+
−#!/usr/bin/python2.5
+
−#
+
−# Copyright 2008 the Melange authors.
+
−#
+
−# Licensed under the Apache License, Version 2.0 (the "License");
+
−# you may not use this file except in compliance with the License.
+
−# You may obtain a copy of the License at
+
−#
+
−#   http://www.apache.org/licenses/LICENSE-2.0
+
−#
+
−# Unless required by applicable law or agreed to in writing, software
+
−# distributed under the License is distributed on an "AS IS" BASIS,
+
−# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+
−# See the License for the specific language governing permissions and
+
−# limitations under the License.
+
−
+
−"""Helpers used to display various views that are forms.
+
−"""
+
−
+
−__authors__ = [
+
−  '"Chen Lunpeng" <forever.clp@gmail.com>',
+
−  '"Todd Larsen" <tlarsen@google.com>',
+
−  '"Pawel Solyga" <pawel.solyga@gmail.com>',
+
−  ]
+
−
+
−
+
−from google.appengine.ext.db import djangoforms
+
−
+
−from django import forms
+
−from django.forms import forms as forms_in
+
−from django.forms import util
+
−from django.utils import encoding
+
−from django.utils import safestring
+
−from django.utils.encoding import force_unicode
+
−from django.utils.html import escape
+
−from django.utils.safestring import mark_safe
+
−
+
−
+
−class CustomErrorList(util.ErrorList):
+
−  """A collection of errors that knows how to display itself in various formats.
+
−  
+
−  This class has customized as_text method output which puts errors inside <span>
+
−  with formfielderrorlabel class.
+
−  """
+
−  def __unicode__(self):
+
−    return self.as_text()
+
−  
+
−  def as_text(self):
+
−    """Returns error list rendered as text inside <span>."""
+
−    if not self:
+
−      return u''
+
−    errors_text = u'\n'.join([u'%s' % encoding.force_unicode(e) for e in self])
+
−    return u'<span class="formfielderrorlabel">%(errors)s</span><br />' % \
+
−        {'errors': errors_text}
+
−
+
−
+
−class DbModelForm(djangoforms.ModelForm):
+
−  """Subclass of Django ModelForm that fixes some label and help_text issues.
+
−
+
−  The default behavior of ModelForm is to use the verbose_name in all
+
−  lowercase, capitalizing only the first character, as the displayed field
+
−  label.  This class uses verbose_name unaltered as the visible field label
+
−  instead.
+
−
+
−  The Property classes used by the App Engine Datastore do not have a
+
−  help_text parameter to their constructor.  In a Model class, a help_text
+
−  attribute *can* be added to the property after it is created, but the
+
−  help text will not be automatically passed along to the Django ModelForm.
+
−  This class detects the presence of a help_text attribute and adds it to
+
−  the corresponding form field object.
+
−
+
−  ugettext_lazy() proxies used for internationalization in the Model will
+
−  still work correctly with this new behavior, as long as the original
+
−  strings are used as the translation keys.
+
−  """
+
−
+
−  def __init__(self, *args, **kwargs):
+
−    """Fixes label and help_text issues after parent initialization.
+
−
+
−    Args:
+
−      *args, **kwargs:  passed through to parent __init__() constructor
+
−    """
+
−    super(DbModelForm, self).__init__(*args, **kwargs)
+
−
+
−    for field_name in self.fields.iterkeys():
+
−      # Since fields can be added only to the ModelForm subclass, check to
+
−      # see if the Model has a corresponding field first.
+
−      if hasattr(self.Meta.model, field_name):
+
−        model_prop = getattr(self.Meta.model, field_name)
+
−
+
−        # Check if the Model property defined verbose_name, and copy that
+
−        # verbatim to the corresponding field label.
+
−        if hasattr(model_prop, 'verbose_name'):
+
−          self.fields[field_name].label = model_prop.verbose_name
+
−
+
−        # Check if the Model property added help_text, and copy that verbatim
+
−        # to the corresponding field help_text.
+
−        if hasattr(model_prop, 'help_text'):
+
−          self.fields[field_name].help_text = model_prop.help_text
+
−
+
−
+
−class BaseForm(DbModelForm):
+
−  """Subclass of DbModelForm that extends as_table HTML output.
+
−  
+
−  BaseForm has additional class names in HTML tags for label and help text
+
−  and those can be used in CSS files for look customization. The way the Form
+
−  prints itself also has changed. Help text is displayed in the same row as 
+
−  label and input.
