From 9706cf0a6287a896e0ec2071c54e3da5680bf563 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Hru=C5=A1ka?= <ondra@ondrovo.com>
Date: Sun, 7 Feb 2021 17:52:10 +0100
Subject: [PATCH] flash messages etc

---
 Cargo.lock                                    | 194 +++++++++++++++-
 yopa-web/Cargo.toml                           |   2 +
 yopa-web/resources/static/style.css           |  15 ++
 .../resources/templates/_layout.html.tera     |  19 +-
 .../resources/templates/_macros.html.tera     |   8 +
 yopa-web/resources/templates/index.html.tera  |  20 +-
 .../templates/model_create.html.tera          |   8 -
 yopa-web/src/main.rs                          | 207 ++++++++++--------
 yopa-web/src/routes.rs                        |  59 ++++-
 yopa-web/src/session_ext.rs                   |  39 ++++
 yopa/src/lib.rs                               |  24 +-
 yopa/src/model.rs                             |   2 -
 yopa/src/tests.rs                             |   1 -
 13 files changed, 472 insertions(+), 126 deletions(-)
 create mode 100644 yopa-web/resources/templates/_macros.html.tera
 create mode 100644 yopa-web/src/session_ext.rs

diff --git a/Cargo.lock b/Cargo.lock
index 81f4c05..9103e30 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -47,7 +47,7 @@ dependencies = [
  "actix-service",
  "actix-threadpool",
  "actix-utils",
- "base64",
+ "base64 0.13.0",
  "bitflags",
  "brotli2",
  "bytes 0.5.6",
@@ -150,6 +150,22 @@ dependencies = [
  "pin-project 0.4.27",
 ]
 
+[[package]]
+name = "actix-session"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cfe0c795741b7a1a6f8eb46680c5a0f6f53484d054226a7af9a86195dfc2c14d"
+dependencies = [
+ "actix-service",
+ "actix-web",
+ "bytes 0.5.6",
+ "derive_more",
+ "futures-util",
+ "serde",
+ "serde_json",
+ "time 0.2.25",
+]
+
 [[package]]
 name = "actix-testing"
 version = "1.0.1"
@@ -290,6 +306,60 @@ version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ee2a4ec343196209d6594e19543ae87a39f96d5534d7174822a3ad825dd6ed7e"
 
+[[package]]
+name = "aead"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7fc95d1bdb8e6666b2b217308eeeb09f2d6728d104be3e31916cc74d15420331"
+dependencies = [
+ "generic-array 0.14.4",
+]
+
+[[package]]
+name = "aes"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "884391ef1066acaa41e766ba8f596341b96e93ce34f9a43e7d24bf0a0eaf0561"
+dependencies = [
+ "aes-soft",
+ "aesni",
+ "cipher",
+]
+
+[[package]]
+name = "aes-gcm"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5278b5fabbb9bd46e24aa69b2fdea62c99088e0a950a9be40e3e0101298f88da"
+dependencies = [
+ "aead",
+ "aes",
+ "cipher",
+ "ctr",
+ "ghash",
+ "subtle",
+]
+
+[[package]]
+name = "aes-soft"
+version = "0.6.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "be14c7498ea50828a38d0e24a765ed2effe92a705885b57d029cd67d45744072"
+dependencies = [
+ "cipher",
+ "opaque-debug 0.3.0",
+]
+
+[[package]]
+name = "aesni"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ea2e11f5e94c2f7d386164cc2aa1f97823fed6f259e486940a71c174dd01b0ce"
+dependencies = [
+ "cipher",
+ "opaque-debug 0.3.0",
+]
+
 [[package]]
 name = "aho-corasick"
 version = "0.7.15"
@@ -332,7 +402,7 @@ dependencies = [
  "actix-http",
  "actix-rt",
  "actix-service",
- "base64",
+ "base64 0.13.0",
  "bytes 0.5.6",
  "cfg-if 1.0.0",
  "derive_more",
@@ -366,6 +436,12 @@ version = "0.2.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a4521f3e3d031370679b3b140beb36dfe4801b09ac77e30c61941f97df3ef28b"
 
+[[package]]
+name = "base64"
+version = "0.12.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3441f0f7b02788e948e47f457ca01f1d7e6d92c693bc132c22b087d3141c03ff"
+
 [[package]]
 name = "base64"
 version = "0.13.0"
@@ -517,6 +593,15 @@ dependencies = [
  "parse-zoneinfo",
 ]
 
