shimmie2/core/page.php

<?php
/**
 * \page themes Themes
 *
 * Each extension has a theme with a specific name -- eg. the extension Setup
 * which is stored in ext/setup/main.php will have a theme called SetupTheme
 * stored in ext/setup/theme.php. If you want to customise it, create a class
 * in the file themes/mytheme/setup.theme.php called CustomSetupTheme which
 * extends SetupTheme and overrides some of its methods.
 *
 * Generally an extension should only deal with processing data; whenever it
 * wants to display something, it should pass the data to be displayed to the
 * theme object, and the theme will add the data into the global $page
 * structure.
 *
 * A page should make sure that all the data it outputs is free from dangerous
 * data by using html_escape(), url_escape(), or int_escape() as appropriate.
 *
 * Because some HTML can be placed anywhere according to the theme, coming up
 * with the correct way to link to a page can be hard -- thus we have the
 * make_link() function, which will take a path like "post/list" and turn it
 * into a full and correct link, eg /myboard/post/list, /foo/index.php?q=post/list,
 * etc depending on how things are set up. This should always be used to link
 * to pages rather than hardcoding a path.
 *
 * Various other common functions are available as part of the Themelet class.
 */

abstract class PageMode
{
    const REDIRECT = 'redirect';
    const DATA = 'data';
    const PAGE = 'page';
}

/**
 * Class Page
 *
 * A data structure for holding all the bits of data that make up a page.
 *
 * The various extensions all add whatever they want to this structure,
 * then Layout turns it into HTML.
 */
class Page
{
    /** @name Overall */
    //@{
    /** @var string */
    public $mode = PageMode::PAGE;
    /** @var string */
    public $type = "text/html; charset=utf-8";

    /**
     * Set what this page should do; "page", "data", or "redirect".
     */
    public function set_mode(string $mode): void
    {
        $this->mode = $mode;
    }

    /**
     * Set the page's MIME type.
     */
    public function set_type(string $type): void
    {
        $this->type = $type;
    }


    //@}
    // ==============================================
    /** @name "data" mode */
    //@{

    /** @var string; public only for unit test */
    public $data = "";

    /** @var string; public only for unit test */
    public $filename = null;

    /**
     * Set the raw data to be sent.
     */
    public function set_data(string $data): void
    {
        $this->data = $data;
    }

    /**
     * Set the recommended download filename.
     */
    public function set_filename(string $filename): void
    {
        $this->filename = $filename;
    }


    //@}
    // ==============================================
    /** @name "redirect" mode */
    //@{

    /** @var string */
    private $redirect = "";

    /**
     * Set the URL to redirect to (remember to use make_link() if linking
     * to a page in the same site).
     */
    public function set_redirect(string $redirect): void
    {
        $this->redirect = $redirect;
    }


    //@}
    // ==============================================
    /** @name "page" mode */
    //@{

    /** @var int */
    public $code = 200;

    /** @var string */
    public $title = "";

    /** @var string */
    public $heading = "";

    /** @var string */
    public $subheading = "";

    /** @var string */
    public $quicknav = "";

    /** @var string[] */
    public $html_headers = [];

    /** @var string[] */
    public $http_headers = [];

    /** @var string[][] */
    public $cookies = [];

    /** @var Block[] */
    public $blocks = [];

    /**
     * Set the HTTP status code
     */
    public function set_code(int $code): void
    {
        $this->code = $code;
    }

    public function set_title(string $title): void
    {
        $this->title = $title;
    }

    public function set_heading(string $heading): void
    {
        $this->heading = $heading;
    }

    public function set_subheading(string $subheading): void
    {
        $this->subheading = $subheading;
    }

    /**
     * Add a line to the HTML head section.
     */
    public function add_html_header(string $line, int $position=50): void
    {
        while (isset($this->html_headers[$position])) {
            $position++;
        }
        $this->html_headers[$position] = $line;
    }

    /**
     * Add a http header to be sent to the client.
     */
    public function add_http_header(string $line, int $position=50): void
    {
        while (isset($this->http_headers[$position])) {
            $position++;
        }
        $this->http_headers[$position] = $line;
    }

    /**
     * The counterpart for get_cookie, this works like php's
     * setcookie method, but prepends the site-wide cookie prefix to
     * the $name argument before doing anything.
     */
    public function add_cookie(string $name, string $value, int $time, string $path): void
    {
        $full_name = COOKIE_PREFIX."_".$name;
        $this->cookies[] = [$full_name, $value, $time, $path];
    }

    public function get_cookie(string $name): ?string
    {
        $full_name = COOKIE_PREFIX."_".$name;
        if (isset($_COOKIE[$full_name])) {
            return $_COOKIE[$full_name];
        } else {
            return null;
        }
    }

    /**
     * Get all the HTML headers that are currently set and return as a string.
     */
    public function get_all_html_headers(): string
    {
        $data = '';
        ksort($this->html_headers);
        foreach ($this->html_headers as $line) {
            $data .= "\t\t" . $line . "\n";
        }
        return $data;
    }

    /**
     * Removes all currently set HTML headers (Be careful..).
     */
    public function delete_all_html_headers(): void
    {
        $this->html_headers = [];
    }

    /**
     * Add a Block of data to the page.
     */
    public function add_block(Block $block): void
    {
        $this->blocks[] = $block;
    }


