silverstripe-framework/core/Requirements.php

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<?php
/**
* Requirements tracker, for javascript and css.
* @todo Document the requirements tracker, and discuss it with the others.
* @package sapphire
* @subpackage view
*/
class Requirements {
/**
* Paths to all required .js files relative to the webroot.
*
* @var array $javascript
*/
protected static $javascript = array();
/**
* Paths to all required .css files relative to the webroot.
*
* @var array $javascript
*/
protected static $css = array();
/**
* All custom javascript code that is inserted
* directly at the bottom of the HTML <head> tag.
*
* @var array $customScript
*/
protected static $customScript = array();
/**
* All custom CSS rules which are inserted
* directly at the bottom of the HTML <head> tag.
*
* @var array $customCSS
*/
protected static $customCSS = array();
/**
* All custom HTML markup which is added before
* the closing <head> tag, e.g. additional metatags.
* This is preferred to entering tags directly into
*/
protected static $customHeadTags = array();
/**
* Remembers the filepaths of all cleared Requirements
* through {@link clear()}.
*
* @usedby {@link restore()}
*
* @var array $disabled
*/
protected static $disabled = array();
/**
* The filepaths (relative to webroot) or
* uniquenessIDs of any included requirements
* which should be blocked when executing {@link inlcudeInHTML()}.
* This is useful to e.g. prevent core classes to modifying
* Requirements without subclassing the entire functionality.
* Use {@link unblock()} or {@link unblock_all()} to revert changes.
*
* @var array $blocked
*/
protected static $blocked = array();
/**
* See {@link combine_files()}.
*
* @var array $combine_files
*/
public static $combine_files = array();
/**
* Using the JSMin library to minify any
* javascript file passed to {@link combine_files()}.
*
* @var boolean
*/
public static $combine_js_with_jsmin = true;
/**
* Put all javascript includes at the bottom of the template
* before the closing <body> tag instead of the <head> tag.
* This means script downloads won't block other HTTP-requests,
* which can be a performance improvement.
* Caution: Doesn't work when modifying the DOM from those external
* scripts without listening to window.onload/document.ready
* (e.g. toplevel document.write() calls).
*
* @see http://developer.yahoo.com/performance/rules.html#js_bottom
*
* @var boolean
*/
public static $write_js_to_body = false;
/**
* Register the given javascript file as required.
* Filenames should be relative to the base, eg, 'sapphire/javascript/loader.js'
*/
static function javascript($file) {
Requirements::$javascript[$file] = true;
}
/**
* Add the javascript code to the header of the page
* @todo Make Requirements automatically put this into a separate file :-)
* @param script The script content
* @param uniquenessID Use this to ensure that pieces of code only get added once.
*/
static function customScript($script, $uniquenessID = null) {
if($uniquenessID)
Requirements::$customScript[$uniquenessID] = $script;
else {
Requirements::$customScript[] = $script;
}
$script .= "\n";
}
/**
* Add the CSS styling to the header of the page
* @todo Make Requirements automatically put this into a separate file :-)
*/
static function customCSS($script, $uniquenessID = null) {
if($uniquenessID)
Requirements::$customCSS[$uniquenessID] = $script;
else {
Requirements::$customCSS[] = $script;
}
}
/**
* Add the following custom code to the <head> section of the page.
*
* @param string $html
* @param string $uniquenessID
*/
static function insertHeadTags($html, $uniquenessID = null) {
if($uniquenessID)
Requirements::$customHeadTags[$uniquenessID] = $html;
else {
Requirements::$customHeadTags[] = $html;
}
}
/**
* Load the given javascript template with the page.
* @param file The template file to load.
* @param vars The array of variables to load. These variables are loaded via string search & replace.
*/
static function javascriptTemplate($file, $vars, $uniquenessID = null) {
$script = file_get_contents(Director::getAbsFile($file));
foreach($vars as $k => $v) {
$search[] = '$' . $k;
$replace[] = str_replace("\\'","'", Convert::raw2js($v));
}
$script = str_replace($search, $replace, $script);
Requirements::customScript($script, $uniquenessID);
}
/**
* Register the given stylesheet file as required.
*
* @param $file String Filenames should be relative to the base, eg, 'jsparty/tree/tree.css'
* @param $media String Comma-separated list of media-types (e.g. "screen,projector")
* @see http://www.w3.org/TR/REC-CSS2/media.html
*/
static function css($file, $media = null) {
Requirements::$css[$file] = array(
"media" => $media
);
}
/**
* Register the given "themeable stylesheet" as required.