+[[package]]
+name = "cipher"
+version = "0.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "12f8e7987cbd042a63249497f41aed09f8e65add917ea6566effbc56578d6801"
+dependencies = [
+ "generic-array 0.14.4",
+]
+
 [[package]]
 name = "const_fn"
 version = "0.4.5"
@@ -529,7 +614,13 @@ version = "0.14.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "784ad0fbab4f3e9cef09f20e0aea6000ae08d2cb98ac4c0abc53df18803d702f"
 dependencies = [
+ "aes-gcm",
+ "base64 0.12.3",
+ "hkdf",
+ "hmac",
  "percent-encoding",
+ "rand 0.7.3",
+ "sha2",
  "time 0.2.25",
  "version_check",
 ]
@@ -546,6 +637,12 @@ version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8aebca1129a03dc6dc2b127edd729435bbc4a37e1d5f4d7513165089ceb02634"
 
+[[package]]
+name = "cpuid-bool"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dcb25d077389e53838a8158c8e99174c5a9d902dee4904320db714f3c653ffba"
+
 [[package]]
 name = "crc32fast"
 version = "1.2.1"
@@ -566,6 +663,25 @@ dependencies = [
  "lazy_static",
 ]
 
+[[package]]
+name = "crypto-mac"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4857fd85a0c34b3c3297875b747c1e02e06b6a0ea32dd892d8192b9ce0813ea6"
+dependencies = [
+ "generic-array 0.14.4",
+ "subtle",
+]
+
+[[package]]
+name = "ctr"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fb4a30d54f7443bf3d6191dcd486aca19e67cb3c49fa7a06a319966346707e7f"
+dependencies = [
+ "cipher",
+]
+
 [[package]]
 name = "derive_more"
 version = "0.99.11"
@@ -817,6 +933,16 @@ dependencies = [
  "wasi 0.10.2+wasi-snapshot-preview1",
 ]
 
+[[package]]
+name = "ghash"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "97304e4cd182c3846f7575ced3890c53012ce534ad9114046b0a9e00bb30a375"
+dependencies = [
+ "opaque-debug 0.3.0",
+ "polyval",
+]
+
 [[package]]
 name = "gimli"
 version = "0.23.0"
@@ -897,6 +1023,26 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "hkdf"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "51ab2f639c231793c5f6114bdb9bbe50a7dbbfcd7c7c6bd8475dec2d991e964f"
+dependencies = [
+ "digest 0.9.0",
+ "hmac",
+]
+
+[[package]]
+name = "hmac"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c1441c6b1e930e2817404b5046f1f989899143a12bf92de603b69f4e0aee1e15"
+dependencies = [
+ "crypto-mac",
+ "digest 0.9.0",
+]
+
 [[package]]
 name = "hostname"
 version = "0.3.1"
@@ -1425,6 +1571,17 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"
 
+[[package]]
+name = "polyval"
+version = "0.4.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eebcc4aa140b9abd2bc40d9c3f7ccec842679cd79045ac3a7ac698c1a064b7cd"
+dependencies = [
+ "cpuid-bool 0.2.0",
+ "opaque-debug 0.3.0",
+ "universal-hash",
+]
+
 [[package]]
 name = "ppv-lite86"
 version = "0.2.10"
@@ -1696,7 +1853,7 @@ checksum = "f4b312c3731e3fe78a185e6b9b911a7aa715b8e31cce117975219aab2acf285d"
 dependencies = [
  "block-buffer 0.9.0",
  "cfg-if 1.0.0",
- "cpuid-bool",
+ "cpuid-bool 0.1.2",
  "digest 0.9.0",
  "opaque-debug 0.3.0",
 ]
@@ -1707,6 +1864,19 @@ version = "0.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2579985fda508104f7587689507983eadd6a6e84dd35d6d115361f530916fa0d"
 
