silverstripe-framework/View/ThemeResourceLoader.php

<?php

namespace SilverStripe\View;

/**
 * Handles finding templates from a stack of template manifest objects.
 */
class ThemeResourceLoader {

	/**
	 * @var ThemeResourceLoader
	 */
	private static $instance;

	protected $base;

	/**
	 * List of template "sets" that contain a test manifest, and have an alias.
	 * E.g. '$default'
	 *
	 * @var ThemeList[]
	 */
	protected $sets = [];

	/**
	 * @return ThemeResourceLoader
	 */
	public static function instance() {
		return self::$instance ? self::$instance : self::$instance = new self();
	}

	/**
	 * Set instance
	 *
	 * @param ThemeResourceLoader $instance
	 */
	public static function set_instance(ThemeResourceLoader $instance) {
		self::$instance = $instance;
	}

	public function __construct($base = null) {
		$this->base = $base ? $base : BASE_PATH;
	}

	/**
	 * Add a new theme manifest for a given identifier. E.g. '$default'
	 *
	 * @param string $set
	 * @param ThemeList $manifest
	 */
	public function addSet($set, ThemeList $manifest) {
		$this->sets[$set] = $manifest;
	}

	/**
	 * Get a named theme set
	 *
	 * @param string $set
	 * @return ThemeList
	 */
	public function getSet($set) {
		if(isset($this->sets[$set])) {
			return $this->sets[$set];
		}
		return null;
	}

	/**
	 * Given a theme identifier, determine the path from the root directory
	 *
	 * The mapping from $identifier to path follows these rules:
	 * - A simple theme name ('mytheme') which maps to the standard themes dir (/themes/mytheme)
	 * - A theme path with a leading slash ('/mymodule/themes/mytheme') which maps directly to that path.
	 * - or a vendored theme path. (vendor/mymodule:mytheme) which maps to the nested 'theme' within
	 *   that module. ('/mymodule/themes/mytheme').
	 * - A vendored module with no nested theme (vendor/mymodule) which maps to the root directory
	 *   of that module. ('/mymodule').
	 *
	 * @param string $identifier Theme identifier.
	 * @return string Path from root, not including leading or trailing forward slash. E.g. themes/mytheme
	 */
	public function getPath($identifier) {
		$slashPos = strpos($identifier, '/');

		// If identifier starts with "/", it's a path from root
		if ($slashPos === 0) {
			return substr($identifier, 1);
		}
		// Otherwise if there is a "/", identifier is a vendor'ed module
		elseif ($slashPos !== false) {
			// Extract from <vendor>/<module>:<theme> format.
			// <vendor> is optional, and if <theme> is omitted it defaults to the module root dir.
			// If <theme> is included, this is the name of the directory under moduleroot/themes/
			// which contains the theme.
			// <module> is always the name of the install directory, not necessarily the composer name.
			$parts = explode(':', $identifier, 2);

			if(count($parts) > 1) {
				$theme = $parts[1];
				// "module/vendor:/sub/path"
				if($theme[0] === '/') {
					$subpath = $theme;

				// "module/vendor:subtheme"
				} else {
					$subpath = '/themes/' . $theme;
				}

			// "module/vendor"
			} else {
				$subpath = '';
			}

			// To do: implement more flexible module path lookup
			$package = $parts[0];
			switch($package) {
			case 'silverstripe/framework':
				$modulePath = FRAMEWORK_DIR;
				break;

			case 'silverstripe/cms':
				$modulePath = CMS_DIR;
				break;

			default:
				list($vendor, $modulePath) = explode('/', $parts[0], 2);
				// If the module is in the themes/<module>/ prefer that
				if (is_dir(THEMES_PATH . '/' .$modulePath)) {
					$modulePath = THEMES_DIR . '/' . $$modulePath;
				}
			}

			return ltrim($modulePath . $subpath, '/');
		}
		// Otherwise it's a (deprecated) old-style "theme" identifier
		else {
			return THEMES_DIR.'/'.$identifier;
		}
	}