* Themeable stylesheets have globally unique names, just like templates and PHP files.
* Because of this, they can be replaced by similarly named CSS files in the theme directory.
*
* @param $name String The identifier of the file. For example, css/MyFile.css would have the identifier "MyFile"
* @param $media String Comma-separated list of media-types (e.g. "screen,projector")
*/
static function themedCSS($name, $media = null) {
global $_CSS_MANIFEST;
$theme = SSViewer::current_theme();
if($theme && isset($_CSS_MANIFEST[$name]) && isset($_CSS_MANIFEST[$name]['themes'])
&& isset($_CSS_MANIFEST[$name]['themes'][$theme]))
Requirements::css($_CSS_MANIFEST[$name]['themes'][$theme], $media);
else if(isset($_CSS_MANIFEST[$name]) && isset($_CSS_MANIFEST[$name]['unthemed'])) Requirements::css($_CSS_MANIFEST[$name]['unthemed'], $media);
// Normal requirements fails quietly when there is no css - we should do the same
// else user_error("themedCSS - No CSS file '$name.css' found.", E_USER_WARNING);
}
/**
* Clear either a single or all requirements.
* Caution: Clearing single rules works only with customCSS and customScript if you specified a {@uniquenessID}.
*
* @param $file String
*/
static function clear($fileOrID = null) {
if($fileOrID) {
foreach(array('javascript','css', 'customScript', 'customCSS') as $type) {
if(isset(Requirements::${$type}[$fileOrID])) {
Requirements::$disabled[$type][$fileOrID] = Requirements::${$type}[$fileOrID];
unset(Requirements::${$type}[$fileOrID]);
}
}
} else {
Requirements::$disabled['javascript'] = Requirements::$javascript;
Requirements::$disabled['css'] = Requirements::$css;
Requirements::$disabled['customScript'] = Requirements::$customScript;
Requirements::$disabled['customCSS'] = Requirements::$customCSS;
Requirements::$javascript = array();
Requirements::$css = array();
Requirements::$customScript = array();
Requirements::$customCSS = array();
Requirements::$customHeadTags = array();
}
}
/**
* Needed to actively prevent the inclusion of a file,
* e.g. when using your own prototype.js.
* Blocking should only be used as an exception, because
* it is hard to trace back. You can just block items with an
* ID, so make sure you add an unique identifier to customCSS() and customScript().
*
* @param string $fileOrID
*/
static function block($fileOrID) {
self::$blocked[$fileOrID] = $fileOrID;
}
/**
* Removes an item from the blocking-list.
* CAUTION: Does not "re-add" any previously blocked elements.
* @param string $fileOrID
*/
static function unblock($fileOrID) {
if(isset(self::$blocked[$fileOrID])) unset(self::$blocked[$fileOrID]);
}
/**
* Removes all items from the blocking-list.
*/
static function unblock_all() {
self::$blocked = array();
}
/**
* Restore requirements cleared by call to Requirements::clear
*/
static function restore() {
Requirements::$javascript = Requirements::$disabled['javascript'];
Requirements::$css = Requirements::$disabled['css'];
Requirements::$customScript = Requirements::$disabled['customScript'];
Requirements::$customCSS = Requirements::$disabled['customCSS'];
}
/**
* Update the given HTML content with the appropriate include tags for the registered
* requirements. Needs to receive a valid HTML/XHTML template in the $content parameter,
* including a <head> tag. The requirements will insert before the closing <head> tag automatically.
*
* @todo Calculate $prefix properly
*
* @param string $templateFilePath Absolute path for the *.ss template file
* @param string $content HTML content that has already been parsed from the $templateFilePath through {@link SSViewer}.
* @return string HTML content thats augumented with the requirements before the closing <head> tag.
