### Initialize and Get Evercookie

Source: https://github.com/samyk/evercookie/blob/master/index.html

Demonstrates how to initialize Evercookie and retrieve a cookie's value. The `getC` function recursively fetches the cookie, updating the UI with the found value and listing all mechanisms used.

```javascript
var val = '' + Math.floor(Math.random()\*1000);
var ec = new evercookie({
	/* Options */
});

getC(0);
//setTimeout(getC, 500, 1);

function getC(dont)
{
	ec.get("uid", function(best, all) {
		document.getElementById('idtag').innerHTML = best;
		var txt = document.getElementById('cookies');
		txt.innerHTML = '';
		for (var item in all)
			txt.innerHTML += item + ' mechanism: ' + (val == all[item] ? '<b>' + all[item] + '</b>' : all[item]) + '<br>';
		if (!dont)
			getC(1);
	}, dont);
}
```

--------------------------------

### Google Analytics Tracking Setup

Source: https://github.com/samyk/evercookie/blob/master/index.html

This JavaScript code sets up Google Analytics tracking for the page. It dynamically loads the Google Analytics JavaScript library.

```javascript
var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www."); document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E")); try { var pageTracker = _gat._getTracker("UA-6127617-2"); pageTracker._trackPageview(); } catch(err) {}
```

--------------------------------

### Retrieve a Cookie with Evercookie (Advanced Callback)

Source: https://github.com/samyk/evercookie/blob/master/index.html

Use the `get` method with an advanced callback function that receives both the best candidate value and an object containing values from all storage mechanisms.

```javascript
// or use a more advanced callback function for getting our cookie
// the cookie value is the first param
// an object containing the different storage methods
// and returned cookie values is the second parameter
**function getCookie(best\_candidate, all\_candidates)
{
    alert("The retrieved cookie is: " + best\_candidate + "\n" +
    	"You can see what each storage mechanism returned " +
		"by looping through the all\_candidates object.");

	for (var item in all\_candidates)
		document.write("Storage mechanism " + item +

```

--------------------------------

### Getting Cookies

Source: https://context7.com/samyk/evercookie/llms.txt

Retrieves a cookie value by checking all storage mechanisms and using a voting system to determine the most likely correct value.

```APIDOC
## Getting Cookies

The `get()` method retrieves a cookie value by checking all storage mechanisms and using a voting system to determine the most likely correct value. An optional third parameter prevents automatic re-propagation to cleared storage mechanisms.

### Method
`ec.get(key, callback, [skip_propagation])`

### Parameters
#### Path Parameters
- **key** (string) - Required - The name of the cookie to retrieve.
- **callback** (function) - Required - A function to be called with the retrieved cookie value(s).
- **skip_propagation** (integer) - Optional - If set to 1, prevents automatic re-propagation to cleared mechanisms.

### Request Example
```javascript
var ec = new evercookie();

// Simple retrieval with callback
ec.get("user_id", function(value) {
    console.log("Cookie value: " + value);
});

// Advanced retrieval with full candidate information
ec.get("user_id", function(best_candidate, all_candidates) {
    console.log("Best match: " + best_candidate);
    for (var mechanism in all_candidates) {
        console.log(mechanism + ": " + all_candidates[mechanism]);
    }
});

// Retrieve WITHOUT re-propagating to cleared mechanisms
ec.get("user_id", function(value, all) {
    console.log("Current value (no restoration): " + value);
}, 1);
```

### Response
#### Success Response (Callback Function)
- **value** (string) - The retrieved cookie value.
- **best_candidate** (string) - The most likely correct cookie value determined by a voting system.
- **all_candidates** (object) - An object containing all candidate values from different storage mechanisms.
```

--------------------------------

### Retrieve a Cookie with Evercookie (Simple Callback)

Source: https://github.com/samyk/evercookie/blob/master/index.html

Use the `get` method with a simple callback function to retrieve the value of a specified cookie. The callback receives the best candidate value.

```javascript
// retrieve a cookie called "id" (simply)
**ec.get("id", function(value) { alert("Cookie value is " + value) });**
```

