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Alarm App Javascript

Hey everyone. Welcome to today’s tutorial. In today’s tutorial, we will learn how to create an alarm clock app. To create this app we need HTML, CSS and Javascript. This app comes with a feature to set multiple alarms at the same time.

This is an intermediate-level javascript project. I would suggest beginners try out some other projects before attempting this one. If you want to learn javascript through more such projects you can check out this playlist here.

This playlist consists of 100+ javascript projects whose difficulty level varies from easy to complex. Hence this playlist is suitable for all kinds of javascript learners.

Video Tutorial:

If you are interested to learn by watching a video tutorial rather than reading this blog post you can check out this video down below. Also, subscribe to my youtube channel. I post new tips tricks and tutorials on my youtube channel regularly. Along with these tutorials, I post multiple-choice questions based on HTML, CSS and Javascript.

 

Project Folder Structure:

Before we start coding We take a look at the project folder structure. We create a project folder called – ‘Alarm App’. The folder consists of three files. These files are index.html, style.css and script.js.

HTML:

We begin with HTML code. First, copy the code below and paste it into your HTML file.

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Alarm App</title>
    <!-- Font Awesome Icons -->
    <link
      rel="stylesheet"
      href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.2.1/css/all.min.css"
    />
    <!-- Google Fonts -->
    <link
      href="https://fonts.googleapis.com/css2?family=Poppins&family=Roboto+Mono:wght@500&display=swap"
      rel="stylesheet"
    />
    <!-- Stylesheet -->
    <link rel="stylesheet" href="style.css" />
  </head>
  <body>
    <div class="wrapper">
      <div class="timer-display">00:00:00</div>
      <div class="container">
        <div class="inputs">
          <input
            type="number"
            id="hourInput"
            placeholder="00"
            min="0"
            max="23"
          />
          <input
            type="number"
            id="minuteInput"
            placeholder="00"
            min="0"
            max="59"
          />
        </div>
        <button id="set">Add Alarm</button>
        <div class="activeAlarms"></div>
      </div>
    </div>
    <!-- Script -->
    <script src="script.js"></script>
  </body>
</html>

CSS:

Next, we style our app using CSS. For this copy, the code provided to you below and paste it into a style sheet.

* {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
  font-family: "Poppins", sans-serif;
}
body {
  background-color: #377dff;
}
.hide {
  display: none;
}
.wrapper {
  background-color: #ffffff;
  width: 90%;
  max-width: 31.25em;
  padding: 3.12em 5em;
  position: absolute;
  transform: translateX(-50%);
  left: 50%;
  top: 1em;
  border-radius: 0.5em;
}
.timer-display {
  font-size: 2.18em;
  text-align: center;
  font-family: "Roboto Mono", monospace;
}
.inputs {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1em;
  margin-top: 2em;
}
.inputs input {
  width: 2.8em;
  font-size: 1.3em;
  border: 1px solid #000000;
  border-radius: 0.3em;
  padding: 0.4em 0.2em;
}
#set {
  background-color: #377dff;
  border: none;
  padding: 0.9em 1.8em;
  display: block;
  margin: 1.5em auto 0 auto;
  border-radius: 2em;
  color: #ffffff;
}
.alarm {
  display: grid;
  grid-template-columns: 8fr 2fr 2fr;
  gap: 1em;
  margin-top: 1.5em;
  align-items: center;
  border-bottom: 1px solid #898f9b;
  padding-bottom: 0.6em;
}
.alarm input[type="checkbox"] {
  appearance: none;
  height: 2em;
  width: 3.75em;
  background-color: #e2e2ec;
  border-radius: 1.25em;
  position: relative;
  cursor: pointer;
  outline: none;
}
.alarm input[type="checkbox"]:before {
  position: absolute;
  content: "";
  background-color: #757683;
  height: 1.43em;
  width: 1.43em;
  border-radius: 50%;
  top: 0.25em;
  left: 0.25em;
}
.alarm input[type="checkbox"]:checked {
  background-color: #d2e2ff;
}
.alarm input[type="checkbox"]:checked:before {
  background-color: #377dff;
  left: 2em;
}
.deleteButton {
  background-color: transparent;
  font-size: 1.5em;
  color: #377dff;
  border: none;
  cursor: pointer;
}

Javascript:

Finally, we implement the functionality using javascript. We do this in the following steps:

  1. Create Initial References
  2. Append zeroes for single digit
  3. Search for value in the object
  4. Display time
  5. Display time(with zeroes appended)
  6. Create alarm div
  7. Set alarm
  8. Start Alarm
  9. Stop Alarm
  10. Delete Alarm
//Initial References
let timerRef = document.querySelector(".timer-display");
const hourInput = document.getElementById("hourInput");
const minuteInput = document.getElementById("minuteInput");
const activeAlarms = document.querySelector(".activeAlarms");
const setAlarm = document.getElementById("set");
let alarmsArray = [];
let alarmSound = new Audio("./alarm.mp3");

let initialHour = 0,
  initialMinute = 0,
  alarmIndex = 0;

