTree is the xne node tree manipulation class. The class operates with a node and provides numerous methods to manipulate the tree as well as changing it. Before a tree is manipulated, it is recommended to make a copy of such tree with the help of the node copy method.

Predicate

    xne-tree-p

Inheritance

    Object

Constructors

    XmlTree (none)
    The XmlTree constructor creates a default tree without a node.

    XmlTree (XmlNode)
    The XmlTree constructor creates a tree with a xml node. The node stored in the object is the root of the tree subject to the operations.

Methods

    depth -> Integer (none)
    The depth method returns the depth of the tree.

    generate-id -> Integer (none)
    The generate-id method generate a unique id for all node in the tree. The id attribute is set by this method.

    set-node -> none (XmlNode)
    The set-node method sets the root tree node.

    get-node -> XmlNode (none)
    The get-node method returns the root tree node.

    set-attribute -> none (none|String)
    The set-attribute method sets an attribute to the whole tree. In the first form, the attribute is set to the whole tree. In the second form with a string argument, the attribute is set only on the tag node those name matches the name argument.

    clear-attribute -> none (none|String)
    The clear-attribute method clear all attributes of the nodes in the tree. In the first form, the node attributes are cleared for all nodes in the tree. In the second form with a string argument, the attributes are cleared only with the tag node those name matches the name argument.

    set-prefix -> none (String)
    The set-prefix method sets a prefix on all nodes in the tree.

    clear-prefix -> none (none)
    The clear-prefix method clear the prefix for all nodes in the tree.

    select -> Vector (XneCond {Boolean])
    The select method selects the node in the tree taht matches the condition argument. In the first form, with one argument, the whole tree is searched. In the seaond form, with a boolean argument, the whole tree is searched if the second argument is false. If the boolean argument is true, the method call behaves like a call with the condition only.

XneChild
The XneCond is the xne condition class. The sole purpose of this class is to define one or several condition that a node must satisfy in order to be selected. The condition are accumulated in a list and later checked for a particular node. Note that an empty condition always succeds.

Predicate

    xne-cond-p

Inheritance

    Object

Constructors

    XneCond (none)
    The XneCond constructor creates a default condition. The default condition is empty. The empty condition always succeds.

Methods

    add -> none (Xne [String|Integer])
    The add adds a condition by type. The first argument is the conditiontype. The second argument is a condition information such like a string or an integer.

    valid-p -> Boolean (XmlNode)
    The valid-p predicate checks that a node matches a condition. If the condition succeeds, the predicate returns true.