How to make a filter of PHP products

Learn how to create a php product filter with an example. Create a custom filter to sort, search, and display products.

Creating a PHP Product Filter

Creating a filter for PHP products can be an effective way to narrow down the selection of products and make it easier for customers to find the right product. The most common way to create a filter is to use a combination of HTML, CSS and JavaScript. This tutorial will walk you through the steps of creating a filter that can be used on any PHP-based website.

Step 1: Design the Filter

The first step in creating a filter is to decide what criteria you want to use to filter the products. This could include things like price, type, size, color, features, etc. Once you have determined the criteria, create a form that allows users to select the criteria they want to filter by. The form should include checkboxes, radio buttons and/or select boxes for each criteria.

Step 2: Write the HTML Code

Once you have designed the form, it's time to write the HTML code. The code should include the form elements, such as checkboxes, radio buttons and select boxes, as well as labels for each element. It should also include a submit button so that users can submit their selections and filter the results. Here is an example of the HTML code for a basic filter:

<form action="process_filter.php" method="post">
  <label>Price Range: </label>
  <input type="checkbox" name="price[]" value="0-50">Under $50
  <input type="checkbox" name="price[]" value="50-100">$50 - $100
  <input type="checkbox" name="price[]" value="100-150">$100 - $150
  <input type="checkbox" name="price[]" value="150+">Over $150<br>
  <label>Features: </label>
  <input type="checkbox" name="features[]" value="1">Option 1
  <input type="checkbox" name="features[]" value="2">Option 2
  <input type="checkbox" name="features[]" value="3">Option 3
  <input type="checkbox" name="features[]" value="4">Option 4<br>
  <input type="submit" value="Filter">
</form>

Step 3: Write the JavaScript Code

Once the HTML form is in place, it's time to write the JavaScript code to make the filter function. The JavaScript code should include a function that takes the user's selections and passes them to the server. The function should also handle any errors that may occur while processing the data. Here is an example of a basic filter JavaScript function:

function filterProducts() {
  // Get the user's selections
  var priceRange = document.querySelectorAll('input[name="price[]"]:checked');
  var features = document.querySelectorAll('input[name="features[]"]:checked');

  // Create an array to hold the selections
  var selections = [];

  // Loop through the selections and add them to the array
  for (var i = 0; i < priceRange.length; i++) {
    selections.push(priceRange[i].value);
  }
  for (var i = 0; i < features.length; i++) {
    selections.push(features[i].value);
  }

  // Send the selections to the server
  var http = new XMLHttpRequest();
  http.open("POST", "process_filter.php", true);
  http.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
  http.send("selections=" + selections);

  // Handle any errors
  http.onreadystatechange = function() {
    if (http.readyState == 4 && http.status == 200) {
      // Do something with the response
    }
  }
}

Step 4: Process the Filter

The last step is to create a file on the server to process the filter selections. This file should take the selections from the JavaScript function and use them to query the database for products that match the criteria. Here is an example of how this could be done in PHP:

<?php
  // Get the selections from the form
  $selections = $_POST['selections'];
  $priceRange = array();
  $features = array();

  // Loop through the selections and separate them into two arrays
  foreach ($selections as $selection) {
    if (strpos($selection, '-') !== false) {
      array_push($priceRange, $selection);
    } else {
      array_push($features, $selection);
    }
  }

  // Build the query
  $query = "SELECT * FROM products WHERE ";

  // Add the price range to the query
  if (!empty($priceRange)) {
    $query .= "price BETWEEN ";
    foreach ($priceRange as $range) {
      list($low, $high) = explode('-', $range);
      $query .= "$low AND $high OR ";
    }
    // Remove the extra "OR" from the end of the query
    $query = substr($query, 0, -4);
    $query .= " AND ";
  }

  // Add the features to the query
  if (!empty($features)) {
    $query .= "feature IN (";
    foreach ($features as $feature) {
      $query .= "$feature, ";
    }
    // Remove the extra comma from the end of the query
    $query = substr($query, 0, -2);
    $query .= ")";
  }

  // Execute the query and get the results
  $result = mysqli_query($conn, $query);
?>

Once the query is complete, the results can be displayed on the page. This can be done using HTML and CSS, or with a library like jQuery.

Creating a filter for PHP products is a relatively simple process. With a few lines of HTML, CSS and JavaScript code, you can create a filter that will make it easy for customers to find the right product.