[7196] | 1 | ## $Id: helpers.py 10678 2013-10-31 17:58:50Z uli $ |
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| 2 | ## |
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| 3 | ## Copyright (C) 2011 Uli Fouquet & Henrik Bettermann |
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| 4 | ## This program is free software; you can redistribute it and/or modify |
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| 5 | ## it under the terms of the GNU General Public License as published by |
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| 6 | ## the Free Software Foundation; either version 2 of the License, or |
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| 7 | ## (at your option) any later version. |
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| 8 | ## |
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| 9 | ## This program is distributed in the hope that it will be useful, |
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| 10 | ## but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 11 | ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 12 | ## GNU General Public License for more details. |
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| 13 | ## |
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| 14 | ## You should have received a copy of the GNU General Public License |
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| 15 | ## along with this program; if not, write to the Free Software |
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| 16 | ## Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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| 17 | ## |
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[7819] | 18 | """General helper functions for Kofa. |
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[4188] | 19 | """ |
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[10677] | 20 | import unicodecsv as csv # XXX: csv ops should move to dedicated module. |
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[8185] | 21 | import datetime |
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[8466] | 22 | import imghdr |
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[9593] | 23 | import logging |
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[4188] | 24 | import os |
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[8185] | 25 | import pytz |
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[4375] | 26 | import re |
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[4188] | 27 | import shutil |
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[8631] | 28 | import tempfile |
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[5731] | 29 | import grok |
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[5848] | 30 | from cStringIO import StringIO |
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| 31 | from docutils.core import publish_string |
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[7943] | 32 | from zope.component import getUtility |
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[5731] | 33 | from zope.component.interfaces import IFactory |
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[5734] | 34 | from zope.interface import implementedBy |
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[7941] | 35 | from zope.interface.interface import Method, Attribute |
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[6071] | 36 | from zope.schema import getFieldNames |
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| 37 | from zope.schema.fieldproperty import FieldProperty |
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[6372] | 38 | from zope.security.interfaces import NoInteraction |
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| 39 | from zope.security.management import getInteraction |
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[7175] | 40 | from zope.pluggableauth.interfaces import IAuthenticatorPlugin |
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[4188] | 41 | |
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[6503] | 42 | BUFSIZE = 8 * 1024 |
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[6372] | 43 | |
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[10677] | 44 | |
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[7186] | 45 | def remove_file_or_directory(filepath): |
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[4188] | 46 | """Remove a file or directory. |
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[5738] | 47 | |
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| 48 | Different to :func:`shutil.rmtree` we also accept not existing |
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| 49 | paths (returning silently) and if a dir turns out to be a regular |
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| 50 | file, we remove that. |
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[4188] | 51 | """ |
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| 52 | filepath = os.path.abspath(filepath) |
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| 53 | if not os.path.exists(filepath): |
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| 54 | return |
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| 55 | if os.path.isdir(filepath): |
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| 56 | shutil.rmtree(filepath) |
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| 57 | else: |
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| 58 | os.unlink(filepath) |
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| 59 | return |
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| 60 | |
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[10677] | 61 | |
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[7186] | 62 | def copy_filesystem_tree(src, dst, overwrite=False, del_old=False): |
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[4188] | 63 | """Copy contents of directory src to directory dst. |
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| 64 | |
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| 65 | Both directories must exists. |
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| 66 | |
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| 67 | If `overwrite` is true, any same named objects will be |
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| 68 | overwritten. Otherwise these files will not be touched. |
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| 69 | |
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| 70 | If `del_old` is true, copied files and directories will be removed |
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| 71 | from the src directory. |
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| 72 | |
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| 73 | This functions returns a list of non-copied files. |
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| 74 | |