*/
static function includeInHTML($templateFile, $content) {
if(isset($_GET['debug_profile'])) Profiler::mark("Requirements::includeInHTML");
if(strpos($content, '</head') !== false && (Requirements::$javascript || Requirements::$css || Requirements::$customScript || Requirements::$customHeadTags)) {
$requirements = '';
$jsRequirements = '';
// Combine files - updates Requirements::$javascript and Requirements::$css
self::process_combined_files();
foreach(array_diff_key(self::$javascript,self::$blocked) as $file => $dummy) {
$path = self::path_for_file($file);
if($path) {
$jsRequirements .= "<script type=\"text/javascript\" src=\"$path\"></script>\n";
}
}
// add all inline javascript *after* including external files which
// they might rely on
if(self::$customScript) {
foreach(array_diff_key(self::$customScript,self::$blocked) as $script) {
$jsRequirements .= "<script type=\"text/javascript\">\n//<![CDATA[\n";
$jsRequirements .= "$script\n";
$jsRequirements .= "\n//]]>\n</script>\n";
}
}
foreach(array_diff_key(self::$css,self::$blocked) as $file => $params) {
$path = self::path_for_file($file);
if($path) {
$media = (isset($params['media']) && !empty($params['media'])) ? " media=\"{$params['media']}\"" : "";
$requirements .= "<link rel=\"stylesheet\" type=\"text/css\"{$media} href=\"$path\" />\n";
}
}
foreach(array_diff_key(self::$customCSS,self::$blocked) as $css) {
$requirements .= "<style type=\"text/css\">\n$css\n</style>\n";
}
foreach(array_diff_key(self::$customHeadTags,self::$blocked) as $customHeadTag) {
$requirements .= "$customHeadTag\n";
}
if(self::$write_js_to_body) {
// Remove all newlines from code to preserve layout
$jsRequirements = preg_replace('/>\n*/', '>', $jsRequirements);
// We put script tags into the body, for performance.
// If your template already has script tags in the body, then we put our script tags at the top of the body.
// Otherwise, we put it at the bottom.
$p1 = strripos($content, '<script');
$p2 = stripos($content, '<body');
if($p1 !== false && $p1 > $p2) {
user_error("You have a script tag in the body, moving requirements to top of <body> for compatibilty. I recommend removing the script tag from your template's body.", E_USER_NOTICE);
$content = eregi_replace("(<body[^>]*>)", "\\1" . $jsRequirements, $content);
} else {
$content = eregi_replace("(</body[^>]*>)", $jsRequirements . "\\1", $content);
}
// Put CSS at the bottom of the head
$content = eregi_replace("(</head[^>]*>)", $requirements . "\\1", $content);
} else {
$content = eregi_replace("(</head[^>]*>)", $requirements . "\\1", $content);
$content = eregi_replace("(</head[^>]*>)", $jsRequirements . "\\1", $content);
}
}
if(isset($_GET['debug_profile'])) Profiler::unmark("Requirements::includeInHTML");
return $content;
}
/**
*
*
* @param string $fileOrUrl
* @return string|boolean
*/
protected static function path_for_file($fileOrUrl) {
if(preg_match('/^http[s]?/', $fileOrUrl)) {
return $fileOrUrl;
} elseif(Director::fileExists($fileOrUrl)) {
$prefix = Director::absoluteBaseURL();
$mtimesuffix = "?m=" . filemtime(Director::baseFolder() . '/' . $fileOrUrl);
return "{$prefix}{$fileOrUrl}{$mtimesuffix}";
} else {
return false;
}
}
/**
* Concatenate several css or javascript files into a single dynamically generated
* file (stored in {@link Director::baseFolder()}). This increases performance
* by fewer HTTP requests.
*
* The combined file is regenerated
* based on every file modification time. Optionally a rebuild can be triggered
* by appending ?flush=1 to the URL.
* If all files to be combined are javascript, we use the external JSMin library
* to minify the javascript. This can be controlled by {@link $combine_js_with_jsmin}.
*
* All combined files will have a comment on the start of each concatenated file
* denoting their original position. For easier debugging, we recommend to only
* minify javascript if not in development mode ({@link Director::isDev()}).
*
* CAUTION: You're responsible for ensuring that the load order for combined files
* is retained - otherwise combining javascript files can lead to functional errors
* in the javascript logic, and combining css can lead to wrong styling inheritance.
* Depending on the javascript logic, you also have to ensure that files are not included
* in more than one combine_files() call.
* Best practice is to include every javascript file in exactly *one* combine_files()
* directive to avoid the issues mentioned above - this is enforced by this function.
*
* Example for combined JavaScript:
* <code>
* Requirements::combine_files(
* 'foobar.js',
* array(
* 'mysite/javascript/foo.js',
* 'mysite/javascript/bar.js',
* )
* );
* </code>
*
* Example for combined CSS:
* <code>
* Requirements::combine_files(
* 'foobar.css',
* array(
* 'mysite/javascript/foo.css',
* 'mysite/javascript/bar.css',
* )
* );
* </code>
*
* @see http://code.google.com/p/jsmin-php/
*
* @todo Should we enforce unique inclusion of files, or leave it to the developer? Can auto-detection cause breaks?
