Add content from last presentation

rust_web.org

@@ -1,14 +1,16 @@
+#+STARTUP: beamer
 #+OPTIONS: ':nil *:t -:t ::t <:t H:3 \n:nil ^:t arch:headline
 #+OPTIONS: author:t broken-links:nil c:nil creator:nil
 #+OPTIONS: d:(not "LOGBOOK") date:t e:t email:nil f:t inline:t num:t
 #+OPTIONS: p:nil pri:nil prop:nil stat:t tags:t tasks:t tex:t
 #+OPTIONS: timestamp:t title:t toc:t todo:t |:t
+#+OPTIONS: ^:nil
 #+TITLE: Rust, Rocket and Diesel
-#+SUBTITLE: Web apps with rust
+#+SUBTITLE: Web apps with Rust
 #+DESCRIPTION: An introduction to Rust, Rocket and Diesel.
 #+KEYWORDS: rust rocket diesel
-#+AUTHOR: \href{mailto:rocket-presentation@onders.org}{finga}
-#+EMAIL: rocket-presentation@onders.org
+#+AUTHOR: \href{mailto:finga@onders.org}{finga}
+#+EMAIL: finga@onders.org
 #+LANGUAGE: en
 #+SELECT_TAGS: export
 #+EXCLUDE_TAGS: noexport
@@ -16,9 +18,10 @@
 
 #+OPTIONS: H:2
 #+LATEX_CLASS: beamer
-#+LATEX_CLASS_OPTIONS: [aspectration=1610]
+#+LATEX_CLASS_OPTIONS: [aspectratio=1610]
 # #+LATEX_HEADER: \hypersetup{colorlinks=true,linkcolor=gray}
 #+LATEX_HEADER: \hypersetup{colorlinks=true,linkcolor=black,urlcolor=gray}
+# #+LATEX_HEADER: \usepackage{listings, listings-rust}
 #+COLUMNS: %45ITEM %10BEAMER_env(Env) %10BEAMER_act(Act) %4BEAMER_col(Col) %8BEAMER_opt(Opt)
 #+BEAMER_THEME: Frankfurt
 #+BEAMER_COLOR_THEME: seagull
@@ -37,48 +40,11 @@
 *** Rust, the language
     - About 10 years young (2010)
     - Memory safe without gcing, optional ref counting
-    - Ownership, lifetimes, traits
+    - Ownership, lifetimes, traits, functional paradigms
     - Variables are immutable by default and can be shadowed
     - Performance of idiomatic Rust is comparable to the performance
       of idiomatic cpp
 
-** Where to get further information?
-
-*** Docs...
-    - [[https://doc.rust-lang.org/book/][The rust book]] (~$ rustup docs --book~)
-    - [[https://doc.rust-lang.org/rust-by-example/][Rust by example]] (~$ rustup docs --rust-by-example~)
-    - [[https://doc.rust-lang.org/std/][The Rust Standard Library]] (~$ rustup docs --std~)
-    - Use '~$ rustup help docs~' to get an overview
-    - [[https://cheats.rs][cheats.rs]]
-    - [[https://programming-idioms.org/cheatsheet/Rust][programming-idioms.org]]
-    - [[https://cargo.io][cargo.io]]/[[https://lib.rs][lib.rs]]
-
-*** Chat (Discord)
-    - [[https://discord.gg/rust-lang][The Rust Programming Language]]
-    - [[https://discord.com/invite/tcbkpyQ][The Rust Programming Language Community Server]]
-
-** What are we going to use?
-
-*** Definitely
-    :PROPERTIES:
-    :BEAMER_col: 0.45
-    :BEAMER_env: block
-    :END:
-    - [[https://rocket.rs][rocket]]
-    - [[https://diesel.rs][diesel]]
-    - log/env_logger
-
-*** Maybe
-    :PROPERTIES:
-    :BEAMER_col: 0.45
-    :BEAMER_env: block
-    :END:
-    - anyhow
-    - lettre
-    - sha3
-    - serde
-    - chrono
-
 ** How to install
 
