diff --git a/re2o/mixins.py b/re2o/mixins.py
index 1432d7d9..307074ff 100644
--- a/re2o/mixins.py
+++ b/re2o/mixins.py
@@ -38,7 +38,7 @@ class FormRevMixin(object):
     def save(self, *args, **kwargs):
         if reversion.get_comment() != "" and self.changed_data != []:
             reversion.set_comment(reversion.get_comment() + ",%s" % ', '.join(field for field in self.changed_data))
-        elif self.changed_data != None:
+        elif self.changed_data:
             reversion.set_comment("Champs modifié(s) : %s" % ', '.join(field for field in self.changed_data))
         return super(FormRevMixin, self).save(*args, **kwargs)
 
diff --git a/topologie/management/commands/graph_topo.py b/topologie/management/commands/graph_topo.py
new file mode 100644
index 00000000..b5d61a80
--- /dev/null
+++ b/topologie/management/commands/graph_topo.py
@@ -0,0 +1,228 @@
+# -*- coding: utf-8 -*-
+import sys
+import json
+
+import six
+from django.conf import settings
+from django.core.management.base import BaseCommand, CommandError
+
+from topologie.management.modelviz import ModelGraph, generate_dot
+from django_extensions.management.utils import signalcommand
+
+try:
+    import pygraphviz
+    HAS_PYGRAPHVIZ = True
+except ImportError:
+    HAS_PYGRAPHVIZ = False
+
+try:
+    try:
+        import pydotplus as pydot
+    except ImportError:
+        import pydot
+    HAS_PYDOT = True
+except ImportError:
+    HAS_PYDOT = False
+
+
+class Command(BaseCommand):
+    help = "Creates a GraphViz dot file for the specified app names. You can pass multiple app names and they will all be combined into a single model. Output is usually directed to a dot file."
+
+    can_import_settings = True
+
+    def __init__(self, *args, **kwargs):
+        """Allow defaults for arguments to be set in settings.GRAPH_MODELS.
+        Each argument in self.arguments is a dict where the key is the
+        space-separated args and the value is our kwarg dict.
+        The default from settings is keyed as the long arg name with '--'
+        removed and any '-' replaced by '_'.
+        """
+        self.arguments = {
+            '--pygraphviz': {
+                'action': 'store_true', 'dest': 'pygraphviz',
+                'help': 'Use PyGraphViz to generate the image.'},
+
+            '--pydot': {'action': 'store_true', 'dest': 'pydot',
+                        'help': 'Use PyDot(Plus) to generate the image.'},
+
+            '--disable-fields -d': {
+                'action': 'store_true', 'dest': 'disable_fields',
+                'help': 'Do not show the class member fields'},
+
+            '--group-models -g': {
+                'action': 'store_true', 'dest': 'group_models',
+                'help': 'Group models together respective to their '
+                'application'},
+
+            '--all-applications -a': {
+                'action': 'store_true', 'dest': 'all_applications',
+                'help': 'Automatically include all applications from '
+                'INSTALLED_APPS'},
+
+            '--output -o': {
+                'action': 'store', 'dest': 'outputfile',
+                'help': 'Render output file. Type of output dependend on file '
+                'extensions. Use png or jpg to render graph to image.'},
+
+            '--layout -l': {
+                'action': 'store', 'dest': 'layout', 'default': 'dot',
+                'help': 'Layout to be used by GraphViz for visualization. '
+                'Layouts: circo dot fdp neato nop nop1 nop2 twopi'},
+
+            '--verbose-names -n': {
+                'action': 'store_true', 'dest': 'verbose_names',
+                'help': 'Use verbose_name of models and fields'},
+
+            '--language -L': {
+                'action': 'store', 'dest': 'language',
+                'help': 'Specify language used for verbose_name localization'},
+
+            '--exclude-columns -x': {
+                'action': 'store', 'dest': 'exclude_columns',
+                'help': 'Exclude specific column(s) from the graph. '
+                'Can also load exclude list from file.'},
+
+            '--exclude-models -X': {
+                'action': 'store', 'dest': 'exclude_models',
+                'help': 'Exclude specific model(s) from the graph. Can also '
+                'load exclude list from file. Wildcards (*) are allowed.'},
+
+            '--include-models -I': {
+                'action': 'store', 'dest': 'include_models',