//Append zeroes for single digit
const appendZero = (value) => (value < 10 ? "0" + value : value);

//Search for value in object
const searchObject = (parameter, value) => {
  let alarmObject,
    objIndex,
    exists = false;
  alarmsArray.forEach((alarm, index) => {
    if (alarm[parameter] == value) {
      exists = true;
      alarmObject = alarm;
      objIndex = index;
      return false;
    }
  });
  return [exists, alarmObject, objIndex];
};

//Display Time
function displayTimer() {
  let date = new Date();
  let [hours, minutes, seconds] = [
    appendZero(date.getHours()),
    appendZero(date.getMinutes()),
    appendZero(date.getSeconds()),
  ];

  //Display time
  timerRef.innerHTML = `${hours}:${minutes}:${seconds}`;

  //Alarm
  alarmsArray.forEach((alarm, index) => {
    if (alarm.isActive) {
      if (`${alarm.alarmHour}:${alarm.alarmMinute}` === `${hours}:${minutes}`) {
        alarmSound.play();
        alarmSound.loop = true;
      }
    }
  });
}

const inputCheck = (inputValue) => {
  inputValue = parseInt(inputValue);
  if (inputValue < 10) {
    inputValue = appendZero(inputValue);
  }
  return inputValue;
};

hourInput.addEventListener("input", () => {
  hourInput.value = inputCheck(hourInput.value);
});

minuteInput.addEventListener("input", () => {
  minuteInput.value = inputCheck(minuteInput.value);
});

//Create alarm div

const createAlarm = (alarmObj) => {
  //Keys from object
  const { id, alarmHour, alarmMinute } = alarmObj;
  //Alarm div
  let alarmDiv = document.createElement("div");
  alarmDiv.classList.add("alarm");
  alarmDiv.setAttribute("data-id", id);
  alarmDiv.innerHTML = `<span>${alarmHour}: ${alarmMinute}</span>`;

  //checkbox
  let checkbox = document.createElement("input");
  checkbox.setAttribute("type", "checkbox");
  checkbox.addEventListener("click", (e) => {
    if (e.target.checked) {
      startAlarm(e);
    } else {
      stopAlarm(e);
    }
  });
  alarmDiv.appendChild(checkbox);
  //Delete button
  let deleteButton = document.createElement("button");
  deleteButton.innerHTML = `<i class="fa-solid fa-trash-can"></i>`;
  deleteButton.classList.add("deleteButton");
  deleteButton.addEventListener("click", (e) => deleteAlarm(e));
  alarmDiv.appendChild(deleteButton);
  activeAlarms.appendChild(alarmDiv);
};

//Set Alarm
setAlarm.addEventListener("click", () => {
  alarmIndex += 1;

  //alarmObject
  let alarmObj = {};
  alarmObj.id = `${alarmIndex}_${hourInput.value}_${minuteInput.value}`;
  alarmObj.alarmHour = hourInput.value;
  alarmObj.alarmMinute = minuteInput.value;
  alarmObj.isActive = false;
  console.log(alarmObj);
  alarmsArray.push(alarmObj);
  createAlarm(alarmObj);
  hourInput.value = appendZero(initialHour);
  minuteInput.value = appendZero(initialMinute);
});

//Start Alarm
const startAlarm = (e) => {
  let searchId = e.target.parentElement.getAttribute("data-id");
  let [exists, obj, index] = searchObject("id", searchId);
  if (exists) {
    alarmsArray[index].isActive = true;
  }
};

//Stop alarm
const stopAlarm = (e) => {
  let searchId = e.target.parentElement.getAttribute("data-id");
  let [exists, obj, index] = searchObject("id", searchId);
  if (exists) {
    alarmsArray[index].isActive = false;
    alarmSound.pause();
  }
};

//delete alarm
const deleteAlarm = (e) => {
  let searchId = e.target.parentElement.parentElement.getAttribute("data-id");
  let [exists, obj, index] = searchObject("id", searchId);
  if (exists) {
    e.target.parentElement.parentElement.remove();
    alarmsArray.splice(index, 1);
  }
};

window.onload = () => {
  setInterval(displayTimer);
  initialHour = 0;
  initialMinute = 0;
  alarmIndex = 0;
  alarmsArray = [];
  hourInput.value = appendZero(initialHour);
  minuteInput.value = appendZero(initialMinute);
};

That’s all for this tutorial. If you face any issues while creating this code you can download the source code by clicking on the download button below. Also, If you have any queries, suggestions, or feedback you can comment on them below.
Happy coding!

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