streamingmarkupbuilder.groovy

大名鼎鼎的java动态脚本语言。已经通过了sun的认证

package groovy.xml

import groovy.xml.streamingmarkupsupport.AbstractStreamingBuilder
import groovy.xml.streamingmarkupsupport.StreamingMarkupWriter
import groovy.xml.streamingmarkupsupport.BaseMarkupBuilder


/*

Copyright 2004 (C) John Wilson. All Rights Reserved.

Redistribution and use of this software and associated documentation
("Software"), with or without modification, are permitted provided
that the following conditions are met:

1. Redistributions of source code must retain copyright
   statements and notices.  Redistributions must also contain a
   copy of this document.

2. Redistributions in binary form must reproduce the
   above copyright notice, this list of conditions and the
   following disclaimer in the documentation and/or other
   materials provided with the distribution.

3. The name "groovy" must not be used to endorse or promote
   products derived from this Software without prior written
   permission of The Codehaus.  For written permission,
   please contact [e-mail].

4. Products derived from this Software may not be called "groovy"
   nor may "groovy" appear in their names without prior written
   permission of The Codehaus. "groovy" is a registered
   trademark of The Codehaus.

5. Due credit should be given to The Codehaus -
   http://groovy.codehaus.org/

THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS
``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
OF THE POSSIBILITY OF SUCH DAMAGE.

*/

    class StreamingMarkupBuilder extends AbstractStreamingBuilder {
        def pendingStack = []
        def commentClosure = {doc, pendingNamespaces, namespaces, namespaceSpecificTags, prefix, attrs, body, out ->
                                        out.unescaped() << "<!--"
                                        out.bodyText() << body
                                        out.unescaped() << "-->"
                                     }
         def piClosure = {doc, pendingNamespaces, namespaces, namespaceSpecificTags, prefix, attrs, body, out ->
                                    attrs.each {target, instruction ->
                                      out.unescaped() << "<?"
                                      if (instruction instanceof Map) {
                                        out.unescaped() << target
                                        instruction.each { name, value ->
                                          if (value.toString().contains('"')) {
                                            out.unescaped() << " $name='$value'"
                                          } else {
                                            out.unescaped() << " $name=\"$value\""                                          
                                          }
                                        }
                                      } else {
                                        out.unescaped() << "$target $instruction"
                                      }
                                      out.unescaped() << "?>"
                                    }
                                 }
        def noopClosure = {doc, pendingNamespaces, namespaces, namespaceSpecificTags, prefix, attrs, body, out ->
                                      if (body instanceof Closure) {
                                        def body1 = body.clone()
                                        
                                        body1.delegate = doc
                                        body1(doc)
                                      } else if (body instanceof Buildable) {
                                          body.build(doc)
                                      } else if (body != null) {
                                          body.each {
                                            if (it instanceof Closure) {
                                              def body1 = it.clone()
                                              
                                              body1.delegate = doc
                                              body1(doc)
                                            } else if (it instanceof Buildable) {
                                              it.build(doc)
                                            } else {
                                              out.bodyText() << it
                                            }
                                          }
                                      }
                                }
        def unescapedClosure = {doc, pendingNamespaces, namespaces, namespaceSpecificTags, prefix, attrs, body, out ->
                                          out.unescaped() << body
                                     }
        def tagClosure = {tag, doc, pendingNamespaces, namespaces, namespaceSpecificTags, prefix, attrs, body, out ->
                                  if (prefix != "") {
                                      if (!(namespaces.containsKey(prefix) || pendingNamespaces.containsKey(prefix))) {
                                          throw new GroovyRuntimeException("Namespace prefix: ${prefix} is not bound to a URI")
                                      }
          
                                      tag = prefix + ":" + tag
                                  }
          
                                  out = out.unescaped() << "<${tag}"
          
                                  attrs.each {key, value ->
                                                  if (key.contains('$')) {
                                                      def parts = key.tokenize('$')
          
                                                      if (namespaces.containsKey(parts[0]) || pendingNamespaces.containsKey(parts[0])) {
                                                          key = parts[0] + ":" + parts[1]
                                                      } else {
                                                          throw new GroovyRuntimeException("bad attribute namespace tag: ${parts[0]} in ${key}")
                                                      }
                                                  }
          
                                                  out << " ${key}='"
                                                  out.attributeValue() << "${value}"
                                                  out << "'"
                                                }
          
                                  def hiddenNamespaces = [:]
          
                                  pendingNamespaces.each {key, value ->
                                      hiddenNamespaces[key] = namespaces[key]
                                      namespaces[key] = value
                                      out << ((key == ":") ? " xmlns='" : " xmlns:${key}='")
                                      out.attributeValue() << "${value}"
                                      out << "'"
                                  }
          
                                  if (body == null) {
                                      out << "/>"
                                  } else {
                                      out << ">"
          
                                      pendingStack.add pendingNamespaces.clone()
                                      pendingNamespaces.clear()
          
                                      if (body instanceof Closure) {
                                        def body1 = body.clone()
                                        
                                        body1.delegate = doc
                                        body1(doc)
                                      } else if (body instanceof Buildable) {
                                          body.build(doc)
                                      } else {
                                          body.each {
                                            if (it instanceof Closure) {
                                              def body1 = it.clone()
                                              
                                              body1.delegate = doc
                                              body1(doc)
                                            } else if (it instanceof Buildable) {
                                              it.build(doc)
                                            } else {
                                              out.bodyText() << it
                                            }
                                          }
                                      }
          
                                      pendingNamespaces.clear()
                                      pendingNamespaces.putAll pendingStack.pop()
          
                                      out << "</${tag}>"
                                  }
          
                                  hiddenNamespaces.each {key, value ->
                                                              if (value == null) {
                                                                  namespaces.remove key
                                                              } else {
                                                                  namespaces[key] = value
                                                              }
                                                         }
                              }

        def builder = null

        StreamingMarkupBuilder() {
            specialTags.putAll(['yield':noopClosure,
                                'yieldUnescaped':unescapedClosure,
                                'comment':commentClosure,
                                'pi':piClosure])

            def nsSpecificTags = [':'                                              : [tagClosure, tagClosure, [:]],    // the default namespace
                                  'http://www.w3.org/XML/1998/namespace'           : [tagClosure, tagClosure, [:]],
                                  'http://www.codehaus.org/Groovy/markup/keywords' : [badTagClosure, tagClosure, specialTags]]

            this.builder = new BaseMarkupBuilder(nsSpecificTags)
        }
        
        def encoding = null

        public bind(closure) {
            def boundClosure = this.builder.bind(closure);
            def enc = encoding; // take a snapshot of the encoding when the cosure is bound to the builder

            {out ->
                out = new StreamingMarkupWriter(out, enc)
                boundClosure.trigger = out
                out.flush()
            }.asWritable()
        }
    }