Generate an SVG file displaying relations using DOT file format and "dot" program

2 files changed, 137 insertions, 0 deletions

diff --git a/example_project/settings.py b/example_project/settings.py
index 46fee04d8..d5efd2891 100644
--- a/example_project/settings.py
+++ b/example_project/settings.py
@@ -253,6 +253,9 @@ ISHTAR_DPTS = []
 
 MAX_ATTEMPTS = 1  # django background tasks
 
+# if you want to generate relation graph provide the path to the "dot" program
+DOT_BINARY = ""
+
 TEST_RUNNER = 'ishtar_common.tests.ManagedModelTestRunner'
 
 try:
diff --git a/ishtar_common/utils.py b/ishtar_common/utils.py
index 01b35dcef..1613b389d 100644
--- a/ishtar_common/utils.py
+++ b/ishtar_common/utils.py
@@ -21,7 +21,11 @@ import datetime
 from functools import wraps
 from itertools import chain
 import hashlib
+import os
 import random
+import shutil
+import subprocess
+import tempfile
 
 from django import forms
 from django.conf import settings
@@ -29,6 +33,7 @@ from django.contrib.gis.geos import GEOSGeometry
 from django.contrib.sessions.backends.db import SessionStore
 from django.core.cache import cache
 from django.core.exceptions import FieldDoesNotExist
+from django.core.files import File
 from django.core.urlresolvers import reverse
 from django.utils.datastructures import MultiValueDict as BaseMultiValueDict
 from django.utils.safestring import mark_safe
@@ -480,3 +485,132 @@ def create_default_areas(models=None):
                 idx += 1
 
     print("* {} town associated to department area".format(idx))
+
+
+def get_relations_for_graph(rel_model, obj_pk, above_relations=None,
+                            equal_relations=None, treated=None):
+    """
+    Get all above and equal relations of an object (get all child and parent
+    relations)
+    :param rel_model: the relation model concerned
+    :param obj_pk: id of an object with relations
+    :param above_relations: list of current above_relations
+    :param equal_relations: list of current equal_relations
+    :param treated: treated relation list to prevent circular call
+    :return: above and equal relations list (each containing lists of two
+    members)
+    """
+    if not above_relations:
+        above_relations = []
+    if not equal_relations:
+        equal_relations = []
+    if not treated:
+        treated = []
+    if obj_pk in treated:
+        return above_relations, equal_relations
+
+    treated.append(obj_pk)
+    q = rel_model.objects.filter(
+        left_record_id=obj_pk,
+        relation_type__logical_relation__isnull=False
+    ).values('right_record_id', 'relation_type__logical_relation')
+    if not q.count():
+        return [], []
+    for relation in q.all():
+        logical_relation = relation['relation_type__logical_relation']
+        right_record = relation['right_record_id']
+        if not logical_relation:
+            continue
+        elif logical_relation == 'above'and \
+                (obj_pk, right_record) not in above_relations:
+            above_relations.append((obj_pk, right_record))
+        elif logical_relation == 'bellow' and \
+                (right_record, obj_pk) not in above_relations:
+            above_relations.append((right_record, obj_pk))
+        elif logical_relation == 'equal' and \
+                (right_record, obj_pk) not in equal_relations and \
+                (obj_pk, right_record) not in equal_relations:
+            equal_relations.append((obj_pk, right_record))
+        else:
+            continue
+        ar, er = get_relations_for_graph(
+            rel_model, right_record, above_relations, equal_relations, treated)
+        for r in ar:
+            if r not in above_relations:
+                above_relations.append(r)
+        for r in er:
+            if r not in equal_relations:
+                equal_relations.append(r)
+    return above_relations, equal_relations
+
+
+def generate_relation_graph(obj, debug=False):
+    if not settings.DOT_BINARY:
+        return
+
+    model = obj.__class__
+    rel_model = model._meta.get_field('right_relations').related_model
+
+    # get relations
+    above_relations, equal_relations = get_relations_for_graph(rel_model,
+                                                               obj.pk)
+    if not above_relations and not equal_relations:
+        obj.relation_image = None
+        obj.save()
+        return
+
+    # generate dotfile
+    dot_str = "digraph relations {\nnode [shape=box];\n"
+    rel_str = ""
+    described = []
+    for list, directed in ((above_relations, True),
+                           (equal_relations, False)):
+        if directed:
+            rel_str += "subgraph Dir {\n"
+        else:
+            rel_str += "subgraph NoDir {\nedge [dir=none,style=dashed];\n"
+        for left_pk, right_pk in list:
+            if left_pk not in described:
+                described.append(left_pk)
+                left = model.objects.get(pk=left_pk)
+                style = 'label="{}"'.format(left.relation_label)
+                if left.pk == obj.pk:
+                    style += ',style=filled,fillcolor="#C6C0C0"'
+                dot_str += u'item{}[{}];\n'.format(left.pk, style)
+            if right_pk not in described:
+                described.append(right_pk)
+                right = model.objects.get(pk=right_pk)
+                style = 'label="{}"'.format(right.relation_label)
+                if right.pk == obj.pk:
+                    style += ',style=filled,fillcolor="#C6C0C0"'
+                dot_str += u'item{}[{}];\n'.format(right.pk, style)
+            if not directed:  # on sthe same level
+                rel_str += u"{{rank = same; item{}; item{};}}\n".format(
+                    left_pk, right_pk)
+            rel_str += u'item{} -> item{};\n'.format(left_pk, right_pk)
+        rel_str += "}\n"
+    dot_str += rel_str + "\n}"
+
+    tempdir = tempfile.mkdtemp("-ishtardot")
+    dot_name = tempdir + os.path.sep + "relations.dot"
+    with open(dot_name, 'w') as dot_file:
+        dot_file.write(dot_str)
+
+    # execute dot program
+    args = (settings.DOT_BINARY, "-Tsvg", dot_name)
+
+    svg_tmp_name = tempdir + os.path.sep + "relations.svg"
+
+    with open(svg_tmp_name, "w") as svg_file:
+        popen = subprocess.Popen(args, stdout=svg_file)
+        popen.wait()
+
+    with open(svg_tmp_name, "r") as svg_file:
+        django_file = File(svg_file)
+        obj.relation_image.save("relations.svg", django_file, save=True)
+
+    if debug:
+        print(u"DOT file: {}. Tmp SVG file: {}.".format(dot_name, svg_tmp_name))
+        return
+    shutil.rmtree(tempdir)
+