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| 75 | Unix hidden files and directories (starting with '.') are not |
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| 76 | processed by this function. |
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| 77 | """ |
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| 78 | if not os.path.exists(src): |
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| 79 | raise ValueError('source path does not exist: %s' % src) |
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| 80 | if not os.path.exists(dst): |
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| 81 | raise ValueError('destination path does not exist: %s' % dst) |
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| 82 | if not os.path.isdir(src): |
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| 83 | raise ValueError('source path is not a directory: %s' % src) |
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| 84 | if not os.path.isdir(dst): |
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| 85 | raise ValueError('destination path is not a directory: %s' % dst) |
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| 86 | not_copied = [] |
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| 87 | for item in os.listdir(src): |
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| 88 | if item.startswith('.'): |
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[10677] | 89 | continue # We do not copy hidden stuff... |
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[4188] | 90 | itemsrc = os.path.join(src, item) |
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| 91 | itemdst = os.path.join(dst, item) |
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| 92 | |
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| 93 | if os.path.exists(itemdst): |
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| 94 | if overwrite is True: |
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[7186] | 95 | remove_file_or_directory(itemdst) |
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[4188] | 96 | else: |
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| 97 | not_copied.append(item) |
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| 98 | continue |
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[6113] | 99 | |
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[4188] | 100 | if os.path.isdir(itemsrc): |
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| 101 | shutil.copytree(itemsrc, itemdst) |
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| 102 | else: |
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| 103 | shutil.copy2(itemsrc, itemdst) |
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| 104 | if del_old: |
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[7186] | 105 | remove_file_or_directory(itemsrc) |
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[4188] | 106 | return not_copied |
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[4375] | 107 | |
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| 108 | |
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[7186] | 109 | def get_inner_HTML_part(html_code): |
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[4375] | 110 | """Return the 'inner' part of a complete HTML snippet. |
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| 111 | |
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| 112 | If there is a form part, get this. |
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| 113 | |
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| 114 | If there is no form part, try to return the body part contents. |
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| 115 | |
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| 116 | If there is no body, return as-is. |
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[5738] | 117 | |
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| 118 | Let's see how that works. If we deliver some doc with form, we |
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| 119 | will get that form only: |
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| 120 | |
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| 121 | >>> doc = '<html><form>My Form</form>Outside the form</html>' |
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[7186] | 122 | >>> get_inner_HTML_part(doc) |
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[5738] | 123 | '<form>My Form</form>' |
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| 124 | |
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| 125 | No form? Then seek for a body part and get the contents: |
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| 126 | |
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| 127 | >>> doc = '<html><body>My Body</body>Trailing Trash</html>' |
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[7186] | 128 | >>> get_inner_HTML_part(doc) |
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[5738] | 129 | 'My Body' |
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| 130 | |
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| 131 | If none of these is included, return what we got: |
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| 132 | |
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| 133 | >>> doc = '<html>without body nor form</html>' |
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[7186] | 134 | >>> get_inner_HTML_part(doc) |
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[5738] | 135 | '<html>without body nor form</html>' |
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| 136 | |
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[4375] | 137 | """ |
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| 138 | |
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| 139 | try: |
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[5738] | 140 | result = re.match('^.+(<form[^\>]*>.*</form>).+$', html_code, |
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[4375] | 141 | re.DOTALL).groups()[0] |
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| 142 | return result |
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| 143 | except AttributeError: |
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| 144 | # No <form> part included |
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| 145 | try: |
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| 146 | result = re.match('^.+<body[^\>]*>(.*)</body>.*$', html_code, |
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| 147 | re.DOTALL).groups()[0] |
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| 148 | return result |
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| 149 | except AttributeError: |
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| 150 | # No <form> and no <body> tag... |
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| 151 | pass |
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| 152 | return html_code |