+[[package]]
+name = "sha2"
+version = "0.9.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fa827a14b29ab7f44778d14a88d3cb76e949c45083f7dbfa507d0cb699dc12de"
+dependencies = [
+ "block-buffer 0.9.0",
+ "cfg-if 1.0.0",
+ "cpuid-bool 0.1.2",
+ "digest 0.9.0",
+ "opaque-debug 0.3.0",
+]
+
 [[package]]
 name = "signal-hook-registry"
 version = "1.3.0"
@@ -1817,6 +1987,12 @@ version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "213701ba3370744dcd1a12960caa4843b3d68b4d1c0a5d575e0d65b2ee9d16c0"
 
+[[package]]
+name = "subtle"
+version = "2.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e81da0851ada1f3e9d4312c704aa4f8806f0f9d69faaf8df2f3464b4a9437c2"
+
 [[package]]
 name = "syn"
 version = "1.0.60"
@@ -2183,6 +2359,16 @@ version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f7fe0bb3479651439c9112f72b6c505038574c9fbb575ed1bf3b797fa39dd564"
 
+[[package]]
+name = "universal-hash"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8326b2c654932e3e4f9196e69d08fdf7cfd718e1dc6f66b347e6024a0c961402"
+dependencies = [
+ "generic-array 0.14.4",
+ "subtle",
+]
+
 [[package]]
 name = "url"
 version = "2.2.0"
@@ -2375,12 +2561,14 @@ dependencies = [
 name = "yopa-web"
 version = "0.1.0"
 dependencies = [
+ "actix-session",
  "actix-web",
  "actix-web-static-files",
  "include_dir",
  "log",
  "once_cell",
  "parking_lot",
+ "rand 0.8.3",
  "serde",
  "serde_json",
  "simple-logging",
diff --git a/yopa-web/Cargo.toml b/yopa-web/Cargo.toml
index 1d27787..e7b3e23 100644
--- a/yopa-web/Cargo.toml
+++ b/yopa-web/Cargo.toml
@@ -15,11 +15,13 @@ serde_json = "1"
 log = "0.4.14"
 simple-logging = "2.0.2"
 actix-web = "3"
+actix-session = "0.4.0"
 parking_lot = "0.11.1"
 include_dir = "0.6.0"
 tera = "1.6.1"
 actix-web-static-files = "3.0"
 once_cell = "1.5.2"
+rand = "0.8.3"
 
 tokio = { version="0.2.6", features=["full"] }
 
diff --git a/yopa-web/resources/static/style.css b/yopa-web/resources/static/style.css
index 0d3d425..b44166a 100644
--- a/yopa-web/resources/static/style.css
+++ b/yopa-web/resources/static/style.css
@@ -205,3 +205,18 @@ textarea:focus,
 li {
 	padding-bottom: .5rem;
 }
+
+.toast {
+	border: 1px solid black;
+	border-radius: 5px;
+	padding: .5rem;
+	margin: .5rem 0;
+}
+
+.toast.error {
+	border-color: #dc143c;
+}
+
+.toast.success {
+	border-color: #32cd32;
+}
diff --git a/yopa-web/resources/templates/_layout.html.tera b/yopa-web/resources/templates/_layout.html.tera
index 190b7da..39c6f7f 100644
--- a/yopa-web/resources/templates/_layout.html.tera
+++ b/yopa-web/resources/templates/_layout.html.tera
@@ -2,17 +2,30 @@
 <html lang="en">
 <head>
 	<meta charset="UTF-8">
-	<title>{% block title %}{% endblock title %} &bull; YOPA</title>
+	<title>{% block title -%}{%- endblock title %} &bull; YOPA</title>
 	<link rel="stylesheet" href="/static/style.css">
 	<link rel="stylesheet" href="/static/taggle.css">
 	<script src="/static/taggle.min.js"></script>
 </head>
 <body>
 <nav class="top-nav">
-	{% block nav %}{% endblock %}
+	{%- block nav -%}{%- endblock -%}
 </nav>
 <div class="content">
-{% block content %}{% endblock %}
+
+{%- if flash_error -%}
+<div class="toast error">
+	{{ flash_error }}
+</div>
+{%- endif -%}
+
+{%- if flash_success -%}
+<div class="toast success">
+	{{ flash_success }}
+</div>
+{%- endif -%}
+
+{%- block content -%}{%- endblock -%}
 </div>
 </body>
 </html>
diff --git a/yopa-web/resources/templates/_macros.html.tera b/yopa-web/resources/templates/_macros.html.tera
new file mode 100644
index 0000000..1860451
--- /dev/null
+++ b/yopa-web/resources/templates/_macros.html.tera
@@ -0,0 +1,8 @@
+{% macro describe_property(prop) %}
+	{{prop.name}}, {{prop.data_type}}
+	{%- if prop.default -%}
+	, default: "{{prop.default | print_typed_value}}"
+	{%- endif -%}
+	{%- if prop.optional %}, OPTIONAL{% endif %}
+	{%- if prop.multiple %}, MULTIPLE{% endif %}
+{% endmacro input %}
diff --git a/yopa-web/resources/templates/index.html.tera b/yopa-web/resources/templates/index.html.tera
index 999ffb0..513ce8c 100644
--- a/yopa-web/resources/templates/index.html.tera
+++ b/yopa-web/resources/templates/index.html.tera
@@ -1,4 +1,5 @@
 {% extends "_layout" %}
+{% import "_macros" as macros %}
 
