Using session storage for managing user-specific email filter rules in JavaScript

21 Sep 2023

sessionstorage

In web applications that involve managing email filters, it is important to provide users with a personalized experience and the ability to define their own rules. In this blog post, we will explore how to use session storage in JavaScript to store and manage user-specific email filter rules.

What is Session Storage?

Session storage is a web storage mechanism available in modern browsers that allows data to be stored and accessed during a user’s session. Unlike local storage, session storage data is cleared when the browser window or tab is closed. This makes it perfectly suited for managing temporary data like user-specific filters.

Implementing Email Filter Rules

To begin, let’s define some basic rules for email filtering. For this example, we will assume that users can define rules based on the sender’s email address. Each user will be able to define multiple rules, and emails matching any of the rules will be filtered accordingly.

Here’s an example HTML layout to get started:

<!DOCTYPE html>
<html>
  <head>
    <title>Email Filter Rules</title>
    <script src="filter.js" type="text/javascript"></script>
  </head>
  <body>
    <h1>Email Filter Rules</h1>
    <form id="filterForm">
      <input type="text" id="filterInput" placeholder="Enter sender's email address" />
      <button type="submit" id="filterButton">Add Filter</button>
    </form>
    <ul id="filterList"></ul>
  </body>
</html>

In the JavaScript file (filter.js), we can write the code that will handle storing and managing the email filter rules:

document.addEventListener('DOMContentLoaded', function() {
  const form = document.getElementById('filterForm');
  const filterInput = document.getElementById('filterInput');
  const filterList = document.getElementById('filterList');

  // Retrieve filter rules from session storage if available
  let filters = sessionStorage.getItem('emailFilters');
  filters = filters ? JSON.parse(filters) : [];

  // Render existing filters
  filters.forEach(function(filter) {
    const li = document.createElement('li');
    li.textContent = filter;
    filterList.appendChild(li);
  });

  form.addEventListener('submit', function(event) {
    event.preventDefault();
    const filterValue = filterInput.value.trim();

    if (filterValue !== '') {
      filters.push(filterValue);
      sessionStorage.setItem('emailFilters', JSON.stringify(filters));

      const li = document.createElement('li');
      li.textContent = filterValue;
      filterList.appendChild(li);

      filterInput.value = '';
    }
  });
});

Managing Email Filter Rules

The code above does the following:

Retrieves the existing filter rules from session storage, if available.
Renders the existing filters on the page.
Adds an event listener to the form’s submit event.
When the form is submitted, it prevents the default form submission behavior.
If the filter value is not empty, it adds the filter to the filters array.
Updates the session storage with the updated filters array.
Appends the new filter to the filter list on the page.
Clears the filter input field.

With this code, users can define their own email filter rules, and the rules will persist across their session. When the user closes the browser, the data will be cleared since session storage is not persistent.

Conclusion

Using session storage in JavaScript allows us to easily manage user-specific email filter rules. By storing the rules in session storage, we can provide a personalized experience and maintain the filters for the duration of the user’s session. Incorporating session storage into your web application can greatly enhance the usability and customization options for your users. #javascript #sessionstorage