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| 153 | |
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[10677] | 154 | |
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[5731] | 155 | class FactoryBase(grok.GlobalUtility): |
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| 156 | """A factory for things. |
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| 157 | |
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| 158 | This is a baseclass for easier creation of factories. Factories |
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| 159 | are utilities that are registered under a certain name and return |
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| 160 | instances of certain classes when called. |
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| 161 | |
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[7811] | 162 | In :mod:`waeup.kofa` we use factories extensively for |
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[7933] | 163 | batching. While processing a batch some processors looks up a |
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[5731] | 164 | factory to create real-world instances that then get filled with |
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| 165 | data from imported CSV files. |
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| 166 | |
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| 167 | To get rid of reimplementing the same stuff over and over again, |
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| 168 | most notably the methods defined here, we offer this base class |
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| 169 | (which will *not* be registered as a factory itself). |
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| 170 | |
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| 171 | Real factories can then be created like this: |
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| 172 | |
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| 173 | >>> import grok |
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[7811] | 174 | >>> from waeup.kofa.utils.helpers import FactoryBase |
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[5731] | 175 | >>> class MyObject(object): |
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| 176 | ... # Some class we want to get instances of. |
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| 177 | ... pass |
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| 178 | >>> class MyObjectFactory(FactoryBase): |
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| 179 | ... # This is the factory for MyObject instances |
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[7811] | 180 | ... grok.name(u'waeup.kofa.factory.MyObject') |
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[5731] | 181 | ... factory = MyObject |
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| 182 | |
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| 183 | That's it. It is essential to set the ``factory`` attribute, which |
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| 184 | will determine the class of which instances should be created when |
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| 185 | called. The given name must even be unique amongst all utilities |
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| 186 | registered during runtime. While you can pick any name you like |
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[7811] | 187 | you might want to prepend ``waeup.kofa.factory.`` to the name |
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[5731] | 188 | string to make sure it does not clash with names of other |
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| 189 | utilities one day. |
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| 190 | |
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| 191 | Before all this works we have to grok the baseclass once and our |
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| 192 | freshly defined factory. This executes all the component |
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| 193 | registration stuff we don't want to do ourselves. In daily use |
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[7811] | 194 | this is done automatically on startup of a :mod:`waeup.kofa` |
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[5731] | 195 | system. |
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[6113] | 196 | |
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[7811] | 197 | >>> grok.testing.grok('waeup.kofa.utils.helpers') |
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[5731] | 198 | >>> grok.testing.grok_component( |
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| 199 | ... 'MyObjectFactory', MyObjectFactory |
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| 200 | ... ) |
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| 201 | True |
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| 202 | |
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[7933] | 203 | After grokking we (and processors) can create objects without |
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[5731] | 204 | knowing about the location of the real class definition, just by |
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| 205 | the factory name: |
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| 206 | |
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| 207 | >>> from zope.component import createObject |
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[7811] | 208 | >>> obj = createObject('waeup.kofa.factory.MyObject') |
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[5731] | 209 | >>> isinstance(obj, MyObject) |
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| 210 | True |
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| 211 | |
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| 212 | We can also use the regular utility lookups to find our new |
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| 213 | factory: |
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| 214 | |
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| 215 | >>> from zope.component import getUtility |
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| 216 | >>> from zope.component.interfaces import IFactory |
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| 217 | >>> factory = getUtility( |
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[7811] | 218 | ... IFactory, name='waeup.kofa.factory.MyObject' |
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[5731] | 219 | ... ) |
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| 220 | >>> isinstance(factory, MyObjectFactory) |
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| 221 | True |
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| 222 | |