+                'help': 'Restrict the graph to specified models. Wildcards '
+                '(*) are allowed.'},
+
+            '--inheritance -e': {
+                'action': 'store_true', 'dest': 'inheritance', 'default': True,
+                'help': 'Include inheritance arrows (default)'},
+
+            '--no-inheritance -E': {
+                'action': 'store_false', 'dest': 'inheritance',
+                'help': 'Do not include inheritance arrows'},
+
+            '--hide-relations-from-fields -R': {
+                'action': 'store_false', 'dest': 'relations_as_fields',
+                'default': True,
+                'help': 'Do not show relations as fields in the graph.'},
+
+            '--disable-sort-fields -S': {
+                'action': 'store_false', 'dest': 'sort_fields',
+                'default': True, 'help': 'Do not sort fields'},
+
+            '--json': {'action': 'store_true', 'dest': 'json',
+                       'help': 'Output graph data as JSON'}
+        }
+
+        defaults = getattr(settings, 'GRAPH_MODELS', None)
+
+        if defaults:
+            for argument in self.arguments:
+                arg_split = argument.split(' ')
+                setting_opt = arg_split[0].lstrip('-').replace('-', '_')
+                if setting_opt in defaults:
+                    self.arguments[argument]['default'] = defaults[setting_opt]
+
+        super(Command, self).__init__(*args, **kwargs)
+
+    def add_arguments(self, parser):
+        """Unpack self.arguments for parser.add_arguments."""
+        parser.add_argument('app_label', nargs='*')
+        for argument in self.arguments:
+            parser.add_argument(*argument.split(' '),
+                                **self.arguments[argument])
+
+    @signalcommand
+    def handle(self, *args, **options):
+        args = options['app_label']
+        if len(args) < 1 and not options['all_applications']:
+            raise CommandError("need one or more arguments for appname")
+
+        use_pygraphviz = options.get('pygraphviz', False)
+        use_pydot = options.get('pydot', False)
+        use_json = options.get('json', False)
+        if use_json and (use_pydot or use_pygraphviz):
+            raise CommandError("Cannot specify --json with --pydot or --pygraphviz")
+
+        cli_options = ' '.join(sys.argv[2:])
+        graph_models = ModelGraph(args, cli_options=cli_options, **options)
+        graph_models.generate_graph_data()
+        graph_data = graph_models.get_graph_data(as_json=use_json)
+        if use_json:
+            self.render_output_json(graph_data, **options)
+            return
+
+        dotdata = generate_dot(graph_data)
+        if not six.PY3:
+            dotdata = dotdata.encode('utf-8')
+        if options['outputfile']:
+            if not use_pygraphviz and not use_pydot:
+                if HAS_PYGRAPHVIZ:
+                    use_pygraphviz = True
+                elif HAS_PYDOT:
+                    use_pydot = True
+            if use_pygraphviz:
+                self.render_output_pygraphviz(dotdata, **options)
+            elif use_pydot:
+                self.render_output_pydot(dotdata, **options)
+            else:
+                raise CommandError("Neither pygraphviz nor pydotplus could be found to generate the image")
+        else:
+            self.print_output(dotdata)
+
+    def print_output(self, dotdata):
+        if six.PY3 and isinstance(dotdata, six.binary_type):
+            dotdata = dotdata.decode()
+
+        print(dotdata)
+
+    def render_output_json(self, graph_data, **kwargs):
+        output_file = kwargs.get('outputfile')
+        if output_file:
+            with open(output_file, 'wt') as json_output_f:
+                json.dump(graph_data, json_output_f)
+        else:
+            print(json.dumps(graph_data))
+
+    def render_output_pygraphviz(self, dotdata, **kwargs):
+        """Renders the image using pygraphviz"""
+        if not HAS_PYGRAPHVIZ:
+            raise CommandError("You need to install pygraphviz python module")
+
+        version = pygraphviz.__version__.rstrip("-svn")
+        try:
+            if tuple(int(v) for v in version.split('.')) < (0, 36):
+                # HACK around old/broken AGraph before version 0.36 (ubuntu ships with this old version)
+                import tempfile
+                tmpfile = tempfile.NamedTemporaryFile()
+                tmpfile.write(dotdata)
+                tmpfile.seek(0)
+                dotdata = tmpfile.name
+        except ValueError:
