GDBackend

class GDBackend extends SS_Object implements Image_Backend

A wrapper class for GD-based images, with lots of manipulation functions.

Config options

default_quality integer
image_interlace integer

Properties

string $class from SS_Object

Methods

static Config_ForClass|null
config()

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

from SS_Object
static SS_Object
create()

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

from SS_Object
static SS_Object
singleton()

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

from SS_Object
static 
create_from_string($classSpec, $firstArg = null)

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().

from SS_Object
static 
parse_class_spec($classSpec)

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

from SS_Object
static SS_Object
strong_create()

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

from SS_Object
static 
useCustomClass(string $oldClass, string $newClass, bool $strong = false)

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

from SS_Object
static string
getCustomClass(string $class)

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

from SS_Object
static any
static_lookup($class, $name, null $default = null)

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.

from SS_Object
static 
get_static($class, $name, $uncached = false) deprecated

No description

from SS_Object
static 
set_static($class, $name, $value) deprecated

No description

from SS_Object
static 
uninherited_static($class, $name, $uncached = false) deprecated

No description

from SS_Object
static 
combined_static($class, $name, $ceiling = false) deprecated

No description

from SS_Object
static 
addStaticVars($class, $properties, $replace = false) deprecated

No description

from SS_Object
static 
add_static_var($class, $name, $value, $replace = false) deprecated

No description

from SS_Object
static 
has_extension(string $classOrExtension, string $requiredExtension = null, boolean $strict = false)

Return TRUE if a class has a specified extension.

from SS_Object
static 
add_extension(string $classOrExtension, string $extension = null)

Add an extension to a specific class.

from SS_Object
static 
remove_extension(string $extension)

Remove an extension from a class.

from SS_Object
static array
get_extensions(string $class, bool $includeArgumentString = false)

No description

from SS_Object
static 
get_extra_config_sources($class = null)

No description

from SS_Object
__construct($filename = null, $args = array())

No description

mixed
__call(string $method, array $arguments)

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

from SS_Object
bool
hasMethod(string $method)

Return TRUE if a method exists on this object

from SS_Object
array
allMethodNames(bool $custom = false)

Return the names of all the methods available on this object

from SS_Object
stat($name, $uncached = false)

No description

from SS_Object
set_stat($name, $value)

No description

from SS_Object
uninherited($name)

No description

from SS_Object
bool
exists()

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

from SS_Object
string
parentClass()

No description

from SS_Object
bool
is_a(string $class)

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

from SS_Object
string
__toString()

No description

from SS_Object
mixed
invokeWithExtensions(string $method, mixed $argument = null)

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

from SS_Object
array
extend(string $method, mixed $a1 = null, mixed $a2 = null, mixed $a3 = null, mixed $a4 = null, mixed $a5 = null, mixed $a6 = null, mixed $a7 = null)

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

from SS_Object
Extension
getExtensionInstance(string $extension)

Get an extension instance attached to this object by name.

from SS_Object
bool
hasExtension(string $extension)

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.

from SS_Object
array
getExtensionInstances()

Get all extension instances for this specific object instance.

from SS_Object
mixed
cacheToFile(string $method, int $lifetime = 3600, string $ID = false, array $arguments = array())

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

from SS_Object
clearCache($method, $ID = false, $arguments = array())

Clears the cache for the given cacheToFile call

from SS_Object
static 
set_default_quality(quality $quality) deprecated

Set the default image quality.

void
setImageResource(mixed $resource)

setImageResource

setGD($gd) deprecated

No description

mixed
getImageResource()

getImageResource

getGD() deprecated

No description

boolean
imageAvailable(string $filename, string $manipulation)

No description

boolean
checkAvailableMemory(string $filename)

Check if we've got enough memory available for resampling this image. This check is rough, so it will not catch all images that are too large - it also won't work accurately on large, animated GIFs as bits per pixel can't be calculated for an animated GIF with a global color table.

boolean
failedResample($filename, $manipulation)

Check if this image has previously crashed GD when attempting to open it - if it's opened successfully, the manipulation's cache key is removed.

void
setQuality(int $quality)

Set the image quality, used when saving JPEGs.

Image_Backend
croppedResize(int $width, int $height)

Resize an image to cover the given width/height completely, and crop off any overhanging edges.

fittedResize($width, $height)

Resizes the image to fit within the given region.

boolean
hasImageResource()

hasImageResource

hasGD() deprecated

No description

Image_Backend
resize(int $width, int $height)

Resize an image, skewing it as necessary.

