HTTPCacheControl

Get a configuration accessor for this class. Short hand for Config::inst()->get($this->class, .....).

An implementation of the factory method, allows you to create an instance of a class

This method first for strong class overloads (singletons & DB interaction), then custom class overloads. If an overload is found, an instance of this is returned rather than the original class. To overload a class, use {@link Object::useCustomClass()}

This can be called in one of two ways - either calling via the class directly, or calling on Object and passing the class name as the first parameter. The following are equivalent: $list = DataList::create('SiteTree'); $list = SiteTree::get();

Creates a class instance by the "singleton" design pattern.

It will always return the same instance for this class, which can be used for performance reasons and as a simple way to access instance methods which don't rely on instance data (e.g. the custom SilverStripe static handling).

Create an object from a string representation. It treats it as a PHP constructor without the 'new' keyword. It also manages to construct the object without the use of eval().

Construction itself is done with Object::create(), so that Object::useCustomClass() calls are respected.

Object::create_from_string("Versioned('Stage','Live')") will return the result of Versioned::create('Stage', 'Live);

It is designed for simple, clonable objects. The first time this method is called for a given string it is cached, and clones of that object are returned.

If you pass the $firstArg argument, this will be prepended to the constructor arguments. It's impossible to pass null as the firstArg argument.

Object::create_from_string("Varchar(50)", "MyField") will return the result of Vachar::create('MyField', '50');

Arguments are always strings, although this is a quirk of the current implementation rather than something that can be relied upon.

Parses a class-spec, such as "Versioned('Stage','Live')", as passed to create_from_string().

Returns a 2-elemnent array, with classname and arguments

Similar to {@link Object::create()}, except that classes are only overloaded if you set the $strong parameter to TRUE when using {@link Object::useCustomClass()}

This class allows you to overload classes with other classes when they are constructed using the factory method {@link Object::create()}

If a class has been overloaded, get the class name it has been overloaded with - otherwise return the class name

Get the value of a static property of a class, even in that property is declared protected (but not private), without any inheritance, merging or parent lookup if it doesn't exist on the given class.

Return TRUE if a class has a specified extension.

This supports backwards-compatible format (static Object::has_extension($requiredExtension)) and new format ($object->has_extension($class, $requiredExtension))

Add an extension to a specific class.

The preferred method for adding extensions is through YAML config, since it avoids autoloading the class, and is easier to override in more specific configurations.

As an alternative, extensions can be added to a specific class directly in the {@link Object::$extensions} array. See {@link SiteTree::$extensions} for examples. Keep in mind that the extension will only be applied to new instances, not existing ones (including all instances created through {@link singleton()}).

Remove an extension from a class.

Keep in mind that this won't revert any datamodel additions of the extension at runtime, unless its used before the schema building kicks in (in your _config.php). Doesn't remove the extension from any {@link Object} instances which are already created, but will have an effect on new extensions. Clears any previously created singletons through {@link singleton()} to avoid side-effects from stale extension information.

Attemps to locate and call a method dynamically added to a class at runtime if a default cannot be located

You can add extra methods to a class using {@link Extensions}, {@link Object::createMethod()} or {@link Object::addWrapperMethod()}

Return TRUE if a method exists on this object

This should be used rather than PHP's inbuild method_exists() as it takes into account methods added via extensions

Return the names of all the methods available on this object

Return true if this object "exists" i.e. has a sensible value

This method should be overriden in subclasses to provide more context about the classes state. For example, a {@link DataObject} class could return false when it is deleted from the database

Check if this class is an instance of a specific class, or has that class as one of its parents

Calls a method if available on both this object and all applied {@link Extensions}, and then attempts to merge all results into an array

Run the given function on all of this object's extensions. Note that this method originally returned void, so if you wanted to return results, you're hosed

Currently returns an array, with an index resulting every time the function is called. Only adds returns if they're not NULL, to avoid bogus results from methods just defined on the parent extension. This is important for permission-checks through extend, as they use min() to determine if any of the returns is FALSE. As min() doesn't do type checking, an included NULL return would fail the permission checks.

The extension methods are defined during {@link __construct()} in {@link defineMethods()}.

Get an extension instance attached to this object by name.

Returns TRUE if this object instance has a specific extension applied in {@link $extension_instances}. Extension instances are initialized at constructor time, meaning if you use {@link add_extension()} afterwards, the added extension will just be added to new instances of the extended class. Use the static method {@link has_extension()} to check if a class (not an instance) has a specific extension.

Caution: Don't use singleton()->hasExtension() as it will give you inconsistent results based on when the singleton was first accessed.

Get all extension instances for this specific object instance.

See {@link get_extensions()} to get all applied extension classes for this class (not the instance).

Cache the results of an instance method in this object to a file, or if it is already cache return the cached results

Clears the cache for the given cacheToFile call

Low level method for setting directives include any experimental or custom ones added via config

Low level method to set directives from an associative array

Low level method for removing directives

Low level method to check if a directive is currently set

Low level method to get the value of a directive

Note that null value is acceptable for a directive

The cache should not store anything about the client request or server response.

Set the no-store directive (also removes max-age and s-maxage for consistency purposes)

Forces caches to submit the request to the origin server for validation before releasing a cached copy.

Specifies the maximum amount of time (seconds) a resource will be considered fresh.

This directive is relative to the time of the request.

Overrides max-age or the Expires header, but it only applies to shared caches (e.g., proxies) and is ignored by a private cache.

The cache must verify the status of the stale resources before using it and expired ones should not be used.

Simple way to set cache control header to a cacheable state.

Use this method over publicCache() if you are unsure about caching details.

Removes no-store and no-cache directives; other directives will remain in place. Use alongside setMaxAge() to indicate caching.

Does not set public directive. Usually, setMaxAge() is sufficient. Use publicCache() if this is explicitly required. See https://developers.google.com/web/fundamentals/performance/optimizing-content-efficiency/http-caching#public_vs_private

Simple way to set cache control header to a non-cacheable state.

Use this method over privateCache() if you are unsure about caching details. Takes precendence over unforced enableCache(), privateCache() or publicCache() calls.

Removes all state and replaces it with no-cache, no-store, must-revalidate. Although no-store is sufficient the others are added under recommendation from Mozilla (https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cache-Control#Examples)

Does not set private directive, use privateCache() if this is explicitly required. See https://developers.google.com/web/fundamentals/performance/optimizing-content-efficiency/http-caching#public_vs_private

Advanced way to set cache control header to a non-cacheable state.

Indicates that the response is intended for a single user and must not be stored by a shared cache. A private cache (e.g. Web Browser) may store the response. Also removes public as this is a contradictory directive.

Advanced way to set cache control header to a cacheable state.

Indicates that the response may be cached by any cache. (eg: CDNs, Proxies, Web browsers) Also removes private as this is a contradictory directive

Generate and add the Cache-Control header to a response object

Generate all headers to output

Reset registered http cache control and force a fresh instance to be built