 *** Install Rust
@@ -92,16 +58,209 @@
     $ rustup toolchain install nightly
     #+END_SRC
 
-*** Install rustfmt (code formatter)
+*** Install rustfmt (linter and code formatter)
     #+BEGIN_SRC sh
     $ rustup component add rustfmt
     #+END_SRC
 
-*** Install clippy (linter and static code analysis)
+*** Install clippy (static code analysis)
     #+BEGIN_SRC sh
     $ rustup component add clippy
     #+END_SRC
 
+** Where to find more information?
+
+*** Docs...
+    - [[https://doc.rust-lang.org/book/][The Rust Book]] (~$ rustup docs --book~)
+    - [[https://doc.rust-lang.org/rust-by-example/][Rust by Example]] (~$ rustup docs --rust-by-example~)
+    - [[https://doc.rust-lang.org/std/][The Rust Standard Library]] (~$ rustup docs --std~)
+    - Use '~$ rustup help docs~' to get an overview
+    - [[https://cheats.rs][cheats.rs]]
+    - [[https://programming-idioms.org/cheatsheet/Rust][programming-idioms.org]]
+    - [[https://crates.io][crates.io]]/[[https://lib.rs][lib.rs]]
+
+*** Chat (Discord)
+    - [[https://discord.gg/rust-lang][The Rust Programming Language]]
+    - [[https://discord.com/invite/tcbkpyQ][The Rust Programming Language Community Server]]
+
+** Hello, World!
+   Executing ~`cargo new foobar`~ creates a new project...
+
+*** foobar/Cargo.toml
+    #+BEGIN_SRC toml
+    [package]
+    name = "foo"
+    version = "0.1.0"
+    authors = ["finga <finga@onders.org>"]
+    edition = "2018"
+    #+END_SRC
+    \tiny
+    #+BEGIN_SRC toml
+    # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+    #+END_SRC
+    \normalsize
+    #+BEGIN_SRC toml
+    [dependencies]
+    #+END_SRC
+
+*** foobar/src/main.rs
+    #+BEGIN_SRC rust
+    fn main() {
+        println!("Hello, world!");
+    }
+    #+END_SRC
+
+** Mutability and shadowing
+
+*** Immutable variable
+    #+BEGIN_SRC rust
+    let foo = 5;
+    #+END_SRC
+
+*** Mutable variable
+    #+BEGIN_SRC rust
+    let mut bar = 5;
+    bar = 6;
+    #+END_SRC
+
+*** Shadowing
+    #+BEGIN_SRC rust
+    let baz = 5;
+    let baz = baz + 3;
+    #+END_SRC
+
+** Structs
+
+*** Definition of a struct
+     #+BEGIN_SRC rust
+     struct Something {
+         id: usize,
+         item: String,
+     }
+     #+END_SRC
+
+*** Instantiation of a struct
+    #+BEGIN_SRC rust
+    let something = Something {
+        id: 0,
+        item: String::from("an item"),
+    };
+    #+END_SRC
+
+*** Access of a struct's field
+    #+BEGIN_SRC rust
+    something.item
+    #+END_SRC
+
+** Tuple structs
+
+*** Definition of a tuple struct
+     #+BEGIN_SRC rust
+     struct Box(usize, usize, usize);
+     #+END_SRC
+
+*** Instantiation of a tuple struct