*
* @param string $combinedFileName Filename of the combined file (will be stored in {@link Director::baseFolder()} by default)
* @param array $files Array of filenames relative to the webroot
*/
static function combine_files($combinedFileName, $files) {
// duplicate check
foreach(self::$combine_files as $_combinedFileName => $_files) {
$duplicates = array_intersect($_files, $files);
if($duplicates) {
user_error("Requirements::combine_files(): Already included files " . implode(',', $duplicates) . " in combined file '{$_combinedFileName}'", E_USER_NOTICE);
return false;
}
}
self::$combine_files[$combinedFileName] = $files;
}
/**
* @return array
*/
static function get_combine_files() {
return self::$combine_files;
}
/**
* Deletes all dynamically generated combined files from the filesystem.
*
* @param string $combinedFileName If left blank, all combined files are deleted.
*/
static function delete_combined_files($combinedFileName = null) {
$combinedFiles = ($combinedFileName) ? array($combinedFileName => null) : self::$combine_files;
foreach($combinedFiles as $combinedFile => $sourceItems) {
$filePath = Director::baseFolder() . '/' . $combinedFile;
if(file_exists($filePath)) {
unlink($filePath);
}
}
}
/**
* Re-sets the combined files definition
*/
static function clear_combined_files() {
self::$combine_files = array();
}
/**
* See {@link combine_files()}.
*/
static function process_combined_files() {
// Make a map of files that could be potentially combined
$combinerCheck = array();
foreach(self::$combine_files as $combinedFile => $sourceItems) {
foreach($sourceItems as $sourceItem) {
if(isset($combinerCheck[$sourceItem]) && $combinerCheck[$sourceItem] != $combinedFile){
user_error("Requirements::process_combined_files - file '$sourceItem' appears in two combined files:" . " '{$combinerCheck[$sourceItem]}' and '$combinedFile'", E_USER_WARNING);
}
$combinerCheck[$sourceItem] = $combinedFile;
}
}
// Figure out which ones apply to this pageview
$combinedFiles = array();
$newJSRequirements = array();
$newCSSRequirements = array();
foreach(Requirements::$javascript as $file => $dummy) {
if(isset($combinerCheck[$file])) {
$newJSRequirements[$combinerCheck[$file]] = true;
$combinedFiles[$combinerCheck[$file]] = true;
} else {
$newJSRequirements[$file] = true;
}
}
foreach(Requirements::$css as $file => $params) {
if(isset($combinerCheck[$file])) {
$newCSSRequirements[$combinerCheck[$file]] = true;
$combinedFiles[$combinerCheck[$file]] = true;
} else {
$newCSSRequirements[$file] = $params;
}
}
// @todo Alters the original information, which means you can't call this
// method repeatedly - it will behave different on the second call!
Requirements::$javascript = $newJSRequirements;
Requirements::$css = $newCSSRequirements;
// Process the combined files
$base = Director::baseFolder() . '/';
foreach(array_diff_key($combinedFiles,self::$blocked) as $combinedFile => $dummy) {
$fileList = self::$combine_files[$combinedFile];
// Determine if we need to build the combined include
if(file_exists($base . $combinedFile) && !isset($_GET['flush'])) {
// file exists, check modification date of every contained file
$srcLastMod = 0;
foreach($fileList as $file) {
$srcLastMod = max(filemtime($base . $file), $srcLastMod);
}
$refresh = $srcLastMod > filemtime($base . $combinedFile);
} else {
// file doesn't exist, or refresh was explicitly required
$refresh = true;
}
if(!$refresh) continue;
$combinedData = "";
foreach(array_diff($fileList,self::$blocked) as $file) {
$fileContent = file_get_contents($base . $file);
// if we have a javascript file and jsmin is enabled, minify the content
if(stripos($file, '.js') && self::$combine_js_with_jsmin) {
$fileContent = JSMin::minify($fileContent);
}
// write a header comment for each file for easier identification and debugging
$combinedData .= "/****** FILE: $file *****/\n" . $fileContent . "\n";
}
if(!file_exists(dirname($base . $combinedFile))) {
Filesytem::makeFolder(dirname($base . $combinedFile));
}
$fh = fopen($base . $combinedFile, 'w');
fwrite($fh, $combinedData);
fclose($fh);
unset($fh);
}
}
static function get_custom_scripts() {
$requirements = "";
if(Requirements::$customScript) {
foreach(Requirements::$customScript as $script) {
$requirements .= "$script\n";
}
}
return $requirements;
}
static function debug() {
Debug::show(Requirements::$javascript);
Debug::show(Requirements::$css);
Debug::show(Requirements::$customCSS);
Debug::show(Requirements::$customScript);
Debug::show(Requirements::$customHeadTags);
Debug::show(Requirements::$combine_files);
}
}
?>