Updating the Methods

Now we need to update our methods so that we can pass two Strings instead of just one.

set_status

    pub fn set_status(&mut self, title: String, body: String) {
        let account_id = env::signer_account_id();
        self.records.insert(&account_id, &Message { title, body });
    }

One thing to note is Message { title, body }, this is how you can directly create a message without using a new function like we saw earlier.

get_status

    pub fn get_status(&self, account_id: AccountId) -> Option<String> {
        self.records
            .get(&account_id)
            .map(|Message { body, title }| format!(r#"{{"body":"{body}", "title": "{title}"}}"#))
    }

Before account_id was a String, but now we can use AccountId directly which will panic the contract if the account id is not valid.

Next we have a new function map, which is a method Option. And a new syntax |Message { body, title}|.

map is a function takes a function as argument. Then if the Option is not None it will pass the inner value to the function. In Rust an anonymous rust has the following syntax, |x| x + 1, if you are familiar with JavaScript it is like an arrow function (x) => x + 1.

Rust let's you ~destructure~ the argument passed to the function.

#![allow(unused)]
fn main() {
|Message { body, title }| format!(r#"{{"body":"{body}", "title": "{title}"}}"#))

// Is the same as the function
|msg| {
  let body = msg.body;
  let title = msg.title;
  format!(r#"{{"body":"{body}", "title": "{title}"}}"#)
})
}

Lastly, we are creating a String that represents the JSON representation of Message, later we won't have to do this by hand.

format! is a macro for injecting strings into another in this case {body} and {title} are replaced by the corresponding variables.

r#".."# is called a raw string, which let's us use a " from within the string. And we need two {{ and }} so that format! understands that it's actually a { or } in the String.