+    #+BEGIN_SRC rust
+    let first_box = Box(3, 5, 7);
+    #+END_SRC
+
+*** Access of a tuple struct's field
+    #+BEGIN_SRC rust
+    first_box.0;
+    first_box.1;
+    first_box.2;
+    #+END_SRC
+
+** Error related types
+   - Heavy use of ~Option<T>~ and ~Result<T, E>~
+
+*** Option
+    #+BEGIN_SRC rust
+    pub enum Option<T> {
+        None,
+        Some(T),
+    }
+    #+END_SRC
+
+*** Result
+    #+BEGIN_SRC rust
+    pub enum Result<T, E> {
+        Ok(T),
+        Err(E),
+    }
+    #+END_SRC
+
+** Error handling
+
+*** Unrecoverable errors \rightarrow panics
+    #+BEGIN_SRC rust
+    fn get_data() -> Data {
+        ...
+        panic!("Cannot get data");
+    }
+    #+END_SRC
+
+*** Recoverable error with anyhow
+    #+BEGIN_SRC rust
+    fn get_data() -> Result<Data> {
+        ...
+        Ok(data) // return is only used for "early" returns
+    }
+    ...
+        let data = get_data()?;
+    ...
+    #+END_SRC
+
+** ~match~ statements
+   - Must be exhaustive
+   - All match arms must return the same type!
+   - Can be used everywhere e.g. ~let foo = match ...~
+   - @@latex:{\color{red}@@All match arms must return the same type!!1!@@latex:}@@
+
+*** Recoverable error with anyhow
+    #+BEGIN_SRC rust
+    match age {
+        0 => unreachable!("Too young to be a person"),
+        n @ 1..=12 => println!("Child of age {}", n),
+        n @ 13..=19 => println!("Teen of age {}", n),
+        n @ 20..=150 => println!("Person of age {}", n),
+        _ => unimplemented!("Nobody I know got that old"),
+    }
+    #+END_SRC
+
+** ~if let~ statements
+
+*** Sometimes an ~if let~ is nicer than a ~match~ or an ~if/else~ statement
+    #+BEGIN_SRC rust
+    if let Some(actual_age) = age {
+        println!("The age is {}", actual_age);
+    }
+    #+END_SRC
+
+** Use functional language features
+   - ~vec![1, 2, 3].iter()~
+   - ~vec![1, 2, 3].iter().sum()~
+   - ~vec![1, 2, 3].iter().map(|x| x + 1).collect()~
+   - ~foo.into_iter().filter(|i| i.bar == 0).collect()~
+   - ~Iterator~ trait
+
+** Tests
+   - Use ~assert!()~ family
+   - Unit tests
+     - Put them into a test module
+     - Annotate the test module with ~#[cfg(test)]~
+     - Annotate the tests with ~#[test]~
+   - Documentation testing
+   - Integration testing
+     - Integration tests are put into the ~src/tests/~ directory
+
+** Docs
+   - Documentation comments: ~///~
+   - Markdown notation
+   - ~cargo doc~ runns ~rustdoc~ which generates html docs
+   - ~cargo doc --open~ runs ~rustdoc~ and opens the result in a browser
+   - ~rustdoc~ documentation: https://doc.rust-lang.org/beta/rustdoc/index.html
+
 * Rocket
 