--------------------------------

### Get Evercookie

Source: https://context7.com/samyk/evercookie/llms.txt

Retrieve a cookie value by checking all storage mechanisms. An optional parameter can prevent automatic re-propagation to cleared mechanisms.

```javascript
var ec = new evercookie();

// Simple retrieval with callback
ec.get("user_id", function(value) {
    console.log("Cookie value: " + value);
    // Output: Cookie value: abc123xyz
});

// Advanced retrieval with full candidate information
ec.get("user_id", function(best_candidate, all_candidates) {
    console.log("Best match: " + best_candidate);

    // Inspect which storage mechanisms returned what values
    for (var mechanism in all_candidates) {
        console.log(mechanism + ": " + all_candidates[mechanism]);
    }

    // Example output:
    // Best match: abc123xyz
    // cookieData: abc123xyz
    // localData: abc123xyz
    // sessionData: abc123xyz
    // windowData: abc123xyz
    // dbData: abc123xyz
    // idbData: abc123xyz
    // etagData: abc123xyz
    // cacheData: abc123xyz
    // pngData: abc123xyz
    // lsoData: abc123xyz
    // slData: abc123xyz
});

// Retrieve WITHOUT re-propagating to cleared mechanisms
// Pass 1 as third parameter to prevent auto-restoration
ec.get("user_id", function(value, all) {
    console.log("Current value (no restoration): " + value);
}, 1);
```

--------------------------------

### Configure HSTS Supercookie Backend

Source: https://context7.com/samyk/evercookie/llms.txt

Deploy this script on multiple subdomains to enable multi-bit storage via HSTS headers. Requires HTTPS to function correctly.

```php
<?php
// hsts_cookie.php - HSTS Supercookie persistence
// Deploy on multiple subdomains for multi-bit storage

// Setup: Deploy this script on N subdomains where N = bits needed
// Example for 8-bit (0-255) values:
// - https://h0.example.com/hsts_cookie.php
// - https://h1.example.com/hsts_cookie.php
// - https://h2.example.com/hsts_cookie.php
// - ... (8 total)

// Client configuration:
var ec = new evercookie({
    hsts: true,
    hsts_domains: [
        'https://h0.example.com/php/hsts_cookie.php',
        'https://h1.example.com/php/hsts_cookie.php',
        'https://h2.example.com/php/hsts_cookie.php',
        'https://h3.example.com/php/hsts_cookie.php',
        'https://h4.example.com/php/hsts_cookie.php',
        'https://h5.example.com/php/hsts_cookie.php',
        'https://h6.example.com/php/hsts_cookie.php',
        'https://h7.example.com/php/hsts_cookie.php'
    ]
});

// How it works:
// SET request: ?SET=1 -> Sets HSTS header (max-age=31536000)
// DEL request: ?DEL=1 -> Clears HSTS header (max-age=0)
// Read: Browser auto-upgrades HTTP->HTTPS if HSTS set (bit=1)
//       Browser allows HTTP if HSTS not set (bit=0)

// To store value 42 (binary: 00101010):
// Set HSTS on: h1, h3, h5
// Clear HSTS on: h0, h2, h4, h6, h7
```

--------------------------------

### Initialize Evercookie

Source: https://github.com/samyk/evercookie/blob/master/index.html

Include the necessary JavaScript files and initialize the Evercookie object with base configuration options.

```javascript
    **<script type="text/javascript" src="jquery-1.4.2.min.js"></script>**
    **<script type="text/javascript" src="swfobject-2.2.min.js"></script>**
    **<script type="text/javascript" src="evercookie.js"></script>**

    **<script>**
    **var ec = new evercookie({**
    	**baseurl: '/test',** _http://localhost/test_
    	**asseturi: '/assets',** _http://localhost/test/assets_
    	**phpuri: '/php'** _http://localhost/test/php_
    **});**
```