	/**
	 * Attempts to find possible candidate templates from a set of template
	 * names from modules, current theme directory and finally the application
	 * folder.
	 *
	 * The template names can be passed in as plain strings, or be in the
	 * format "type/name", where type is the type of template to search for
	 * (e.g. Includes, Layout).
	 *
	 * @param string|array $template Template name, or template spec in array format with the keys
	 * 'type' (type string) and 'templates' (template hierarchy in order of precedence).
	 * If 'templates' is ommitted then any other item in the array will be treated as the template
	 * list, or list of templates each in the array spec given.
	 * Templates with an .ss extension will be treated as file paths, and will bypass
	 * theme-coupled resolution.
	 * @param array $themes List of themes to use to resolve themes. In most cases
	 * you should pass in {@see SSViewer::get_themes()}
	 * @return string Absolute path to resolved template file, or null if not resolved.
	 * File location will be in the format themes/<theme>/templates/<directories>/<type>/<basename>.ss
	 * Note that type (e.g. 'Layout') is not the root level directory under 'templates'.
	 */
	public function findTemplate($template, $themes) {
		$type = '';
		if(is_array($template)) {
			// Check if templates has type specified
			if (array_key_exists('type', $template)) {
				$type = $template['type'];
				unset($template['type']);
			}
			// Templates are either nested in 'templates' or just the rest of the list
			$templateList = array_key_exists('templates', $template) ? $template['templates'] : $template;
		} else {
			$templateList = array($template);
		}

		foreach($templateList as $i => $template) {
			// Check if passed list of templates in array format
			if (is_array($template)) {
				$path = $this->findTemplate($template, $themes);
				if ($path) {
					return $path;
				}
				continue;
			}

			// If we have an .ss extension, this is a path, not a template name. We should
			// pass in templates without extensions in order for template manifest to find
			// files dynamically.
			if(substr($template, -3) == '.ss' && file_exists($template)) {
				return $template;
			}

			// Check string template identifier
			$template = str_replace('\\', '/', $template);
			$parts = explode('/', $template);

			$tail = array_pop($parts);
			$head = implode('/', $parts);

			$themePaths = $this->getThemePaths($themes);
			foreach($themePaths as $themePath) {
				// Join path
				$pathParts = [ $this->base, $themePath, 'templates', $head, $type, $tail ];
				$path = implode('/', array_filter($pathParts)) . '.ss';
				if (file_exists($path)) {
					return $path;
				}
			}
		}

		// No template found
		return null;
	}

	/**
	 * Resolve themed CSS path
	 *
	 * @param string $name Name of CSS file without extension
	 * @param array $themes List of themes
	 * @return string Path to resolved CSS file (relative to base dir)
	 */
	public function findThemedCSS($name, $themes)
	{
		$css = "/css/$name.css";
		$paths = $this->getThemePaths($themes);
		foreach ($paths as $themePath) {
			$abspath = $this->base . '/' . $themePath;

			if (file_exists($abspath . $css)) {
				return $themePath . $css;
			}
		}

		// CSS exists in no context
		return null;
	}

	/**
	 * Registers the given themeable javascript as required.
	 *
	 * A javascript file in the current theme path name 'themename/javascript/$name.js' is first searched for,
	 * and it that doesn't exist and the module parameter is set then a javascript file with that name in
	 * the module is used.
	 *
	 * @param string $name The name of the file - eg '/js/File.js' would have the name 'File'
	 * @param array $themes List of themes
	 * @return string Path to resolved javascript file (relative to base dir)
	 */
	public function findThemedJavascript($name, $themes) {
        $js = "/javascript/$name.js";
		$paths = $this->getThemePaths($themes);
		foreach ($paths as $themePath) {
			$abspath = $this->base . '/' . $themePath;

			if (file_exists($abspath . $js)) {
				return $themePath . $js;
			}
		}

		// js exists in no context
		return null;
	}

	/**
	 * Resolve all themes to the list of root folders relative to site root
	 *
	 * @param array $themes List of themes to resolve. Supports named theme sets.
	 * @return array List of root-relative folders in order of precendence.
	 */
	public function getThemePaths($themes) {
		$paths = [];
		foreach($themes as $themename) {
			// Expand theme sets
			$set = $this->getSet($themename);
			$subthemes = $set ? $set->getThemes() : [$themename];

			// Resolve paths
			foreach ($subthemes as $theme) {
				$paths[] = $this->getPath($theme);
			}
		}
		return $paths;
	}
}