GD
rotate(angle $angle)

Rotates image by given angle.

GD
rotatePixelByPixel(angle $angle)

Rotates image by given angle. It's slow because makes it pixel by pixel rather than using built-in function. Used when imagerotate function is not available(i.e. Ubuntu)

GD
crop(top $top, left $left, width $width, height $height)

Crop's part of image.

integer
getWidth()

Method return width of image.

integer
getHeight()

Method return height of image.

Image_Backend
resizeByWidth(int $width)

Resize an image by width. Preserves aspect ratio.

Image_Backend
resizeByHeight(int $height)

Resize an image by height. Preserves aspect ratio

Image_Backend
resizeRatio($maxWidth, $maxHeight, $useAsMinimum = false)

Resize the image by preserving aspect ratio. By default, it will keep the image inside the maxWidth and maxHeight. Passing useAsMinimum will make the smaller dimension equal to the maximum corresponding dimension

static 
color_web2gd($image, $webColor, $transparencyPercent)

No description

Image_Backend
paddedResize($width, $height, $backgroundColor = "FFFFFF", transparencyPercent $transparencyPercent)

Resize to fit fully within the given box, without resizing. Extra space left around the image will be padded with the background color.

greyscale($R = 299, $G = 587, $B = 114, $brightness = 100)

Make the image greyscale.

makeDir($dirname)

No description

void
writeTo($filename)

writeTo

void
onBeforeDelete(Image $frontend)

No description

Details

in SS_Object at line 60
static Config_ForClass|null config()

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

....).

Return Value

Config_ForClass|null

in SS_Object at line 132
static SS_Object create()

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();

Return Value

SS_Object

in SS_Object at line 155
static SS_Object singleton()

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).

Return Value

SS_Object The singleton instance

in SS_Object at line 190
static create_from_string($classSpec, $firstArg = null)

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.

Parameters

$classSpec
$firstArg

in SS_Object at line 215
static parse_class_spec($classSpec)

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

Returns a 2-elemnent array, with classname and arguments

Parameters

$classSpec

in SS_Object at line 341
static SS_Object strong_create()

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

Return Value

SS_Object

in SS_Object at line 361
static useCustomClass(string $oldClass, string $newClass, bool $strong = false)

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

Parameters

string $oldClass the class to replace
string $newClass the class to replace it with
bool $strong allows you to enforce a certain class replacement under all circumstances. This is used in singletons and DB interaction classes

in SS_Object at line 375
static string getCustomClass(string $class)

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

Parameters

string $class the class to check

Return Value

string the class that would be created if you called {@link Object::create()} with the class

in SS_Object at line 396
static any static_lookup($class, $name, null $default = null)

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.

Parameters

$class
  • The class to get the static from
$name
  • The property to get from the class
null $default
  • The value to return if property doesn't exist on class

Return Value

any
  • The value of the static property $name on class $class, or $default if that property is not defined

in SS_Object at line 436
static get_static($class, $name, $uncached = false) deprecated

deprecated

Parameters

$class
$name
$uncached

in SS_Object at line 444
static set_static($class, $name, $value) deprecated

deprecated

Parameters

$class
$name
$value

in SS_Object at line 452
static uninherited_static($class, $name, $uncached = false) deprecated

deprecated

Parameters

$class
$name
$uncached

in SS_Object at line 460
static combined_static($class, $name, $ceiling = false) deprecated

deprecated

Parameters

$class
$name
$ceiling

in SS_Object at line 470
static addStaticVars($class, $properties, $replace = false) deprecated

deprecated

Parameters

$class
$properties
$replace

in SS_Object at line 478
static add_static_var($class, $name, $value, $replace = false) deprecated

deprecated

Parameters

$class
$name
$value
$replace

in SS_Object at line 494
static has_extension(string $classOrExtension, string $requiredExtension = null, boolean $strict = false)

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))

Parameters

string $classOrExtension if 1 argument supplied, the class name of the extension to check for; if 2 supplied, the class name to test
string $requiredExtension used only if 2 arguments supplied
boolean $strict if the extension has to match the required extension and not be a subclass

in SS_Object at line 536
static add_extension(string $classOrExtension, string $extension = null)

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()}).