--------------------------------

### Initialize Evercookie Constructor

Source: https://context7.com/samyk/evercookie/llms.txt

Instantiate Evercookie with default or custom options. Configure storage mechanisms, asset paths, and server-side backend paths.

```javascript
var ec = new evercookie();
```

```javascript
var ec = new evercookie({
    // Base URL for all assets (e.g., '/myapp' for http://localhost/myapp)
    baseurl: '',

    // Path to assets directory containing .swf, .xap, .jnlp files
    asseturi: '/assets',

    // Path to PHP backend files
    phpuri: '/php',

    // Domain for cookies (default: current host)
    domain: '.example.com',

    // Enable/disable specific storage mechanisms
    history: true,        // CSS history knocking (network intensive)
    java: true,           // Java applet (may prompt user)
    silverlight: true,    // Silverlight isolated storage
    lso: true,            // Flash Local Shared Objects
    db: true,             // Web SQL Database
    idb: true,            // IndexedDB

    // HSTS cookie settings
    hsts: false,
    hsts_domains: ['https://domain1.example.com/hsts.php', 'https://domain2.example.com/hsts.php'],

    // Backend file paths
    pngCookieName: 'evercookie_png',
    pngPath: '/evercookie_png.php',
    etagCookieName: 'evercookie_etag',
    etagPath: '/evercookie_etag.php',
    cacheCookieName: 'evercookie_cache',
    cachePath: '/evercookie_cache.php'
});
```

--------------------------------

### Define Server Directory Structure

Source: https://context7.com/samyk/evercookie/llms.txt

Required file organization for deploying Evercookie with all storage backends.

```text
project-root/
├── index.html              # Main HTML page
├── js/
│   ├── evercookie.js       # Main Evercookie JavaScript library
│   └── swfobject-2.2.min.js # SWFObject for Flash embedding
├── assets/
│   ├── evercookie.swf      # Flash LSO storage (compiled from evercookie.fla)
│   ├── evercookie.xap      # Silverlight isolated storage
│   ├── evercookie.jnlp     # Java Web Start descriptor
│   └── evercookie.jar      # Java applet for cross-browser persistence
├── php/
│   ├── _cookie_name.php    # Helper function for cookie name resolution
│   ├── evercookie_cache.php # HTTP cache-based storage
│   ├── evercookie_etag.php  # ETag-based storage
│   ├── evercookie_png.php   # Canvas/PNG-based storage
│   └── hsts_cookie.php      # HSTS supercookie storage (requires HTTPS)
└── css/
    └── master.css          # Optional styling
```

--------------------------------

### Evercookie Constructor

Source: https://context7.com/samyk/evercookie/llms.txt

Initializes a new Evercookie instance with configurable options for storage mechanisms and server-side backend paths.

```APIDOC
## Evercookie Constructor

Creates a new Evercookie instance with configurable options for storage mechanisms and server-side backend paths. The constructor accepts an options object that allows enabling/disabling specific storage mechanisms and customizing paths to PHP backend files.

### Parameters
#### Request Body
- **options** (object) - Optional - Configuration options for Evercookie.
  - **baseurl** (string) - Optional - Base URL for all assets.
  - **asseturi** (string) - Optional - Path to assets directory containing .swf, .xap, .jnlp files.
  - **phpuri** (string) - Optional - Path to PHP backend files.
  - **domain** (string) - Optional - Domain for cookies.
  - **history** (boolean) - Optional - Enable/disable CSS history knocking.
  - **java** (boolean) - Optional - Enable/disable Java applet.
  - **silverlight** (boolean) - Optional - Enable/disable Silverlight isolated storage.
  - **lso** (boolean) - Optional - Enable/disable Flash Local Shared Objects.
  - **db** (boolean) - Optional - Enable/disable Web SQL Database.
  - **idb** (boolean) - Optional - Enable/disable IndexedDB.
  - **hsts** (boolean) - Optional - Enable/disable HSTS cookie settings.
  - **hsts_domains** (array of strings) - Optional - List of HSTS domains.
  - **pngCookieName** (string) - Optional - Name for the PNG cookie.
  - **pngPath** (string) - Optional - Path to the PNG cookie backend file.
  - **etagCookieName** (string) - Optional - Name for the ETag cookie.
  - **etagPath** (string) - Optional - Path to the ETag cookie backend file.
  - **cacheCookieName** (string) - Optional - Name for the cache cookie.
  - **cachePath** (string) - Optional - Path to the cache cookie backend file.

### Request Example
```javascript
// Basic initialization with default options
var ec = new evercookie();

