templatags: rendering of $id/$ref in jsonschema (#81643)

passerelle/base/templatetags/passerelle.py

@@ -110,7 +110,10 @@ def censor(string):
     return re.sub(r'://([^/]*):([^/]*?)@', r'://\1:***@', string)
 
 
-def render_json_schema(schema):
+def render_json_schema(schema, anchor_map=None):
+    if anchor_map is None:
+        anchor_map = {}
+
     if not isinstance(schema, dict):
         if schema is True:
             return mark_safe('<em>%s</em>') % _('always valid')
@@ -133,6 +136,11 @@ def render_json_schema(schema):
     def html_type(s):
         return '<span class="type">%s</span>' % s
 
+    def to_id(ref):
+        _ref = ref.lstrip('#')
+        _id = id(anchor_map.get(_ref))
+        return f'schema-object-{_ref}-{_id}'
+
     if 'anyOf' in schema:
         return many_of('anyOf', schema['anyOf'])
 
@@ -145,10 +153,17 @@ def render_json_schema(schema):
     original_schema = schema
     schema = schema.copy()
     schema.pop('$schema', None)
-    schema.pop('$id', None)
+    _anchor = schema.pop('$anchor', None)
+    if _anchor:
+        anchor_map.setdefault(_anchor, original_schema)
     title = schema.pop('title', None)
     description = schema.pop('description', None)
     typ = schema.pop('type', None)
+    _ref = schema.pop('$ref', None)
+    if _ref and _ref.startswith('#'):
+        target_schema = anchor_map.get(_ref[1:], {})
+        target_title = target_schema.get('title') or target_schema.get('description') or 'referenced schema'
+        return format_html('<a href="#{}">{}</a>', to_id(_ref), target_title)
     if typ == 'null':
         return mark_safe(html_type('null'))
     if typ == 'string':
@@ -181,10 +196,12 @@ def render_json_schema(schema):
     if typ == 'array':
         s = html_type('array') + ' '
         if 'items' in schema:
-            s += render_json_schema(schema['items'])
+            s += render_json_schema(schema['items'], anchor_map)
         return mark_safe(s)
     if typ == 'object':
         s = html_type('object')
+        if _anchor:
+            s += f'<a id="{to_id(_anchor)}"></a>'
         unflatten = schema.pop('unflatten', False)
         merge_extra = schema.pop('merge_extra', False)
         properties = schema.pop('properties', {})
@@ -211,6 +228,9 @@ def render_json_schema(schema):
         def render_property_schema(key, html, sub):
             nonlocal s
 
+            _anchor = sub.get('$anchor', None)
+            if _anchor:
+                anchor_map.setdefault(_anchor, sub.copy())
             required = key in required_keys
             sub_description = sub.pop('description', '')
             sub_title = sub.pop('title', '')
@@ -226,7 +246,7 @@ def render_json_schema(schema):
             if sub_title or '\n' in sub_description:
                 s += format_html('\n<p class="description">{}</p>', sub_description)
             if sub:
-                s += format_html('\n{0}', render_json_schema(sub))
+                s += format_html('\n{0}', render_json_schema(sub, anchor_map))
             s += '</li>'
 
         if properties or pattern_properties:

tests/test_templatetags.py

@@ -15,6 +15,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import inspect
+import re
 
 from django.apps import apps
 from django.utils import translation
@@ -99,3 +100,29 @@ def test_render_oneof_property_required():
         ],
     }
     assert "<b>oneOf</b> [ <em>required 'a'</em> | <em>required 'b'</em> ]" in render_json_schema(schema)
+
+
+def test_render_json_schema_anchor():
+    SCHEMA = {
+        '$schema': 'http://json-schema.org/draft-04/schema#',
+        'type': 'object',
+        'required': ['foo'],
+        'additionalProperties': False,
+        'properties': {
+            'foo': {
+                'type': 'object',
+                '$anchor': 'foo',
+                'title': 'foo object',
+                'properties': {'a': {'type': 'string'}},
+            },
+            'zorglub': {
+                '$ref': '#foo',
+            },
+        },
+    }
+    # Check that no unicode crash occurs
+    with translation.override('fr'):
+        fragment = render_json_schema(SCHEMA)
+        match = re.search(r'id="(schema-object-foo-[^"]+)"', fragment)
+        assert match
+        assert f'href="#{match.group(1)}">foo object</a>' in fragment