使用过wordpress程序做网站的朋友都会发现，wordpress后台会经常有wordpress升级提示和wordpress主题升级的相关提示。那么，如果开发了一款wordpress企业主题，而后期有版本升级，如何才能给这款主题使用者有升级提醒？也就是说，怎样给这款wordpress企业主题添加主题升级更新提醒功能呢？其实，实现起来并不复杂，下面就一起来看看吧。
第一步：服务器端设置：
这个服务器就是这款wordpress企业主题用来升级的地方，可以是主题的官网，如：ssmay主题的官网就是高时银博客。
1：在这款服务器添加一个themes目录。
2：在themes目录下新建details.html文件，这个是用来显示主题升级的提示内容。代码如：
这只是一个范例。
<style>
a{color:red;font-size:18px;font-weight:800;}
a:hover{color:blue;}
h2{font-weight:800;font-size:16px;}
h1{font-weight:800;font-size:22px;}
</style><h1>主题升级地址：</h1>
<h2>2019-2-20 ssmay 4.1 （ PC版 和 PC+移动版 ）</h2>
1、添加“商城”页面，让“CMS与商城”得以完美组合，具体可参阅时美网效果。</br>
2、添加“投稿”页面，美化“登录与注册”页面也可以“注册”后发表文章（当然要你后台开放注册。）。</br>
3、对手机端进一步优化，让视觉效果更加美好。详情： http://wanlimm.com/77201503232983.html
3：再在themes目录下新建一个info.json文件，这个文件是版本升级提醒内容，代码如下：
{"version" : "4.1", /*主题新版本, 如大于该wordpress企业主题style.css中版本号，就触发升级提示。*/"details_url" : "http://xxxxx.com/themes/details.html", /*这是上面创建的details.html 地址。*/"download_url" : "http://xxxxx.com/themes/ssmay.zip" /* 这是ssmay主题的地址, 这里自定。 */}
4：把这款wordpress企业主题的最新版上传到themes目录下。
第二步：主题包中的设置：
1：给这款wordpress企业主题添加一个theme-updates目录。
2：在这个theme-updates目录下添加一个theme-update-checker.php的文件，这个文件是一个用来检查主题升级的PHP类文件，代码如下：
<?phpif ( !class_exists('ThemeUpdateChecker') ):/*** A custom theme update checker.** @author Janis Elsts* @copyright 2012* @version 1.2* @access public*/class ThemeUpdateChecker {public $theme = ''; //The theme associated with this update checker instance.public $metadataUrl = ''; //The URL of the theme's metadata file.public $enableAutomaticChecking = true; //Enable/disable automatic update checks.protected $optionName = ''; //Where to store update info.protected $automaticCheckDone = false;protected static $filterPrefix = 'tuc_request_update_';/*** Class constructor.** @param string $theme Theme slug, e.g. "twentyten".* @param string $metadataUrl The URL of the theme metadata file.* @param boolean $enableAutomaticChecking Enable/disable automatic update checking. If set to FALSE, you'll need to explicitly call checkForUpdates() to, err, check for updates.*/public function __construct($theme, $metadataUrl, $enableAutomaticChecking = true){$this->metadataUrl = $metadataUrl;$this->enableAutomaticChecking = $enableAutomaticChecking;$this->theme = $theme;$this->optionName = 'external_theme_updates-'.$this->theme;$this->installHooks();}/*** Install the hooks required to run periodic update checks and inject update info* into WP data structures.** @return void*/public function installHooks(){//Check for updates when WordPress does. We can detect when that happens by tracking//updates to the "update_themes" transient, which only happen in wp_update_themes().if ( $this->enableAutomaticChecking ){add_filter('pre_set_site_transient_update_themes', array($this, 'onTransientUpdate'));}//Insert our update info into the update list maintained by WP.add_filter('site_transient_update_themes', array($this,'injectUpdate'));//Delete our update info when WP deletes its own.//This usually happens when a theme is installed, removed or upgraded.add_action('delete_site_transient_update_themes', array($this, 'deleteStoredData'));}/*** Retrieve update info from the configured metadata URL.** Returns either an instance of ThemeUpdate, or NULL if there is* no newer version available or if there's an error.** @uses wp_remote_get()** @param array $queryArgs Additional query arguments to append to the request. Optional.* @return ThemeUpdate*/public function requestUpdate($queryArgs = array()){//Query args to append to the URL. Themes can add their own by using a filter callback (see addQueryArgFilter()).$queryArgs['installed_version'] = $this->getInstalledVersion();$queryArgs = apply_filters(self::$filterPrefix.'query_args-'.$this->theme, $queryArgs);//Various options for the wp_remote_get() call. Themes can filter these, too.$options = array('timeout' => 10, //seconds);$options = apply_filters(self::$filterPrefix.'options-'.$this->theme, $options);$url = $this->metadataUrl;if ( !empty($queryArgs) ){$url = add_query_arg($queryArgs, $url);}//Send the request.$result = wp_remote_get($url, $options);//Try to parse the response$themeUpdate = null;$code = wp_remote_retrieve_response_code($result);$body = wp_remote_retrieve_body($result);if ( ($code == 200) && !empty($body) ){$themeUpdate = ThemeUpdate::fromJson($body);//The update should be newer than the currently installed version.if ( ($themeUpdate != null) && version_compare($themeUpdate->version, $this->getInstalledVersion(), '<=') ){$themeUpdate = null;}}$themeUpdate = apply_filters(self::$filterPrefix.'result-'.$this->theme, $themeUpdate, $result);return $themeUpdate;}/*** Get the currently installed version of our theme.** @return string Version number.