+            pass
+
+        graph = pygraphviz.AGraph(dotdata)
+        graph.layout(prog=kwargs['layout'])
+        graph.draw(kwargs['outputfile'])
+
+    def render_output_pydot(self, dotdata, **kwargs):
+        """Renders the image using pydot"""
+        if not HAS_PYDOT:
+            raise CommandError("You need to install pydot python module")
+
+        graph = pydot.graph_from_dot_data(dotdata)
+        if not graph:
+            raise CommandError("pydot returned an error")
+        if isinstance(graph, (list, tuple)):
+            if len(graph) > 1:
+                sys.stderr.write("Found more then one graph, rendering only the first one.\n")
+            graph = graph[0]
+
+        output_file = kwargs['outputfile']
+        formats = ['bmp', 'canon', 'cmap', 'cmapx', 'cmapx_np', 'dot', 'dia', 'emf',
+                   'em', 'fplus', 'eps', 'fig', 'gd', 'gd2', 'gif', 'gv', 'imap',
+                   'imap_np', 'ismap', 'jpe', 'jpeg', 'jpg', 'metafile', 'pdf',
+                   'pic', 'plain', 'plain-ext', 'png', 'pov', 'ps', 'ps2', 'svg',
+                   'svgz', 'tif', 'tiff', 'tk', 'vml', 'vmlz', 'vrml', 'wbmp', 'xdot']
+        ext = output_file[output_file.rfind('.') + 1:]
+        format = ext if ext in formats else 'raw'
+        graph.write(output_file, format=format)
diff --git a/topologie/management/commands/modelviz.py b/topologie/management/commands/modelviz.py
new file mode 100644
index 00000000..0f01bb4d
--- /dev/null
+++ b/topologie/management/commands/modelviz.py
@@ -0,0 +1,405 @@
+# -*- coding: utf-8 -*-
+"""
+modelviz.py - DOT file generator for Django Models
+Based on:
+  Django model to DOT (Graphviz) converter
+  by Antonio Cavedoni <antonio@cavedoni.org>
+  Adapted to be used with django-extensions
+"""
+
+import datetime
+import os
+import re
+
+import six
+from django.apps import apps
+from django.db.models.fields.related import (
+    ForeignKey, ManyToManyField, OneToOneField, RelatedField,
+)
+from django.contrib.contenttypes.fields import GenericRelation
+from django.template import Context, Template, loader
+from django.utils.encoding import force_bytes, force_str
+from django.utils.safestring import mark_safe
+from django.utils.translation import activate as activate_language
+
+
+__version__ = "1.1"
+__license__ = "Python"
+__author__ = "Bas van Oostveen <v.oostveen@gmail.com>",
+__contributors__ = [
+    "Antonio Cavedoni <http://cavedoni.com/>"
+    "Stefano J. Attardi <http://attardi.org/>",
+    "limodou <http://www.donews.net/limodou/>",
+    "Carlo C8E Miron",
+    "Andre Campos <cahenan@gmail.com>",
+    "Justin Findlay <jfindlay@gmail.com>",
+    "Alexander Houben <alexander@houben.ch>",
+    "Joern Hees <gitdev@joernhees.de>",
+    "Kevin Cherepski <cherepski@gmail.com>",
+    "Jose Tomas Tocino <theom3ga@gmail.com>",
+    "Adam Dobrawy <naczelnik@jawnosc.tk>",
+    "Mikkel Munch Mortensen <https://www.detfalskested.dk/>",
+    "Andrzej Bistram <andrzej.bistram@gmail.com>",
+]
+
+
+def parse_file_or_list(arg):
+    if not arg:
+        return []
+    if isinstance(arg, (list, tuple, set)):
+        return arg
+    if ',' not in arg and os.path.isfile(arg):
+        return [e.strip() for e in open(arg).readlines()]
+    return [e.strip() for e in arg.split(',')]
+
+
+class ModelGraph(object):
+    def __init__(self, app_labels, **kwargs):
+        self.graphs = []
+        self.cli_options = kwargs.get('cli_options', None)
+        self.disable_fields = kwargs.get('disable_fields', False)
+        self.include_models = parse_file_or_list(
+            kwargs.get('include_models', "")
+        )
+        self.all_applications = kwargs.get('all_applications', False)
+        self.use_subgraph = kwargs.get('group_models', False)
+        self.verbose_names = kwargs.get('verbose_names', False)
+        self.inheritance = kwargs.get('inheritance', True)
+        self.relations_as_fields = kwargs.get("relations_as_fields", True)
+        self.sort_fields = kwargs.get("sort_fields", True)
+        self.language = kwargs.get('language', None)
+        if self.language is not None:
+            activate_language(self.language)
+        self.exclude_columns = parse_file_or_list(
+            kwargs.get('exclude_columns', "")
+        )
+        self.exclude_models = parse_file_or_list(
+            kwargs.get('exclude_models', "")
+        )
+        if self.all_applications:
+            self.app_labels = [app.label for app in apps.get_app_configs()]
