-
Notifications
You must be signed in to change notification settings - Fork 1
/
Copy pathrender1.py
180 lines (129 loc) · 4.92 KB
/
render1.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
#!/usr/bin/env python3
# Copyright © 2012-13 Qtrac Ltd. All rights reserved.
# This program or module is free software: you can redistribute it
# and/or modify it under the terms of the GNU General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version. It is provided for
# educational purposes and is distributed in the hope that it will be
# useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
import abc
import collections
import sys
import textwrap
if sys.version_info[:2] < (3, 2):
from xml.sax.saxutils import escape
else:
from html import escape
# Thanks to Nick Coghlan for these!
if sys.version_info[:2] >= (3, 3):
class Renderer(metaclass=abc.ABCMeta):
@classmethod
def __subclasshook__(Class, Subclass):
if Class is Renderer:
attributes = collections.ChainMap(*(Superclass.__dict__
for Superclass in Subclass.__mro__))
methods = ("header", "paragraph", "footer")
if all(method in attributes for method in methods):
return True
return NotImplemented
else:
class Renderer(metaclass=abc.ABCMeta):
@classmethod
def __subclasshook__(Class, Subclass):
if Class is Renderer:
needed = {"header", "paragraph", "footer"}
for Superclass in Subclass.__mro__:
for meth in needed.copy():
if meth in Superclass.__dict__:
needed.discard(meth)
if not needed:
return True
return NotImplemented
MESSAGE = """This is a very short {} paragraph that demonstrates
the simple {} class."""
def main():
paragraph1 = MESSAGE.format("plain-text", "TextRenderer")
paragraph2 = """This is another short paragraph just so that we can
see two paragraphs in action."""
title = "Plain Text"
textPage = Page(title, TextRenderer(22))
textPage.add_paragraph(paragraph1)
textPage.add_paragraph(paragraph2)
textPage.render()
print()
paragraph1 = MESSAGE.format("HTML", "HtmlRenderer")
title = "HTML"
file = sys.stdout
htmlPage = Page(title, HtmlRenderer(HtmlWriter(file)))
htmlPage.add_paragraph(paragraph1)
htmlPage.add_paragraph(paragraph2)
htmlPage.render()
try:
page = Page(title, HtmlWriter())
page.render()
print("ERROR! rendering with an invalid renderer")
except TypeError as err:
print(err)
class Page:
def __init__(self, title, renderer):
if not isinstance(renderer, Renderer):
raise TypeError("Expected object of type Renderer, got {}".
format(type(renderer).__name__))
self.title = title
self.renderer = renderer
self.paragraphs = []
def add_paragraph(self, paragraph):
self.paragraphs.append(paragraph)
def render(self):
self.renderer.header(self.title)
for paragraph in self.paragraphs:
self.renderer.paragraph(paragraph)
self.renderer.footer()
class TextRenderer:
def __init__(self, width=80, file=sys.stdout):
self.width = width
self.file = file
self.previous = False
def header(self, title):
self.file.write("{0:^{2}}\n{1:^{2}}\n".format(title,
"=" * len(title), self.width))
def paragraph(self, text):
if self.previous:
self.file.write("\n")
self.file.write(textwrap.fill(text, self.width))
self.file.write("\n")
self.previous = True
def footer(self):
pass
class HtmlWriter:
def __init__(self, file=sys.stdout):
self.file = file
def header(self):
self.file.write("<!doctype html>\n<html>\n")
def title(self, title):
self.file.write("<head><title>{}</title></head>\n".format(
escape(title)))
def start_body(self):
self.file.write("<body>\n")
def body(self, text):
self.file.write("<p>{}</p>\n".format(escape(text)))
def end_body(self):
self.file.write("</body>\n")
def footer(self):
self.file.write("</html>\n")
class HtmlRenderer:
def __init__(self, htmlWriter):
self.htmlWriter = htmlWriter
def header(self, title):
self.htmlWriter.header()
self.htmlWriter.title(title)
self.htmlWriter.start_body()
def paragraph(self, text):
self.htmlWriter.body(text)
def footer(self):
self.htmlWriter.end_body()
self.htmlWriter.footer()
if __name__ == "__main__":
main()