Class | Builder::XmlMarkup |
In: |
vendor/rails/activesupport/lib/active_support/vendor/builder/xmlmarkup.rb
|
Parent: | XmlBase |
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.h1("Header") # <h1>Header</h1> xm.p("paragraph") # <p>paragraph</p> } # </body> } # </html>
Example:
xm.div { # <div> xm.text! "line"; xm.br # line<br/> xm.text! "another line"; xmbr # another line<br/> } # </div>
Example:
xml.tag!("SOAP:Envelope") { ... }
will produce …
<SOAP:Envelope> ... </SOAP:Envelope>"
tag! 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).
xml.SOAP :Envelope do ... end
Just put a space before the colon in a namespace to produce the right form for builder (e.g. "SOAP:Envelope" => "xml.SOAP :Envelope")
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+.
Example:
xm = Builder.new(:ident=>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>
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") }
Create an XML markup builder. Parameters are specified by an option hash.
:target=>target_object: | Object receiving the markup. out must respond to the << operator. The default is a plain string target. |
:indent=>indentation: | Number of spaces used for indentation. The default is no indentation and no line breaks. |
:margin=>initial_indentation_level: | 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. |
# File vendor/rails/activesupport/lib/active_support/vendor/builder/xmlmarkup.rb, line 184 184: def initialize(options={}) 185: indent = options[:indent] || 0 186: margin = options[:margin] || 0 187: super(indent, margin) 188: @target = options[:target] || "" 189: 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]]>
# File vendor/rails/activesupport/lib/active_support/vendor/builder/xmlmarkup.rb, line 258 258: def cdata!(text) 259: _ensure_no_block block_given? 260: _special("<![CDATA[", "]]>", text, nil) 261: end
# File vendor/rails/activesupport/lib/active_support/vendor/builder/xmlmarkup.rb, line 196 196: def comment!(comment_text) 197: _ensure_no_block block_given? 198: _special("<!-- ", " -->", comment_text, nil) 199: end
Insert an XML declaration into the XML markup.
For example:
xml.declare! :ELEMENT, :blah, "yada" # => <!ELEMENT blah "yada">
# File vendor/rails/activesupport/lib/active_support/vendor/builder/xmlmarkup.rb, line 207 207: def declare!(inst, *args, &block) 208: _indent 209: @target << "<!#{inst}" 210: args.each do |arg| 211: case arg 212: when String 213: @target << %{ "#{arg}"} 214: when Symbol 215: @target << " #{arg}" 216: end 217: end 218: if block_given? 219: @target << " [" 220: _newline 221: _nested_structures(block) 222: @target << "]" 223: end 224: @target << ">" 225: _newline 226: 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"?>
# File vendor/rails/activesupport/lib/active_support/vendor/builder/xmlmarkup.rb, line 237 237: def instruct!(directive_tag=:xml, attrs={}) 238: _ensure_no_block block_given? 239: if directive_tag == :xml 240: a = { :version=>"1.0", :encoding=>"UTF-8" } 241: attrs = a.merge attrs 242: end 243: _special( 244: "<?#{directive_tag}", 245: "?>", 246: nil, 247: attrs, 248: [:version, :encoding, :standalone]) 249: end