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| 223 | And this factory generates `MyObject` instances: |
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| 224 | |
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| 225 | >>> obj = factory() |
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| 226 | >>> isinstance(obj, MyObject) |
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| 227 | True |
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| 228 | |
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| 229 | """ |
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[10677] | 230 | grok.baseclass() # Do not grok this class, do not register us. |
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[5731] | 231 | grok.implements(IFactory) |
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| 232 | # You can override any of the following attributes in derived |
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| 233 | # classes. The `grok.name` setting *must* even be set to some |
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| 234 | # unique value. |
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| 235 | grok.name(u'waeup.Factory') |
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| 236 | title = u"Create instances of ``factory``.", |
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| 237 | description = u"This factory instantiates new applicant instances." |
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| 238 | factory = None |
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| 239 | |
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| 240 | def __call__(self, *args, **kw): |
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| 241 | """The main factory function. |
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| 242 | |
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| 243 | Returns an instance of the requested object. |
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| 244 | """ |
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| 245 | return self.factory() |
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| 246 | |
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| 247 | def getInterfaces(self): |
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| 248 | # Required by IFactory |
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| 249 | return implementedBy(self.factory) |
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[5848] | 250 | |
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[10677] | 251 | |
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[5848] | 252 | def ReST2HTML_w_warnings(source_string): |
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| 253 | """Convert a reStructuredText string to HTML preserving warnings. |
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| 254 | |
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| 255 | Returns a tuple ``(<HTML_CODE>, <WARNINGS>)``, both being |
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| 256 | strings. Where ``<HTML_CODE>`` is the HTML code generated from the |
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[5876] | 257 | source string (in unicode), ``<WARNINGS>`` is a string containing |
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| 258 | any warning messages or ``None``. |
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[6113] | 259 | |
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[5848] | 260 | Regular multi-line ReStructuredText strings will be returned as |
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| 261 | HTML code: |
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| 262 | |
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[7811] | 263 | >>> from waeup.kofa.utils.helpers import ReST2HTML |
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[5848] | 264 | >>> source = ''' |
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| 265 | ... Headline |
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| 266 | ... ======== |
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| 267 | ... |
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| 268 | ... - A list item |
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| 269 | ... - Another item |
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| 270 | ... |
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| 271 | ... Thanks for watching! |
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| 272 | ... ''' |
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| 273 | >>> html, warnings = ReST2HTML_w_warnings(source) |
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| 274 | >>> print html |
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| 275 | <div class="document" id="headline"> |
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| 276 | <h1 class="title">Headline</h1> |
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| 277 | <BLANKLINE> |
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| 278 | <ul class="simple"> |
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| 279 | <li>A list item</li> |
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| 280 | <li>Another item</li> |
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| 281 | </ul> |
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| 282 | <p>Thanks for watching!</p> |
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| 283 | </div> |
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| 284 | |
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| 285 | Here no warnings happened, so the `warnings` are ``None``: |
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| 286 | |
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| 287 | >>> warnings is None |
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| 288 | True |
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[6113] | 289 | |
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[5848] | 290 | If warnings happen then they can be retrieved in the returned |
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| 291 | ``warnings``. We try to render an erraneous document: |
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| 292 | |
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| 293 | >>> source = ''' |
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| 294 | ... Headline |
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| 295 | ... ====== |
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| 296 | ... |
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| 297 | ... Thanks for watching! |
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| 298 | ... ''' |
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| 299 | >>> html, warnings = ReST2HTML_w_warnings(source) |
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| 300 | >>> print html |
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| 301 | <div class="document" id="headline"> |
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| 302 | <h1 class="title">Headline</h1> |