Parameters

string $classOrExtension Class that should be extended - has to be a subclass of {@link Object}
string $extension Subclass of {@link Extension} with optional parameters as a string, e.g. "Versioned" or "Translatable('Param')"

See also

http://doc.silverstripe.org/framework/en/trunk/reference/dataextension

in SS_Object at line 594
static remove_extension(string $extension)

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.

Parameters

string $extension Classname of an {@link Extension} subclass, without parameters

in SS_Object at line 633
static array get_extensions(string $class, bool $includeArgumentString = false)

Parameters

string $class
bool $includeArgumentString Include the argument string in the return array, FALSE would return array("Versioned"), TRUE returns array("Versioned('Stage','Live')").

Return Value

array Numeric array of either {@link DataExtension} classnames, or eval'ed classname strings with constructor arguments.

in SS_Object at line 655
static get_extra_config_sources($class = null)

Parameters

$class

at line 38
__construct($filename = null, $args = array())

Parameters

$filename
$args

in SS_Object at line 725
mixed __call(string $method, array $arguments)

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()}

Parameters

string $method
array $arguments

Return Value

mixed

in SS_Object at line 792
bool hasMethod(string $method)

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

Parameters

string $method

Return Value

bool

in SS_Object at line 802
array allMethodNames(bool $custom = false)

Return the names of all the methods available on this object

Parameters

bool $custom include methods added dynamically at runtime

Return Value

array

in SS_Object at line 963
stat($name, $uncached = false)

Parameters

$name
$uncached

See also

SS_Object::get_static()

in SS_Object at line 970
set_stat($name, $value)

Parameters

$name
$value

See also

SS_Object::set_static()

in SS_Object at line 977
uninherited($name)

Parameters

$name

See also

SS_Object::uninherited_static()

in SS_Object at line 991
bool exists()

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

Return Value

bool

in SS_Object at line 998
string parentClass()

Return Value

string this classes parent class

in SS_Object at line 1008
bool is_a(string $class)

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

Parameters

string $class

Return Value

bool

in SS_Object at line 1015
string __toString()

Return Value

string the class name

in SS_Object at line 1030
mixed invokeWithExtensions(string $method, mixed $argument = null)

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

Parameters

string $method the method name to call
mixed $argument a single argument to pass

Return Value

mixed

in SS_Object at line 1058
array extend(string $method, mixed $a1 = null, mixed $a2 = null, mixed $a3 = null, mixed $a4 = null, mixed $a5 = null, mixed $a6 = null, mixed $a7 = null)

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()}.

Parameters

string $method the name of the method to call on each extension
mixed $a1
mixed $a2
mixed $a3
mixed $a4
mixed $a5
mixed $a6
mixed $a7

Return Value

array

in SS_Object at line 1097
Extension getExtensionInstance(string $extension)

Get an extension instance attached to this object by name.

Parameters

string $extension

Return Value

Extension

in SS_Object at line 1115
bool hasExtension(string $extension)

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.

Parameters

string $extension Classname of an {@link Extension} subclass without parameters

Return Value

bool

in SS_Object at line 1126
array getExtensionInstances()

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).

Return Value

array Map of {@link DataExtension} instances, keyed by classname.

in SS_Object at line 1142
mixed cacheToFile(string $method, int $lifetime = 3600, string $ID = false, array $arguments = array())

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

Parameters

string $method the method name to cache
int $lifetime the cache lifetime in seconds
string $ID custom cache ID to use
array $arguments an optional array of arguments

Return Value

mixed the cached data

in SS_Object at line 1171
clearCache($method, $ID = false, $arguments = array())

Clears the cache for the given cacheToFile call

Parameters

$method
$ID
$arguments

at line 31
static set_default_quality(quality $quality) deprecated

deprecated 4.0 Use the "GDBackend.default_quality" config setting instead

Set the default image quality.