// Advanced initialization with custom configuration
var ec = new evercookie({
    baseurl: '',
    asseturi: '/assets',
    phpuri: '/php',
    domain: '.example.com',
    history: true,
    java: true,
    silverlight: true,
    lso: true,
    db: true,
    idb: true,
    hsts: false,
    hsts_domains: ['https://domain1.example.com/hsts.php', 'https://domain2.example.com/hsts.php'],
    pngCookieName: 'evercookie_png',
    pngPath: '/evercookie_png.php',
    etagCookieName: 'evercookie_etag',
    etagPath: '/evercookie_etag.php',
    cacheCookieName: 'evercookie_cache',
    cachePath: '/evercookie_cache.php'
});
```
```

--------------------------------

### Integrate Evercookie in HTML

Source: https://context7.com/samyk/evercookie/llms.txt

Full HTML boilerplate including required script dependencies and Evercookie API usage for setting and retrieving cookies.

```html
<!DOCTYPE html>
<html>
<head>
    <title>Evercookie Demo</title>
    <!-- Required: SWFObject for Flash LSO support -->
    <script src="js/swfobject-2.2.min.js"></script>

    <!-- Required: Java deployment toolkit for Java applet support -->
    <script src="http://www.java.com/js/dtjava.js"></script>

    <!-- Required: Main Evercookie library -->
    <script src="js/evercookie.js"></script>
</head>
<body>
    <div id="status">Checking cookies...</div>
    <button id="setBtn">Set Cookie</button>
    <button id="getBtn">Get Cookie</button>
    <div id="results"></div>

    <script>
    // Initialize evercookie
    var ec = new evercookie({
        baseurl: '',
        asseturi: '/assets',
        phpuri: '/php'
    });

    // Generate random ID for demo
    var randomId = 'user_' + Math.floor(Math.random() * 1000000);

    // Set cookie button handler
    document.getElementById('setBtn').onclick = function() {
        document.getElementById('status').textContent = 'Setting cookie...';
        ec.set('uid', randomId);
        setTimeout(function() {
            document.getElementById('status').textContent = 'Cookie set: ' + randomId;
        }, 1000);
    };

    // Get cookie button handler
    document.getElementById('getBtn').onclick = function() {
        document.getElementById('status').textContent = 'Retrieving cookie...';

        ec.get('uid', function(best, all) {
            document.getElementById('status').textContent = 'Cookie found: ' + best;

            var html = '<h3>Storage Mechanism Results:</h3><ul>';
            for (var mechanism in all) {
                var value = all[mechanism] || '(empty)';
                var match = value === best ? ' (match)' : '';
                html += '<li><strong>' + mechanism + '</strong>: ' + value + match + '</li>';
            }
            html += '</ul>';
            document.getElementById('results').innerHTML = html;
        });
    };

    // Auto-check on page load
    ec.get('uid', function(best, all) {
        if (best) {
            document.getElementById('status').textContent = 'Existing cookie found: ' + best;
        } else {
            document.getElementById('status').textContent = 'No cookie found';
        }
    }, 1); // Don't auto-restore
    </script>
</body>
</html>
```

--------------------------------

### Setting Cookies

Source: https://context7.com/samyk/evercookie/llms.txt

Stores a key-value pair across all enabled storage mechanisms simultaneously. The operation is asynchronous.

```APIDOC
## Setting Cookies

The `set()` method stores a key-value pair across all enabled storage mechanisms simultaneously. The operation is asynchronous and propagates to Flash, Silverlight, server-side caches, and all client-side storage.

### Method
`ec.set(key, value)`

### Parameters
#### Path Parameters
- **key** (string) - Required - The name of the cookie to set.
- **value** (string) - Required - The value of the cookie.

### Request Example
```javascript
var ec = new evercookie();

// Set a simple cookie
ec.set("user_id", "abc123xyz");