+
−  """
+
−  
+
−  DEF_NORMAL_ROW = u'<tr title="%(help_text)s"><td class=' \
+
−      '"%(field_class_type)s">%(label)s</td><td>' \
+
−      '%(errors)s%(field)s%(required)s</td></tr>'
+
−  DEF_ERROR_ROW = u'<tr><td>&nbsp;</td><td class="formfielderror">%s</td></tr>'
+
−  DEF_ROW_ENDER = '</td></tr>'
+
−  DEF_REQUIRED_HTML = u'<td class="formfieldrequired">(required)</td>'
+
−  DEF_HELP_TEXT_HTML = u'%s'
+
−
+
−  def __init__(self, *args, **kwargs):
+
−    """Parent class initialization.
+
−
+
−    Args:
+
−      *args, **kwargs:  passed through to parent __init__() constructor
+
−    """
+
−    super(BaseForm, self).__init__(error_class=CustomErrorList, *args, **kwargs)
+
−  
+
−  def _html_output_with_required(self, normal_row, error_row, row_ender, 
+
−          help_text_html, required_html, errors_on_separate_row):
+
−    """Helper function for outputting HTML.
+
−    
+
−    Used by as_table(), as_ul(), as_p(). Displays information
+
−    about required fields.
+
−    """
+
−    # Errors that should be displayed above all fields.
+
−    top_errors = self.non_field_errors()
+
−    output, hidden_fields = [], []
+
−    for name, field in self.fields.items():
+
−      bf = forms_in.BoundField(self, field, name)
+
−      # Escape and cache in local variable.
+
−      bf_errors = self.error_class([escape(error) for error in bf.errors])
+
−      if bf.is_hidden:
+
−        if bf_errors:
+
−          top_errors.extend([u'(Hidden field %s) %s' % \
+
−              (name, force_unicode(e)) for e in bf_errors])
+
−        hidden_fields.append(unicode(bf))
+
−      else:
+
−        if errors_on_separate_row and bf_errors:
+
−          output.append(error_row % force_unicode(bf_errors))
+
−
+
−        if bf.label:
+
−          label = escape(force_unicode(bf.label))
+
−          # Only add the suffix if the label does not end in
+
−          # punctuation.
+
−          if self.label_suffix:
+
−            if label[-1] not in ':?.!':
+
−              label += self.label_suffix
+
−          label = bf.label_tag(label) or ''
+
−        else:
+
−          label = ''
+
−        if field.help_text:
+
−          help_text = help_text_html % force_unicode(field.help_text)
+
−        else:
+
−          help_text = u''
+
−
+
−        if bf_errors:
+
−          field_class_type = u'formfielderrorlabel'
+
−        else:
+
−          field_class_type = u'formfieldlabel'
+
−
+
−        if field.required:
+
−          required = required_html
+
−        else:
+
−          required = u''
+
−        
+
−        if errors_on_separate_row and bf_errors:
+
−          errors = u''
+
−        else:
+
−          errors = force_unicode(bf_errors)
+
−        
+
−        output.append(normal_row % {'field_class_type': field_class_type,
+
−                                    'errors': errors, 
+
−                                    'label': force_unicode(label), 
+
−                                    'field': unicode(bf),
+
−                                    'required': required,
+
−                                    'help_text': help_text})
+
−    if top_errors:
+
−      output.insert(0, error_row % force_unicode(top_errors))
+
−    if hidden_fields: # Insert any hidden fields in the last row.
+
−      str_hidden = u''.join(hidden_fields)
+
−      if output:
+
−        last_row = output[-1]
+
−        # Chop off the trailing row_ender (e.g. '</td></tr>') and
+
−        # insert the hidden fields.
+
−        if not last_row.endswith(row_ender):
+
−          # This can happen in the as_p() case (and possibly others
+
−          # that users write): if there are only top errors, we may
+
−          # not be able to conscript the last row for our purposes,
+
−          # so insert a new, empty row.
+
−          last_row = normal_row % {'errors': '', 'label': '',
+
−                                   'field': '', 'help_text': ''}
+
−          output.append(last_row)
+
−        output[-1] = last_row[:-len(row_ender)] + str_hidden + row_ender
+
−      else:
+
−        # If there aren't any rows in the output, just append the
+
−        # hidden fields.
+
−        output.append(str_hidden)
+
−    return mark_safe(u'\n'.join(output))
+
−
+
−  def as_table(self):
+
−    """Returns form rendered as HTML <tr> rows -- with no <table></table>."""
