silverstripe-framework/src/View/SSViewer_DataPresenter.php

418 lines
13 KiB
PHP

<?php
namespace SilverStripe\View;
use InvalidArgumentException;
use SilverStripe\Core\ClassInfo;
use SilverStripe\ORM\FieldType\DBField;
/**
* This extends SSViewer_Scope to mix in data on top of what the item provides. This can be "global"
* data that is scope-independant (like BaseURL), or type-specific data that is layered on top cross-cut like
* (like $FirstLast etc).
*
* It's separate from SSViewer_Scope to keep that fairly complex code as clean as possible.
*/
class SSViewer_DataPresenter extends SSViewer_Scope
{
/**
* List of global property providers
*
* @internal
* @var TemplateGlobalProvider[]|null
*/
private static $globalProperties = null;
/**
* List of global iterator providers
*
* @internal
* @var TemplateIteratorProvider[]|null
*/
private static $iteratorProperties = null;
/**
* Overlay variables. Take precedence over anything from the current scope
*
* @var array|null
*/
protected $overlay;
/**
* Underlay variables. Concede precedence to overlay variables or anything from the current scope
*
* @var array
*/
protected $underlay;
/**
* @var object $item
* @var array $overlay
* @var array $underlay
* @var SSViewer_Scope $inheritedScope
*/
public function __construct(
$item,
array $overlay = null,
array $underlay = null,
SSViewer_Scope $inheritedScope = null
) {
parent::__construct($item, $inheritedScope);
$this->overlay = $overlay ?: [];
$this->underlay = $underlay ?: [];
$this->cacheGlobalProperties();
$this->cacheIteratorProperties();
}
/**
* Build cache of global properties
*/
protected function cacheGlobalProperties()
{
if (self::$globalProperties !== null) {
return;
}
self::$globalProperties = $this->getPropertiesFromProvider(
TemplateGlobalProvider::class,
'get_template_global_variables'
);
}
/**
* Build cache of global iterator properties
*/
protected function cacheIteratorProperties()
{
if (self::$iteratorProperties !== null) {
return;
}
self::$iteratorProperties = $this->getPropertiesFromProvider(
TemplateIteratorProvider::class,
'get_template_iterator_variables',
true // Call non-statically
);
}
/**
* @var string $interfaceToQuery
* @var string $variableMethod
* @var boolean $createObject
* @return array
*/
protected function getPropertiesFromProvider($interfaceToQuery, $variableMethod, $createObject = false)
{
$methods = [];
$implementors = ClassInfo::implementorsOf($interfaceToQuery);
if ($implementors) {
foreach ($implementors as $implementor) {
// Create a new instance of the object for method calls
if ($createObject) {
$implementor = new $implementor();
$exposedVariables = $implementor->$variableMethod();
} else {
$exposedVariables = $implementor::$variableMethod();
}
foreach ($exposedVariables as $varName => $details) {
if (!is_array($details)) {
$details = [
'method' => $details,
'casting' => ViewableData::config()->uninherited('default_cast')
];
}
// If just a value (and not a key => value pair), use method name for both key and value
if (is_numeric($varName)) {
$varName = $details['method'];
}
// Add in a reference to the implementing class (might be a string class name or an instance)
$details['implementor'] = $implementor;
// And a callable array
if (isset($details['method'])) {
$details['callable'] = [$implementor, $details['method']];
}
// Save with both uppercase & lowercase first letter, so either works
$lcFirst = strtolower($varName[0]) . substr($varName, 1);
$result[$lcFirst] = $details;
$result[ucfirst($varName)] = $details;
}
}
}
return $result;
}
/**
* Look up injected value - it may be part of an "overlay" (arguments passed to <% include %>),
* set on the current item, part of an "underlay" ($Layout or $Content), or an iterator/global property
*
* @param string $property Name of property
* @param array $params
* @param bool $cast If true, an object is always returned even if not an object.
* @return array|null
*/
public function getInjectedValue($property, array $params, $cast = true)
{
// Get source for this value
$source = $this->getValueSource($property);
if (!$source) {
return null;
}
// Look up the value - either from a callable, or from a directly provided value
$res = [];
if (isset($source['callable'])) {
$res['value'] = $source['callable'](...$params);
} elseif (isset($source['value'])) {
$res['value'] = $source['value'];
} else {
throw new InvalidArgumentException(
"Injected property $property does't have a value or callable value source provided"
);
}
// If we want to provide a casted object, look up what type object to use
if ($cast) {
$res['obj'] = $this->castValue($res['value'], $source);
}
return $res;
}
/**
* Store the current overlay (as it doesn't directly apply to the new scope
* that's being pushed). We want to store the overlay against the next item
* "up" in the stack (hence upIndex), rather than the current item, because
* SSViewer_Scope::obj() has already been called and pushed the new item to
* the stack by this point
*
* @return SSViewer_Scope
*/
public function pushScope()
{
$scope = parent::pushScope();
$upIndex = $this->getUpIndex();
if ($upIndex !== null) {
$itemStack = $this->getItemStack();
$itemStack[$upIndex][SSViewer_Scope::ITEM_OVERLAY] = $this->overlay;
$this->setItemStack($itemStack);
$this->overlay = array();
}
return $scope;
}
/**
* Now that we're going to jump up an item in the item stack, we need to
* restore the overlay that was previously stored against the next item "up"
* in the stack from the current one
*
* @return SSViewer_Scope
*/
public function popScope()
{
$upIndex = $this->getUpIndex();
if ($upIndex !== null) {
$itemStack = $this->getItemStack();
$this->overlay = $itemStack[$this->getUpIndex()][SSViewer_Scope::ITEM_OVERLAY];
}
return parent::popScope();
}
/**
* $Up and $Top need to restore the overlay from the parent and top-level
* scope respectively.
