1 #

     2 # Copyright (c) 2008-2015 Thierry Florac <tflorac AT ulthar.net>

     3 # All Rights Reserved.

     4 #

     5 # This software is subject to the provisions of the Zope Public License,

     6 # Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.

     7 # THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED

     8 # WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

     9 # WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS

    10 # FOR A PARTICULAR PURPOSE.

    11 #

    12 

    13 __docformat__ = 'restructuredtext'

    14 

    15 

    16 # import standard library

    17 from html import escape

    18 

    19 # import interfaces

    20 from pyams_zodbbrowser.interfaces import IValueRenderer

    21 

    22 # import packages

    23 

    24 

    25 ADDED = 'added'

    26 REMOVED = 'removed'

    27 CHANGED = 'changed to'

    28 

    29 

    30 def compareDicts(new, old):

    31     """Compare two state dictionaries, return dict."""

    32     diffs = {}

    33     for key, value in list(new.items()):

    34         if key not in old:

    35             diffs[key] = (ADDED, value, None)

    36         elif old[key] != value:

    37             diffs[key] = (CHANGED, value, old[key])

    38     for key, value in list(old.items()):

    39         if key not in new:

    40             diffs[key] = (REMOVED, None, value)

    41     return diffs

    42 

    43 

    44 def isascii(s):

    45     """See if the string can be safely converted to unicode."""

    46     try:

    47         s.encode('ascii')

    48     except UnicodeError:

    49         return False

    50     else:

    51         return True

    52 

    53 

    54 def compareTuples(new, old):

    55     """Compare two tuples.

    56 

    57     Return (common_prefix, middle_of_old, middle_of_new, common_suffix)

    58     """

    59     first = 0

    60     for oldval, newval in zip(old, new):

    61         if oldval != newval:

    62             break

    63         first += 1

    64     last = 0

    65     for oldval, newval in zip(reversed(old[first:]), reversed(new[first:])):

    66         if oldval != newval:

    67             break

    68         last += 1

    69     return (old[:first],

    70             old[first:len(old) - last],

    71             new[first:len(new) - last],

    72             old[len(old) - last:])

    73 

    74 

    75 def compareTuplesHTML(new, old, tid=None, indent=''):

    76     """Compare two tuples, return HTML."""

    77     html = [indent + '<div class="diff">\n']

    78     prefix, removed, added, suffix = compareTuples(new, old)

    79     if len(prefix) > 0:

    80         html.append(indent + '  <div class="diffitem %s">\n' % 'same')

    81         if len(prefix) == 1:

    82             html.append(indent + '    first item kept the same\n')

    83         else:

    84             html.append(indent + '    first %d items kept the same\n' % len(prefix))

    85         html.append(indent + '  </div>\n')

    86     for oldval in removed:

    87         html.append(indent + '  <div class="diffitem %s">\n' % REMOVED)

    88         html.append(indent + '    %s %s\n' % (

    89             REMOVED, IValueRenderer(oldval).render(tid)))

    90         html.append(indent + '  </div>\n')

    91     for newval in added:

    92         html.append(indent + '  <div class="diffitem %s">\n' % ADDED)

    93         html.append(indent + '    %s %s\n' % (

    94             ADDED, IValueRenderer(newval).render(tid)))

    95         html.append(indent + '  </div>\n')

    96     if len(suffix) > 0:

    97         html.append(indent + '  <div class="diffitem %s">\n' % 'same')

    98         if len(suffix) == 1:

    99             html.append(indent + '    last item kept the same\n')

   100         else:

   101             html.append(indent + '    last %d items kept the same\n' % len(suffix))

   102         html.append(indent + '  </div>\n')

   103     html.append(indent + '</div>\n')

   104     return ''.join(html)

   105 

   106 

   107 def compareDictsHTML(new, old, tid=None, indent=''):

   108     """Compare two state dictionaries, return HTML."""

   109     html = [indent + '<div class="diff">\n']

   110     diff = compareDicts(new, old)

   111     for key, (action, newvalue, oldvalue) in sorted(list(diff.items()),

   112                                                     key=lambda k_v: (str(type(k_v[0])), k_v[0])):

   113         what = action.split()[0]

   114         html.append(indent + '  <div class="diffitem %s">\n' % escape(what))

   115         if isinstance(key, str) and isascii(key):

   116             html.append(indent + '    <strong>%s</strong>: ' % escape(key))

   117         else:

   118             html.append(indent + '    <strong>%s</strong>: ' % IValueRenderer(key).render(tid))

   119         if (action == CHANGED and isinstance(oldvalue, dict) and isinstance(newvalue, dict)):

   120             html.append('dictionary changed:\n')

   121             html.append(compareDictsHTML(newvalue, oldvalue, tid, indent=indent + '    '))

   122         elif (action == CHANGED and isinstance(oldvalue, tuple) and isinstance(newvalue, tuple)):

   123             html.append('tuple changed:\n')

   124             html.append(compareTuplesHTML(newvalue, oldvalue, tid, indent=indent + '    '))

   125         else:

   126             html.append(action)

   127             html.append(' ')

   128             if action == REMOVED:

   129                 value = oldvalue

   130             else:

   131                 value = newvalue

   132             html.append(IValueRenderer(value).render(tid))

   133             html.append('\n')

   134         html.append(indent + '  </div>\n')

   135     html.append(indent + '</div>\n')

   136     return ''.join(html)