+        else:
+            self.app_labels = app_labels
+
+    def generate_graph_data(self):
+        self.process_apps()
+
+        nodes = []
+        for graph in self.graphs:
+            nodes.extend([e['name'] for e in graph['models']])
+
+        for graph in self.graphs:
+            for model in graph['models']:
+                for relation in model['relations']:
+                    if relation is not None:
+                        if relation['target'] in nodes:
+                            relation['needs_node'] = False
+
+    def get_graph_data(self, as_json=False):
+        now = datetime.datetime.now()
+        graph_data = {
+            'created_at': now.strftime("%Y-%m-%d %H:%M"),
+            'cli_options': self.cli_options,
+            'disable_fields': self.disable_fields,
+            'use_subgraph': self.use_subgraph,
+        }
+
+        if as_json:
+            graph_data['graphs'] = [context.flatten() for context in self.graphs]
+        else:
+            graph_data['graphs'] = self.graphs
+
+        return graph_data
+
+    def add_attributes(self, field, abstract_fields):
+        if self.verbose_names and field.verbose_name:
+            label = force_bytes(field.verbose_name)
+            if label.islower():
+                label = label.capitalize()
+        else:
+            label = field.name
+
+        t = type(field).__name__
+        if isinstance(field, (OneToOneField, ForeignKey)):
+            remote_field = field.remote_field if hasattr(field, 'remote_field') else field.rel  # Remove me after Django 1.8 is unsupported
+            t += " ({0})".format(remote_field.field_name)
+        # TODO: ManyToManyField, GenericRelation
+
+        return {
+            'name': field.name,
+            'label': label,
+            'type': t,
+            'blank': field.blank,
+            'abstract': field in abstract_fields,
+            'relation': isinstance(field, RelatedField),
+            'primary_key': field.primary_key,
+        }
+
+    def add_relation(self, field, model, extras=""):
+        if self.verbose_names and field.verbose_name:
+            label = force_bytes(field.verbose_name)
+            if label.islower():
+                label = label.capitalize()
+        else:
+            label = field.name
+
+        # show related field name
+        if hasattr(field, 'related_query_name'):
+            related_query_name = field.related_query_name()
+            if self.verbose_names and related_query_name.islower():
+                related_query_name = related_query_name.replace('_', ' ').capitalize()
+            label = '{} ({})'.format(label, force_str(related_query_name))
+
+        # handle self-relationships and lazy-relationships
+        remote_field = field.remote_field if hasattr(field, 'remote_field') else field.rel  # Remove me after Django 1.8 is unsupported
+        remote_field_model = remote_field.model if hasattr(remote_field, 'model') else remote_field.to  # Remove me after Django 1.8 is unsupported
+        if isinstance(remote_field_model, six.string_types):
+            if remote_field_model == 'self':
+                target_model = field.model
+            else:
+                if '.' in remote_field_model:
+                    app_label, model_name = remote_field_model.split('.', 1)
+                else:
+                    app_label = field.model._meta.app_label
+                    model_name = remote_field_model
+                target_model = apps.get_model(app_label, model_name)
+        else:
+            target_model = remote_field_model
+
+        _rel = self.get_relation_context(target_model, field, label, extras)
+
+        if _rel not in model['relations'] and self.use_model(_rel['target']):
+            return _rel
+
+    def get_abstract_models(self, appmodels):
+        abstract_models = []
+        for appmodel in appmodels:
+            abstract_models += [abstract_model for abstract_model in
+                                appmodel.__bases__ if
+                                hasattr(abstract_model, '_meta') and
+                                abstract_model._meta.abstract]
+        abstract_models = list(set(abstract_models))  # remove duplicates
+        return abstract_models
+
+    def get_app_context(self, app):
+        return Context({
+            'name': '"%s"' % app.name,
+            'app_name': "%s" % app.name,
+            'cluster_app_name': "cluster_%s" % app.name.replace(".", "_"),
+            'models': []
