How do I set a persistent global template variable from the controller using Revel / Golang

I'm new to Golang and I'm switching over from Node.js server to a Golang server, I'm trying to rewrite an app I had previously written for Node.

I want to set Template variables when a user is signed in, but I'm not sure how and yes, I've tried googling it.

This is my register user controller:

func (c User) RegisterUser(user_email, user_password,
user_password_confirmation, user_first_name,
user_last_name string) revel.Result {
// Validate Email
c.Validation.Required(user_email).Message("Username is required")
c.Validation.Email(user_email).Message("Email is not a valid email")
c.Validation.MinSize(user_email, 5).Message("Email must be greater than 5 characters")
// Validate Password
c.Validation.Required(user_password).Message("Password is required")
c.Validation.MinSize(user_password, 5).Message("Password must be greater than 5 characters.")
// Validate Password Confirmation
c.Validation.Required(user_password_confirmation).Message("Password Confirmation is required")
c.Validation.MinSize(user_password_confirmation, 5).Message("Password must be greater than 5 characters.")
c.Validation.Required(user_password == user_password_confirmation).Message("Your passwords do not match")
// Validate First Name
c.Validation.Required(user_first_name).Message("First Name is required")
c.Validation.MinSize(user_first_name, 3).Message("Your First Name must be greater than 3 characters")
// Validate Last Name
c.Validation.Required(user_last_name).Message("Last Name is required")
c.Validation.MinSize(user_last_name, 3).Message("Your Last Name must be greater than 3 characters")
// If anything wasn't right, set flash and display errors to user
if c.Validation.HasErrors() {
c.Validation.Keep()
c.FlashParams()
return c.Redirect(User.Register)
}
// Hash The Users Password
password := []byte(user_password_confirmation)
hashedPassword, err := bcrypt.GenerateFromPassword(password, 10)
if err != nil {
c.Flash.Error("Invalid Username or Password Combination")
return c.Redirect(User.Register)
}
// Connect to database
db, err := sql.Open("mysql", "root:******@/WebRTC")
if err != nil {
c.Flash.Error("Unable to connect to database. Try again later!")
return c.Redirect(User.Register)
}
defer db.Close()
// Ping the database, ensure there is a connection
err = db.Ping()
if err != nil {
c.Flash.Error("Unable to connect to database. Try again later!")
return c.Redirect(User.Register)
}
// Prepare SQL Statement for Security
stmtIns, err := db.Prepare("INSERT INTO users (user_email, user_first_name, user_last_name, " +
"user_password_hash, user_created_at, user_created_ip, user_last_ip) VALUES (?, ?, ?, ?, ?, ?, ?)")
if err != nil {
c.Flash.Error("Unable to Register you. Please try again later")
return c.Redirect(User.Register)
}
defer stmtIns.Close()
// Insert Data into Database
_, err = stmtIns.Exec(user_email, user_first_name, user_last_name, hashedPassword,
time.Now().Local(), c.Request.RemoteAddr, c.Request.RemoteAddr)
if err != nil {
c.Flash.Error("Unable to register you. Please try again later")
return c.Redirect(User.Register)
}
// Here I want to add the global template variable
return c.Redirect(User.Register)
}

I've read about c.RenderArgs but it doesn't seem to do what I want it to.

I want to be able to set the users' username, so that I can display it in the navbar so that they know they're logged in.

You are on the right track if you are using c.RenderArgs unless I have misunderstood your intentions.

Here's an example (or rather, a walkthrough) of how you may use it (taken from Revel's booking sample app):

1. init.go: Register an interceptor to add the user's information before an action is taken (AddUser will be fired before Render).

2. app.go: Check if the user is connected and if so, store the user's data in the RenderArgs map like so:

c.RenderArgs["user"] = user

3. Line 31 deals with the model.

4. header.html: Pass the username template variable in.

I hope this helps.

EDIT: I should probably add that the user's username is stored in a session upon login. It's used to retrieve more information.