    //@}
    // ==============================================

    /**
     * Display the page according to the mode and data given.
     */
    public function display(): void
    {
        global $page, $user;

        header("HTTP/1.0 {$this->code} Shimmie");
        header("Content-type: ".$this->type);
        header("X-Powered-By: SCore-".SCORE_VERSION);

        if (!headers_sent()) {
            foreach ($this->http_headers as $head) {
                header($head);
            }
            foreach ($this->cookies as $c) {
                setcookie($c[0], $c[1], $c[2], $c[3]);
            }
        } else {
            print "Error: Headers have already been sent to the client.";
        }

        switch ($this->mode) {
            case PageMode::PAGE:
                if (CACHE_HTTP) {
                    header("Vary: Cookie, Accept-Encoding");
                    if ($user->is_anonymous() && $_SERVER["REQUEST_METHOD"] == "GET") {
                        header("Cache-control: public, max-age=600");
                        header('Expires: ' . gmdate('D, d M Y H:i:s', time() + 600) . ' GMT');
                    } else {
                        #header("Cache-control: private, max-age=0");
                        header("Cache-control: no-cache");
                        header('Expires: ' . gmdate('D, d M Y H:i:s', time() - 600) . ' GMT');
                    }
                }
                #else {
                #	header("Cache-control: no-cache");
                #	header('Expires: ' . gmdate('D, d M Y H:i:s', time() - 600) . ' GMT');
                #}
                if ($this->get_cookie("flash_message") !== null) {
                    $this->add_cookie("flash_message", "", -1, "/");
                }
                usort($this->blocks, "blockcmp");
                $this->add_auto_html_headers();
                $layout = new Layout();
                $layout->display_page($page);
                break;
            case PageMode::DATA:
                header("Content-Length: ".strlen($this->data));
                if (!is_null($this->filename)) {
                    header('Content-Disposition: attachment; filename='.$this->filename);
                }
                print $this->data;
                break;
            case PageMode::REDIRECT:
                header('Location: '.$this->redirect);
                print 'You should be redirected to <a href="'.$this->redirect.'">'.$this->redirect.'</a>';
                break;
            default:
                print "Invalid page mode";
                break;
        }
    }

    /**
     * This function grabs all the CSS and JavaScript files sprinkled throughout Shimmie's folders,
     * concatenates them together into two large files (one for CSS and one for JS) and then stores
     * them in the /cache/ directory for serving to the user.
     *
     * Why do this? Two reasons:
     *  1. Reduces the number of files the user's browser needs to download.
     *  2. Allows these cached files to be compressed/minified by the admin.
     *
     * TODO: This should really be configurable somehow...
     */
    public function add_auto_html_headers(): void
    {
        global $config;

        $data_href = get_base_href();
        $theme_name = $config->get_string('theme', 'default');

        $this->add_html_header("<script type='text/javascript'>base_href = '$data_href';</script>", 40);

        # static handler will map these to themes/foo/static/bar.ico or ext/handle_static/static/bar.ico
        $this->add_html_header("<link rel='icon' type='image/x-icon' href='$data_href/favicon.ico'>", 41);
        $this->add_html_header("<link rel='apple-touch-icon' href='$data_href/apple-touch-icon.png'>", 42);

        //We use $config_latest to make sure cache is reset if config is ever updated.
        $config_latest = 0;
        foreach (zglob("data/config/*") as $conf) {
            $config_latest = max($config_latest, filemtime($conf));
        }

        /*** Generate CSS cache files ***/
        $css_latest = $config_latest;
        $css_files = array_merge(
            zglob("ext/{".ENABLED_EXTS."}/style.css"),
            zglob("themes/$theme_name/style.css")
        );
        foreach ($css_files as $css) {
            $css_latest = max($css_latest, filemtime($css));
        }
        $css_md5 = md5(serialize($css_files));
        $css_cache_file = data_path("cache/style/{$theme_name}.{$css_latest}.{$css_md5}.css");
        if (!file_exists($css_cache_file)) {
            $css_data = "";
            foreach ($css_files as $file) {
                $file_data = file_get_contents($file);
                $pattern = '/url[\s]*\([\s]*["\']?([^"\'\)]+)["\']?[\s]*\)/';
                $replace = 'url("../../../'.dirname($file).'/$1")';
                $file_data = preg_replace($pattern, $replace, $file_data);
                $css_data .= $file_data . "\n";
            }
            file_put_contents($css_cache_file, $css_data);
        }
        $this->add_html_header("<link rel='stylesheet' href='$data_href/$css_cache_file' type='text/css'>", 43);

        /*** Generate JS cache files ***/
        $js_latest = $config_latest;
        $js_files = array_merge(
            [
                "vendor/bower-asset/jquery/dist/jquery.min.js",
                "vendor/bower-asset/jquery-timeago/jquery.timeago.js",
                "vendor/bower-asset/tablesorter/jquery.tablesorter.min.js",
                "vendor/bower-asset/js-cookie/src/js.cookie.js",
                "ext/handle_static/modernizr-3.3.1.custom.js",
            ],
            zglob("ext/{".ENABLED_EXTS."}/script.js"),
            zglob("themes/$theme_name/script.js")
        );
        foreach ($js_files as $js) {
            $js_latest = max($js_latest, filemtime($js));
        }
        $js_md5 = md5(serialize($js_files));
        $js_cache_file = data_path("cache/script/{$theme_name}.{$js_latest}.{$js_md5}.js");
        if (!file_exists($js_cache_file)) {
            $js_data = "";
            foreach ($js_files as $file) {
                $js_data .= file_get_contents($file) . "\n";
            }
            file_put_contents($js_cache_file, $js_data);
        }
        $this->add_html_header("<script src='$data_href/$js_cache_file' type='text/javascript'></script>", 44);
    }
}