add request::Flash (inspired by Rocket)v0.3.4

bump version to 0.3.4

2 files changed, 64 insertions, 3 deletions

diff --git a/Cargo.toml b/Cargo.toml
index 91ced92..278de4e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "sputnik"
-version = "0.3.3"
+version = "0.3.4"
 authors = ["Martin Fischer <martin@push-f.com>"]
 license = "MIT"
 description = "A lightweight layer on top of hyper to facilitate building web applications."
diff --git a/src/request.rs b/src/request.rs
index f2392b8..195e601 100644
--- a/src/request.rs
+++ b/src/request.rs
@@ -9,7 +9,7 @@ use std::{collections::HashMap, sync::Arc};
 use rand::{Rng, distributions::Alphanumeric};
 use async_trait::async_trait;
 
-use crate::response::SputnikHeaders;
+use crate::response::{SputnikHeaders, delete_cookie};
 
 const CSRF_COOKIE_NAME : &str = "csrf";
 
@@ -88,6 +88,67 @@ impl std::fmt::Display for CsrfToken {
     }
 }
 
+const FLASH_COOKIE_NAME: &str = "flash";
+
+/// Show the user a message after redirecting them.
+pub struct Flash {
+    name: String,
+    message: String,
+}
+
+impl From<Flash> for Cookie<'_> {
+    fn from(flash: Flash) -> Self {
+        Cookie::build(FLASH_COOKIE_NAME, format!("{}:{}", flash.name, flash.message))
+        .max_age(Duration::minutes(5)).finish()
+    }
+}
+
+impl Flash {
+    /// If the request has a flash cookie retrieve it and append a set-cookie
+    /// header to delete the cookie to [`SputnikParts::response_headers`].
+    pub fn from_request(req: &mut Parts) -> Option<Self> {
+        req.cookies().get(FLASH_COOKIE_NAME)
+        .and_then(|cookie| {
+            req.response_headers().set_cookie(delete_cookie(FLASH_COOKIE_NAME));
+            let mut iter = cookie.value().splitn(2, ':');
+            if let (Some(name), Some(message)) = (iter.next(), iter.next()) {
+                return Some(Flash{name: name.to_owned(), message: message.to_owned()})
+            }
+            None
+        })
+    }
+
+    /// Constructs a new Flash message. The name must not contain a colon (`:`).
+    pub fn new(name: String, message: String) -> Self {
+        Flash{name, message}
+    }
+
+    /// Constructs a new "success" Flash message.
+    pub fn success(message: String) -> Self {
+        Flash{name: "success".to_owned(), message}
+    }
+
+    /// Constructs a new "warning" Flash message.
+    pub fn warning(message: String) -> Self {
+        Flash{name: "warning".to_owned(), message}
+    }
+
+    /// Constructs a new "error" Flash message.
+    pub fn error(message: String) -> Self {
+        Flash{name: "error".to_owned(), message}
+    }
+
+    /// Returns the name of the Flash message.
+    pub fn name(&self) -> &str {
+        &self.name
+    }
+
+    /// Returns the message of the Flash message.
+    pub fn message(&self) -> &str {
+        &self.message
+    }
+}
+
 impl CsrfToken {
     /// Returns a CSRF token, either extracted from the `csrf` cookie or newly
     /// generated if the cookie wasn't sent (in which case a set-cookie header is
@@ -96,7 +157,7 @@ impl CsrfToken {
     /// If there is no cookie, calling this method multiple times only generates
     /// a new token on the first call, further calls return the previously
     /// generated token.
-    pub fn from_request(req: &mut Parts) -> CsrfToken {
+    pub fn from_request(req: &mut Parts) -> Self {
         if let Some(token) = req.extensions.get::<CsrfToken>() {
             return token.clone()
         }