// Set multiple cookies
ec.set("session_token", "9f8e7d6c5b4a");
ec.set("preferences", "theme=dark;lang=en");
```

### Notes
Cookie values are stored in various mechanisms including HTTP cookies, Flash LSO, Silverlight Isolated Storage, HTML5 localStorage, sessionStorage, globalStorage, IndexedDB, Web SQL Database, window.name, IE userData, HTTP ETag, Web cache, PNG canvas cache, CSS history knocking, and HSTS supercookies.
```

--------------------------------

### HTTP Cache Persistence Backend

Source: https://context7.com/samyk/evercookie/llms.txt

Persists data by returning it as plain text with long-term cache headers. Relies on 304 Not Modified responses to force browser cache retrieval when cookies are cleared.

```php
<?php
// evercookie_cache.php - HTTP Cache-based persistence
// Automatically included in evercookie distribution

// Simple caching mechanism:
// 1. Cookie value is stored in response body
// 2. Response is cached with 20-year expiration
// 3. When cookie deleted, 304 forces cache retrieval

// Cache headers:
// Content-Type: text/html
// Last-Modified: Wed, 30 Jun 2010 21:36:48 GMT
// Expires: Tue, 31 Dec 2030 23:30:45 GMT
// Cache-Control: private, max-age=630720000

// Client request:
// GET /php/evercookie_cache.php?name=user_id&cookie=evercookie_cache

// Response with cookie present:
// HTTP/1.1 200 OK
// Body: myvalue

// Response without cookie:
// HTTP/1.1 304 Not Modified
// (browser uses cached response)
```

--------------------------------

### Set a Cookie with Evercookie

Source: https://github.com/samyk/evercookie/blob/master/index.html

Use the `set` method to store a key-value pair. This method attempts to use all available storage mechanisms for maximum persistence.

```javascript
// set a cookie "id" to "12345"
// usage: ec.set(key, value)
**ec.set("id", "12345");**
```

--------------------------------

### Retrieve Cookie Candidates with Evercookie

Source: https://github.com/samyk/evercookie/blob/master/index.html

This snippet demonstrates how to use the Evercookie API to retrieve cookie candidates. It defines a callback function to process the results.

```javascript
ec.get("id", getCookie);
```

--------------------------------

### ETag Persistence Backend

Source: https://context7.com/samyk/evercookie/llms.txt

Uses HTTP ETag headers to store and retrieve cookie data. Requires the client to set the cookie before requesting the endpoint.

```php
<?php
// evercookie_etag.php - ETag-based persistence
// Automatically included in evercookie distribution

// Request flow:
// 1. Client sets cookie, makes request to this endpoint
// 2. Server stores value in ETag header
// 3. Client deletes cookie, makes new request
// 4. Server checks If-None-Match header for previous ETag
// 5. Returns 304 Not Modified with stored value

// Client-side sets the cookie first:
// document.cookie = "evercookie_etag=myvalue; path=/; domain=.example.com"

// Then requests:
// GET /php/evercookie_etag.php?name=user_id&cookie=evercookie_etag

// Server response when cookie exists:
// HTTP/1.1 200 OK
// ETag: "myvalue"
// Body: myvalue

// Server response when cookie cleared (uses If-None-Match from browser):
// HTTP/1.1 304 Not Modified
// ETag: "myvalue"
// Body: myvalue
```