 {% block title -%}
 	Index
@@ -26,12 +27,7 @@
 		<ul>
 			{% for prop in model.properties %}
 				<li>
-					{{prop.name}}, {{prop.data_type}}
-						{%- if prop.default -%}
-							, default: "{{prop.default | print_typed_value}}"
-						{%- endif -%}
-					{%- if prop.optional %}, OPTIONAL{% endif %}
-					{%- if prop.multiple %}, MULTIPLE{% endif %}
+					{{ macros::describe_property(prop=prop) }}
 				</li>
 			{% endfor %}
 		</ul>
@@ -44,19 +40,17 @@
 		<ul>
 			{% for rel in model.relations %}
 			<li>
-				<span title="{{rel.model.id}}">"{{rel.model.name}}", pointing to: <i>{{rel.related_name}}</i></span><br>
+				<span title="{{rel.model.id}}">"{{rel.model.name}}", pointing to: <i>{{rel.related_name}}</i></span>
+				{%- if rel.model.optional %}, OPTIONAL{% endif %}
+				{%- if rel.model.multiple %}, MULTIPLE{% endif %}
+				<br>
 
 				{% if rel.properties %}
 				Properties:
 				<ul>
 					{% for prop in rel.properties %}
 					<li title="{{prop.id}}">
-						{{prop.name}}, {{prop.data_type}}
-						{%- if prop.default -%}
-						, default: "{{prop.default | print_typed_value}}"
-						{%- endif -%}
-						{%- if prop.optional %}, OPTIONAL{% endif %}
-						{%- if prop.multiple %}, MULTIPLE{% endif %}
+						{{ macros::describe_property(prop=prop) }}
 					</li>
 					{% endfor %}
 				</ul>
diff --git a/yopa-web/resources/templates/model_create.html.tera b/yopa-web/resources/templates/model_create.html.tera
index 0a314f1..75508d3 100644
--- a/yopa-web/resources/templates/model_create.html.tera
+++ b/yopa-web/resources/templates/model_create.html.tera
@@ -13,14 +13,6 @@ Define object
 <h1>Define new object model</h1>
 
 <form action="/model/object/create" method="POST">
-	<label for="parent">Parent:</label>
-	<select name="parent" id="parent">
-		<option value="">No parent</option>
-		{%- for model in all_models %}
-		<option value="{{model.id}}">{{model.name}}</option>
-		{%- endfor %}
-	</select><br>
-
 	<label for="name">Name:</label>
 	<input type="text" id="name" name="name"><br>
 
diff --git a/yopa-web/src/main.rs b/yopa-web/src/main.rs
index d00d4f5..c83a89c 100644
--- a/yopa-web/src/main.rs
+++ b/yopa-web/src/main.rs
@@ -18,9 +18,13 @@ use std::borrow::Borrow;
 use std::ops::Deref;
 use yopa::{Storage, TypedValue};
 use std::collections::HashMap;
+use actix_session::CookieSession;
+use rand::Rng;
+use actix_web_static_files::ResourceFiles as StaticFiles;
 
 mod tera_ext;
 mod routes;
+mod session_ext;
 
 // Embed static files
 include!(concat!(env!("OUT_DIR"), "/static_files.rs"));
@@ -30,7 +34,7 @@ static TEMPLATES: include_dir::Dir = include_dir::include_dir!("./resources/temp
 
 pub(crate) static TERA : Lazy<Tera> = Lazy::new(|| {
     let mut tera = Tera::default();
-    tera.add_include_dir_templates(&TEMPLATES);
+    tera.add_include_dir_templates(&TEMPLATES).unwrap();
 
