XML bindings

From ESEwiki

XML bindings can be created using the eseb tool (Enterprise SmartEiffel Binder), using a DTD file (XML schemas to be supported later).

Contents 1 Synopsis 2 Usage 2.1 Elements 2.2 Attributes 2.3 The parser 3 A complete example 3.1 The DTD file 3.2 The TREE_PARSER class 3.3 The ROOT class 3.4 The DATA class 3.5 The CHILD class

Synopsis

• se eseb --help
• se eseb [--verbose] [--directory <output directory>] [--prefix <class prefix>] <DTD file>

The options are:

--help	Give help on the tool usage
--verbose	Tell the tool to talk about what it does (default is be quiet and just do the job)
--directory <output directory>	Specify the directory where the generated classes should be put (default is the current directory)
--prefix <class prefix>	Specify a prefix for the generated classes (default is no prefix)
<DTD file>	Specify the DTD file to read

Usage

The DTD file contains elements and attributes.

Elements

The elements are directly converted into classes; for instance <!ELEMENT foo #PCDATA> creates a class named FOO (or PREFIX_FOO if --prefix PREFIX was used). Each created class is a direct heir of VISITABLE.

The visitor is also generated; it is named after its visiting class, suffixed by _VISITOR and holds one feature called visit_ followed by the element class name in lower-case.

A simple element:

<!ELEMENT root node*>

will be generated as:

class interface ROOT
feature {ANY}
   node (i: INTEGER): NODE
end

There can be anonymous lists; they are generated as alternative classes. For example, the following:

<!ELEMENT node (node|data)*>

will use an alternative:

class interface NODE
feature {ANY}
   alternative (i: INTEGER): ALTERNATIVE_NODE
end

class interface ALTERNATIVE_NODE
inherit
   VISITABLE
end

class interface ALTERNATIVE_NODE_0
inherit
   ALTERNATIVE_NODE
feature {ANY}
   child: CHILD
end

class interface ALTERNATIVE_NODE_1
inherit
   ALTERNATIVE_NODE
feature {ANY}
   data: DATA
end

You distinguish between alternatives by using visitors (alternatives are visitable).

Attributes

The attributes are put in a dictionary. There is a single getter for all attributes (attribute), which takes a STRING (the attribute name) and returns a STRING (the attribute value). The internal code is a string inspect. The precondition is known_attribute.

In the same way, there is only one setter (set_attribute) which sets the attribute value. The precondition is also known_attribute.

For instance, <!ATTLIST foo bar CDATA #REQUIRED> generates the inspect branch "bar" in the method attribute of the class FOO. It also generates an argument a_bar to the make constructor, because the attribute is required. Furthermore, the invariant will state that

attribute(once "bar") /= Void

The parser

The parser name is the prefix followed by the name of the DTD. It inherits from XML_TREE and can be used as such. The constructor is make.

A complete example

The DTD file

<!ELEMENT root data*,child* >
<!ELEMENT data PCDATA >
<!ELEMENT child EMPTY >
<!ATTLIST data id #CDATA REQUIRED >
<!ATTLIST child refid #CDATA REQUIRED >

The TREE_PARSER class

TODO:

eseb tree.dtd

The ROOT class

TODO:

eseb tree.dtd

The DATA class

TODO:

eseb tree.dtd

The CHILD class

TODO:

eseb tree.dtd