--------------------------------

### PNG Cache Persistence Backend

Source: https://context7.com/samyk/evercookie/llms.txt

Encodes data into RGB pixel values of a generated PNG image cached for 20 years. JavaScript extracts the data by drawing the image to an HTML5 canvas.

```php
<?php
// evercookie_png.php - Canvas/PNG-based persistence
// Automatically included in evercookie distribution

// How it works:
// 1. Cookie value is sent to this PHP script
// 2. Script converts each character to RGB values
// 3. Generates a 200x1 pixel PNG with the encoded data
// 4. PNG is returned with 20-year cache headers
// 5. When cookie is deleted, script returns 304 Not Modified
// 6. Browser loads PNG from cache
// 7. JavaScript draws PNG to canvas, reads pixels back as characters

// Cache headers set:
// Content-Type: image/png
// Last-Modified: Wed, 30 Jun 2010 21:36:48 GMT
// Expires: Tue, 31 Dec 2030 23:30:45 GMT
// Cache-Control: private, max-age=630720000

// Client request:
// GET /php/evercookie_png.php?name=user_id&cookie=evercookie_png

// JavaScript extraction (simplified):
// var canvas = document.createElement('canvas');
// var ctx = canvas.getContext('2d');
// var img = new Image();
// img.onload = function() {
//     ctx.drawImage(img, 0, 0);
//     var data = ctx.getImageData(0, 0, 200, 1).data;
//     var value = '';
//     for (var i = 0; i < data.length; i += 4) {
//         if (data[i] === 0) break;
//         value += String.fromCharCode(data[i]);
//         if (data[i+1] === 0) break;
//         value += String.fromCharCode(data[i+1]);
//         if (data[i+2] === 0) break;
//         value += String.fromCharCode(data[i+2]);
//     }
//     console.log('Recovered: ' + value);
// };
// img.src = '/php/evercookie_png.php?name=user_id&cookie=evercookie_png';
```

--------------------------------

### Basic CSS Styling for Evercookie

Source: https://github.com/samyk/evercookie/blob/master/assets/evercookie_sl/evercookie/Bin/Debug/evercookieTestPage.html

These CSS rules set the height and overflow properties for the HTML body and set padding to zero. They are likely used to ensure proper layout and display of content within the Evercookie project's web interface.

```css
html, body { height: 100%; overflow: auto; }
body { padding: 0; margin: 0; }
#silverlightControlHost { height: 100%; text-align:center; }
```

--------------------------------

### Set Evercookie

Source: https://context7.com/samyk/evercookie/llms.txt

Store a key-value pair across all enabled storage mechanisms. This operation is asynchronous and propagates to various client-side and server-side storage.

```javascript
var ec = new evercookie();

// Set a simple cookie
ec.set("user_id", "abc123xyz");

// Set multiple cookies
ec.set("session_token", "9f8e7d6c5b4a");
ec.set("preferences", "theme=dark;lang=en");

// Cookie values are stored in:
// - HTTP cookies
// - Flash LSO (evercookie.swf)
// - Silverlight Isolated Storage (evercookie.xap)
// - HTML5 localStorage
// - HTML5 sessionStorage
// - HTML5 globalStorage (Firefox)
// - IndexedDB
// - Web SQL Database
// - window.name
// - IE userData
// - HTTP ETag (via evercookie_etag.php)
// - Web cache (via evercookie_cache.php)
// - PNG canvas cache (via evercookie_png.php)
// - CSS history knocking (if enabled)
// - HSTS supercookies (if configured)
```

--------------------------------

### Silverlight Error Handling Function

Source: https://github.com/samyk/evercookie/blob/master/assets/evercookie_sl/evercookie/Bin/Debug/evercookieTestPage.html

This JavaScript function is designed to handle errors that occur within Silverlight applications. It logs detailed error information, including error type, code, message, and specific details for parser or runtime errors. Use this function to gracefully manage and report Silverlight exceptions.

```javascript
function onSilverlightError(sender, args) {
  var appSource = "";
  if (sender != null && sender != 0) {
    appSource = sender.getHost().Source;
  }
  var errorType = args.ErrorType;
  var iErrorCode = args.ErrorCode;
  if (errorType == "ImageError" || errorType == "MediaError") {
    return;
  }
  var errMsg = "Unhandled Error in Silverlight Application " + appSource + "\n" ;
  errMsg += "Code: "+ iErrorCode + " \n";
  errMsg += "Category: " + errorType + " \n";
  errMsg += "Message: " + args.ErrorMessage + " \n";
  if (errorType == "ParserError") {
    errMsg += "File: " + args.xamlFile + " \n";
    errMsg += "Line: " + args.lineNumber + " \n";
    errMsg += "Position: " + args.charPosition + " \n";
  } else if (errorType == "RuntimeError") {
    if (args.lineNumber != 0) {
      errMsg += "Line: " + args.lineNumber + " \n";
      errMsg += "Position: " + args.charPosition + " \n";
    }
    errMsg += "MethodName: " + args.methodName + " \n";
  }
  throw new Error(errMsg);
}
```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.