--- /dev/null
+#!/usr/bin/env ruby
+#--
+# Copyright 2004, 2005 by Jim Weirich (jim@weirichhouse.org).
+# All rights reserved.
+
+# Permission is granted for use, copying, modification, distribution,
+# and distribution of modified versions of this work as long as the
+# above copyright notice is included.
+#++
+
+# Provide a flexible and easy to use Builder for creating XML markup.
+# See XmlBuilder for usage details.
+
+require 'builder/xmlbase'
+
+module Builder
+
+ # Create XML markup easily. All (well, almost all) methods sent to
+ # an XmlMarkup object will be translated to the equivalent XML
+ # markup. Any method with a block will be treated as an XML markup
+ # tag with nested markup in the block.
+ #
+ # Examples will demonstrate this easier than words. In the
+ # following, +xm+ is an +XmlMarkup+ object.
+ #
+ # xm.em("emphasized") # => <em>emphasized</em>
+ # xm.em { xmm.b("emp & bold") } # => <em><b>emph & bold</b></em>
+ # xm.a("A Link", "href"=>"http://onestepback.org")
+ # # => <a href="http://onestepback.org">A Link</a>
+ # xm.div { br } # => <div><br/></div>
+ # xm.target("name"=>"compile", "option"=>"fast")
+ # # => <target option="fast" name="compile"\>
+ # # NOTE: order of attributes is not specified.
+ #
+ # xm.instruct! # <?xml version="1.0" encoding="UTF-8"?>
+ # xm.html { # <html>
+ # xm.head { # <head>
+ # xm.title("History") # <title>History</title>
+ # } # </head>
+ # xm.body { # <body>
+ # xm.comment! "HI" # <! -- HI -->
+ # xm.h1("Header") # <h1>Header</h1>
+ # xm.p("paragraph") # <p>paragraph</p>
+ # } # </body>
+ # } # </html>
+ #
+ # == Notes:
+ #
+ # * The order that attributes are inserted in markup tags is
+ # undefined.
+ #
+ # * Sometimes you wish to insert text without enclosing tags. Use
+ # the <tt>text!</tt> method to accomplish this.
+ #
+ # Example:
+ #
+ # xm.div { # <div>
+ # xm.text! "line"; xm.br # line<br/>
+ # xm.text! "another line"; xmbr # another line<br/>
+ # } # </div>
+ #
+ # * The special XML characters <, >, and & are converted to <,
+ # > and & automatically. Use the <tt><<</tt> operation to
+ # insert text without modification.
+ #
+ # * Sometimes tags use special characters not allowed in ruby
+ # identifiers. Use the <tt>tag!</tt> method to handle these
+ # cases.
+ #
+ # Example:
+ #
+ # xml.tag!("SOAP:Envelope") { ... }
+ #
+ # will produce ...
+ #
+ # <SOAP:Envelope> ... </SOAP:Envelope>"
+ #
+ # <tt>tag!</tt> will also take text and attribute arguments (after
+ # the tag name) like normal markup methods. (But see the next
+ # bullet item for a better way to handle XML namespaces).
+ #
+ # * Direct support for XML namespaces is now available. If the
+ # first argument to a tag call is a symbol, it will be joined to
+ # the tag to produce a namespace:tag combination. It is easier to
+ # show this than describe it.
+ #
+ # xml.SOAP :Envelope do ... end
+ #
+ # Just put a space before the colon in a namespace to produce the
+ # right form for builder (e.g. "<tt>SOAP:Envelope</tt>" =>
+ # "<tt>xml.SOAP :Envelope</tt>")
+ #
+ # * XmlMarkup builds the markup in any object (called a _target_)
+ # that accepts the <tt><<</tt> method. If no target is given,
+ # then XmlMarkup defaults to a string target.
+ #
+ # Examples:
+ #
+ # xm = Builder::XmlMarkup.new
+ # result = xm.title("yada")
+ # # result is a string containing the markup.
+ #
+ # buffer = ""
+ # xm = Builder::XmlMarkup.new(buffer)
+ # # The markup is appended to buffer (using <<)
+ #
+ # xm = Builder::XmlMarkup.new(STDOUT)
+ # # The markup is written to STDOUT (using <<)
+ #
+ # xm = Builder::XmlMarkup.new
+ # x2 = Builder::XmlMarkup.new(:target=>xm)
+ # # Markup written to +x2+ will be send to +xm+.
+ #
+ # * Indentation is enabled by providing the number of spaces to
+ # indent for each level as a second argument to XmlBuilder.new.
+ # Initial indentation may be specified using a third parameter.
+ #
+ # Example:
+ #
+ # xm = Builder.new(:indent=>2)
+ # # xm will produce nicely formatted and indented XML.
+ #
+ # xm = Builder.new(:indent=>2, :margin=>4)
+ # # xm will produce nicely formatted and indented XML with 2
+ # # spaces per indent and an over all indentation level of 4.
+ #
+ # builder = Builder::XmlMarkup.new(:target=>$stdout, :indent=>2)
+ # builder.name { |b| b.first("Jim"); b.last("Weirich) }
+ # # prints:
+ # # <name>
+ # # <first>Jim</first>
+ # # <last>Weirich</last>
+ # # </name>
+ #
+ # * The instance_eval implementation which forces self to refer to
+ # the message receiver as self is now obsolete. We now use normal
+ # block calls to execute the markup block. This means that all
+ # markup methods must now be explicitly send to the xml builder.
