59 lines
1.5 KiB
Python
59 lines
1.5 KiB
Python
"""
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Provides a django model field to store a signature captured
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with jSignature jQuery plugin
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"""
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import json
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from django.db import models
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from django.core.exceptions import ValidationError
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from .forms import (
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JSignatureField as JSignatureFormField,
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JSIGNATURE_EMPTY_VALUES,
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)
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try:
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from django.utils import six
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string_types = six.string_types
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except ImportError:
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string_types = str
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class JSignatureField(models.Field):
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"""
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A model field handling a signature captured with jSignature
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"""
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description = "A signature captured with jSignature"
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def get_internal_type(self):
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return 'TextField'
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def to_python(self, value):
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"""
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Validates that the input can be red as a JSON object. Returns a Python
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datetime.date object.
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"""
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if value in JSIGNATURE_EMPTY_VALUES:
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return None
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elif isinstance(value, list):
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return value
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try:
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return json.loads(value)
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except ValueError:
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raise ValidationError('Invalid JSON format.')
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def get_prep_value(self, value):
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if value in JSIGNATURE_EMPTY_VALUES:
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return None
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elif isinstance(value, string_types):
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return value
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elif isinstance(value, list):
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return json.dumps(value)
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raise ValidationError('Invalid format.')
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def formfield(self, **kwargs):
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defaults = {'form_class': JSignatureFormField}
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defaults.update(kwargs)
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return super(JSignatureField, self).formfield(**defaults)
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