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| 303 | <BLANKLINE> |
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| 304 | <p>Thanks for watching!</p> |
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| 305 | </div> |
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| 306 | |
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| 307 | >>> print warnings |
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| 308 | <string>:3: (WARNING/2) Title underline too short. |
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| 309 | <BLANKLINE> |
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| 310 | Headline |
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| 311 | ====== |
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| 312 | <BLANKLINE> |
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| 313 | |
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| 314 | As you can see, the warnings are not displayed inline the document |
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| 315 | but can be retrieved from the returned warnings, which is a string |
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| 316 | or ``None``. |
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| 317 | """ |
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| 318 | warnings = StringIO() |
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| 319 | fulldoc = publish_string( |
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| 320 | source_string, writer_name='html4css1', |
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| 321 | settings_overrides={ |
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| 322 | 'report_level': 0, |
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| 323 | 'warning_stream': warnings, |
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| 324 | }) |
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| 325 | warnings.seek(0) |
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| 326 | warning_msgs = warnings.read() |
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| 327 | if warning_msgs: |
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| 328 | # Render again, this time with no warnings inline... |
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[10677] | 329 | fulldoc = publish_string( |
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[5848] | 330 | source_string, writer_name='html4css1', |
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| 331 | settings_overrides={ |
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| 332 | 'report_level': 10000, |
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| 333 | 'halt_level': 10000, |
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| 334 | 'warning_stream': warnings, |
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| 335 | }) |
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| 336 | if warning_msgs == '': |
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| 337 | warning_msgs = None |
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[7186] | 338 | result = get_inner_HTML_part(fulldoc).strip() |
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[5876] | 339 | if not isinstance(result, unicode): |
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| 340 | result = result.decode('utf-8') |
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| 341 | return result, warning_msgs |
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[5848] | 342 | |
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[10677] | 343 | |
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[5848] | 344 | def ReST2HTML(source_string): |
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| 345 | """Render a string containing ReStructuredText to HTML. |
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| 346 | |
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| 347 | Any warnings about too short headings, etc. are silently |
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| 348 | discarded. Use :func:`ReST2HTML_w_warnings` if you want to get any |
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| 349 | warnings. |
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| 350 | |
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[5876] | 351 | The returned string will be unicode. |
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[6113] | 352 | |
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[5848] | 353 | A regular document will be rendered like this: |
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| 354 | |
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| 355 | >>> source = ''' |
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| 356 | ... Headline |
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| 357 | ... ======== |
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| 358 | ... |
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| 359 | ... Thanks for watching! |
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| 360 | ... ''' |
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| 361 | >>> html = ReST2HTML(source) |
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| 362 | >>> print html |
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| 363 | <div class="document" id="headline"> |
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| 364 | <h1 class="title">Headline</h1> |
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| 365 | <BLANKLINE> |
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| 366 | <p>Thanks for watching!</p> |
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| 367 | </div> |
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| 368 | |
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| 369 | A document with markup problems (here: the underline is too short) |
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| 370 | will look similar: |
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| 371 | |
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| 372 | >>> source = ''' |
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| 373 | ... Headline |
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| 374 | ... ====== |
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| 375 | ... |
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| 376 | ... Thanks for watching! |
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| 377 | ... ''' |
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| 378 | >>> html = ReST2HTML(source) |
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| 379 | >>> print html |
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| 380 | <div class="document" id="headline"> |
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| 381 | <h1 class="title">Headline</h1> |
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| 382 | <BLANKLINE> |
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| 383 | <p>Thanks for watching!</p> |