     // Special filter for the TypedValue map
     use serde_json::Value;
@@ -46,6 +50,16 @@ pub(crate) static TERA : Lazy<Tera> = Lazy::new(|| {
         Err(tera::Error::msg("Expected nonenmpty object"))
     });
 
+    // TODO need to inject HttpRequest::url_for() into tera context, but it then can't be accessed by the functions.
+    // tera.register_function("url_for", |args: HashMap<String, Value>| -> tera::Result<Value> {
+    //     match args.get("name") {
+    //         Some(Value::String(s)) => {
+    //             let r =
+    //         },
+    //         _ => Err("Expected string argument".into()),
+    //     }
+    // });
+
     tera
 });
 
@@ -58,98 +72,117 @@ async fn main() -> std::io::Result<()> {
     // Ensure the lazy ref is initialized early (to catch template bugs ASAP)
     let _ = TERA.deref();
 
-    let database : YopaStoreWrapper = {
-        let mut store = Storage::new();
-
-        // Seed the store with some dummy data for view development
-        use yopa::model;
-        use yopa::DataType;
-
-        let id_recipe = store.define_object(model::ObjectModel {
-            id: Default::default(),
-            name: "Recipe".to_string(),
-            parent: None
-        }).unwrap();
-        let id_book = store.define_object(model::ObjectModel {
-            id: Default::default(),
-            name: "Book".to_string(),
-            parent: None
-        }).unwrap();
-        let id_ing = store.define_object(model::ObjectModel {
-            id: Default::default(),
-            name: "Ingredient".to_string(),
-            parent: None
-        }).unwrap();
-
-        store.define_property(model::PropertyModel {
-            id: Default::default(),
-            object: id_recipe,
-            name: "name".to_string(),
-            optional: false,
-            multiple: true,
-            data_type: DataType::String,
-            default: None
-        }).unwrap();
-
-        store.define_property(model::PropertyModel {
-            id: Default::default(),
-            object: id_book,
-            name: "title".to_string(),
-            optional: false,
-            multiple: false,
-            data_type: DataType::String,
-            default: None
-        }).unwrap();
-
-        store.define_property(model::PropertyModel {
-            id: Default::default(),
-            object: id_book,
-            name: "author".to_string(),
-            optional: true,
-            multiple: true,
-            data_type: DataType::String,
-            default: Some(TypedValue::String("Pepa Novák".into()))
-        }).unwrap();
-
-        let rel_book_id = store.define_relation(model::RelationModel {
-            id: Default::default(),
-            object: id_recipe,
-            name: "book reference".to_string(),
-            optional: true,
-            multiple: true,
-            related: id_book
-        }).unwrap();
-
-        store.define_property(model::PropertyModel {
-            id: Default::default(),
-            object: rel_book_id,
-            name: "page".to_string(),
-            optional: true,
-            multiple: false,
-            data_type: DataType::Integer,
-            default: None
-        }).unwrap();
-
-        store.define_relation(model::RelationModel {
-            id: Default::default(),
-            object: id_recipe,
-            name: "related recipe".to_string(),
-            optional: true,
-            multiple: true,
-            related: id_recipe
-        }).unwrap();
-
-        web::Data::new(tokio::sync::RwLock::new(store))
-    };
+    let yopa_store: YopaStoreWrapper = init_yopa();
+
+    let mut session_key = [0u8; 32];
+    rand::thread_rng().fill(&mut session_key);
+
+    debug!("Session key: {:?}", session_key);
 
     HttpServer::new(move || {
-        let static_files = actix_web_static_files::ResourceFiles::new("/static", included_static_files())
+        let static_files = StaticFiles::new("/static", included_static_files())
             .do_not_resolve_defaults();
 