+        })
+
+    def get_appmodel_attributes(self, appmodel):
+        if self.relations_as_fields:
+            attributes = [field for field in appmodel._meta.local_fields]
+        else:
+            # Find all the 'real' attributes. Relations are depicted as graph edges instead of attributes
+            attributes = [field for field in appmodel._meta.local_fields if not
+                          isinstance(field, RelatedField)]
+        return attributes
+
+    def get_appmodel_abstracts(self, appmodel):
+        return [abstract_model.__name__ for abstract_model in
+                appmodel.__bases__ if
+                hasattr(abstract_model, '_meta') and
+                abstract_model._meta.abstract]
+
+    def get_appmodel_context(self, appmodel, appmodel_abstracts):
+        context = {
+            'app_name': appmodel.__module__.replace(".", "_"),
+            'name': appmodel.__name__,
+            'abstracts': appmodel_abstracts,
+            'fields': [],
+            'relations': []
+        }
+
+        if self.verbose_names and appmodel._meta.verbose_name:
+            context['label'] = force_bytes(appmodel._meta.verbose_name)
+        else:
+            context['label'] = context['name']
+
+        return context
+
+    def get_bases_abstract_fields(self, c):
+        _abstract_fields = []
+        for e in c.__bases__:
+            if hasattr(e, '_meta') and e._meta.abstract:
+                _abstract_fields.extend(e._meta.fields)
+                _abstract_fields.extend(self.get_bases_abstract_fields(e))
+        return _abstract_fields
+
+    def get_inheritance_context(self, appmodel, parent):
+        label = "multi-table"
+        if parent._meta.abstract:
+            label = "abstract"
+        if appmodel._meta.proxy:
+            label = "proxy"
+        label += r"\ninheritance"
+        return {
+            'target_app': parent.__module__.replace(".", "_"),
+            'target': parent.__name__,
+            'type': "inheritance",
+            'name': "inheritance",
+            'label': label,
+            'arrows': '[arrowhead=empty, arrowtail=none, dir=both]',
+            'needs_node': True,
+        }
+
+    def get_models(self, app):
+        appmodels = list(app.get_models())
+        return appmodels
+
+    def get_relation_context(self, target_model, field, label, extras):
+        return {
+            'target_app': target_model.__module__.replace('.', '_'),
+            'target': target_model.__name__,
+            'type': type(field).__name__,
+            'name': field.name,
+            'label': label,
+            'arrows': extras,
+            'needs_node': True
+        }
+
+    def process_attributes(self, field, model, pk, abstract_fields):
+        newmodel = model.copy()
+        if self.skip_field(field) or pk and field == pk:
+            return newmodel
+        newmodel['fields'].append(self.add_attributes(field, abstract_fields))
+        return newmodel
+
+    def process_apps(self):
+        for app_label in self.app_labels:
+            app = apps.get_app_config(app_label)
+            if not app:
+                continue
+            app_graph = self.get_app_context(app)
+            app_models = self.get_models(app)
+            abstract_models = self.get_abstract_models(app_models)
+            app_models = abstract_models + app_models
+
+            for appmodel in app_models:
+                if not self.use_model(appmodel._meta.object_name):
+                    continue
+                appmodel_abstracts = self.get_appmodel_abstracts(appmodel)
+                abstract_fields = self.get_bases_abstract_fields(appmodel)
+                model = self.get_appmodel_context(appmodel, appmodel_abstracts)
+                attributes = self.get_appmodel_attributes(appmodel)
+
+                # find primary key and print it first, ignoring implicit id if other pk exists
+                pk = appmodel._meta.pk
+                if pk and not appmodel._meta.abstract and pk in attributes:
+                    model['fields'].append(self.add_attributes(pk, abstract_fields))
+
+                for field in attributes:
+                    model = self.process_attributes(field, model, pk, abstract_fields)
+
+                if self.sort_fields:
+                    model = self.sort_model_fields(model)
+
+                for field in appmodel._meta.local_fields:
+                    model = self.process_local_fields(field, model, abstract_fields)
+
