cpython/Lib/htmllib.py

"""HTML 2.0 parser.

See the HTML 2.0 specification:
http://www.w3.org/hypertext/WWW/MarkUp/html-spec/html-spec_toc.html
"""


import sys
import regsub
import string
from sgmllib import SGMLParser
from formatter import AS_IS


class HTMLParser(SGMLParser):

    def __init__(self, formatter):
        SGMLParser.__init__(self)
        self.formatter = formatter
        self.savedata = None
        self.isindex = 0
        self.title = None
        self.base = None
        self.anchor = None
        self.anchorlist = []
        self.nofill = 0
        self.list_stack = []

    # ------ Methods used internally; some may be overridden

    # --- Formatter interface, taking care of 'savedata' mode;
    # shouldn't need to be overridden

    def handle_data(self, data):
        if self.savedata is not None:
	    self.savedata = self.savedata + data
        else:
	    if self.nofill:
		self.formatter.add_literal_data(data)
	    else:
		self.formatter.add_flowing_data(data)

    # --- Hooks to save data; shouldn't need to be overridden

    def save_bgn(self):
        self.savedata = ''

    def save_end(self):
        data = self.savedata
        self.savedata = None
        return string.join(string.split(data))

    # --- Hooks for anchors; should probably be overridden

    def anchor_bgn(self, href, name, type):
        self.anchor = href
        if self.anchor:
	    self.anchorlist.append(href)

    def anchor_end(self):
        if self.anchor:
	    self.handle_data("[%d]" % len(self.anchorlist))
	    self.anchor = None

    # --- Hook for images; should probably be overridden

    def handle_image(self, src, alt):
        self.handle_data(alt)

    # --- Hooks for forms; should probably be overridden

    def form_bgn(self, action, method, enctype):
        self.do_p([])
        self.handle_data("<FORM>")

    def form_end(self):
        self.handle_data("</FORM>")
        self.do_p([])

    def handle_input(self, type, options):
        self.handle_data("<INPUT>")

    def select_bgn(self, name, size, multiple):
        self.handle_data("<SELECT>")

    def select_end(self):
        self.handle_data("</SELECT>")

    def handle_option(self, value, selected):
        self.handle_data("<OPTION>")

    def textarea_bgn(self, name, rows, cols):
        self.handle_data("<TEXTAREA>")
        self.start_pre([])

    def textarea_end(self):
        self.end_pre()
        self.handle_data("</TEXTAREA>")

    # --------- Top level elememts

    def start_html(self, attrs): pass
    def end_html(self): pass

    def start_head(self, attrs): pass
    def end_head(self): pass

    def start_body(self, attrs): pass
    def end_body(self): pass

    # ------ Head elements

    def start_title(self, attrs):
        self.save_bgn()

    def end_title(self):
        self.title = self.save_end()

    def do_base(self, attrs):
        for a, v in attrs:
            if a == 'href':
                self.base = v

    def do_isindex(self, attrs):
        self.isindex = 1

    def do_link(self, attrs):
        pass

    def do_meta(self, attrs):
        pass

    def do_nextid(self, attrs): # Deprecated
        pass

    # ------ Body elements

    # --- Headings

    def start_h1(self, attrs):
        self.formatter.end_paragraph(1)
        self.formatter.push_font(('h1', 0, 1, 0))

    def end_h1(self):
        self.formatter.end_paragraph(1)
        self.formatter.pop_font()

    def start_h2(self, attrs):
        self.formatter.end_paragraph(1)
        self.formatter.push_font(('h2', 0, 1, 0))

    def end_h2(self):
        self.formatter.end_paragraph(1)
        self.formatter.pop_font()

    def start_h3(self, attrs):
        self.formatter.end_paragraph(1)
        self.formatter.push_font(('h3', 0, 1, 0))

    def end_h3(self):
        self.formatter.end_paragraph(1)
        self.formatter.pop_font()

    def start_h4(self, attrs):
        self.formatter.end_paragraph(1)
        self.formatter.push_font(('h4', 0, 1, 0))

    def end_h4(self):
        self.formatter.end_paragraph(1)
        self.formatter.pop_font()

    def start_h5(self, attrs):
        self.formatter.end_paragraph(1)
        self.formatter.push_font(('h5', 0, 1, 0))

    def end_h5(self):
        self.formatter.end_paragraph(1)
        self.formatter.pop_font()

    def start_h6(self, attrs):
        self.formatter.end_paragraph(1)
        self.formatter.push_font(('h6', 0, 1, 0))

    def end_h6(self):
        self.formatter.end_paragraph(1)
        self.formatter.pop_font()