*
* @param string $name
* @param array $arguments
* @param bool $cache
* @param string $cacheName
* @return $this
*/
public function obj($name, $arguments = [], $cache = false, $cacheName = null)
{
$overlayIndex = false;
switch ($name) {
case 'Up':
$upIndex = $this->getUpIndex();
if ($upIndex === null) {
user_error('Up called when we\'re already at the top of the scope', E_USER_ERROR);
}
$overlayIndex = $upIndex; // Parent scope
break;
case 'Top':
$overlayIndex = 0; // Top-level scope
break;
}
if ($overlayIndex !== false) {
$itemStack = $this->getItemStack();
if (!$this->overlay && isset($itemStack[$overlayIndex][SSViewer_Scope::ITEM_OVERLAY])) {
$this->overlay = $itemStack[$overlayIndex][SSViewer_Scope::ITEM_OVERLAY];
}
}
parent::obj($name, $arguments, $cache, $cacheName);
return $this;
}
/**
* {@inheritdoc}
*/
public function getObj($name, $arguments = [], $cache = false, $cacheName = null)
{
$result = $this->getInjectedValue($name, (array)$arguments);
if ($result) {
return $result['obj'];
}
return parent::getObj($name, $arguments, $cache, $cacheName);
}
/**
* {@inheritdoc}
*/
public function __call($name, $arguments)
{
// Extract the method name and parameters
$property = $arguments[0]; // The name of the public function being called
// The public function parameters in an array
$params = (isset($arguments[1])) ? (array)$arguments[1] : [];
$val = $this->getInjectedValue($property, $params);
if ($val) {
$obj = $val['obj'];
if ($name === 'hasValue') {
$result = ($obj instanceof ViewableData) ? $obj->exists() : (bool)$obj;
} else {
$result = $obj->forTemplate(); // XML_val
}
$this->resetLocalScope();
return $result;
}
return parent::__call($name, $arguments);
}
/**
* Evaluate a template override
*
* @param string $property Name of override requested
* @param array $overrides List of overrides available
* @return null|array Null if not provided, or array with 'value' or 'callable' key
*/
protected function processTemplateOverride($property, $overrides)
{
if (!isset($overrides[$property])) {
return null;
}
// Detect override type
$override = $overrides[$property];
// Late-evaluate this value
if (!is_string($override) && is_callable($override)) {
$override = $override();
// Late override may yet return null
if (!isset($override)) {
return null;
}
}
return [ 'value' => $override ];
}
/**
* Determine source to use for getInjectedValue
*
* @param string $property
* @return array|null
*/
protected function getValueSource($property)
{
// Check for a presenter-specific override
$overlay = $this->processTemplateOverride($property, $this->overlay);
if (isset($overlay)) {
return $overlay;
}
// Check if the method to-be-called exists on the target object - if so, don't check any further
// injection locations
$on = $this->itemIterator ? $this->itemIterator->current() : $this->item;
if (isset($on->$property) || method_exists($on, $property)) {
return null;
}
// Check for a presenter-specific override
$underlay = $this->processTemplateOverride($property, $this->underlay);
if (isset($underlay)) {
return $underlay;
}
// Then for iterator-specific overrides
if (array_key_exists($property, self::$iteratorProperties)) {
$source = self::$iteratorProperties[$property];
/** @var TemplateIteratorProvider $implementor */
$implementor = $source['implementor'];
if ($this->itemIterator) {
// Set the current iterator position and total (the object instance is the first item in
// the callable array)
$implementor->iteratorProperties(
$this->itemIterator->key(),
$this->itemIteratorTotal
);
} else {
// If we don't actually have an iterator at the moment, act like a list of length 1
$implementor->iteratorProperties(0, 1);
}
return $source;
}
// And finally for global overrides
if (array_key_exists($property, self::$globalProperties)) {
return self::$globalProperties[$property]; //get the method call
}
// No value
return null;
}
/**
* Ensure the value is cast safely
*
* @param mixed $value
* @param array $source
* @return DBField
*/
protected function castValue($value, $source)
{
// Already cast
if (is_object($value)) {
return $value;
}
// Get provided or default cast
$casting = empty($source['casting'])
? ViewableData::config()->uninherited('default_cast')
: $source['casting'];
return DBField::create_field($casting, $value);
}
}