*/public function getInstalledVersion(){if ( function_exists('wp_get_theme') ) {$theme = wp_get_theme($this->theme);return $theme->get('Version');}/** @noinspection PhpDeprecationInspection get_themes() used for compatibility with WP 3.3 and below. */foreach(get_themes() as $theme){if ( $theme['Stylesheet'] === $this->theme ){return $theme['Version'];}}return '';}/*** Check for theme updates.** @return void*/public function checkForUpdates(){$state = get_option($this->optionName);if ( empty($state) ){$state = new StdClass;$state->lastCheck = 0;$state->checkedVersion = '';$state->update = null;}$state->lastCheck = time();$state->checkedVersion = $this->getInstalledVersion();update_option($this->optionName, $state); //Save before checking in case something goes wrong$state->update = $this->requestUpdate();update_option($this->optionName, $state);}/*** Run the automatic update check, but no more than once per page load.* This is a callback for WP hooks. Do not call it directly.** @param mixed $value* @return mixed*/public function onTransientUpdate($value){if ( !$this->automaticCheckDone ){$this->checkForUpdates();$this->automaticCheckDone = true;}return $value;}/*** Insert the latest update (if any) into the update list maintained by WP.** @param StdClass $updates Update list.* @return array Modified update list.*/public function injectUpdate($updates){$state = get_option($this->optionName);//Is there an update to insert?if ( !empty($state) && isset($state->update) && !empty($state->update) ){$updates->response[$this->theme] = $state->update->toWpFormat();}return $updates;}/*** Delete any stored book-keeping data.** @return void*/public function deleteStoredData(){delete_option($this->optionName);}/*** Register a callback for filtering query arguments.** The callback function should take one argument - an associative array of query arguments.* It should return a modified array of query arguments.** @param callable $callback* @return void*/public function addQueryArgFilter($callback){add_filter(self::$filterPrefix.'query_args-'.$this->theme, $callback);}/*** Register a callback for filtering arguments passed to wp_remote_get().** The callback function should take one argument - an associative array of arguments -* and return a modified array or arguments. See the WP documentation on wp_remote_get()* for details on what arguments are available and how they work.** @param callable $callback* @return void*/public function addHttpRequestArgFilter($callback){add_filter(self::$filterPrefix.'options-'.$this->theme, $callback);}/*** Register a callback for filtering the theme info retrieved from the external API.** The callback function should take two arguments. If a theme update was retrieved* successfully, the first argument passed will be an instance of ThemeUpdate. Otherwise,* it will be NULL. The second argument will be the corresponding return value of* wp_remote_get (see WP docs for details).** The callback function should return a new or modified instance of ThemeUpdate or NULL.** @param callable $callback* @return void*/public function addResultFilter($callback){add_filter(self::$filterPrefix.'result-'.$this->theme, $callback, 10, 2);}}endif;if ( !class_exists('ThemeUpdate') ):/*** A simple container class for holding information about an available update.** @author Janis Elsts* @copyright 2012* @version 1.0* @access public*/class ThemeUpdate {public $version; //Version number.public $details_url; //The URL where the user can learn more about this version.public $download_url; //The download URL for this version of the theme. Optional./*** Create a new instance of ThemeUpdate from its JSON-encoded representation.** @param string $json Valid JSON string representing a theme information object.* @return ThemeUpdate New instance of ThemeUpdate, or NULL on error.*/public static function fromJson($json){$apiResponse = json_decode($json);if ( empty($apiResponse) || !is_object($apiResponse) ){return null;}//Very, very basic validation.$valid = isset($apiResponse->version) && !empty($apiResponse->version) && isset($apiResponse->details_url) && !empty($apiResponse->details_url);if ( !$valid ){return null;}$update = new self();foreach(get_object_vars($apiResponse) as $key => $value){$update->$key = $value;}return $update;}/*** Transform the update into the format expected by the WordPress core.** @return array*/public function toWpFormat(){$update = array('new_version' => $this->version,'url' => $this->details_url,);if ( !empty($this->download_url) ){$update['package'] = $this->download_url;}return $update;}}endif;
这个类是从网上弄的，直接拿来用了。
3：在这款wordpress企业主题的functions.php文件中添加如下代码，引入上面这个检查主题升级的类来检查主题升级：
//主题更新
require 'theme-updates/theme-update-checker.php'; //引入类文件
$example_update_checker = new ThemeUpdateChecker(
'ssmay', //主题名，要与这款wordpress企业主题style.css里面设置的一样，大小写一样.
'http://xxxxx.com/themes/info.json' //第一步中服务器中添加的info.json文件的地址 ，
);
到这里，我们就为这款wordpress企业主题添加好了后台升级更新提醒功能。在后期主题有新版本时，只需要修改服务器端的info.json文件中的版本号以及修改default.html文件的相关提示，就可以了。当然，如果想让用户直接能从服务器下载，就把主题新版本上传到服务器端的themes目录覆盖原版本。
