1 | """ |
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2 | htmlgen |
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3 | |
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4 | Kind of like HTMLGen, only much simpler. Like stan, only not. The |
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5 | only important symbol that is exported is ``html``. |
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6 | |
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7 | You create tags with attribute access. I.e., the ``A`` anchor tag is |
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8 | ``html.a``. The attributes of the HTML tag are done with keyword |
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9 | arguments. The contents of the tag are the non-keyword arguments |
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10 | (concatenated). You can also use the special ``c`` keyword, passing a |
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11 | list, tuple, or single tag, and it will make up the contents (this is |
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12 | useful because keywords have to come after all non-keyword arguments, |
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13 | which is non-intuitive). |
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14 | |
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15 | If the value of an attribute is None, then no attribute will be |
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16 | inserted. So:: |
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17 | |
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18 | >>> html.a(href='http://www.yahoo.com', name=None, c='Click Here') |
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19 | '<a href=\"http://www.yahoo.com\">Click Here</a>' |
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20 | |
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21 | If a non-string is passed in, then ``webhelpers.escapes.html_escape`` |
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22 | is called on the value. |
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23 | |
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24 | ``html`` can also be called, and it will concatenate the string |
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25 | representations of its arguments. |
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26 | |
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27 | ``html.comment`` will generate an HTML comment, like |
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28 | ``html.comment('comment text', 'and some more text')`` -- note that it |
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29 | cannot take keyword arguments (because they wouldn't mean anything). |
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30 | |
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31 | For cases where you cannot use a name (e.g., for the ``class`` |
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32 | attribute) you can append an underscore to the name, like |
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33 | ``html.span(class_='alert')``. |
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34 | |
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35 | Examples:: |
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36 | |
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37 | >>> print html.html( |
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38 | ... html.head(html.title(\"Page Title\")), |
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39 | ... html.body( |
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40 | ... bgcolor='#000066', |
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41 | ... text='#ffffff', |
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42 | ... c=[html.h1('Page Title'), |
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43 | ... html.p('Hello world!')], |
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44 | ... )) |
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45 | <html> |
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46 | <head> |
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47 | <title>Page Title</title> |
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48 | </head> |
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49 | <body text=\"#ffffff\" bgcolor=\"#000066\"> |
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50 | <h1>Page Title</h1><p> |
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51 | Hello world! |
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52 | </p> |
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53 | </body> |
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54 | </html> |
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55 | >>> html.a(href='#top', c='return to top') |
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56 | '<a href=\"#top\">return to top</a>' |
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57 | >>> 1.4 |
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58 | 1.4 |
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59 | |
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60 | .. note:: |
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61 | |
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62 | Should this return objects instead of strings? That would allow |
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63 | things like ``html.a(href='foo')('title')``. Also, the objects |
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64 | could have a method that shows that they are trully HTML, and thus |
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65 | should not be further quoted. |
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66 | |
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67 | However, in some contexts you can't use objects, you need actual |
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68 | strings. But maybe we can just make sure those contexts don't |
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69 | happen in webhelpers. |
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70 | """ |
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71 | |
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72 | from util import html_escape |
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73 | |
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74 | __all__ = ['html'] |
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75 | |
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76 | def strify(s): |
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77 | if s is None: |
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78 | return '' |
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79 | if not isinstance(s, basestring): |
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80 | s = unicode(s) |
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81 | if isinstance(s, unicode): |
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82 | s = s.encode('ascii', 'xmlcharrefreplace') |
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83 | return s |
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84 | |
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85 | class UnfinishedComment: |
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86 | |
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87 | def __call__(self, *args): |
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88 | return '<!--%s-->' % '\n'.join(map(strify, args)) |
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89 | |
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90 | class Base: |
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91 | |
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92 | comment = UnfinishedComment() |
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93 | |
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94 | def __getattr__(self, attr): |
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95 | if attr.startswith('__'): |
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96 | raise AttributeError |
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97 | attr = attr.lower() |
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98 | return UnfinishedTag(attr) |
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99 | |
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100 | def __call__(self, *args): |
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101 | return ''.join(map(str, args)) |
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102 | |
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103 | def escape(self, *args): |
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104 | return ''.join(map(html_escape, args)) |
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105 | |
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106 | def str(self, arg): |
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107 | return strify(arg) |
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108 | |
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109 | class UnfinishedTag: |
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110 | |
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111 | def __init__(self, tag): |
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112 | self._tag = tag |
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113 | |
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114 | def __call__(self, *args, **kw): |
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115 | return tag(self._tag, *args, **kw) |
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116 | |
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117 | def __str__(self): |
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118 | if self._tag in empty_tags: |
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119 | return '<%s />' % self._tag |
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120 | else: |
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121 | return '<%s></%s>' % (self._tag, self._tag) |
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122 | |
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123 | def tag(tag, *args, **kw): |
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124 | if kw.has_key("c"): |
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125 | if args: |
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126 | raise TypeError( |
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127 | "The special 'c' keyword argument cannot be used in " |
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128 | "conjunction with non-keyword arguments") |
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129 | args = kw["c"] |
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130 | del kw["c"] |
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131 | attrargs = [] |
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132 | for attr, value in kw.items(): |
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133 | if value is None: |
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134 | continue |
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135 | if attr.endswith('_'): |
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136 | attr = attr[:-1] |
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137 | attrargs.append(' %s="%s"' % (attr, html_escape(value))) |
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138 | if not args and tag in empty_tags: |
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139 | return '<%s%s />' % (tag, ''.join(attrargs)) |
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140 | else: |
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141 | return '<%s%s>%s</%s>' % ( |
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142 | tag, ''.join(attrargs), ''.join(map(strify, args)), |
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143 | tag) |
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144 | |
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145 | # Taken from: http://www.w3.org/TR/REC-html40/index/elements.html |
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146 | empty_tags = {} |
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147 | for _t in ("area base basefont br col frame hr img input isindex " |
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148 | "link meta param".split()): |
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149 | empty_tags[_t] = None |
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150 | |
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151 | block_level_tags = {} |
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152 | for _t in ("applet blockquote body br dd div dl dt fieldset " |
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153 | "form frameset head hr html iframe map menu noframes " |
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154 | "noscript object ol optgroup p param script select " |
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155 | "table tbody tfoot thead tr ul var"): |
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156 | block_level_tags[_t] = None |
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157 | |
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158 | html = Base() |
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159 | |
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