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Table of Content

DOM Manipulation

The Document Object Model (DOM) is a representation of an HTML document that JavaScript can manipulate dynamically. Using JavaScript, developers can access, modify, and update HTML elements and styles in real time.

This Privacy Policy describes how Alevio ("we," "our," or "us"), founded and led by Felix Danyluk (CEO and Founder), collects, uses, and discloses your information when you use our application, website, and services (collectively, the "Service").

Important:

Alevio is designed as a privacy-first application. All your personal data is stored locally on your device and is not transferred to our servers unless you explicitly activate cloud functions.

1. Information We Collect

Alevio operates primarily as a local application.
The information stored includes:

Personal information: name and preferences (stored locally only).
Usage data: daily responses and insights (stored locally only).
Device information: app preferences and settings (stored locally only).
AI Chat data: when using AI features, conversation history is stored locally on your device.
Image data: when using vision features, uploaded images are processed locally and may be temporarily stored for AI analysis.
Generated images: DALL-E generated images are saved locally on your device for display purposes.
Usage limits: daily usage tracking for cloud models and image generation is stored locally to enforce fair usage policies.

2. How We Use Your Information

We use the information we collect to:

Provide and maintain our Service
Improve and personalize your experience
Communicate with you about updates and features
Ensure the security and integrity of our Service

3. Data Storage and Security

Your data is stored locally on your device using secure, industry-standard encryption. We do not have access to your personal information unless you explicitly choose to share it through cloud features.

4. Third-Party Services

Alevio may integrate with third-party AI services for enhanced functionality. When using these features, only the necessary data is transmitted to provide the service. We carefully select partners who share our commitment to privacy.

Cloud Services: When you use cloud-based AI models (such as GPT-4o, Claude, or other cloud providers), your messages and uploaded images are sent to these services for processing. We use secure API connections and do not store your data on our servers.
Image Generation: When using DALL-E image generation, your text prompts are sent to OpenAI's servers to generate images. Generated images are returned to your device and stored locally.
Web Search: When using web search features, your search queries are sent to our search partners to retrieve relevant information. Search results are processed and returned to your device.
Apple Shortcuts: When using Apple Shortcuts integration, your device's Shortcuts app may access Alevio through URL schemes. This integration is handled entirely by your device's operating system.

5. Your Rights

You have the right to:

Access your personal data stored on your device
Delete your data at any time through the app settings
Opt out of cloud features and keep all data local
Contact us with any privacy concerns

6. Changes to This Policy

We may update this Privacy Policy from time to time. We will notify you of any changes by posting the new Privacy Policy on this page and updating the "Last Updated" date.

7. Contact Us

If you have any questions about this Privacy Policy or our privacy practices, please contact us at:

privacy.alevio@gmail.com

Accessing DOM Elements

JavaScript provides several methods to select elements from the DOM.

Using `getElementById` (Select by ID)

Returns a single element matching the specified id.

let heading = document.getElementById("main-title");
console.log(heading.textContent);

Using `getElementsByClassName` (Select by Class)

Returns a collection (HTMLCollection) of elements that match the class name.

let items = document.getElementsByClassName("list-item");
console.log(items[0].textContent);

Using `getElementsByTagName` (Select by Tag)

Returns a collection of elements matching the tag name.

let paragraphs = document.getElementsByTagName("p");
console.log(paragraphs.length);

Using `querySelector` (Select First Match)

Returns the first matching element based on a CSS selector.

let firstItem = document.querySelector(".list-item");
console.log(firstItem.textContent);

Using `querySelectorAll` (Select All Matches)

Returns a NodeList of elements that match a CSS selector.

let allItems = document.querySelectorAll(".list-item");
allItems.forEach(item => console.log(item.textContent));

Modifying DOM Elements

Changing Text Content

The textContent and innerHTML properties allow updating element content.

let title = document.getElementById("main-title");
title.textContent = "Updated Title";

innerHTML allows inserting HTML inside an element.

let container = document.getElementById("content");
container.innerHTML = "<p>New paragraph added!</p>";

Changing Attributes

The setAttribute and getAttribute methods modify element attributes.

let link = document.querySelector("a");
link.setAttribute("href", "https://www.example.com");
console.log(link.getAttribute("href"));

Removing an attribute:

<script>link.removeAttribute("target");</script>

Modifying Styles

The style property allows modifying CSS properties directly.

let box = document.getElementById("box");
box.style.backgroundColor = "blue";
box.style.color = "white";
box.style.padding = "10px";

Adding or removing a CSS class:

box.classList.add("highlight");
box.classList.remove("highlight");

Creating and Removing Elements

Creating New Elements

Use document.createElement() to generate new HTML elements dynamically.

let newParagraph = document.createElement("p");
newParagraph.textContent = "This is a new paragraph.";
document.body.appendChild(newParagraph);

Removing Elements

Use remove() to delete an element.

let unwantedElement = document.getElementById("old-item");
unwantedElement.remove();

Removing a child element:

let parent = document.getElementById("list");
let child = document.getElementById("list-item");
parent.removeChild(child);

Handling Events in JavaScript

Adding Event Listeners

The addEventListener() method attaches event handlers to elements.

let button = document.getElementById("btn");
button.addEventListener("click", () => {
  alert("Button clicked!");
});

Common Event Types

click – When an element is clicked.
mouseover – When the mouse hovers over an element.
keydown – When a key is pressed.
submit – When a form is submitted.

Example:

let inputField = document.getElementById("input-box");
inputField.addEventListener("keydown", event => {
  console.log("Key pressed:", event.key);
});

Removing Event Listeners

Use removeEventListener() to detach event handlers.

function sayHello() {
  console.log("Hello!");
}
  
button.addEventListener("click", sayHello);
button.removeEventListener("click", sayHello);

Event Delegation

Instead of adding an event listener to multiple elements, use event delegation on a parent element.

document.getElementById("list").addEventListener("click", event => {
  if (event.target.tagName === "LI") {
    console.log("Item clicked:", event.target.textContent);
  }
});

Conclusion

DOM manipulation is essential for dynamic web applications. This section covered selecting, modifying, and interacting with elements. The next section will focus on event handling in depth, covering advanced techniques and best practices.