+ # For instance, instead of
+ #
+ # xml.div { strong("text") }
+ #
+ # you need to write:
+ #
+ # xml.div { xml.strong("text") }
+ #
+ # Although more verbose, the subtle change in semantics within the
+ # block was found to be prone to error. To make this change a
+ # little less cumbersome, the markup block now gets the markup
+ # object sent as an argument, allowing you to use a shorter alias
+ # within the block.
+ #
+ # For example:
+ #
+ # xml_builder = Builder::XmlMarkup.new
+ # xml_builder.div { |xml|
+ # xml.stong("text")
+ # }
+ #
+ class XmlMarkup < XmlBase
+
+ # Create an XML markup builder. Parameters are specified by an
+ # option hash.
+ #
+ # :target=><em>target_object</em>::
+ # Object receiving the markup. +out+ must respond to the
+ # <tt><<</tt> operator. The default is a plain string target.
+ #
+ # :indent=><em>indentation</em>::
+ # Number of spaces used for indentation. The default is no
+ # indentation and no line breaks.
+ #
+ # :margin=><em>initial_indentation_level</em>::
+ # Amount of initial indentation (specified in levels, not
+ # spaces).
+ #
+ # :escape_attrs=><b>OBSOLETE</em>::
+ # The :escape_attrs option is no longer supported by builder
+ # (and will be quietly ignored). String attribute values are
+ # now automatically escaped. If you need unescaped attribute
+ # values (perhaps you are using entities in the attribute
+ # values), then give the value as a Symbol. This allows much
+ # finer control over escaping attribute values.
+ #
+ def initialize(options={})
+ indent = options[:indent] || 0
+ margin = options[:margin] || 0
+ super(indent, margin)
+ @target = options[:target] || ""
+ end
+
+ # Return the target of the builder.
+ def target!
+ @target
+ end
+
+ def comment!(comment_text)
+ _ensure_no_block block_given?
+ _special("<!-- ", " -->", comment_text, nil)
+ end
+
+ # Insert an XML declaration into the XML markup.
+ #
+ # For example:
+ #
+ # xml.declare! :ELEMENT, :blah, "yada"
+ # # => <!ELEMENT blah "yada">
+ def declare!(inst, *args, &block)
+ _indent
+ @target << "<!#{inst}"
+ args.each do |arg|
+ case arg
+ when String
+ @target << %{ "#{arg}"} # " WART
+ when Symbol
+ @target << " #{arg}"
+ end
+ end
+ if block_given?
+ @target << " ["
+ _newline
+ _nested_structures(block)
+ @target << "]"
+ end
+ @target << ">"
+ _newline
+ end
+
+ # Insert a processing instruction into the XML markup. E.g.
+ #
+ # For example:
+ #
+ # xml.instruct!
+ # #=> <?xml version="1.0" encoding="UTF-8"?>
+ # xml.instruct! :aaa, :bbb=>"ccc"
+ # #=> <?aaa bbb="ccc"?>
+ #
+ def instruct!(directive_tag=:xml, attrs={})
+ _ensure_no_block block_given?
+ if directive_tag == :xml
+ a = { :version=>"1.0", :encoding=>"UTF-8" }
+ attrs = a.merge attrs
+ end
+ _special(
+ "<?#{directive_tag}",
+ "?>",
+ nil,
+ attrs,
+ [:version, :encoding, :standalone])
+ end
+
+ # Insert a CDATA section into the XML markup.
+ #
+ # For example:
+ #
+ # xml.cdata!("text to be included in cdata")
+ # #=> <![CDATA[text to be included in cdata]]>
+ #
+ def cdata!(text)
+ _ensure_no_block block_given?
+ _special("<![CDATA[", "]]>", text, nil)
+ end
+
+ private
+
+ # NOTE: All private methods of a builder object are prefixed when
+ # a "_" character to avoid possible conflict with XML tag names.
+
+ # Insert text directly in to the builder's target.
+ def _text(text)
+ @target << text
+ end
+
+ # Insert special instruction.
+ def _special(open, close, data=nil, attrs=nil, order=[])
+ _indent
+ @target << open
+ @target << data if data
+ _insert_attributes(attrs, order) if attrs
+ @target << close
+ _newline
+ end
+
+ # Start an XML tag. If <tt>end_too</tt> is true, then the start
+ # tag is also the end tag (e.g. <br/>
+ def _start_tag(sym, attrs, end_too=false)
+ @target << "<#{sym}"
+ _insert_attributes(attrs)
+ @target << "/" if end_too
+ @target << ">"
+ end
+
+ # Insert an ending tag.
+ def _end_tag(sym)
+ @target << "</#{sym}>"
+ end
+
+ # Insert the attributes (given in the hash).
+ def _insert_attributes(attrs, order=[])
+ return if attrs.nil?
+ order.each do |k|
+ v = attrs[k]
+ @target << %{ #{k}="#{_attr_value(v)}"} if v # " WART
+ end
+ attrs.each do |k, v|
+ @target << %{ #{k}="#{_attr_value(v)}"} unless order.member?(k) # " WART
+ end
+ end
+
+ def _attr_value(value)
+ case value
+ when Symbol
+ value.to_s
+ else
+ _escape_quote(value.to_s)
+ end
+ end
+
+ def _ensure_no_block(got_block)
+ if got_block
+ fail IllegalBlockError,
+ "Blocks are not allowed on XML instructions"
+ end
+ end
+
+ end
+
+end
projects / depot.git / blobdiff