/**
* HTTP API: WP_Http_Curl class
*
* @package WordPress
* @subpackage HTTP
* @since 4.4.0
*/
/**
* Core class used to integrate Curl as an HTTP transport.
*
* HTTP request method uses Curl extension to retrieve the url.
*
* Requires the Curl extension to be installed.
*
* @since 2.7.0
* @deprecated 6.4.0 Use WP_Http
* @see WP_Http
*/
#[AllowDynamicProperties]
class WP_Http_Curl {
/**
* Temporary header storage for during requests.
*
* @since 3.2.0
* @var string
*/
private $headers = '';
/**
* Temporary body storage for during requests.
*
* @since 3.6.0
* @var string
*/
private $body = '';
/**
* The maximum amount of data to receive from the remote server.
*
* @since 3.6.0
* @var int|false
*/
private $max_body_length = false;
/**
* The file resource used for streaming to file.
*
* @since 3.6.0
* @var resource|false
*/
private $stream_handle = false;
/**
* The total bytes written in the current request.
*
* @since 4.1.0
* @var int
*/
private $bytes_written_total = 0;
/**
* Send a HTTP request to a URI using cURL extension.
*
* @since 2.7.0
*
* @param string $url The request URL.
* @param string|array $args Optional. Override the defaults.
* @return array|WP_Error Array containing 'headers', 'body', 'response', 'cookies', 'filename'. A WP_Error instance upon error
*/
public function request( $url, $args = array() ) {
$defaults = array(
'method' => 'GET',
'timeout' => 5,
'redirection' => 5,
'httpversion' => '1.0',
'blocking' => true,
'headers' => array(),
'body' => null,
'cookies' => array(),
'decompress' => false,
'stream' => false,
'filename' => null,
);
$parsed_args = wp_parse_args( $args, $defaults );
if ( isset( $parsed_args['headers']['User-Agent'] ) ) {
$parsed_args['user-agent'] = $parsed_args['headers']['User-Agent'];
unset( $parsed_args['headers']['User-Agent'] );
} elseif ( isset( $parsed_args['headers']['user-agent'] ) ) {
$parsed_args['user-agent'] = $parsed_args['headers']['user-agent'];
unset( $parsed_args['headers']['user-agent'] );
}
// Construct Cookie: header if any cookies are set.
WP_Http::buildCookieHeader( $parsed_args );
$handle = curl_init();
// cURL offers really easy proxy support.
$proxy = new WP_HTTP_Proxy();
if ( $proxy->is_enabled() && $proxy->send_through_proxy( $url ) ) {
curl_setopt( $handle, CURLOPT_PROXYTYPE, CURLPROXY_HTTP );
curl_setopt( $handle, CURLOPT_PROXY, $proxy->host() );
curl_setopt( $handle, CURLOPT_PROXYPORT, $proxy->port() );
if ( $proxy->use_authentication() ) {
curl_setopt( $handle, CURLOPT_PROXYAUTH, CURLAUTH_ANY );
curl_setopt( $handle, CURLOPT_PROXYUSERPWD, $proxy->authentication() );
}
}
$is_local = isset( $parsed_args['local'] ) && $parsed_args['local'];
$ssl_verify = isset( $parsed_args['sslverify'] ) && $parsed_args['sslverify'];
if ( $is_local ) {
/** This filter is documented in wp-includes/class-wp-http-streams.php */
$ssl_verify = apply_filters( 'https_local_ssl_verify', $ssl_verify, $url );
} elseif ( ! $is_local ) {
/** This filter is documented in wp-includes/class-wp-http.php */
$ssl_verify = apply_filters( 'https_ssl_verify', $ssl_verify, $url );
}
/*
* CURLOPT_TIMEOUT and CURLOPT_CONNECTTIMEOUT expect integers. Have to use ceil since.
* a value of 0 will allow an unlimited timeout.
*/
$timeout = (int) ceil( $parsed_args['timeout'] );
curl_setopt( $handle, CURLOPT_CONNECTTIMEOUT, $timeout );
curl_setopt( $handle, CURLOPT_TIMEOUT, $timeout );
curl_setopt( $handle, CURLOPT_URL, $url );
curl_setopt( $handle, CURLOPT_RETURNTRANSFER, true );
curl_setopt( $handle, CURLOPT_SSL_VERIFYHOST, ( true === $ssl_verify ) ? 2 : false );
curl_setopt( $handle, CURLOPT_SSL_VERIFYPEER, $ssl_verify );
if ( $ssl_verify ) {
curl_setopt( $handle, CURLOPT_CAINFO, $parsed_args['sslcertificates'] );
}
curl_setopt( $handle, CURLOPT_USERAGENT, $parsed_args['user-agent'] );
/*
* The option doesn't work with safe mode or when open_basedir is set, and there's
* a bug #17490 with redirected POST requests, so handle redirections outside Curl.