Parameters

quality $quality int A number from 0 to 100, 100 being the best quality.

at line 83
void setImageResource(mixed $resource)

setImageResource

Set the backend-specific resource handling the manipulations. Replaces Image::setGD()

Parameters

mixed $resource

Return Value

void

at line 92
setGD($gd) deprecated

deprecated

Parameters

$gd

at line 97
mixed getImageResource()

getImageResource

Get the backend-specific resource handling the manipulations. Replaces Image::getGD()

Return Value

mixed

at line 104
getGD() deprecated

deprecated

at line 114
boolean imageAvailable(string $filename, string $manipulation)

Parameters

string $filename
string $manipulation

Return Value

boolean

at line 127
boolean checkAvailableMemory(string $filename)

Check if we've got enough memory available for resampling this image. This check is rough, so it will not catch all images that are too large - it also won't work accurately on large, animated GIFs as bits per pixel can't be calculated for an animated GIF with a global color table.

Parameters

string $filename

Return Value

boolean

at line 159
boolean failedResample($filename, $manipulation)

Check if this image has previously crashed GD when attempting to open it - if it's opened successfully, the manipulation's cache key is removed.

Parameters

$filename
$manipulation

Return Value

boolean

at line 167
void setQuality(int $quality)

Set the image quality, used when saving JPEGs.

Parameters

int $quality

Return Value

void

at line 174
Image_Backend croppedResize(int $width, int $height)

Resize an image to cover the given width/height completely, and crop off any overhanging edges.

Parameters

int $width
int $height

Return Value

Image_Backend

at line 226
fittedResize($width, $height)

Resizes the image to fit within the given region.

Behaves similarly to paddedResize but without the padding.

Parameters

$width
$height

at line 239
boolean hasImageResource()

hasImageResource

Return Value

boolean

at line 246
hasGD() deprecated

deprecated

at line 256
Image_Backend resize(int $width, int $height)

Resize an image, skewing it as necessary.

Parameters

int $width
int $height

Return Value

Image_Backend

at line 295
GD rotate(angle $angle)

Rotates image by given angle.

Parameters

angle $angle

Return Value

GD

at line 318
GD rotatePixelByPixel(angle $angle)

Rotates image by given angle. It's slow because makes it pixel by pixel rather than using built-in function. Used when imagerotate function is not available(i.e. Ubuntu)

Parameters

angle $angle

Return Value

GD

at line 363
GD crop(top $top, left $left, width $width, height $height)

Crop's part of image.

Parameters

top $top y position of left upper corner of crop rectangle
left $left x position of left upper corner of crop rectangle
width $width rectangle width
height $height rectangle height

Return Value

GD

at line 387
integer getWidth()

Method return width of image.

Return Value

integer width.

at line 397
integer getHeight()

Method return height of image.

Return Value

integer height

at line 404
Image_Backend resizeByWidth(int $width)

Resize an image by width. Preserves aspect ratio.

Parameters

int $width

Return Value

Image_Backend

at line 413
Image_Backend resizeByHeight(int $height)

Resize an image by height. Preserves aspect ratio

Parameters

int $height

Return Value

Image_Backend

at line 423
Image_Backend resizeRatio($maxWidth, $maxHeight, $useAsMinimum = false)

Resize the image by preserving aspect ratio. By default, it will keep the image inside the maxWidth and maxHeight. Passing useAsMinimum will make the smaller dimension equal to the maximum corresponding dimension

Parameters

$maxWidth
$maxHeight
$useAsMinimum

Return Value

Image_Backend

at line 436
static color_web2gd($image, $webColor, $transparencyPercent)

Parameters

$image
$webColor
$transparencyPercent

at line 460
Image_Backend paddedResize($width, $height, $backgroundColor = "FFFFFF", transparencyPercent $transparencyPercent)

Resize to fit fully within the given box, without resizing. Extra space left around the image will be padded with the background color.

Parameters

$width
$height
$backgroundColor
transparencyPercent $transparencyPercent

Return Value

Image_Backend

at line 523
greyscale($R = 299, $G = 587, $B = 114, $brightness = 100)

Make the image greyscale.

Default color weights are based on standard BT.601 (those used in PAL, NTSC and many software packages, also see https://en.wikipedia.org/wiki/Grayscale#Luma_coding_in_video_systems )

$R = red weight, defaults to 299 $G = green weight, defaults to 587 $B = blue weight, defaults to 114 $brightness = brightness in percentage, defaults to 100

Parameters

$R
$G
$B
$brightness

at line 554
makeDir($dirname)

Parameters

$dirname

at line 559
void writeTo($filename)

writeTo

Parameters

$filename

Return Value

void

at line 602
void onBeforeDelete(Image $frontend)

Parameters

Image $frontend

Return Value

void