 ** What is Rocket?
@@ -120,7 +279,7 @@
      - Type Safe
      - Extensible
      - Templating
-     - Cookies
+     - (Secure) Cookies
 
 **** Col right
      :PROPERTIES:
@@ -129,6 +288,112 @@
      - Streams
      - Testing (Unit tests)
      - Typed URIs
+     - Single binary
+
+** Create a new Rocket project
+*** Create the crate
+    #+BEGIN_SRC sh
+    cargo init new_project
+    cd new_project
+    rustup override set nightly
+    cargo r
+    #+END_SRC
+
+*** Add Rocket dependencies to ~Cargo.toml~
+    #+BEGIN_SRC toml
+    [dependencies]
+    rocket = "0.4"
+    #+END_SRC
+
+** Hello Rocket
+*** ~src/main.rs~
+   #+BEGIN_SRC rust
+   #![feature(decl_macro)]
+
+   use rocket::{get, routes};
+
+   #[get("/hello/<name>/<age>")]
+   fn hello(name: String, age: u8) -> String {
+       format!("Hello, {} year old named {}!", age, name)
+   }
+
+   fn main() {
+       rocket::ignite().mount("/", routes![hello]).launch();
+   }
+   #+END_SRC
+
+** Receive data
+*** Struct ~EmailForm~
+    #+BEGIN_SRC rust
+    #[derive(Debug, FromForm)]
+    struct EmailForm {
+        email: String,
+    }
+    #+END_SRC
+
+*** Procedure using that form data
+    #+BEGIN_SRC rust
+    #[post("/reset", data = "<email>")]
+    fn reset_email(email: Form<EmailForm>) -> Flash<Redirect> {
+        ...
+        Flash::success(
+            Redirect::to(uri!(reset)),
+            format!("Email was sent to {}", email.email),
+        )
+    }
+    #+END_SRC
+
+** Flash messages
+   #+BEGIN_SRC rust
+   #[get("/reset")]
+   fn reset(flash: Option<FlashMessage>) -> String {
+       if let Some(ref msg) = flash { // `let ref x = y` is
+           msg.msg()                  // equivalent to `let x = &y`
+       } else {
+           format!("Hello, reset!");
+       }
+   }
+   #+END_SRC
+
+** Templates
+   - Use the ~rocket_contrib~ crate!
+*** ~templates/name.html.tera~
+    :PROPERTIES:
+    :BEAMER_col: 0.35
+    :BEAMER_env: block
+    :END:
+    #+BEGIN_SRC html
+    <!DOCTYPE html>
+    <html>
+      <head>
+        ...
+      </head>
+      <body>
+        <p> Hello,
+        {{ name }}!</p>
+      </body>
+    </html>
+    #+END_SRC
+
+*** ~src/main.rs~
+    :PROPERTIES:
+    :BEAMER_col: 0.60
+    :BEAMER_env: block
+    :END:
+    #+BEGIN_SRC rust
+    #[get("/hello/<name>")]
+    fn hello(name: String) -> Template {
+        let mut context = HashMap::new();
+        context.insert("name", name);
+
+        Template::render("name", &context)
+    }
+    ...
+        rocket::ignite()
+            .mount(...)
+            .attach(Template::fairing())
+            .launch();
+    #+END_SRC
 
 ** Where to get further information?
 
@@ -152,7 +417,7 @@
 
 * Diesel
 
-** What is an ORM?
+** ORM
    Object-relational-mapping is a programming technique for converting
    data between incompatible type systems using the paradigms of your
    programming language.
@@ -219,11 +484,21 @@
         comment: "A comment",
     };
 
+    ...
+
     insert_into(comments)
         .values(&user)
         .execute(conn);
     #+END_SRC
 
+** About Diesel
+   - Enable connection pooling via the ~r2d2~ crate
+   - Nested joins are not yet nicely implemented
+   - Database specific SQL regarding each DBMS
+   - Take a look at the [[https://github.com/diesel-rs/diesel/tree/master/diesel_cli][diesel_cli]] crate for multi DBMS support
+   - Use ~diesel_cli~ macros and functions for compiling migration
+     functionality into the application
+
 ** Where to get further information?
 
 *** Docs...
@@ -247,7 +522,7 @@
 * Lets code something
 
 ** Lets create a small web app
-   A mini text board where everybody can post and reply.
+   A chat box where everybody can post.
 
 *** Caution
     HTML is not disabled!
@@ -286,9 +561,11 @@
 
 ***** Modify ~src/main.rs~ for Rockets "~Hello, world!~" program
       #+BEGIN_SRC rust
-      #![feature(proc_macro_hygiene, decl_macro)]
+        // #![feature(proc_macro_hygiene, decl_macro)]
+        #![feature(decl_macro)]
 
-      #[macro_use] extern crate rocket;
+        // #[macro_use] extern crate rocket;
+        // #[macro_use] extern crate diesel;
 
         #[get("/")]
         fn index() -> &'static str {
@@ -535,15 +812,109 @@
       }
       #+END_SRC
 