         App::new()
-            .app_data(database.clone())
+            /* Middlewares */
+            .wrap(
+                CookieSession::signed(&session_key)
+                    .secure(false)
+            )
+
+            /* Bind shared objects */
+            .app_data(yopa_store.clone())
+
+            /* Routes */
             .service(routes::index)
+            .service(routes::object_model_create_form)
+            .service(routes::object_model_create)
             .service(static_files)
+            .default_service(web::to(|| HttpResponse::NotFound().body("Not found")))
     })
-        .bind("127.0.0.1:8080")?.run().await
+        .bind("127.0.0.1:8080")?
+        .run().await
+}
+
+fn init_yopa() -> YopaStoreWrapper {
+    let mut store = Storage::new();
+
+    // Seed the store with some dummy data for view development
+    use yopa::model;
+    use yopa::DataType;
+
+    let id_recipe = store.define_object(model::ObjectModel {
+        id: Default::default(),
+        name: "Recipe".to_string(),
+    }).unwrap();
+
+    let id_book = store.define_object(model::ObjectModel {
+        id: Default::default(),
+        name: "Book".to_string(),
+    }).unwrap();
+
+    let id_ing = store.define_object(model::ObjectModel {
+        id: Default::default(),
+        name: "Ingredient".to_string(),
+    }).unwrap();
+
+    store.define_property(model::PropertyModel {
+        id: Default::default(),
+        object: id_recipe,
+        name: "name".to_string(),
+        optional: false,
+        multiple: true,
+        data_type: DataType::String,
+        default: None
+    }).unwrap();
+
+    store.define_property(model::PropertyModel {
+        id: Default::default(),
+        object: id_book,
+        name: "title".to_string(),
+        optional: false,
+        multiple: false,
+        data_type: DataType::String,
+        default: None
+    }).unwrap();
+
+    store.define_property(model::PropertyModel {
+        id: Default::default(),
+        object: id_book,
+        name: "author".to_string(),
+        optional: true,
+        multiple: true,
+        data_type: DataType::String,
+        default: Some(TypedValue::String("Pepa Novák".into()))
+    }).unwrap();
+
+    let rel_book_id = store.define_relation(model::RelationModel {
+        id: Default::default(),
+        object: id_recipe,
+        name: "book reference".to_string(),
+        optional: true,
+        multiple: true,
+        related: id_book
+    }).unwrap();
+
+    store.define_property(model::PropertyModel {
+        id: Default::default(),
+        object: rel_book_id,
+        name: "page".to_string(),
+        optional: true,
+        multiple: false,
+        data_type: DataType::Integer,
+        default: None
+    }).unwrap();
+
+    store.define_relation(model::RelationModel {
+        id: Default::default(),
+        object: id_recipe,
+        name: "related recipe".to_string(),
+        optional: true,
+        multiple: true,
+        related: id_recipe
+    }).unwrap();
+
+    web::Data::new(tokio::sync::RwLock::new(store))
 }
diff --git a/yopa-web/src/routes.rs b/yopa-web/src/routes.rs
index 4256021..14571f7 100644
--- a/yopa-web/src/routes.rs
+++ b/yopa-web/src/routes.rs
@@ -1,9 +1,12 @@
-use actix_web::{web, HttpRequest, Responder};
+use actix_web::{web, HttpRequest, Responder, HttpResponse};
 use crate::TERA;
 use crate::tera_ext::TeraExt;
-use yopa::Storage;
-use serde::Serialize;
-use yopa::model::{PropertyModel, RelationModel};
+use yopa::{Storage, StorageError};
+use serde::{Deserialize, Serialize};
+use yopa::model::{PropertyModel, RelationModel, ObjectModel};
+use std::ops::DerefMut;
+use actix_session::Session;
+use crate::session_ext::SessionExt;
 
 #[derive(Serialize, Debug)]
 struct ObjectModelDisplay<'a> {
@@ -21,7 +24,7 @@ struct RelationModelDisplay<'a> {
 }
 
 #[get("/")]
-pub(crate) async fn index(req: HttpRequest, store : crate::YopaStoreWrapper) -> actix_web::Result<impl Responder> {
+pub(crate) async fn index(session : Session, store : crate::YopaStoreWrapper) -> actix_web::Result<impl Responder> {
 
     let rg = store.read().await;
 
@@ -63,6 +66,52 @@ pub(crate) async fn index(req: HttpRequest, store : crate::YopaStoreWrapper) ->
 
     let mut ctx = tera::Context::new();
     ctx.insert("models", &models);
+    session.render_flash(&mut ctx);
 