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| 384 | </div> |
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[6113] | 385 | |
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[5848] | 386 | """ |
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| 387 | html, warnings = ReST2HTML_w_warnings(source_string) |
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| 388 | return html |
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[6071] | 389 | |
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[10677] | 390 | |
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[9689] | 391 | def attrs_to_fields(cls, omit=[]): |
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[6071] | 392 | """Turn the attributes of a class into FieldProperty instances. |
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[6113] | 393 | |
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| 394 | With Python >= 2.6 we can even use this function as a class decorator. |
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[9689] | 395 | |
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| 396 | `omit` is a list of field names that should _not_ be turned into |
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| 397 | field properties. This is useful for properties and the like. |
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[6071] | 398 | """ |
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| 399 | iface = list(implementedBy(cls))[0] |
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| 400 | for field_name in getFieldNames(iface): |
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[9689] | 401 | if field_name in omit: |
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| 402 | continue |
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[6071] | 403 | setattr(cls, field_name, FieldProperty(iface[field_name])) |
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| 404 | return cls |
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[6372] | 405 | |
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[10677] | 406 | |
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[6372] | 407 | def get_current_principal(): |
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| 408 | """Get the 'current' principal. |
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| 409 | |
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| 410 | This method works without a request. Examining a request is the |
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| 411 | regular (and recommended) way to get a principal involved |
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| 412 | 'currently'. |
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| 413 | |
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| 414 | Use this method only if you really have no access to the current |
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| 415 | request. |
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| 416 | |
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| 417 | Returns ``None`` when no principal is involved (for instance |
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| 418 | during tests). |
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| 419 | """ |
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| 420 | try: |
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| 421 | principal = getInteraction().participations[0].principal |
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| 422 | except NoInteraction: |
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| 423 | return None |
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[10677] | 424 | except IndexError: # No participations present |
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[6372] | 425 | return None |
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| 426 | return principal |
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[6503] | 427 | |
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[10677] | 428 | |
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[6503] | 429 | def cmp_files(file_descr1, file_descr2): |
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| 430 | """Compare two files by their file descriptors. |
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| 431 | |
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| 432 | Returns ``True`` if both are equal, ``False`` otherwise. |
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| 433 | """ |
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[6531] | 434 | file_descr1.seek(0) |
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| 435 | file_descr2.seek(0) |
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[6503] | 436 | while True: |
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| 437 | b1 = file_descr1.read(BUFSIZE) |
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| 438 | b2 = file_descr2.read(BUFSIZE) |
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| 439 | if b1 != b2: |
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| 440 | return False |
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| 441 | if not b1: |
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| 442 | return True |
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[7078] | 443 | |
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[10677] | 444 | |
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[7078] | 445 | def string_from_bytes(number): |
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| 446 | """Turn a number into some textual representation. |
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| 447 | |
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| 448 | Examples: |
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| 449 | |
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| 450 | >>> string_from_bytes(1) |
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| 451 | u'1 byte(s)' |
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| 452 | |
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| 453 | >>> string_from_bytes(1025) |
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| 454 | u'1 KB' |
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| 455 | |
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| 456 | >>> string_from_bytes(1.5 * 1024*1024) |
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| 457 | u'1.50 MB' |
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| 458 | |
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| 459 | >>> string_from_bytes(673.286 * 1024**3) |
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| 460 | u'673.29 GB' |
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| 461 | |
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| 462 | """ |
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| 463 | if number < 1024: |
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| 464 | return u'%s byte(s)' % (str(number),) |