+**** Create a template to list all posts
+
+***** Add a template for the index page ~templates/index.html.tera~
+      #+BEGIN_SRC html
+      {% extends "base" %}
+
+      {% block content %}
+      <h1>simple text board</h1>
+      <h2>index</h2>
+      <ul>
+        {% for post in posts %}
+        <li>{{ loop.index }} - <a href="post/{{ post.id }}">{{ post.title }}</a> - {{ post.author }}</li>
+        {% endfor %}
+      </ul>
+      {% endblock content %}
+      #+END_SRC
+
+***** Add serde dependencies to ~Cargo.toml~
+      #+BEGIN_SRC toml
+      chrono = { version = "0.4", features = ["serde"] }
+      ...
+      serde = { version = "1.0", features = ["derive"] }
+      #+END_SRC
+
+***** Add `Post` to ~src/models.rs~
+      #+BEGIN_SRC rust
+      ...
+      use diesel::{QueryResult, RunQueryDsl, SqliteConnection};
+      use serde::Serialize;
+
+      ...
+
+      #[derive(Debug, Queryable, Serialize)]
+      pub struct Post {
+          pub id: i32,
+          pub parent: Option<i32>,
+          pub timestamp: NaiveDateTime,
+          pub author: String,
+          pub email: String,
+          pub title: String,
+          pub content: String,
+      }
+
+      impl Post {
+          pub fn get_all(connection: &SqliteConnection) -> QueryResult<Vec<Post>> {
+              posts::table.load::<Post>(connection)
+          }
+      }
+      #+END_SRC
+
+***** Add index template in ~src/main.rs~
+      #+BEGIN_SRC rust
+      ...
+      use serde::Serialize;
+
+      ...
+
+      use models::{NewPost, Post};
+
+      ...
+
+      #[derive(Serialize)]
+      struct Posts {
+          posts: Vec<Post>,
+      }
+
+      #[get("/")]
+      fn index(conn: DbCon) -> Template {
+          Template::render(
+              "index",
+              Posts {
+                  posts: Post::get_all(&conn).unwrap(),
+              },
+          )
+      }
+      #+END_SRC
+
+**** Create page for posts
+
+***** Create template ~templates/post.html.tera~
+
+**** Create possibility to reply
+
 * Conclusion
 
+** In general
+   - Rust's community and ecosystem is growing steadily
+   - Rust covers a broad field from low level code to high level
+   - Rocket and libraries alike improve creating security and
+     performance focused web application development
+   - Diesel is on a good way to become a serious ORM
+   - Alltogether Rust is ready to be used for web apps
+
 ** What did we do?
    - Setup Rust and Diesel
    - Create a project with Rocket and Diesel prerequisites
-   - Handle a SQLite DB with Diesel
-   - Create Tera templates
+   - Store a small model with Diesel in a SQLite DB
+   - Create and use Tera templates
 
-** What did you hopefully learn!
+** Where to continue
+   - Move DB setup into the project
+   - Add features (List posts by Author, paging, etc..)
+   - (Private) Cookies
 
 ** Two small projects
 
@@ -553,17 +924,18 @@
     :BEAMER_env: block
     :END:
     - LDAP password reset tool
-    - ($\sim$ 300 SloC)
+    - ($\sim$ 300 SloC without tests)
     - First release
     - Tests
 
-*** [[https://git.onders.org/finga/filerly][filerly]]
+*** [[https://git.onders.org/finga/webhookey][webhookey]]
     :PROPERTIES:
     :BEAMER_col: 0.45
     :BEAMER_env: block
     :END:
-    - File sharing a la NextCloud
-    - Not yet ready, work in progress...
+    - Execute scripts triggered by http(s) requests
+    - Is becoming more and more robust
+    - ($\sim$ 400 SloC without tests)
 