+                for field in appmodel._meta.local_many_to_many:
+                    model = self.process_local_many_to_many(field, model)
+
+                if self.inheritance:
+                    # add inheritance arrows
+                    for parent in appmodel.__bases__:
+                        model = self.process_parent(parent, appmodel, model)
+
+                app_graph['models'].append(model)
+            if app_graph['models']:
+                self.graphs.append(app_graph)
+
+    def process_local_fields(self, field, model, abstract_fields):
+        newmodel = model.copy()
+        if (field.attname.endswith('_ptr_id') or  # excluding field redundant with inheritance relation
+                field in abstract_fields or  # excluding fields inherited from abstract classes. they too show as local_fields
+                self.skip_field(field)):
+            return newmodel
+        if isinstance(field, OneToOneField):
+            newmodel['relations'].append(self.add_relation(field, newmodel, '[arrowhead=none, arrowtail=none, dir=both]'))
+        elif isinstance(field, ForeignKey):
+            newmodel['relations'].append(self.add_relation(field, newmodel, '[arrowhead=none, arrowtail=dot, dir=both]'))
+        return newmodel
+
+    def process_local_many_to_many(self, field, model):
+        newmodel = model.copy()
+        if self.skip_field(field):
+            return newmodel
+        if isinstance(field, ManyToManyField):
+            remote_field = field.remote_field if hasattr(field, 'remote_field') else field.rel  # Remove me after Django 1.8 is unsupported
+            if hasattr(remote_field.through, '_meta') and remote_field.through._meta.auto_created:
+                newmodel['relations'].append(self.add_relation(field, newmodel, '[arrowhead=dot arrowtail=dot, dir=both]'))
+        elif isinstance(field, GenericRelation):
+            newmodel['relations'].append(self.add_relation(field, newmodel, mark_safe('[style="dotted", arrowhead=normal, arrowtail=normal, dir=both]')))
+        return newmodel
+
+    def process_parent(self, parent, appmodel, model):
+        newmodel = model.copy()
+        if hasattr(parent, "_meta"):  # parent is a model
+            _rel = self.get_inheritance_context(appmodel, parent)
+            # TODO: seems as if abstract models aren't part of models.getModels, which is why they are printed by this without any attributes.
+            if _rel not in newmodel['relations'] and self.use_model(_rel['target']):
+                newmodel['relations'].append(_rel)
+        return newmodel
+
+    def sort_model_fields(self, model):
+        newmodel = model.copy()
+        newmodel['fields'] = sorted(newmodel['fields'], key=lambda field: (not field['primary_key'], not field['relation'], field['label']))
+        return newmodel
+
+    def use_model(self, model_name):
+        """
+        Decide whether to use a model, based on the model name and the lists of
+        models to exclude and include.
+        """
+        # Check against exclude list.
+        if self.exclude_models:
+            for model_pattern in self.exclude_models:
+                model_pattern = '^%s$' % model_pattern.replace('*', '.*')
+                if re.search(model_pattern, model_name):
+                    return False
+        # Check against exclude list.
+        elif self.include_models:
+            for model_pattern in self.include_models:
+                model_pattern = '^%s$' % model_pattern.replace('*', '.*')
+                if re.search(model_pattern, model_name):
+                    return True
+        # Return `True` if `include_models` is falsey, otherwise return `False`.
+        return not self.include_models
+
+    def skip_field(self, field):
+        if self.exclude_columns:
+            if self.verbose_names and field.verbose_name:
+                if field.verbose_name in self.exclude_columns:
+                    return True
+            if field.name in self.exclude_columns:
+                return True
+        return False
+
+
+def generate_dot(graph_data, template='django_extensions/graph_models/digraph.dot'):
+    t = loader.get_template(template)
+
+    if not isinstance(t, Template) and not (hasattr(t, 'template') and isinstance(t.template, Template)):
+        raise Exception("Default Django template loader isn't used. "
+                        "This can lead to the incorrect template rendering. "
+                        "Please, check the settings.")