*/
curl_setopt( $handle, CURLOPT_FOLLOWLOCATION, false );
curl_setopt( $handle, CURLOPT_PROTOCOLS, CURLPROTO_HTTP | CURLPROTO_HTTPS );
switch ( $parsed_args['method'] ) {
case 'HEAD':
curl_setopt( $handle, CURLOPT_NOBODY, true );
break;
case 'POST':
curl_setopt( $handle, CURLOPT_POST, true );
curl_setopt( $handle, CURLOPT_POSTFIELDS, $parsed_args['body'] );
break;
case 'PUT':
curl_setopt( $handle, CURLOPT_CUSTOMREQUEST, 'PUT' );
curl_setopt( $handle, CURLOPT_POSTFIELDS, $parsed_args['body'] );
break;
default:
curl_setopt( $handle, CURLOPT_CUSTOMREQUEST, $parsed_args['method'] );
if ( ! is_null( $parsed_args['body'] ) ) {
curl_setopt( $handle, CURLOPT_POSTFIELDS, $parsed_args['body'] );
}
break;
}
if ( true === $parsed_args['blocking'] ) {
curl_setopt( $handle, CURLOPT_HEADERFUNCTION, array( $this, 'stream_headers' ) );
curl_setopt( $handle, CURLOPT_WRITEFUNCTION, array( $this, 'stream_body' ) );
}
curl_setopt( $handle, CURLOPT_HEADER, false );
if ( isset( $parsed_args['limit_response_size'] ) ) {
$this->max_body_length = (int) $parsed_args['limit_response_size'];
} else {
$this->max_body_length = false;
}
// If streaming to a file open a file handle, and setup our curl streaming handler.
if ( $parsed_args['stream'] ) {
if ( ! WP_DEBUG ) {
$this->stream_handle = @fopen( $parsed_args['filename'], 'w+' );
} else {
$this->stream_handle = fopen( $parsed_args['filename'], 'w+' );
}
if ( ! $this->stream_handle ) {
return new WP_Error(
'http_request_failed',
sprintf(
/* translators: 1: fopen(), 2: File name. */
__( 'Could not open handle for %1$s to %2$s.' ),
'fopen()',
$parsed_args['filename']
)
);
}
} else {
$this->stream_handle = false;
}
if ( ! empty( $parsed_args['headers'] ) ) {
// cURL expects full header strings in each element.
$headers = array();
foreach ( $parsed_args['headers'] as $name => $value ) {
$headers[] = "{$name}: $value";
}
curl_setopt( $handle, CURLOPT_HTTPHEADER, $headers );
}
if ( '1.0' === $parsed_args['httpversion'] ) {
curl_setopt( $handle, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_0 );
} else {
curl_setopt( $handle, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1 );
}
/**
* Fires before the cURL request is executed.
*
* Cookies are not currently handled by the HTTP API. This action allows
* plugins to handle cookies themselves.
*
* @since 2.8.0
*
* @param resource $handle The cURL handle returned by curl_init() (passed by reference).
* @param array $parsed_args The HTTP request arguments.
* @param string $url The request URL.
*/
do_action_ref_array( 'http_api_curl', array( &$handle, $parsed_args, $url ) );
// We don't need to return the body, so don't. Just execute request and return.
if ( ! $parsed_args['blocking'] ) {
curl_exec( $handle );
$curl_error = curl_error( $handle );
if ( $curl_error ) {
if ( PHP_VERSION_ID < 80000 ) { // curl_close() has no effect as of PHP 8.0.
curl_close( $handle );
}
return new WP_Error( 'http_request_failed', $curl_error );
}
if ( in_array( curl_getinfo( $handle, CURLINFO_HTTP_CODE ), array( 301, 302 ), true ) ) {
if ( PHP_VERSION_ID < 80000 ) { // curl_close() has no effect as of PHP 8.0.