 ** The End
    #+BEGIN_CENTER

simple_text_board/Cargo.lock

@@ -195,6 +195,7 @@ dependencies = [
  "libc",
  "num-integer",
  "num-traits",
+ "serde",
  "time",
  "winapi 0.3.9",
 ]
@@ -1124,6 +1125,20 @@ name = "serde"
 version = "1.0.119"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9bdd36f49e35b61d49efd8aa7fc068fd295961fd2286d0b2ee9a4c7a14e99cc3"
+dependencies = [
+ "serde_derive",
+]
+
+[[package]]
+name = "serde_derive"
+version = "1.0.119"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "552954ce79a059ddd5fd68c271592374bd15cab2274970380c000118aeffe1cd"
+dependencies = [
+ "proc-macro2 1.0.24",
+ "quote 1.0.8",
+ "syn 1.0.58",
+]
 
 [[package]]
 name = "serde_json"
@@ -1169,6 +1184,7 @@ dependencies = [
  "log 0.4.13",
  "rocket",
  "rocket_contrib",
+ "serde",
 ]
 
 [[package]]

simple_text_board/Cargo.toml

@@ -6,9 +6,10 @@ edition = "2018"
 
 [dependencies]
 rocket = "0.4"
-chrono = "0.4"
+chrono = { version = "0.4", features = ["serde"] }
 diesel = { version = "1.4", features = ["sqlite", "chrono"] }
 log = "0.4"
+serde = { version = "1.0", features = ["derive"] }
 
 [dependencies.rocket_contrib]
 version = "0.4"

simple_text_board/src/main.rs

@@ -15,11 +15,12 @@ use rocket::{
     routes, uri, FromForm,
 };
 use rocket_contrib::{database, templates::Template};
+use serde::Serialize;
 
 mod models;
 mod schema;
 
-use models::NewPost;
+use models::{NewPost, Post};
 
 #[database("sqlite")]
 struct DbCon(SqliteConnection);
@@ -32,6 +33,21 @@ struct PostForm {
     content: String,
 }
 
+#[derive(Serialize)]
+struct Posts {
+    posts: Vec<Post>,
+}
+
+#[get("/")]
+fn index(conn: DbCon) -> Template {
+    Template::render(
+        "index",
+        Posts {
+            posts: Post::get_all(&conn).unwrap(),
+        },
+    )
+}
+
 #[get("/create")]
 fn create_form(flash: Option<FlashMessage>) -> Template {
     let mut context = HashMap::new();
@@ -73,11 +89,6 @@ fn create_post(
     }
 }
 
-#[get("/")]
-fn index() -> &'static str {
-    "Hello, world!"
-}
-
 fn main() {
     rocket::ignite()
         .mount("/", routes![index, create_form, create_post])

simple_text_board/src/models.rs

@@ -1,6 +1,7 @@
 use crate::schema::posts::{self, dsl::posts as table_posts};
 use chrono::NaiveDateTime;
-use diesel::{QueryResult, RunQueryDsl};
+use diesel::{QueryResult, RunQueryDsl, SqliteConnection};
+use serde::Serialize;
 
 #[derive(Insertable)]
 #[table_name = "posts"]
@@ -18,3 +19,20 @@ impl NewPost<'_> {
         diesel::insert_into(table_posts).values(self).execute(conn)
     }
 }
+
+#[derive(Debug, Queryable, Serialize)]
+pub struct Post {
+    pub id: i32,
+    pub parent: Option<i32>,
+    pub timestamp: NaiveDateTime,
+    pub author: String,
+    pub email: String,
+    pub title: String,
+    pub content: String,
+}
+
+impl Post {
+    pub fn get_all(connection: &SqliteConnection) -> QueryResult<Vec<Post>> {
+        posts::table.load::<Post>(connection)
+    }
+}

simple_text_board/templates/index.html.tera

@@ -0,0 +1,11 @@
+{% extends "base" %}
+
+{% block content %}
+<h1>simple text board</h1>
+<h2>index</h2>
+<ul>
+  {% for post in posts %}
+  <li>{{ loop.index }} - <a href="post/{{ post.id }}">{{ post.title }}</a> - {{ post.author }}</li>
+  {% endfor %}
+</ul>
+{% endblock content %}