    """
        This module holds the classes that generate the python code reulting from the PSP template file.
        As the parser encounters PSP elements, it creates a new Generator object for that type of element.
        Each of these elements is put into a list maintained by the ParseEventHandler object.  When it comes
        time to output the Source Code, each generator is called in turn to create it's source.

    --------------------------------------------------------------------------------
        (c) Copyright by Jay Love, 2000 (mailto:jsliv@jslove.net)

        Permission to use, copy, modify, and distribute this software and its
        documentation for any purpose and without fee or royalty is hereby granted,
        provided that the above copyright notice appear in all copies and that
        both that copyright notice and this permission notice appear in
        supporting documentation or portions thereof, including modifications,
        that you make.

        THE AUTHORS DISCLAIM ALL WARRANTIES WITH REGARD TO
        THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
        FITNESS, IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL,
        INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
        FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
        NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
        WITH THE USE OR PERFORMANCE OF THIS SOFTWARE !

            This software is based in part on work done by the Jakarta group.

    """

    import PSPUtils
    import BraceConverter
    try:
        import string
    except:
        pass

    try:
        import os
    except:
        pass

    #these are global so that the ParseEventHandler and this module agree.
    ResponseObject = 'res'
    AwakeCreated = 0

    class GenericGenerator:
        """ Base class for the generators """
        def __init__(self, ctxt=None):
            self._ctxt = ctxt
            self.phase='Service'

    class ExpressionGenerator(GenericGenerator):
        """ This class handles expression blocks.  It simply outputs
        the (hopefully) python expression within the block wrapped
        with a _formatter() call. """

        def __init__(self, chars):
            self.chars = chars
            GenericGenerator.__init__(self)

        def generate(self, writer, phase=None):
            writer.println('res.write(_formatter(' + PSPUtils.removeQuotes(self.chars) + '))')

    class CharDataGenerator(GenericGenerator):
        """This class handles standard character output, mostly HTML.  It just dumps it out.
        Need to handle all the escaping of characters.  It's just skipped for now."""

        def __init__(self, chars):
            GenericGenerator.__init__(self)
            self.chars = chars

        def generate(self, writer, phase=None):
            # Quote any existing backslash so generated python will not interpret it when running.
            self.chars = string.replace(self.chars, '\\', r'\\')

            # quote any single quotes so it does not get confused with our triple-quotes
            self.chars = string.replace(self.chars,'"',r'\"')

            self.generateChunk(writer)

        def generateChunk(self, writer, start=0, stop=None):
            writer.printIndent()#gives a tab
            writer.printChars(ResponseObject+'.write("""')
            writer.printChars(self.chars)
            writer.printChars('""")')
            writer.printChars('\n')

        def mergeData(self, cdGen):
            self.chars = self.chars + cdGen.chars

    class ScriptGenerator(GenericGenerator):
        """generates scripts"""
        def __init__(self, chars, attrs):
            GenericGenerator.__init__(self)
            self.chars = chars

        def generate(self, writer, phase=None):

            if writer._useBraces:
                # send lines to be output by the braces generator
                bc = BraceConverter.BraceConverter()
                for line in string.splitfields(PSPUtils.removeQuotes(self.chars),'\n'):
                    bc.parseLine(line,writer)
                return

            #check for whitespace at the beginning and if less than 2 spaces, remove
            if self.chars[:1]==' ' and self.chars[:2]!= '  ':
                self.chars=string.lstrip(self.chars)
            lines = string.splitfields(PSPUtils.removeQuotes(self.chars),'\n')
            #writer.printList(string.splitfields(PSPUtils.removeQuotes(self.chars),'\n'))

            #userIndent check
            if len(lines[-1])>0 and lines[-1][-1] == '$':
                lastline = lines[-1] = lines[-1][:-1]
                if lastline == '': lastline = lines[-2] #handle endscript marker on its own line
                count=0
                while lastline[count] in string.whitespace:
                    count=count+1
                userIndent = lastline[:count]
            else:
                userIndent = writer.EMPTY_STRING
                lastline=lines[-1]

            #print out code, (moved from above)
            writer._userIndent = writer.EMPTY_STRING #reset to none
            writer.printList(lines)
            writer.printChars('\n')

            #check for a block
            #lastline = string.splitfields(PSPUtils.removeQuotes(self.chars),'\n')[-1]
            commentstart = string.find(lastline,'#')
            if commentstart > 0: lastline = lastline[:commentstart]
            blockcheck=string.rstrip(lastline)
            if len(blockcheck)>0 and blockcheck[-1] == ':':
                writer.pushIndent()
                writer.println()
                writer._blockcount = writer._blockcount+1
                #check for end of block, "pass" by itself
            if string.strip(self.chars) == 'pass' and writer._blockcount>0:
                writer.popIndent()
                writer.println()
                writer._blockcount = writer._blockcount-1