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[10677] | 465 | elif number < 1024 ** 2: |
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[7078] | 466 | return u'%s KB' % (number / 1024,) |
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[10677] | 467 | elif number < 1024 ** 3: |
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| 468 | return u'%.2f MB' % (number / 1024 ** 2,) |
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| 469 | return u'%.2f GB' % (number / 1024 ** 3,) |
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[7079] | 470 | |
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[10677] | 471 | |
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[7079] | 472 | def file_size(file_like_obj): |
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| 473 | """Determine file size in most effective manner. |
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| 474 | |
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| 475 | Returns the number of bytes in a file. This function works for |
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| 476 | both, real files as well as file-like objects like cStringIO based |
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| 477 | 'files'. |
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| 478 | |
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| 479 | Example: |
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| 480 | |
---|
| 481 | >>> from cStringIO import StringIO |
---|
| 482 | >>> file_size(StringIO('my file content')) |
---|
| 483 | 15 |
---|
| 484 | |
---|
| 485 | Please note that this function expects the file-like object passed |
---|
| 486 | in to be at first reading position (it does no seek(0)) and that |
---|
| 487 | when finished the file pointer might be at end of file. |
---|
| 488 | """ |
---|
| 489 | if hasattr(file_like_obj, 'fileno'): |
---|
| 490 | return os.fstat(file_like_obj.fileno())[6] |
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[10677] | 491 | file_like_obj.seek(0, 2) # seek to last position in file |
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[7079] | 492 | return file_like_obj.tell() |
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[7175] | 493 | |
---|
[10677] | 494 | |
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[7175] | 495 | def get_user_account(request): |
---|
| 496 | """Return local user account. |
---|
| 497 | """ |
---|
| 498 | principal_id = request.principal.id |
---|
[7234] | 499 | authenticator = getUtility(IAuthenticatorPlugin, name='users') |
---|
| 500 | account = authenticator.getAccount(principal_id) |
---|
[7175] | 501 | return account |
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[7941] | 502 | |
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[10677] | 503 | |
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[7941] | 504 | def iface_names(iface, omit=[], exclude_attribs=True, exclude_methods=True): |
---|
| 505 | """Get all attribute names of an interface. |
---|
| 506 | |
---|
| 507 | Searches also base interfaces. |
---|
| 508 | |
---|
| 509 | Names of fields that are pure attributes |
---|
| 510 | (i.e. zope.interface.Attribute) or methods are excluded by |
---|
| 511 | default. |
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| 512 | |
---|
| 513 | Names of typical fields derived from zope.schema are included. |
---|
| 514 | |
---|
| 515 | The `omit` paramter can give a list of names to exclude. |
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| 516 | |
---|
| 517 | Returns an unsorted list of strings. |
---|
| 518 | """ |
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[8370] | 519 | ifaces = set((iface,)) |
---|
| 520 | # Collect all interfaces (also bases) recursively |
---|
| 521 | while True: |
---|
| 522 | ext_ifaces = set(ifaces) |
---|
| 523 | for iface in ext_ifaces: |
---|
| 524 | ext_ifaces = set.union(ext_ifaces, set(iface.getBases())) |
---|
| 525 | if ext_ifaces == ifaces: |
---|
| 526 | # No new interfaces found, list complete |
---|
| 527 | break |
---|
| 528 | ifaces = ext_ifaces |
---|
| 529 | # Collect (filtered) names of collected interfaces |
---|
[7941] | 530 | result = [] |
---|
[8370] | 531 | for iface in ifaces: |
---|
| 532 | for name, descr in iface.namesAndDescriptions(): |
---|
| 533 | if name in omit: |
---|
| 534 | continue |
---|
| 535 | if exclude_attribs and descr.__class__ is Attribute: |
---|
| 536 | continue |
---|
| 537 | if exclude_methods and isinstance(descr, Method): |
---|
| 538 | continue |
---|
[9043] | 539 | if name in result: |
---|
| 540 | continue |
---|
[8370] | 541 | result.append(name) |
---|
[7941] | 542 | return result |
---|
[7968] | 543 | |
---|
[10677] | 544 | |
---|
[7968] | 545 | def get_sorted_preferred(tuples_iterable, preferred_list): |
---|
| 546 | """Get a list of tuples (<TITLE>,<TOKEN>) with values in |
---|
| 547 | `preferred_list` put in front. |
---|
| 548 | |
---|
| 549 | The rest of the tuples iterable is returned in orginal order. This |
---|
| 550 | is useful for putting default entries on top of (already sorted) |
---|
| 551 | lists of choice values, for instance when sorting countries and |
---|
| 552 | their code. |
---|
| 553 | |
---|
| 554 | Sample: |
---|
| 555 | |
---|
| 556 | We have a list of tuples with uppercase 'titles' and lowercase |
---|
| 557 | 'tokens'. This list is already sorted but we want certain values |
---|
| 558 | of this list to show up before other values. For instance we want |
---|
| 559 | to see the 'C' entry to come first. |
---|
| 560 | |
---|
| 561 | >>> get_sorted_preferred([('A','a'), ('B','b'), ('C','c')], |
---|
| 562 | ... ['c']) |
---|
| 563 | (('C', 'c'), ('A', 'a'), ('B', 'b')) |
---|
| 564 | |
---|
| 565 | i.e. the entry with 'c' as second value moved to head of result. |
---|
| 566 | |
---|
| 567 | We can also require multiple entries at head of list: |
---|
| 568 | |
---|
| 569 | >>> get_sorted_preferred([('A','a'), ('B','b'), ('C','c')], |
---|
| 570 | ... ['b', 'c']) |
---|
| 571 | (('B', 'b'), ('C', 'c'), ('A', 'a')) |
---|
| 572 | |
---|
| 573 | We required the 'b' entry to come before the 'c' entry and then |
---|
| 574 | the rest of the input list. That's what we got. |
---|
| 575 | |
---|
| 576 | The result is returned as a tuple of tuples to keep order of values. |
---|
| 577 | """ |
---|
| 578 | result = [None for x in preferred_list] |
---|
| 579 | for title, code in tuples_iterable: |
---|
| 580 | if code in preferred_list: |
---|
| 581 | index = preferred_list.index(code) |
---|
| 582 | result[index] = (title, code) |
---|
| 583 | else: |
---|
| 584 | result.append((title, code)) |
---|
| 585 | return tuple(result) |
---|
[8185] | 586 | |
---|
[10677] | 587 | |
---|
[8185] | 588 | def now(tz=None): |
---|
| 589 | """Get current datetime in timezone of `tz`. |
---|
| 590 | |
---|
| 591 | If `tz`, a `tzinfo` instance, is None, UTC time is returned. |
---|
| 592 | |
---|
