Merge pull request #7 from girardinsamuel/feat/add-partial-reloads

Author: zodman

inertia/views.py

@@ -1,4 +1,5 @@
 import json
+from inspect import signature
 from django.core.exceptions import ImproperlyConfigured
 from django.views.generic import View
 from django.views.generic.list import BaseListView
@@ -20,6 +21,18 @@
 log = logging.getLogger(__name__)
 
 
+def load_lazy_props(d, request):
+    for k, v in d.items():
+        if isinstance(v, dict):
+            load_lazy_props(v, request)
+        elif callable(v):
+            # evaluate prop and pass request if prop accept it
+            if len(signature(v).parameters) > 0:
+                d[k] = v(request)
+            else:
+                d[k] = v()
+
+
 def _build_context(component_name, props, version, url):
     context = {
         "page": {
@@ -72,17 +85,34 @@ def render_inertia(request, component_name, props=None, template_name=None):
     inertia_version = get_version()
     is_version_correct = 'X-Inertia-Version' in request.headers and \
                          request.headers["X-Inertia-Version"] == str(inertia_version)
+
+    # check if partial reload is requested
+    only_props = request.headers.get("X-Inertia-Partial-Data", [])
+    if (
+        only_props
+        and request.headers.get("X-Inertia-Partial-Component", "") == component_name
+    ):
+        _props = {}
+        for key in props:
+            if key in only_props:
+                _props.update({key: props[key]})
+    else:
+        _props = props
+
+    # lazy load props and make request available to props being lazy loaded
+    load_lazy_props(_props, request)
+
     if 'X-Inertia' in request.headers:
         response = JsonResponse({
             "component": component_name,
-            "props": props,
+            "props": _props,
             "version": inertia_version,
             "url": request.get_full_path()
         })
         response['X-Inertia'] = True
         response['Vary'] = 'Accept'
         return response
-    context = _build_context(component_name, props,
+    context = _build_context(component_name, _props,
                              inertia_version,
                              url=request.get_full_path())
     return render(request, inertia_template, context)

test.py

@@ -70,7 +70,7 @@ def test_middleware(self):
             'X-Inertia-Version': get_version(),
             'x-Requested-With': 'XMLHttpRequest'
         }
-        request = RequestFactory().get("/", **defaults)
+        request = RequestFactory().get("/") #, **defaults)
         request.headers = defaults
         self.set_session(request)
         response = InertiaMiddleware(view)(request)
@@ -99,3 +99,30 @@ def test_redirect_303_for_put_patch_delete_requests(self):
         self.set_session(request)
         response = InertiaMiddleware(lambda x: HttpResponseRedirect(redirect_to="/users"))(request)
         self.assertTrue(response.status_code==303, response.status_code)
+
+    def test_resolve_lazy_loading_props(self):
+        requestfactory = RequestFactory()
+        request = requestfactory.get("/")
+        self.set_session(request)
+        def lazy_loaded_prop():
+            return "2"
+        response = render_inertia(request, "Index", {"a": "1", "b": lazy_loaded_prop})
+        self.assertTrue(b'"props": {"a": "1", "b": "2"}' in response.content)
+
+    def test_partial_loading(self):
+        defaults = {
+            'X-Inertia': 'true',
+            'X-Inertia-Version': get_version(),
+            'X-Requested-With': 'XMLHttpRequest',
+            'X-Inertia-Partial-Data': ["a"],
+            "X-Inertia-Partial-Component": "Index"
+        }
+        requestfactory = RequestFactory()
+        request = requestfactory.get("/")
+        request.headers = defaults
+        self.set_session(request)
+        def lazy_loaded_prop():
+            return "2"
+        response = render_inertia(request, "Index", {"a": "1", "b": lazy_loaded_prop})
+        # check that b is not returned because we only ask for a
+        self.assertIn(b'"props": {"a": "1"},', response.content)