Update WordPress Plugin from GitHub Releases

wp-github-plugin-updater.php

<?php

/**
 * Retrieve updates from GitHub
 * Add the following snipped to your main wordpress plugin file
 * Note that the public github API has a rate limit of 60 per hour per IP
 */
add_filter('site_transient_update_plugins', function($transient) {
    // Config
    $wpPluginSlug = 'my-wordpress-plugin';
    $githubRepoSlug = '<user>/<repository_name>';
    $githubRepoUrl = "https://github.com/$githubRepoSlug";
    $githubReleasesUrl = "https://api.github.com/repos/$githubRepoSlug/releases";

    $cacheFilename = 'github-releases.json';
    $cacheCreatedFilename = 'github-checked-at.txt';

    if (empty($transient->checked)) {
        return $transient;
    }

    // Check if the cache file exists
    $cacheFile = plugin_dir_path(__FILE__) . $cacheFilename;
    $cacheCreatedFile = plugin_dir_path(__FILE__) . $cacheCreatedFilename;

    // Check if cache is older than 1 hour
    $isCacheOld = false;
    if (file_exists($cacheCreatedFile)) {
        $cacheCreated = file_get_contents($cacheCreatedFile);
        $cacheCreatedTimestamp = (int)$cacheCreated;
        $currentTimestamp = time();
        $diff = $currentTimestamp - $cacheCreatedTimestamp;
        if ($diff > 3600) {
            $isCacheOld = true;
        }
    }

    if (file_exists($cacheFile) && !$isCacheOld) {
        $releaseData = json_decode(file_get_contents($cacheFile), true);
    } else {
        // Fetch the release data from GitHub
        $response = wp_remote_get($githubReleasesUrl, [
            'timeout' => 10,
            'headers' => [
                'Accept' => 'application/vnd.github.v3+json',
            ],
        ]);
        if (is_wp_error($response)) {
            return $transient;
        }
        $releaseData = json_decode(wp_remote_retrieve_body($response), true);
    }

    if (!empty($releaseData) && !isset($releaseData['message'])) {
        // Cache the response in a file
        $time = time();
        $cacheFile = plugin_dir_path(__FILE__) . $cacheFilename;
        file_put_contents($cacheFile, json_encode($releaseData));
        $cacheCreatedFile = plugin_dir_path(__FILE__) . $cacheCreatedFilename;
        file_put_contents($cacheCreatedFile, $time);

        $currentVersion = $transient->checked["$wpPluginSlug/$wpPluginSlug.php"];
        $latestVersion = ltrim($releaseData[0]['tag_name'], 'v');

        if (version_compare($currentVersion, $latestVersion, '<')) {
            // Find asset, which name contains 'wordpress'
            foreach ($releaseData[0]['assets'] as $key => $asset) {
                if (strpos($asset['name'], 'wordpress') !== false) {
                    $wpAssetKey = $key;
                    break;
                }
            }

            if ($wpAssetKey === false) {
                return $transient;
            }

            $wpAsset = $releaseData[0]['assets'][$wpAssetKey];
            $transient->response["$wpPluginSlug/$wpPluginSlug.php"] = (object) [
                'slug' => $wpPluginSlug,
                'new_version' => $latestVersion,
                'package' => $wpAsset['browser_download_url'],
                'url' => $githubRepoUrl,
            ];
        }
    }

    return $transient;
});

wp-github-theme-updater.php

<?php

/**
 * Retrieve updates for a WordPress theme from GitHub.
 * Add this snippet to your theme's functions.php file.
 * Note: The public GitHub API has a rate limit of 60 requests per hour per IP.
 */
add_filter('site_transient_update_themes', function($transient) {
    // Config
    $wpThemeSlug = 'your-theme-slug'; // Change this to your theme slug
    $githubRepoSlug = 'your-github-username/your-repo-name'; // Change this to your GitHub repo slug
    $githubRepoUrl = "https://github.com/$githubRepoSlug";
    $githubReleasesUrl = "https://api.github.com/repos/$githubRepoSlug/releases";

    $cacheFilename = 'github-releases.json';
    $cacheCreatedFilename = 'github-checked-at.txt';

    if (empty($transient->checked)) {
        return $transient;
    }

    // Check if the cache file exists
    $cacheFile = get_theme_file_path($cacheFilename);
    $cacheCreatedFile = get_theme_file_path($cacheCreatedFilename);

    // Check if cache is older than 1 hour
    $isCacheOld = false;
    if (file_exists($cacheCreatedFile)) {
        $cacheCreated = file_get_contents($cacheCreatedFile);
        $cacheCreatedTimestamp = (int)$cacheCreated;
        $currentTimestamp = time();
        $diff = $currentTimestamp - $cacheCreatedTimestamp;
        if ($diff > 3600) { // Cache is old if more than 1 hour
            $isCacheOld = true;
        }
    }

    // Use cached data if available and not old
    if (file_exists($cacheFile) && !$isCacheOld) {
        $releaseData = json_decode(file_get_contents($cacheFile), true);
    } else {
        // Fetch the release data from GitHub
        $response = wp_remote_get($githubReleasesUrl, [
            'timeout' => 10,
            'headers' => [
                'Accept' => 'application/vnd.github.v3+json',
            ],
        ]);
        if (is_wp_error($response)) {
            return $transient;
        }
        $releaseData = json_decode(wp_remote_retrieve_body($response), true);
    }

    if (!empty($releaseData) && !isset($releaseData['message'])) {
        // Cache the response
        file_put_contents($cacheFile, json_encode($releaseData));
        file_put_contents($cacheCreatedFile, time());

        // Get current theme version
        $theme_data = wp_get_theme($wpThemeSlug);
        $currentVersion = $theme_data->Version;

        $latestVersion = ltrim($releaseData[0]['tag_name'], 'v');

        if (version_compare($currentVersion, $latestVersion, '<')) {
            // Find asset in the release data
            $wpAssetKey = false;
            foreach ($releaseData[0]['assets'] as $key => $asset) {
                if (strpos($asset['name'], 'wordpress') !== false) {
                    $wpAssetKey = $key;
                    break;
                }
            }

            if ($wpAssetKey === false) {
                return $transient;
            }

            $wpAsset = $releaseData[0]['assets'][$wpAssetKey];
            $transient->response[$wpThemeSlug] = [
                'theme' => $wpThemeSlug,
                'new_version' => $latestVersion,
                'url' => $githubRepoUrl,
                'package' => $wpAsset['browser_download_url']
            ];
        }
    }

    return $transient;
});