Short question regarding to weird behaviour in forms

[jzisking]

Hello guys. I have the following html form

<form action="/publish">
            <label for="id_title">Title of the paste:</label><br>
            <input type="text" id="id_title" name="id_title" value=""><br>
            <label for="id_content">Content of the paste:</label><br>
            <input type="text" id="id_content" name="id_content" value=""><br><br>
            <input type="submit" value="Submit">
        </form>

I want to parse this data in rocket.
When I use the following route, it works as intended:

#[get("/publish?<id_title>&<id_content>")]
async fn publish(id_title: String, id_content: String) -> String {
    format!("Title: {}, Content: {}", id_title, id_content)
}

But when I use this code, it does not work. But I dont understand why.

#[derive(FromForm)]
struct PublishForm<'a >{
    id_title: &'a str,
    id_content: &'a str
}

#[get("/publish", data = "<user_input>")]
async fn publish(user_input: Form<PublishForm<'_>>) -> String {
    format!("Title: {}, Content: {}", user_input.id_title, user_input.id_content)
}

In my understanding, he should parse this data into the form structure. But it does not seem so.
Does anybody have an idea why? Thanks for answering in advance.

[blackghost1987]

By default a HTML form uses a "GET" method and puts the values in the URI as query parameters, that's why your first solution works.
If you want to put the data in the body (as form-urlencoded), you have to use the "POST" method. So this should work:

<form method="post" action="/publish">
            <label for="id_title">Title of the paste:</label><br>
            <input type="text" id="id_title" name="id_title" value=""><br>
            <label for="id_content">Content of the paste:</label><br>
            <input type="text" id="id_content" name="id_content" value=""><br><br>
            <input type="submit" value="Submit">
        </form>

#[post("/publish", data = "<user_input>")]
async fn publish(user_input: Form<PublishForm<'_>>) -> String {
    format!("Title: {}, Content: {}", user_input.id_title, user_input.id_content)
}