     TERA.build_response("index", &ctx)
 }
+
+#[get("/model/object/create")]
+pub(crate) async fn object_model_create_form(session : Session) -> actix_web::Result<impl Responder> {
+    let mut context = tera::Context::new();
+    session.render_flash(&mut context);
+
+    TERA.build_response("model_create", &context)
+}
+
+#[derive(Deserialize)]
+pub(crate) struct ObjectModelCreate {
+    pub name : String,
+}
+
+#[post("/model/object/create")]
+pub(crate) async fn object_model_create(
+    form : web::Form<ObjectModelCreate>,
+    store : crate::YopaStoreWrapper,
+    session : Session
+) -> actix_web::Result<impl Responder> {
+    let mut wg = store.write().await;
+    let form = form.into_inner();
+    match wg.define_object(ObjectModel {
+        id: Default::default(),
+        name: form.name.clone()
+    }) {
+        Ok(_id) => {
+            debug!("Object created, redirecting to root");
+            session.flash_success(format!("Object model \"{}\" created.", form.name));
+
+            Ok(HttpResponse::SeeOther()
+                .header("location", "/")
+                .finish())
+        }
+        Err(e) => {
+            warn!("Error creating model: {}", e);
+            session.flash_error(e.to_string());
+
+            // Redirect back
+            Ok(HttpResponse::SeeOther()
+                .header("location", "/model/object/create")
+                .finish())
+        }
+    }
+}
diff --git a/yopa-web/src/session_ext.rs b/yopa-web/src/session_ext.rs
new file mode 100644
index 0000000..1ec8ae7
--- /dev/null
+++ b/yopa-web/src/session_ext.rs
@@ -0,0 +1,39 @@
+use serde::de::DeserializeOwned;
+use actix_session::Session;
+
+pub trait SessionExt {
+    /// Get a `value` from the session.
+    fn take<T: DeserializeOwned>(&self, key: &str) -> Result<Option<T>, actix_web::error::Error>;
+
+    fn render_flash(&self, context : &mut tera::Context);
+
+    fn flash_error(&self, msg : impl AsRef<str>);
+
+    fn flash_success(&self, msg : impl AsRef<str>);
+}
+
+impl SessionExt for Session {
+    fn take<T: DeserializeOwned>(&self, key: &str) -> Result<Option<T>, actix_web::error::Error> {
+        let val = self.get(key);
+        self.remove(key); // Always remove, even if parsing failed
+        Ok(val?)
+    }
+
+    fn render_flash(&self, context : &mut tera::Context) {
+        if let Ok(Some(msg)) = self.take::<String>("flash_error") {
+            context.insert("flash_error", &msg);
+        }
+
+        if let Ok(Some(msg)) = self.take::<String>("flash_success") {
+            context.insert("flash_success", &msg);
+        }
+    }
+
+    fn flash_error(&self, msg : impl AsRef<str>) {
+        self.set("flash_error", msg.as_ref()).unwrap();
+    }
+
+    fn flash_success(&self, msg : impl AsRef<str>) {
+        self.set("flash_success", msg.as_ref()).unwrap();
+    }
+}
diff --git a/yopa/src/lib.rs b/yopa/src/lib.rs
index a338e1b..f298d55 100644
--- a/yopa/src/lib.rs
+++ b/yopa/src/lib.rs
@@ -1,4 +1,5 @@
 #[macro_use] extern crate serde_json;
+#[macro_use] extern crate log;
 
 use std::borrow::Cow;
 use std::collections::HashMap;
@@ -63,16 +64,15 @@ impl Storage {
 
     /// Define a data object
     pub fn define_object(&mut self, mut tpl: model::ObjectModel) -> Result<ID, StorageError> {
-        if let Some(pid) = tpl.parent {
-            if !self.obj_models.contains_key(&pid) {
-                return Err(StorageError::NotExist(format!("parent object model {}", pid).into()));
-            }
+        if tpl.name.is_empty() {
+            return Err(StorageError::ConstraintViolation("name must not be empty".into()));
         }
 
         if self.obj_models.iter().find(|(_, t)| t.name == tpl.name).is_some() {
             return Err(StorageError::ConstraintViolation(format!("object model with the name \"{}\" already exists", tpl.name).into()));
         }
 
+        debug!("Define object model \"{}\"", tpl.name);
         let id = next_id();
         tpl.id = id;
         self.obj_models.insert(id, tpl);
@@ -81,6 +81,10 @@ impl Storage {
 
