我如何在不同文件中的 php 中的 html 标签内写入？

Question

I am learning to program in PHP and I have a problem, I want to write in a html tag from php in different files, but I don't get how to do it. This is my code:

index.php

            <form action="back_end_files/ControllerUsuarios.php" method="post">
                <div class="input-group form-group">
                    <input type="email" class="form-control" id="loginEmail" placeholder="Email"
                           onfocusout="validatesLogin()" name="vEmail" required/>
                </div>
                <div class="input-group form-group">
                    <input type="password" class="form-control " id="loginPassword" placeholder="Password"
                           name="vPass" required>
                </div>
                <div>
                    <p id="status"></p>
                </div>
                <div class="alert">
                    <?php echo isset($alert) ? $alert : ''; ?>
                </div>
                <div class="form-group">
                    <button class="btn btn-primary btn-sm float-right" type="submit" name="submitLogin">
                        Login
                    </button>
                </div>
                <div class="form-group">
                </div>
            </form>

Here i want to write the message

            <div>
                <p id="status"></p>
            </div>

controllerUsuarios.php

function loginCase(){
    require 'DAOUsuarios.php';
    $connection = new DAOUsuarios();
    $connection->connectDB();

    $username = $_POST['vEmail'];
    $pass = $_POST['vPass'];

    if($connection->login($username,$pass, $connection) == true){
        session_start();
        $_SESSION['active'] = true;
        $_SESSION['email'] = $username;
        header("Location: https://localhost/logged.php");
    }
    else{
        $alert = "Email or password incorrect";
    }
}

Answer 1

basically. post to the same index file is easiest, redirect if authenticated, otherwise just show the form again.

index.php

<?php
     // include your login functions...
     require 'back_end_files/controllerUsuarios.php';

     if(logged_in()) {
        // already logged in.
        header("Location: https://localhost/logged.php");
     } else {
        // this will redirect if authenticated.
        loginCase();
     }
?>


            <form action="index.php" method="post">
                <div class="input-group form-group">
                    <input type="email" class="form-control" id="loginEmail" placeholder="Email" onfocusout="validatesLogin()" name="vEmail" required/>
                </div>
                <div class="input-group form-group">
                    <input type="password" class="form-control " id="loginPassword" placeholder="Password"
                           name="vPass" required>
                </div>
                <div>
                    <p id="status"></p>
                </div>
                <div class="alert">
                    <?php echo isset($alert) ? $alert : ''; ?>
                </div>
                <div class="form-group">
                    <button class="btn btn-primary btn-sm float-right" type="submit" name="submitLogin">
                        Login
                    </button>
                </div>
                <div class="form-group">
                </div>
            </form>

back_end_files/controllerUsuarios.php

/**
 * check logged in now
 *
 * @return boolean if logged in.
 **/
function logged_in() {
     session_start();
     return !empty($_SESSION['active']);
}

/**
 * log in the user and goto the next page or show form again.
 *
 * @return void
 **/
function loginCase(){
    require 'DAOUsuarios.php';
    $connection = new DAOUsuarios();
    $connection->connectDB();

    // only try to authenticate if the data is set.
    if(!empty($_POST['vEmail']) && !empty($_POST['vPass'])) {
        $username = $_POST['vEmail'];
        $pass = $_POST['vPass'];

        if($connection->login($username,$pass, $connection) == true){
            $_SESSION['active'] = true;
            $_SESSION['email'] = $username;
            header("Location: https://localhost/logged.php");
        }
    }

    // did not authenticate, so show the form again.
    return false;
}