| 593 | `tz` should be a timezone as defined in pytz. |
---|
| 594 | """ |
---|
| 595 | return to_timezone(datetime.datetime.utcnow(), tz=tz) |
---|
| 596 | |
---|
[10677] | 597 | |
---|
[8185] | 598 | def to_timezone(dt, tz=None): |
---|
| 599 | """Shift datetime into timezone `tz`. |
---|
| 600 | |
---|
| 601 | If datetime `dt` contains no `tzinfo` (i.e. it is 'naive'), it is |
---|
| 602 | assumed to be UTC. |
---|
| 603 | |
---|
| 604 | If no `tz` is given, shift to UTC is performed. |
---|
[8192] | 605 | |
---|
| 606 | If `dt` is not a datetime.datetime, the input value is returned |
---|
| 607 | unchanged. |
---|
[8185] | 608 | """ |
---|
[8192] | 609 | if not isinstance(dt, datetime.datetime): |
---|
| 610 | return dt |
---|
[8185] | 611 | if tz is None: |
---|
| 612 | tz = pytz.utc |
---|
| 613 | if dt.tzinfo is None: |
---|
| 614 | dt = pytz.utc.localize(dt) |
---|
| 615 | return tz.normalize(dt.tzinfo.normalize(dt).astimezone(tz)) |
---|
[8466] | 616 | |
---|
[10677] | 617 | |
---|
[8466] | 618 | def get_fileformat(path, bytestream=None): |
---|
| 619 | """Try to determine the file format of a given media file. |
---|
| 620 | |
---|
| 621 | Although checks done here are not done very thoroughly, they make |
---|
| 622 | no assumptions about the filetype by looking at its filename |
---|
| 623 | extension or similar. Instead they check header data to comply |
---|
| 624 | with common known rules (Magic Words). |
---|
| 625 | |
---|
| 626 | If bytestream is not `None` the `path` is ignored. |
---|
| 627 | |
---|
| 628 | Returns filetype as string (something like ``'jpg'``) if |
---|
| 629 | file-format can be recognized, ``None`` else. |
---|
| 630 | |
---|
| 631 | Tested recognized filetypes currently are `jpg`, `png`, and `pdf`. |
---|
| 632 | |
---|
| 633 | More filetypes (though untested in waeup.kofa) are automatically |
---|
| 634 | recognized because we deploy the stdlib `imghdr` library. See this |
---|
| 635 | module's docs for a complete list of filetypes recognized. |
---|
| 636 | """ |
---|
| 637 | if path is None and bytestream is None: |
---|
| 638 | return None |
---|
| 639 | |
---|
| 640 | img_type = None |
---|
| 641 | if bytestream is not None: |
---|
| 642 | img_type = imghdr.what(path, bytestream) |
---|
| 643 | else: |
---|
| 644 | img_type = imghdr.what(path) |
---|
| 645 | for name, replacement in (('jpeg', 'jpg'), ('tiff', 'tif')): |
---|
| 646 | if img_type == name: |
---|
| 647 | img_type = replacement |
---|
| 648 | return img_type |
---|
| 649 | |
---|
[10677] | 650 | |
---|
[8466] | 651 | def check_pdf(bytestream, file): |
---|
| 652 | """Tell whether a file or bytestream is a PDF file. |
---|
| 653 | |
---|
| 654 | Works as a test/plugin for the stdlib `imghdr` library. |
---|
| 655 | """ |
---|
| 656 | if file is not None: |
---|
| 657 | file.seek(0) |
---|
| 658 | bytestream = file.read(4) |
---|
| 659 | file.seek(0) |
---|
| 660 | |
---|
| 661 | if bytestream.startswith('%PDF'): |
---|
| 662 | return 'pdf' |
---|
| 663 | return None |
---|
| 664 | |
---|
| 665 | # register check_pdf as header check function with `imghdr` |
---|
| 666 | if check_pdf not in imghdr.tests: |
---|
| 667 | imghdr.tests.append(check_pdf) |
---|
[8631] | 668 | |
---|
[10677] | 669 | |
---|
[8631] | 670 | def merge_csv_files(path1, path2): |
---|
| 671 | """Merge two CSV files into one (appending). |
---|
| 672 | |
---|
| 673 | CSV data from `path2` will be merged into `path1` csv file. This |
---|
| 674 | is a bit like 'appending' data from path2 to data from path1. |
---|
| 675 | |
---|
| 676 | The path of the resulting temporary file will be returned. |
---|
| 677 | |
---|
| 678 | In the result file data from `path2` will always come _after_ data |
---|
| 679 | from `path1`. |
---|
| 680 | |
---|
| 681 | **Caution**: It is the _callers_ responsibility to remove the |
---|
| 682 | result file (which is created by tempfile.mkstemp) after usage. |
---|
| 683 | |
---|
| 684 | This CSV file merging copes with different column orders in both |
---|
| 685 | CSV files and even with different column sets in both files. |
---|
[8633] | 686 | |
---|
| 687 | Also broken/empty CSV files can be handled. |
---|
[8631] | 688 | """ |
---|
| 689 | # sniff the col names |
---|
[8633] | 690 | try: |
---|
| 691 | row10 = csv.DictReader(open(path1, 'rb')).next() |
---|
| 692 | except StopIteration: |
---|
| 693 | row10 = dict() |
---|
| 694 | try: |
---|
| 695 | row20 = csv.DictReader(open(path2, 'rb')).next() |
---|
| 696 | except StopIteration: |
---|
| 697 | row20 = dict() |
---|
[8631] | 698 | fieldnames = sorted(list(set(row10.keys() + row20.keys()))) |
---|
| 699 | # now read/write the real data |
---|
| 700 | reader1 = csv.DictReader(open(path1, 'rb')) |
---|
| 701 | reader2 = csv.DictReader(open(path2, 'rb')) |
---|
| 702 | wp, tmp_path = tempfile.mkstemp() |
---|
| 703 | writer = csv.DictWriter(os.fdopen(wp, 'wb'), fieldnames) |
---|
[10677] | 704 | writer.writerow(dict((x, x) for x in fieldnames)) # header |
---|
[8631] | 705 | for row in reader1: |
---|
| 706 | writer.writerow(row) |
---|
| 707 | for row in reader2: |
---|
| 708 | writer.writerow(row) |
---|
| 709 | return tmp_path |
---|
[9372] | 710 | |
---|
[10677] | 711 | |
---|
[9372] | 712 | def product(sequence, start=1): |
---|
| 713 | """Returns the product of a sequence of numbers (_not_ strings) |
---|
| 714 | multiplied by the parameter `start` (defaults to 1). If the |
---|
| 715 | sequence is empty, returns 0. |
---|
| 716 | """ |
---|
| 717 | if not len(sequence): |
---|
| 718 | return 0 |
---|
| 719 | result = start |
---|
| 720 | for item in sequence: |
---|
| 721 | result *= item |
---|
| 722 | return result |
---|
[9593] | 723 | |
---|
[10677] | 724 | |
---|
[9593] | 725 | class NullHandler(logging.Handler): |
---|
| 726 | """A logging NullHandler. |
---|
| 727 | |
---|
| 728 | Does not log anything. Useful if you want to shut up a log. |
---|
| 729 | |
---|
| 730 | Defined here for backwards compatibility with Python < 2.7. |
---|
| 731 | """ |
---|
| 732 | def emit(self, record): |
---|
| 733 | pass |
---|
[10676] | 734 | |
---|
| 735 | |
---|
| 736 | def check_csv_charset(iterable): |
---|
| 737 | """Check contents of `iterable` regarding valid CSV encoding. |
---|
| 738 | |
---|
| 739 | `iterable` is expected to be an iterable on _rows_ (not |
---|
| 740 | chars). This is true for instance for |
---|
| 741 | filehandlers. `zope.publisher.browser.FileUpload` instances are |
---|
| 742 | _not_ iterable, unfortunately. |
---|
| 743 | |
---|
| 744 | Returns line num of first illegal char or ``None``. Line nums |
---|
| 745 | start counting with 1 (not zero). |
---|
| 746 | """ |
---|
| 747 | linenum = 1 |
---|
| 748 | reader = csv.DictReader(iterable) |
---|
| 749 | try: |
---|
| 750 | for row in reader: |
---|
| 751 | linenum += 1 |
---|
| 752 | except UnicodeDecodeError: |
---|
| 753 | return linenum |
---|
| 754 | except: |
---|
| 755 | return linenum + 1 |
---|
| 756 | return None |
---|