            #set userIndent for subsequent HTML
            writer._userIndent = userIndent

    class EndBlockGenerator(GenericGenerator):
        def __init__(self):
            GenericGenerator.__init__(self)

        def generate(self, writer, phase=None):
            if writer._blockcount>0:
                writer.popIndent()
                writer.println()
                writer._blockcount = writer._blockcount-1
            writer._userIndent = writer.EMPTY_STRING

    class MethodGenerator(GenericGenerator):
        """ generates class methods defined in the PSP page.  There are two parts to method generation.  This
        class handles getting the method name and parameters set up."""
        def __init__(self, chars, attrs):
            GenericGenerator.__init__(self)
            self.phase='Declarations'
            self.attrs=attrs

        def generate(self, writer, phase=None):
            writer.printIndent()
            writer.printChars('def ')
            writer.printChars(self.attrs['name'])
            writer.printChars('(')
            #self.attrs['params']
            writer.printChars('self')
            if self.attrs.has_key('params') and self.attrs['params'] != '':
                writer.printChars(', ')
                writer.printChars(self.attrs['params'])
            writer.printChars('):\n')
            if self.attrs['name'] == 'awake':  #This is hacky, need better method, but it works: MAybe I should require a standard parent and do the intPSP call in that awake???????
                AwakeCreated = 1
                #below indented on 6/1/00, was outside if block
                writer.pushIndent()
                writer.println('self.initPSP()\n')
                writer.popIndent()
                writer.println()

    class MethodEndGenerator(GenericGenerator):
        """ Part of class method generation.  After MethodGenerator, MethodEndGenerator actually generates
        the code for th method body."""
        def __init__(self, chars, attrs):
            GenericGenerator.__init__(self)
            self.phase='Declarations'
            self.attrs=attrs
            self.chars=chars

        def generate(self, writer, phase=None):
            writer.pushIndent()
            writer.printList(string.splitfields(PSPUtils.removeQuotes(self.chars),'\n'))
            writer.printChars('\n')
            writer.popIndent()

    class IncludeGenerator(GenericGenerator):
        """
        Handles psp:include directives.  This is a new version of this directive that actually
        forwards the request to the specified page.
        """

    #   _theFunction = """
    #__pspincludepath = self.transaction().request().urlPathDir() + "%s"
    #self.transaction().application().includeURL(self.transaction(), __pspincludepath)
        _theFunction = """
    __pspincludepath = "%s"
    self.transaction().application().includeURL(self.transaction(), __pspincludepath)
    """

        def __init__(self, attrs, param, ctxt):
            GenericGenerator.__init__(self,ctxt)
            self.attrs = attrs
            self.param = param
            self.scriptgen = None

            self.url = attrs.get('path')
            if self.url == None:
                raise "No path attribute in Include"

            self.scriptgen = ScriptGenerator(self._theFunction % self.url, None)

        def generate(self, writer, phase=None):
            """
            Just insert theFunction
            """
            self.scriptgen.generate(writer, phase)

    class InsertGenerator(GenericGenerator):
        """ Include files designated by the psp:insert syntax.
        If the attribute static is set to true or 1, we include the file now, at compile time.
        Otherwise, we use a function added to every PSP page named __includeFile, which reads the file at run time.
        """
        def __init__(self, attrs, param, ctxt):
            GenericGenerator.__init__(self,ctxt)
            self.attrs = attrs
            self.param = param
            self.static=1
            self.scriptgen = None

            self.page = attrs.get('file')
            if self.page == None:
                raise "No Page attribute in Include"
            thepath=self._ctxt.resolveRelativeURI(self.page)

            self.static = attrs.get('static', None)
            if self.static == string.lower("true") or self.static == "1":
                self.static=1

            if not os.path.exists(thepath):
                print self.page
                raise "Invalid included file",thepath
            self.page=thepath

            if not self.static:
                self.scriptgen = ScriptGenerator("self.__includeFile('%s')" % string.replace(thepath, '\\', '\\\\'), None)

        def generate(self, writer, phase=None):
            """ JSP does this in the servlet.  I'm doing it here because I have triple quotes.
            Note: res.write statements inflate the size of the resulting classfile when it is cached.
            Cut down on those by using a single res.write on the whole file, after escaping any triple-double quotes."""

            if self.static:
                data = open(self.page).read()
                data=string.replace(data,'"""',r'\"""')
                writer.println('res.write("""'+data+'""")')
                writer.println()
            else:
                self.scriptgen.generate(writer, phase)