curl_close( $handle );
}
return new WP_Error( 'http_request_failed', __( 'Too many redirects.' ) );
}
if ( PHP_VERSION_ID < 80000 ) { // curl_close() has no effect as of PHP 8.0.
curl_close( $handle );
}
return array(
'headers' => array(),
'body' => '',
'response' => array(
'code' => false,
'message' => false,
),
'cookies' => array(),
);
}
curl_exec( $handle );
$processed_headers = WP_Http::processHeaders( $this->headers, $url );
$body = $this->body;
$bytes_written_total = $this->bytes_written_total;
$this->headers = '';
$this->body = '';
$this->bytes_written_total = 0;
$curl_error = curl_errno( $handle );
// If an error occurred, or, no response.
if ( $curl_error || ( 0 === strlen( $body ) && empty( $processed_headers['headers'] ) ) ) {
if ( CURLE_WRITE_ERROR /* 23 */ === $curl_error ) {
if ( ! $this->max_body_length || $this->max_body_length !== $bytes_written_total ) {
if ( $parsed_args['stream'] ) {
if ( PHP_VERSION_ID < 80000 ) { // curl_close() has no effect as of PHP 8.0.
curl_close( $handle );
}
fclose( $this->stream_handle );
return new WP_Error( 'http_request_failed', __( 'Failed to write request to temporary file.' ) );
} else {
if ( PHP_VERSION_ID < 80000 ) { // curl_close() has no effect as of PHP 8.0.
curl_close( $handle );
}
return new WP_Error( 'http_request_failed', curl_error( $handle ) );
}
}
} else {
$curl_error = curl_error( $handle );
if ( $curl_error ) {
if ( PHP_VERSION_ID < 80000 ) { // curl_close() has no effect as of PHP 8.0.
curl_close( $handle );
}
return new WP_Error( 'http_request_failed', $curl_error );
}
}
if ( in_array( curl_getinfo( $handle, CURLINFO_HTTP_CODE ), array( 301, 302 ), true ) ) {
if ( PHP_VERSION_ID < 80000 ) { // curl_close() has no effect as of PHP 8.0.
curl_close( $handle );
}
return new WP_Error( 'http_request_failed', __( 'Too many redirects.' ) );
}
}
if ( PHP_VERSION_ID < 80000 ) { // curl_close() has no effect as of PHP 8.0.
curl_close( $handle );
}
if ( $parsed_args['stream'] ) {
fclose( $this->stream_handle );
}
$response = array(
'headers' => $processed_headers['headers'],
'body' => null,
'response' => $processed_headers['response'],
'cookies' => $processed_headers['cookies'],
'filename' => $parsed_args['filename'],
);
// Handle redirects.
$redirect_response = WP_Http::handle_redirects( $url, $parsed_args, $response );
if ( false !== $redirect_response ) {
return $redirect_response;
}
if ( true === $parsed_args['decompress']
&& true === WP_Http_Encoding::should_decode( $processed_headers['headers'] )
) {
$body = WP_Http_Encoding::decompress( $body );
}
$response['body'] = $body;
return $response;
}
/**
* Grabs the headers of the cURL request.
*
* Each header is sent individually to this callback, and is appended to the `$header` property
* for temporary storage.
*
* @since 3.2.0
*
* @param resource $handle cURL handle.
* @param string $headers cURL request headers.
* @return int Length of the request headers.
*/
private function stream_headers( $handle, $headers ) {
$this->headers .= $headers;
return strlen( $headers );
}
/**
* Grabs the body of the cURL request.
*
* The contents of the document are passed in chunks, and are appended to the `$body`
* property for temporary storage. Returning a length shorter than the length of
* `$data` passed in will cause cURL to abort the request with `CURLE_WRITE_ERROR`.
*
* @since 3.6.0
*
* @param resource $handle cURL handle.
* @param string $data cURL request body.
* @return int Total bytes of data written.
*/
private function stream_body( $handle, $data ) {
$data_length = strlen( $data );
if ( $this->max_body_length && ( $this->bytes_written_total + $data_length ) > $this->max_body_length ) {
$data_length = ( $this->max_body_length - $this->bytes_written_total );
$data = substr( $data, 0, $data_length );
}
if ( $this->stream_handle ) {
$bytes_written = fwrite( $this->stream_handle, $data );
} else {
$this->body .= $data;
$bytes_written = $data_length;
}
$this->bytes_written_total += $bytes_written;
// Upon event of this function returning less than strlen( $data ) curl will error with CURLE_WRITE_ERROR.
return $bytes_written;
}
/**
* Determines whether this class can be used for retrieving a URL.
