further extension of the system

It is now possible to use the database. The authentication middleware is
the first module to use it. We will see, how it will work out.

controller/admin/login.go

@@ -0,0 +1,23 @@
+package admin
+
+import (
+  "log"
+  "github.com/gibheer/zero-blog/lib"
+)
+
+func LoginGet(c *lib.Context) error {
+  c.Env.Template.Lookup("login/index").Execute(c.Response, struct {}{})
+  return nil
+}
+
+func LoginPost(c *lib.Context) error {
+  username := c.Request.PostFormValue("username")
+  password := c.Request.PostFormValue("password")
+  if username == "" && password == "" {
+    log.Print("There was nothing at all!")
+  } else {
+    log.Print(username, password)
+  }
+  c.Env.Template.Lookup("login/index").Execute(c.Response, struct {}{})
+  return nil
+}

controller/controller.go

@@ -2,9 +2,15 @@ package controller
 
 import (
   "github.com/gibheer/zero-blog/lib"
+  "github.com/gibheer/zero-blog/middleware"
+  "github.com/gibheer/zero-blog/controller/admin"
   "github.com/gibheer/zero-blog/controller/welcome"
 )
 
 func DefineRoutes(router *lib.Router) {
   router.Get("/", welcome.Welcome)
+  router.Get( "/login", admin.LoginGet)
+  router.Post("/login", admin.LoginPost)
+  authentication := router.NewGroup("/admin")
+  authentication.Use(middleware.Authentication)
 }

lib/router.go

@@ -4,6 +4,7 @@ import (
   "log"
   "net/http"
   "github.com/julienschmidt/httprouter"
+  "github.com/gibheer/zero-blog/repository"
 )
 
 // the following is inspired by the gin framework
@@ -36,6 +37,8 @@ type Context struct {
   Response http.ResponseWriter
   // parameters provided by the router
   Params httprouter.Params
+  // current session
+  Session *repository.Session
 
   // the list of functions to run
   funcList []ContextFunc
@@ -93,10 +96,16 @@ func (r *Router) createHandleFunction(target ContextFunc) httprouter.Handle {
     params   httprouter.Params) {
 
     ctx := &Context{
-      request, response, params, append(r.fullFuncList(), target), 0, r.env,
+      Request:  request,
+      Response: response,
+      Params:   params,
+      funcList: append(r.fullFuncList(), target),
+      current:  0,
+      Env:      r.env,
     }
-    for i := 0; i < len(ctx.funcList); i++ {
-      ctx.funcList[i](ctx)
+    for !ctx.Aborted() && ctx.current < len(ctx.funcList) {
+      ctx.funcList[ctx.current](ctx)
+      ctx.current++
     }
   }
 }
@@ -113,3 +122,14 @@ func (r *Router) Start() {
   log.Print("Starting to listen for incoming requests ...")
   log.Fatal(http.ListenAndServe(":9292", r.router))
 }
+
+func (c *Context) Aborted() bool {
+  if c.current < 0 {
+    return true
+  }
+  return false
+}
+
+func (c *Context) Abort() {
+  c.current = -1
+}

middleware/authentication.go

@@ -0,0 +1,27 @@
+package middleware
+
+import (
+  "net/http"
+  "github.com/gibheer/zero-blog/lib"
+  "github.com/gibheer/zero-blog/repository"
+)
+
+func Authentication(c *lib.Context) error {
+  session_id, err := c.Request.Cookie("session")
+  if err != nil {
+    redirectToLogin(c)
+    return err
+  }
+  session := repository.GetSession(c.Env.DB.Conn, session_id.Value)
+  if session == nil {
+    redirectToLogin(c)
+    return err
+  }
+  c.Session = session
+  return nil
+}
+
+func redirectToLogin(c *lib.Context) {
+  c.Abort()
+  http.Redirect(c.Response, c.Request, "/login", 307)
+}

repository/account.go

@@ -0,0 +1,29 @@
+package repository
+
+import (
+  "database/sql"
+)
+
+type Account struct {
+  Id       int
+  Username string
+  Email    string
+  Password string
+  Role     string
+}
+
+func GetAccount(db *sql.DB, account_id string) *Account {
+  account := &Account{}
+  err := db.QueryRow(
+    `select id, username, email from accounts where id = ?`,
+    account_id).Scan(
+    &account.Id,
+    &account.Username,
+    &account.Email,
+  )
+  // TODO do something with the error
+  if err != nil {
+    return nil
+  }
+  return account
+}

repository/session.go

@@ -0,0 +1,28 @@
+package repository
+
+import (
+  "database/sql"
+)
+
+type Session struct {
+  Id      string
+  Account *Account
+}
+
+func GetSession(db *sql.DB, session_id string) *Session {
+  session := &Session{Account: &Account{}}
+
+  err := db.QueryRow(
+    `select session_id, id, username
+       from sessions s
+       join accounts a
+         on s.account_id = a.id
+      where session_id = ?
+        and last_change > now() - interval '1 hour'`,
+     session_id).Scan(&session.Id, &session.Account.Id, &session.Account.Username)
+  // TODO do something with the error
+  if err != nil {
+    return nil
+  }
+  return session
+}

templates/login/index.tmpl

@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html>
+  <head></head>
+  <body>
+    This is not working correctly yet, but who cares
+    <form action="/login" method="post">
+      <input name="username" />
+      <input name="password" />
+      <button type="submit">send?</button>
+    </form>
+  </body>
+</html>