    # --- Block Structuring Elements

    def do_p(self, attrs):
        self.formatter.end_paragraph(1)

    def start_pre(self, attrs):
        self.formatter.end_paragraph(1)
        self.formatter.push_font((AS_IS, AS_IS, AS_IS, 1))
        self.nofill = self.nofill + 1

    def end_pre(self):
        self.formatter.end_paragraph(1)
        self.formatter.pop_font()
        self.nofill = max(0, self.nofill - 1)

    def start_xmp(self, attrs):
        self.start_pre(attrs)
        self.setliteral('xmp') # Tell SGML parser

    def end_xmp(self):
        self.end_pre()

    def start_listing(self, attrs):
        self.start_pre(attrs)
        self.setliteral('listing') # Tell SGML parser

    def end_listing(self):
        self.end_pre()

    def start_address(self, attrs):
        self.formatter.end_paragraph(0)
        self.formatter.push_font((AS_IS, 1, AS_IS, AS_IS))

    def end_address(self):
        self.formatter.end_paragraph(0)
        self.formatter.pop_font()

    def start_blockquote(self, attrs):
        self.formatter.end_paragraph(1)
        self.formatter.push_margin('blockquote')

    def end_blockquote(self):
        self.formatter.end_paragraph(0)
        self.formatter.pop_margin()

    # --- List Elements

    def start_ul(self, attrs):
        self.formatter.end_paragraph(not self.list_stack)
        self.formatter.push_margin('ul')
        self.list_stack.append(['ul', '*', 0])

    def end_ul(self):
        if self.list_stack: del self.list_stack[-1]
        self.formatter.end_paragraph(not self.list_stack)
        self.formatter.pop_margin()

    def do_li(self, attrs):
        self.formatter.end_paragraph(0)
        if self.list_stack:
	    [dummy, label, counter] = top = self.list_stack[-1]
	    top[2] = counter = counter+1
        else:
	    label, counter = '*', 0
        self.formatter.add_label_data(label, counter)

    def start_ol(self, attrs):
        self.formatter.end_paragraph(not self.list_stack)
        self.formatter.push_margin('ol')
        label = '1.'
        for a, v in attrs:
            if a == 'type':
		if len(v) == 1: v = v + '.'
		label = v
        self.list_stack.append(['ol', label, 0])

    def end_ol(self):
        if self.list_stack: del self.list_stack[-1]
        self.formatter.end_paragraph(not self.list_stack)
        self.formatter.pop_margin()

    def start_menu(self, attrs):
        self.start_ul(attrs)

    def end_menu(self):
        self.end_ul()

    def start_dir(self, attrs):
        self.start_ul(attrs)

    def end_dir(self):
        self.end_ul()

    def start_dl(self, attrs):
        self.formatter.end_paragraph(0)
        self.list_stack.append(['dl', '', 0])

    def end_dl(self):
        self.ddpop()
        if self.list_stack: del self.list_stack[-1]

    def do_dt(self, attrs):
        self.ddpop()

    def do_dd(self, attrs):
        self.ddpop()
        self.formatter.push_margin('dd')
        self.list_stack.append(['dd', '', 0])

    def ddpop(self):
        self.formatter.end_paragraph(0)
        if self.list_stack:
            if self.list_stack[-1][0] == 'dd':
		del self.list_stack[-1]
		self.formatter.pop_margin()