     /// Define a relation between two data objects
     pub fn define_relation(&mut self, mut rel: model::RelationModel) -> Result<ID, StorageError> {
+        if rel.name.is_empty() {
+            return Err(StorageError::ConstraintViolation("name must not be empty".into()));
+        }
+
         if !self.obj_models.contains_key(&rel.object) {
             return Err(StorageError::NotExist(format!("source object model {}", rel.object).into()));
         }
@@ -93,6 +97,7 @@ impl Storage {
                 format!("relation with the name \"{}\" and on model {} already exists", rel.name, rel.object).into()));
         }
 
+        debug!("Define relation model \"{}\" from {} to {}", rel.name, self.describe_model(rel.object), self.describe_model(rel.related));
         let id = next_id();
         rel.id = id;
         self.rel_models.insert(id, rel);
@@ -101,6 +106,10 @@ impl Storage {
 
     /// Define a property attached to an object or a relation
     pub fn define_property(&mut self, mut prop: model::PropertyModel) -> Result<ID, StorageError> {
+        if prop.name.is_empty() {
+            return Err(StorageError::ConstraintViolation("name must not be empty".into()));
+        }
+
         if !self.obj_models.contains_key(&prop.object) {
             // Maybe it's attached to a relation?
             if !self.rel_models.contains_key(&prop.object) {
@@ -121,6 +130,7 @@ impl Storage {
             });
         }
 
+        debug!("Define property model \"{}\" of {}", prop.name, self.describe_model(prop.object));
         let id = next_id();
         prop.id = id;
         self.prop_models.insert(id, prop);
@@ -130,6 +140,7 @@ impl Storage {
     /// Delete an object definition and associated data
     pub fn undefine_object(&mut self, id: ID) -> Result<ObjectModel, StorageError> {
         return if let Some(t) = self.obj_models.remove(&id) {
+            debug!("Undefine object model \"{}\"", t.name);
             // Remove relation templates
             let removed_relation_ids = map_drain_filter(&mut self.rel_models, |_k, v| v.object == id || v.related == id)
                 .keys();
@@ -158,6 +169,8 @@ impl Storage {
     /// Delete a relation definition and associated data
     pub fn undefine_relation(&mut self, id: ID) -> Result<model::RelationModel, StorageError> {
         return if let Some(t) = self.rel_models.remove(&id) {
+            debug!("Undefine relation model \"{}\"", t.name);
+
             // Remove relations
             let _ = map_drain_filter(&mut self.relations, |_k, v| v.model == id).keys();
 
@@ -177,6 +190,8 @@ impl Storage {
     /// Delete a property definition and associated data
     pub fn undefine_property(&mut self, id: ID) -> Result<model::PropertyModel, StorageError> {
         return if let Some(t) = self.prop_models.remove(&id) {
+            debug!("Undefine property model \"{}\"", t.name);
+
             // Remove relations
             let _ = map_drain_filter(&mut self.properties, |_k, v| v.model == id);
             Ok(t)
@@ -214,6 +229,7 @@ impl Storage {
     /// Insert object with relations, validating the data model constraints
     pub fn insert_object(&mut self, insobj: InsertObj) -> Result<ID, StorageError> {
         let obj_model_id = insobj.model_id;
+        debug!("Insert object {:?}", insobj);
 
         let obj_model = match self.obj_models.get(&obj_model_id) {
             Some(m) => m,
diff --git a/yopa/src/model.rs b/yopa/src/model.rs
index a38e9ed..acfd88a 100644
--- a/yopa/src/model.rs
+++ b/yopa/src/model.rs
@@ -23,8 +23,6 @@ pub struct ObjectModel {
     pub id: ID,
     /// Template name, unique within the database
     pub name: String,
-    /// Parent object template ID
-    pub parent: Option<ID>,
 }
 
 /// Relation between templates
diff --git a/yopa/src/tests.rs b/yopa/src/tests.rs
index 7b2c193..e9e1130 100644
--- a/yopa/src/tests.rs
+++ b/yopa/src/tests.rs
@@ -5,7 +5,6 @@ fn test1() {
     let model = crate::model::ObjectModel {
         id: Default::default(),
         name: "Name".to_string(),
-        parent: None
     };
 
     println!("{}", serde_json::to_string_pretty(&model).unwrap());