diff options
Diffstat (limited to 'stackexchange/parse_models.py')
| -rw-r--r-- | stackexchange/parse_models.py | 225 |
1 files changed, 0 insertions, 225 deletions
diff --git a/stackexchange/parse_models.py b/stackexchange/parse_models.py deleted file mode 100644 index 64796e57..00000000 --- a/stackexchange/parse_models.py +++ /dev/null @@ -1,225 +0,0 @@ -from xml.etree import ElementTree as et -import sys -import re -import os -if __name__ != '__main__':#hack do not import models if run as script - from django.db import models -from datetime import datetime - -table_prefix = ''#StackExchange or something, if needed -date_time_format = '%Y-%m-%dT%H:%M:%S' #note that fractional part of second is lost -time_re = re.compile(r'(\.[\d]+)?$') -loader_app_name = os.path.dirname(__file__) - -types = { - 'unsignedByte':'models.IntegerField', - 'FK':'models.ForeignKey', - 'PK':'models.IntegerField', - 'string':'models.CharField', - 'text':'models.TextField', - 'int':'models.IntegerField', - 'boolean':'models.NullBooleanField', - 'dateTime':'models.DateTimeField', - 'base64Binary':'models.TextField', - 'double':'models.IntegerField', -} - -def camel_to_python(camel): - """http://stackoverflow.com/questions/1175208/ - """ - s1 = re.sub('(.)([A-Z][a-z]+)', r'\1_\2', camel) - return re.sub('([a-z0-9])([A-Z])', r'\1_\2', s1).lower() - -def singular(word): - if word.endswith('s'): - return word[:-1] - else: - return word - -def get_table_name(name): - """Determine db table name - from the basename of the .xml file - """ - out = table_prefix - if name.find('2') == -1: - out += singular(name) - else: - bits = name.split('2') - bits = map(singular, bits) - out += '2'.join(bits) - return out - -class DjangoModel(object): - def __init__(self, name): - self.name = get_table_name(name) - self.fields = [] - def add_field(self,field): - field.table = self - self.fields.append(field) - def __str__(self): - out = 'class %s(models.Model):\n' % self.name - for f in self.fields: - out += ' %s\n' % str(f) - return out - -class DjangoField(object): - def __init__(self, name, type, restriction = None): - self.name = camel_to_python(name) - if self.name == 'class': - self.name = 'class_type'#work around python keyword - self.type = type - self.table = None - self.restriction = restriction - self.relation = None - - def __str__(self): - out = '%s = %s(' % (self.name, types[self.type]) - if self.type == 'FK': - out += "'%s'" % self.relation - out += ", related_name='%s_by_%s_set'" % (self.table.name, self.name) - out += ', null=True'#nullable to make life easier - elif self.type == 'PK': - out += 'primary_key=True' - elif self.restriction != -1: - if self.type == 'string': - out += 'max_length=%s' % self.restriction - out += ', null=True' - else: - raise Exception('restriction (max_length) supported only for string type') - else: - out += 'null=True' - out += ')' - return out - - def get_type(self): - return self.type - -class DjangoPK(DjangoField): - def __init__(self): - self.name = 'id' - self.type = 'PK' - -class DjangoFK(DjangoField): - def __init__(self, source_name): - bits = source_name.split('Id') - if len(bits) == 2 and bits[1] == '': - name = bits[0] - super(DjangoFK, self).__init__(name, 'FK') - self.set_relation(name) - - def set_relation(self, name): - """some relations need to be mapped - to actual tables - """ - self.relation = table_prefix - if name.endswith('User'): - self.relation += 'User' - elif name.endswith('Post'): - self.relation += 'Post' - elif name in ('AcceptedAnswer','Parent'): - self.relation = 'self' #self-referential Post model - else: - self.relation += name - def get_relation(self): - return self.relation - -def get_col_type(col): - type = col.get('type') - restriction = -1 - if type == None: - type_e = col.find('.//simpleType/restriction') - type = type_e.get('base') - try: - restriction = int(type_e.getchildren()[0].get('value')) - except: - restriction = -1 - if restriction > 400: - type = 'text' - restriction = -1 - return type, restriction - -def make_field_from_xml_tree(xml_element): - """used by the model parser - here we need to be detailed about field types - because this defines the database schema - """ - name = xml_element.get('name') - if name == 'LinkedVoteId':#not used - return None - if name == 'Id': - field = DjangoPK() - elif name.endswith('Id') and name not in ('OpenId','PasswordId'): - field = DjangoFK(name) - elif name.endswith('GUID'): - field = DjangoField(name, 'string', 64) - else: - type, restriction = get_col_type(xml_element) - field = DjangoField(name, type, restriction) - return field - -def parse_field_name(input): - """used by the data reader - - The problem is that I've scattered - code for determination of field name over three classes: - DjangoField, DjangoPK and DjangoFK - so the function actually cretes fake field objects - many time over - """ - if input == 'Id': - return DjangoPK().name - elif input in ('OpenId', 'PasswordId'): - return DjangoField(input, 'string', 7).name#happy fake field - elif input.endswith('Id'): - return DjangoFK(input).name#real FK field - else: - return DjangoField(input, 'string', 7).name#happy fake field - -def parse_value(input, field_object): - if isinstance(field_object, models.ForeignKey): - try: - id = int(input) - except: - raise Exception('non-numeric foreign key %s' % input) - related_model = field_object.rel.to - try: - return related_model.objects.get(id=id) - except related_model.DoesNotExist: - obj = related_model(id=id) - obj.save()#save fake empty object - return obj - elif isinstance(field_object, models.IntegerField): - try: - return int(input) - except: - raise Exception('expected integer, found %s' % input) - elif isinstance(field_object, models.CharField): - return input - elif isinstance(field_object, models.TextField): - return input - elif isinstance(field_object, models.BooleanField): - try: - return bool(input) - except: - raise Exception('boolean value expected %s found' % input) - elif isinstance(field_object, models.DateTimeField): - input = time_re.sub('', input) - try: - return datetime.strptime(input, date_time_format) - except: - raise Exception('datetime expected "%s" found' % input) - -print 'from django.db import models' -for file in sys.argv: - if '.xsd' in file: - tname = os.path.basename(file).replace('.xsd','') - tree = et.parse(file) - - model = DjangoModel(tname) - - row = tree.find('.//sequence') - for col in row.getchildren(): - field = make_field_from_xml_tree(col) - if field: - model.add_field(field) - print model |