+
−    
+
−    return self._html_output_with_required(self.DEF_NORMAL_ROW,
+
−                                           self.DEF_ERROR_ROW,
+
−                                           self.DEF_ROW_ENDER,
+
−                                           self.DEF_HELP_TEXT_HTML,
+
−                                           self.DEF_REQUIRED_HTML, True)
+
−
+
−
+
−class SelectQueryArgForm(forms.Form):
+
−  """URL query argument change control implemented as a Django form.
+
−  """
+
−
+
−  ONCHANGE_JAVASCRIPT_FMT = '''
+
−<script type="text/javascript"> 
+
−  function changeArg_%(arg_name)s(item) 
+
−  {
+
−    var idx=item.selectedIndex;
+
−    item.selected=true;
+
−    var value=item.value 
+
−    var url = location.href 
+
−    var reg = /%(arg_name)s=\d+/ 
+
−    url = url.replace(reg, "%(arg_name)s="+value) 
+
−    if(url.match(reg))
+
−      document.location.href = url 
+
−   else
+
−      document.location.href = "%(page_path)s?%(arg_name)s="+value; 
+
−  }
+
−</script>
+
−'''
+
−
+
−  def __init__(self, page_path, arg_name, choices, field_name,
+
−               *form_args, **form_kwargs):
+
−    """
+
−    Args:
+
−      page_path: (usually request.path)
+
−      arg_name: the URL query parameter that determines which choice is
+
−        selected in the selection control
+
−      choices: list (or tuple) of value/label string two-tuples, for example:
+
−        (('10', '10 items per page'), ('25', '25 items per page'))
+
−      field_name: name of the selection field in the form
+
−      *form_args: positional arguments passed on to the Form base
+
−        class __init__()
+
−      *form_kwargs: keyword arguments passed on to the Form base
+
−        class __init__()
+
−    """
+
−    super(SelectQueryArgForm, self).__init__(*form_args, **form_kwargs)
+
−    
+
−    self._script = safestring.mark_safe(self.ONCHANGE_JAVASCRIPT_FMT % {
+
−        'arg_name': arg_name, 'page_path': page_path,})
+
− 
+
−    onchange_js_call = 'changeArg_%s(this)' % arg_name
+
−    
+
−    self.fields[field_name] = forms.ChoiceField(
+
−        label='', choices=choices,
+
−        widget=forms.widgets.Select(attrs={'onchange': onchange_js_call}))
+
−      
+
−  def as_table(self):
+
−    """Returns form rendered as HTML <tr> rows -- with no <table></table>.
+
−    
+
−    Prepends <script> section with onchange function included.
+
−    """
+
−    return self._script + super(SelectQueryArgForm, self).as_table()
+
−
+
−  def as_ul(self):
+
−    """Returns form rendered as HTML <li> list items -- with no <ul></ul>.
+
−    
+
−    Prepends <script> section with onchange function included.
+
−    """
+
−    return self._script + super(SelectQueryArgForm, self).as_ul()
+
−
+
−  def as_p(self):
+
−    """Returns form rendered as HTML <p> paragraphs.
+
−    
+
−    Prepends <script> section with onchange function included.
+
−    """
+
−    return self._script + super(SelectQueryArgForm, self).as_p()
+
−
+
−
+
−DEF_SELECT_QUERY_ARG_FIELD_NAME_FMT = 'select_query_arg_%(arg_name)s'
+
−
+
−def makeSelectQueryArgForm(
+
−    request, arg_name, initial_value, choices,
+
−    field_name_fmt=DEF_SELECT_QUERY_ARG_FIELD_NAME_FMT):
+
−  """Wrapper that creates a customized SelectQueryArgForm.
+
−
+
−  Args:
+
−    request: the standard Django HTTP request object
+
−    arg_name: the URL query parameter that determines which choice is
+
−      selected in the selection control
+
−    initial_value: the initial value of the selection control
+
−    choices: list (or tuple) of value/label string two-tuples, for example:
+
−      (('10', '10 items per page'), ('25', '25 items per page'))
+
−    field_name_fmt: optional form field name format string; default is
+
−      DEF_SELECT_QUERY_ARG_FIELD_NAME_FMT; contains these named format
+
−      specifiers:
+
−        arg_name: replaced with the arg_name argument
+
−
+
−  Returns:
+
−    a Django form implementing a query argument selection control, for
+
−    insertion into a template
+
−  """
+
−  field_name = field_name_fmt % {'arg_name': arg_name}
+
−  return SelectQueryArgForm(request.path, arg_name, choices, field_name,
+
−                            initial={field_name: initial_value})