    # --- Phrase Markup

    # Idiomatic Elements

    def start_cite(self, attrs): self.start_i(attrs)
    def end_cite(self): self.end_i()

    def start_code(self, attrs): self.start_tt(attrs)
    def end_code(self): self.end_tt()

    def start_em(self, attrs): self.start_i(attrs)
    def end_em(self): self.end_i()

    def start_kbd(self, attrs): self.start_tt(attrs)
    def end_kbd(self): self.end_tt()

    def start_samp(self, attrs): self.start_tt(attrs)
    def end_samp(self): self.end_tt()

    def start_string(self, attrs): self.start_b(attrs)
    def end_b(self): self.end_b()

    def start_var(self, attrs): self.start_i(attrs)
    def end_var(self): self.end_var()

    # Typographic Elements

    def start_i(self, attrs):
	self.formatter.push_font((AS_IS, 1, AS_IS, AS_IS))
    def end_i(self):
	self.formatter.pop_font()

    def start_b(self, attrs):
	self.formatter.push_font((AS_IS, AS_IS, 1, AS_IS))
    def end_b(self):
	self.formatter.pop_font()

    def start_tt(self, attrs):
	self.formatter.push_font((AS_IS, AS_IS, AS_IS, 1))
    def end_tt(self):
	self.formatter.pop_font()

    def start_a(self, attrs):
        href = ''
        name = ''
        type = ''
        for attrname, value in attrs:
            if attrname == 'href':
                href = value
            if attrname == 'name':
                name = value
            if attrname == 'type':
                type = string.lower(value)
        self.anchor_bgn(href, name, type)

    def end_a(self):
        self.anchor_end()

    # --- Line Break

    def do_br(self, attrs):
        self.formatter.add_line_break()

    # --- Horizontal Rule

    def do_hr(self, attrs):
        self.formatter.add_hor_rule()

    # --- Image

    def do_img(self, attrs):
        align = ''
        alt = '(image)'
        ismap = ''
        src = ''
        for attrname, value in attrs:
            if attrname == 'align':
                align = value
            if attrname == 'alt':
                alt = value
            if attrname == 'ismap':
                ismap = value
            if attrname == 'src':
                src = value
        self.handle_image(src, alt)

    # ------ Forms

    def start_form(self, attrs):
        action = ''
        method = ''
        enctype = ''
        for a, v in attrs:
            if a == 'action': action = v
            if a == 'method': method = v
            if a == 'enctype': enctype = v
        self.form_bgn(action, method, enctype)

    def end_form(self):
        self.form_end()

    def do_input(self, attrs):
        type = ''
        options = {}
        for a, v in attrs:
	    if a == 'type': type = string.lower(v)
	    else: options[a] = v
        self.handle_input(type, options)

    def start_select(self, attrs):
        name = ''
        size = 0
        multiple = 0
        for a, v in attrs:
            if a == 'multiple': multiple = 1
            if a == 'name': name = v
            if a == 'size':
                try: size = string.atoi(size)
                except: pass
        self.select_bgn(name, size, multiple)

    def end_select(self):
        self.select_end()

    def do_option(self, attrs):
        value = ''
        selected = 1
        for a, v in attrs:
            if a == 'value': value = v
            if a == 'selected': selected = 1
        self.handle_option(value, selected)

    def start_textarea(self, attrs):
        name = ''
        rows = 0
        cols = 0
        for a, v in attrs:
            if a == 'name': name = v
            if a == 'rows':
                try: rows = string.atoi(v)
                except: pass
            if a == 'cols':
                try: cols = string.atoi(v)
                except: pass
        self.textarea_bgn(name, rows, cols)

    def end_textarea(self):
        self.textarea_end()

    # --- Really Old Unofficial Deprecated Stuff

    def do_plaintext(self, attrs):
        self.start_pre(attrs)
        self.setnomoretags() # Tell SGML parser

    # --- Unhandled tags

    def unknown_starttag(self, tag, attrs):
        pass

    def unknown_endtag(self, tag):
        pass


def test():
    import sys
    file = 'test.html'
    if sys.argv[1:]: file = sys.argv[1]
    fp = open(file, 'r')
    data = fp.read()
    fp.close()
    from formatter import DumbWriter, AbstractFormatter
    w = DumbWriter()
    f = AbstractFormatter(w)
    p = HTMLParser(f)
    p.feed(data)
    p.close()


if __name__ == '__main__':
    test()