+
+    c = Context(graph_data).flatten()
+    dot = t.render(c)
+
+    return dot
+
+
+def generate_graph_data(*args, **kwargs):
+    generator = ModelGraph(*args, **kwargs)
+    generator.generate_graph_data()
+    return generator.get_graph_data()
+
+
+def use_model(model, include_models, exclude_models):
+    generator = ModelGraph([], include_models=include_models, exclude_models=exclude_models)
+    return generator.use_model(model)
+
diff --git a/topologie/views.py b/topologie/views.py
index b2ac8d71..f87213fa 100644
--- a/topologie/views.py
+++ b/topologie/views.py
@@ -279,8 +279,9 @@ def edit_port(request, port_object, portid):
 
     port = EditPortForm(request.POST or None, instance=port_object)
     if port.is_valid():
-        port.save()
-        messages.success(request, "Le port a bien été modifié")
+        if port.changed_data:
+            port.save()
+            messages.success(request, "Le port a bien été modifié")
         return redirect(reverse(
             'topologie:index-port',
             kwargs={'switchid': str(port_object.switch.id)}
@@ -323,8 +324,9 @@ def edit_stack(request, stack, stackid):
     """Edition d'un stack (nombre de switches, nom...)"""
     stack = StackForm(request.POST or None, instance=stack)
     if stack.is_valid():
-        stack.save()
-        return redirect(reverse('topologie:index-stack'))
+        if stack.changed_data:
+            stack.save()
+            return redirect(reverse('topologie:index-stack'))
     return form({'topoform': stack, 'action_name' : 'Editer'}, 'topologie/topo.html', request)
 
 
@@ -463,9 +465,12 @@ def edit_switch(request, switch, switchid):
         new_switch = switch_form.save(commit=False)
         new_interface_instance = interface_form.save(commit=False)
         new_domain = domain_form.save(commit=False)
-        new_switch.save()
-        new_interface_instance.save()
-        new_domain.save()
+        if switch_form.changed_data:
+            new_switch.save()
+        if interface_form.changed_data:
+            new_interface_instance.save()
+        if domain_form.changed_data:
+            new_domain.save()
         messages.success(request, "Le switch a bien été modifié")
         return redirect(reverse('topologie:index'))
     i_mbf_param = generate_ipv4_mbf_param(interface_form, False )
@@ -553,9 +558,12 @@ def edit_ap(request, ap, accesspointid):
         new_ap = ap_form.save(commit=False)
         new_interface = interface_form.save(commit=False)
         new_domain = domain_form.save(commit=False)
-        new_ap.save()
-        new_interface.save()
-        new_domain.save()
+        if ap_form.changed_data:
+            new_ap.save()
+        if interface_form.changed_data:
+            new_interface.save()
+        if domain_form.changed_data:
+            new_domain.save()
         messages.success(request, "La borne a été modifiée")
         return redirect(reverse('topologie:index-ap'))
     i_mbf_param = generate_ipv4_mbf_param(interface_form, False )
@@ -586,8 +594,9 @@ def edit_room(request, room, roomid):
     """ Edition numero et details de la chambre"""
     room = EditRoomForm(request.POST or None, instance=room)
     if room.is_valid():
-        room.save()
-        messages.success(request, "La chambre a bien été modifiée")
+        if room.changed_data:
+            room.save()
+            messages.success(request, "La chambre a bien été modifiée")
         return redirect(reverse('topologie:index-room'))
     return form({'topoform': room, 'action_name' : 'Editer'}, 'topologie/topo.html', request)
 
@@ -629,8 +638,9 @@ def edit_model_switch(request, model_switch, modelswitchid):
 
     model_switch = EditModelSwitchForm(request.POST or None, instance=model_switch)
     if model_switch.is_valid():
-        model_switch.save()
-        messages.success(request, "Le modèle a bien été modifié")
+        if model_switch.changed_data:
+            model_switch.save()
+            messages.success(request, "Le modèle a bien été modifié")
         return redirect(reverse('topologie:index-model-switch'))
     return form({'topoform': model_switch, 'action_name' : 'Editer'}, 'topologie/topo.html', request)
 
@@ -672,8 +682,9 @@ def edit_constructor_switch(request, constructor_switch, constructorswitchid):
 
     constructor_switch = EditConstructorSwitchForm(request.POST or None, instance=constructor_switch)
     if constructor_switch.is_valid():
-        constructor_switch.save()
-        messages.success(request, "Le modèle a bien été modifié")
+        if constructor_switch.changed_data:
+            constructor_switch.save()
+            messages.success(request, "Le modèle a bien été modifié")
         return redirect(reverse('topologie:index-model-switch'))
     return form({'topoform': constructor_switch, 'action_name' : 'Editer'}, 'topologie/topo.html', request)