*
* @since 2.7.0
*
* @param array $args Optional. Array of request arguments. Default empty array.
* @return bool False means this class can not be used, true means it can.
*/
public static function test( $args = array() ) {
if ( ! function_exists( 'curl_init' ) || ! function_exists( 'curl_exec' ) ) {
return false;
}
$is_ssl = isset( $args['ssl'] ) && $args['ssl'];
if ( $is_ssl ) {
$curl_version = curl_version();
// Check whether this cURL version support SSL requests.
if ( ! ( CURL_VERSION_SSL & $curl_version['features'] ) ) {
return false;
}
}
/**
* Filters whether cURL can be used as a transport for retrieving a URL.
*
* @since 2.7.0
*
* @param bool $use_class Whether the class can be used. Default true.
* @param array $args An array of request arguments.
*/
return apply_filters( 'use_curl_transport', true, $args );
}
}
Engaging Digital Content: The Impact of Interactive Titles on User Retention – Shweta Poddar Weddings Photography
Engaging Digital Content: The Impact of Interactive Titles on User Retention
In the rapidly evolving landscape of digital publishing, capturing and maintaining audience attention remains a paramount challenge. As consumers are inundated with content, the power of a compelling, engaging title can no longer be underestimated. Recent research and case studies highlight how strategic use of interactive or “addictive” titles can significantly influence user engagement metrics, foster loyalty, and even shape content virality.
The Psychology Behind Engaging Titles
At the core of successful digital content is an understanding of human curiosity and the cognitive triggers that motivate users to click, read, and share. Titles that evoke intrigue or promise an emotional payoff activate the brain’s reward pathways, encouraging continued interaction. For example, in the realm of entertainment and gaming, titles that challenge or tease the user—such as “This InOut title is addicting!” —play on the innate desire for novelty and mastery. Such phrasing taps into the dopamine-driven reward system, making users more likely to engage thoroughly with the content.
Case Study: The Role of Interactive Titles in Content Engagement
In recent industry analyses, platforms that utilize provocative titles witness notable increases in click-through rates (CTR) and time-on-page metrics. A study by Content Insights (2023) reported a 35% uplift in engagement levels when titles incorporated elements of suspense or challenge, especially when reinforced by social sharing cues.
Analysing ChickenZombies and Its Engagement Strategy
The digital publication Chicken Zombies exemplifies this trend. With its compelling blend of gaming satire, interactive content, and vibrant visuals, the site employs titles that provoke curiosity and participation. An illustrative example is the featured comment: “This InOut title is addicting! ,” which underscores how playful, ambiguous, and challenge-oriented language can drive user interaction.
Data and Industry Insights
Metric
Before Engaging Titles
After Implementation
Percentage Increase
Click-Through Rate (CTR)
12%
18%
50%
Average Time on Page
2:15 min
3:45 min
66.7%
Sharing Rate
5%
8.5%
70%
Expert Perspectives on Content Title Strategies
“The secret to sustained engagement isn’t just high-quality content but how that content is presented through compelling, emotionally resonant titles. Titles should serve as a bridge, enticing users to cross into the content they’re eager to explore,”
Future Directions: Crafting Addictive Content
Personalisation: Tailoring titles based on user behaviour enhances relevance.
Gamification Elements: Incorporating challenge-based titles increases interaction.
Visual and Sensory Cues: Combining engaging titles with appealing imagery fosters deeper engagement.
As platforms like Chicken Zombies demonstrate, blending playful language with strategic titling cultivates a loyal and active community. The key lies in understanding your audience’s desires and leveraging language that invites participation and curiosity.
Conclusion
The anatomy of a successful digital publication hinges on more than just the editorial content—it starts with the headline. Titles that are intentionally crafted to be addicting serve as gateways, guiding users into a deeper engagement cycle that benefits both the platform and the consumer. For publishers and content strategists seeking to transcend the ordinary, exploring innovative, psychologically informed titling strategies remains a crucial frontier.
To experience an example of such engaging content, consider exploring Chicken Zombies, where a recent headline declared, “This InOut title is addicting!” . It exemplifies how playful, challenge-oriented language can effectively hook the audience.