alg_add.js

let dialogAddAlg = document.getElementById("dialog-add-alg"); // The modal window for inputting information about an algorithm
let close2 = document.getElementById("cross2"); // The modal window's cross
let confButton1 = document.getElementById("conf1"); // Button OK of the modal window
let inputName1 = document.getElementById("str-inp-alg-name"); // String input for inputting an algorithm's name
let inputDescription1 = document.getElementById("str-inp-alg-info"); // String input for inputting the algorithm's descriprion
let inputDifficulty = document.getElementById("str-inp-alg-dif"); // String input for inputting the algorithm's difficulty
let algName = ''; // Let for keeping the algorithm's name which has been input
let algDesrcription = ''; // Let for keeping the algorithm's description which has been input
let algDifficulty = ''; // Let for keeping the algorithm's difficulty which has been input
let algContainer = ''; // Let for keeping the id of the container to which the inserted algorithm refers

close2.onclick = function() {
    /* Event listener for the cross of the modal window
    * The function disables visibity of the modal window and cleans input strings
    * Input parameter: none. Output parameter: none.
    * Author: Elena Karelina
    */
    cleanDialogAdd();
};

confButton1.onclick = function() {
    /* Event listener for clicking on the button "OK"
    * The function sends the input information to the server
    * and inserts a new algorithm in te interface in case of successful inserting
    * Input parameter: none. Output parameter: none.
    * Author: Elena Karelina
    */
    let keepContainer = 'add-alg-'+ algContainer;
    algName = inputName1.value;
    if(algName === "")
        alert('Необходимо ввести имя алгоритма');
    else {
        algDesrcription = inputDescription1.value;
        algDifficulty = inputDifficulty.value;
        let xhr = new XMLHttpRequest(); // Creating new HTTP request
        xhr.open("POST", "include/alg_add.php", true); // Setting destination and type
        xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded'); // Setting encoding
        xhr.send('name=' + encodeURIComponent(algName) + '&descr=' + encodeURIComponent(algDesrcription)
            + '&diff=' + encodeURIComponent(algDifficulty) + '&cont=' + encodeURIComponent(algContainer)); // Sending
        // the container's name and description
        xhr.onreadystatechange = function () { // Waiting for the server's answer
            /* Event listener for getting response from server
            * Inserts the container's name into the list if confirmation of inserting into database was received from server
            * Input parameter: none. Output parameter: none.
            * Author: Elena Karelina
            */
            if (xhr.readyState == 4) { // The answer has been got
                if (xhr.status == 200) { // The server's returned code 200 (success)
                    let results = xhr.responseText.split(' ');
                    if (results[0] === "1") { // If the inserting into database was successful insert into the list
                        let new_element = document.createElement('LI');
                        let cur = document.getElementById(keepContainer);
                        new_element.innerHTML = algName;
                        new_element.id = 'alg-' + results[1];
                        new_element.classList.add("one-algorithm");
                        cur.before(new_element);
                    } else {
                        alert('При добавлении в базу данных произошла ошибка'); // Informing about the error
                    }
                }
            }
        };
        inputName1.value = '';
        inputDescription1.value = '';
        inputDifficulty.value = '';
        dialogAddAlg.style.display = 'none';
    }
};

function inputAlgorithm(event) {
    /* Event listener for clicking on the button "Добавить контейнер"
    * The function makes the dialog window visible and keeps the target container's id
    * Input parameter: event. Output parameter: none.
    * Author: Elena Karelina
    */
    dialogAddAlg.style.display = 'block';
    algContainer = event.target.id.split('-')[2];
}

function cleanDialogAdd() {
    /* The function makes the dialog window for adding an algorithm invisible.
    * The function resets all values of the text strings.
    * Input parameter: none. Output parameter: none.
    * Author: Elena Karelina.
    */
    dialogAddAlg.style.display = 'none';
    inputName1.value = '';
    inputDescription1.value = '';
    inputDifficulty.value = '';
    dialogAddAlg.style.display = 'none';
}