#!/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.

"""A Django template tag library containing forms helpers.

"""

__authors__ = [

  '"Todd Larsen" <tlarsen@google.com>',

  '"Pawel Solyga" <pawel.solyga@gmail.com>',

  '"Sverre Rabbelier" <sverre@rabbelier.nl>',

  ]

from google.appengine.ext import db

from django import template

from django.forms import forms as forms_in

from django.utils.encoding import force_unicode

from django.utils.html import escape

register = template.Library()

@register.inclusion_tag('soc/templatetags/_field_as_table_row.html')

def field_as_table_row(field):

  """Prints a newforms field as a table row.

  This function actually does very little, simply passing the supplied

  form field instance in a simple context used by the _field_as_table_row.html

  template (which is actually doing all of the work).

  See soc/templates/soc/templatetags/_field_as_table_row.html for the CSS

  styles used by this template tag.

  Usage:

    {% load forms_helpers %}

    ...

    <table>

     {% field_as_table_row form.fieldname %}

     ...

    </table>

  Args:

    field: a Django newforms field instance

  Returns:

    a simple context containing the supplied newforms field instance:

      { 'field': field }

  """

  return {'field': field}

@register.inclusion_tag('soc/templatetags/_readonly_field_as_table_row.html')

def readonly_field_as_table_row(field_label, field_value):

  """Prints a field value and it's verbose name as a table row.

  This function actually does very little, simply passing the 

  supplied field_label and field_value in a simple context used by the 

  _readonly_field_as_table_row.html template (which is actually 

  doing all of the work).

  See soc/templates/soc/templatetags/_readonly_field_as_table_row.html for

  the CSS styles used by this template tag.

  Usage:

    {% load forms_helpers %}

    ...

    <table>

     {% readonly_field_as_table_row field_label field_value %}

     ...

    </table>

  Args:

    field_label: label of the field to render

    field_value: value of the field to render

  Returns:

    a simple context containing the supplied newforms field instance:

      { 'field_label': field_label',

        'field_value': field_value'}

  """

  return {'field_label': field_label,

          'field_value': field_value}

@register.inclusion_tag('soc/templatetags/_readonly_field_as_twoline_table_row.html')

def readonly_field_as_twoline_table_row(field_label, field_value):

  """See readonly_field_as_table_row().

  """

  return {'field_label': field_label,

          'field_value': field_value}

@register.inclusion_tag(

    'soc/templatetags/_readonly_multiline_field_as_table_row.html')

def readonly_multiline_field_as_table_row(field_label, field_value):

  """See readonly_field_as_table_row, but with a different template tag.

  """

  return {'field_label': field_label,

          'field_value': field_value}

@register.inclusion_tag('soc/templatetags/_as_table.html', takes_context=True)

def as_table(context, form):

  """Outputs a form as a properly formatted html table.

  Args:

    form: the form that should be converted to a table

  """

  return as_table_helper(context, form)

@register.inclusion_tag('soc/templatetags/_as_twoline_table.html',

                        takes_context=True)

def as_twoline_table(context, form):

  """Outputs a form as a properly formatted html table.

  Args:

    form: the form that should be converted to a table

  """

  return as_table_helper(context, form)

def get_reference_url(form, name):

  Args:

    form: the form the field is defined in

    name: the name of the field

  """

  if not hasattr(form, 'Meta'):

    return None

  if not hasattr(form.Meta, 'model'):

    return None

  if not hasattr(form.Meta.model, name):

    return None

  field = getattr(form.Meta.model, name)

  if not isinstance(field, db.ReferenceProperty):

    return None

  return getattr(field, 'redirect_url', None)

def as_table_helper(context, form):

  fields = []

  hidden_fields = []

  hidden_fields_errors = []

  entity = context['entity']

  # Iterate over all fields and prepare it for adding 

  for name, field in form.fields.items():

    bf = forms_in.BoundField(form, field, name)

    reference = None

    if name.endswith('_link_id'):

      reference = get_reference_url(form, name[:-8])

    # If the field is hidden we display it elsewhere

    if not bf.is_hidden:

      example_text = ''

      if hasattr(field, 'example_text'):

        example_text = force_unicode(field.example_text)

      item = (bf, field.required, example_text, reference)

      fields.append(item)

    else:

      hidden_fields.append(unicode(bf))

      for e in bf.errors:

        item = (name, force_unicode(e))

        hidden_fields_errors.append(item)

  context.update({

      'top_errors': form.non_field_errors() or '',

      'hidden_field_errors': hidden_fields_errors or '',

      'fields': fields or '',

      'hidden_fields': hidden_fields or '',

      })

  return context

@register.inclusion_tag('soc/templatetags/_as_table_row.html',

                        takes_context=True)

def as_table_row(context, field, required, example_text, reference):

  """Outputs a field as a properly formatted html row.

  Args:

    form: the form that the row belongs to

    field: the field that should be converted to a row

    required: whether the field is required

    example_text: the example_text for this row

    reference: the entity_suffix if the field is a reference

  """

  return as_table_row_helper(context, field, required, example_text, reference)

@register.inclusion_tag('soc/templatetags/_as_twoline_table_row.html',

                        takes_context=True)

def as_twoline_table_row(context, field, required, example_text, reference):

  """See as_table_row().

  """

  return as_table_row_helper(context, field, required, example_text, reference)

def as_table_row_helper(context, field, required, example_text, reference):

  """See as_table_row().

  """

  # Escape and cache in local variable.

  errors = [force_unicode(escape(error)) for error in field.errors]

  form = context['form']

  entity = context['entity']

  if reference:

    from soc.views.helper import redirects

    params = {

        'url_name': reference,

        'field_name': field.name,

        'return_url': context['return_url']

        }

    select_url = redirects.getSelectRedirect(entity, params)

  if field.label:

    label = escape(force_unicode(field.label))

    # Only add the suffix if the label does not end in punctuation.

    if form.label_suffix and (label[-1] not in ':?.!'):

      label += form.label_suffix

    label = field.label_tag(label) or ''

  field_class_type = 'formfield%slabel' % ('error' if errors else '')

  help_text = field.help_text

  context.update({

      'help_text': force_unicode(help_text) if help_text else '',

      'field_class_type': field_class_type,

      'label': force_unicode(label) if field.label else '',

      'field': unicode(field),

      'required': required,

      'example_text': example_text,

      'select_url': select_url if reference else None,

      'errors': errors,

      })

  return context