/**
* Retrieves opposite reference on selected node also involved in current
* reference.
*
* @example
* Consider relation spanning over nodes/models "a", "b" and "c". This
* relation consists of two references "a"-"b" and "b"-"c", with the latter
* referencing from "b" to "c" ("b"->"c").
*
* The opposite reference of its referencing node ("b") is "a"-"b" while the
* opposite reference of its referenced node ("c") is missing, thus
* returning null here.
*
* @param model_relation_node $node either end of current reference
* @return model_relation_reference|null opposite reference at selected end,
* null if missing another reference there
*/
public function getOppositeReferenceAtNode(model_relation_node $node)
{
if ($node != $this->predecessorEnd && $node != $this->successorEnd) {
throw new \InvalidArgumentException('foreign node rejected');
}
if ($node == $this->predecessorEnd && $this->intIndexInRelation == 0) {
// there is no opposite of predecessor if current reference is first
// one in relation
return null;
}
try {
return $this->relation->referenceAtIndex($this->intIndexInRelation + ($node == $this->predecessorEnd ? -1 : +1));
} catch (\OutOfRangeException $e) {
return null;
}
}
public function onSelectingItem(model_editor $editor, model $item, model_editor_field $field)
{
// bind element's relation with item sharing its data source
$this->relation->setDatasource($item->source())->bindNodeOnItem(0, $item);
}
/**
* @param model_relation $relation
* @param $relationSpecification
* @return model_relation
*/
protected static function _compileRelation(model_relation $relation = null, $relationSpecification)
{
// extract declaration of next reference from provided specs
$toNext = is_array(@$relationSpecification['referencing']) ? $relationSpecification['referencing'] : null;
$fromNext = is_array(@$relationSpecification['referencedBy']) ? $relationSpecification['referencedBy'] : null;
// ensure specs are containing either of the two options, only
if (!(is_array($toNext) ^ is_array($fromNext))) {
throw new \InvalidArgumentException('invalid reference mode in relation');
}
// select found declaration of next reference
$referenceToAppend = $toNext ? $toNext : $fromNext;
/*
* get current end node of relation for appending new reference
*/
if (is_null($relation)) {
// there isn't any "current end node" for relation is empty, yet
// -> start new relation on current model
$previousNode = model_relation_node::createOnModel(new \ReflectionClass(get_called_class()));
// -> apply optionally given global alias
if (@$relationSpecification['alias']) {
$previousNode->setAlias($relationSpecification['alias']);
}
} else {
// get end node of existing relation
$previousNode = $relation->nodeAtIndex(-1);
}
/*
* extract description of model associated with next node to append
*/
if (array_key_exists('model', $referenceToAppend)) {
// got explicit name of model existing in code
$model = static::normalizeModel($referenceToAppend['model']);
$model = model_relation_model::createOnModel($model);
} else {
// missing explicit name of model existing in code
// -> need to manage virtual model
if ($fromNext && @$referenceToAppend['referencing'] && !@$referenceToAppend['referencedBy']) {
// next node in relation is of type many-to-many
// -> suitable for deriving virtual model
$succeedingReference =& $referenceToAppend['referencing'];
/*
* in a relation a < m > c ...
*
* ... this code is about to describe virtual model of m
* ... $previousNode refers to node a
* ... $referenceToAppend provides information on a<m or m more specifically
* ... $succeedingReference provides information on m>c or c more specifically
*/
if (!@$succeedingReference['model']) {
// don't support chains of virtual models in relations
throw new \InvalidArgumentException('invalid chaining of nodes with virtual models');
}
// get model of node succeeding reference is referring to (model of c in example above)
$nextModel = model_relation_model::createOnModel(static::normalizeModel($succeedingReference['model']));
/*
* get names of either neighbouring model's set
*
* (don't care for aliases here for these might change occasionally)
*/
$previousSetName = $previousNode->getName(true);
$nextSetName = $nextModel->getSetName();
if (!$previousSetName || !$nextSetName) {
throw new \InvalidArgumentException('missing set names of models neighbouring virtual one');
}
/*
* extract name of virtual model's data set
*/
if (array_key_exists('dataset', $referenceToAppend)) {
// specification provides set name explicitly
$setName = $referenceToAppend['dataset'];
} else {
// specification does not provide set name explicitly
// -> derive name from set names of neighbouring models
$setName = "{$previousSetName}_{$nextSetName}";
}
/*
* derive properties and types of virtual model's data set
*/
// get definitions of properties in either neighbouring model
$previousDefinition = $previousNode->getModel()->getDefinition();
$nextDefinition = $nextModel->getDefinition();
// get properties in either neighbouring model to refer to in virtual
$previousNames = array_values((array) \de\toxa\txf\_1(@$referenceToAppend['on'], 'id'));
$nextNames = array_values((array) \de\toxa\txf\_1(@$succeedingReference['on'], 'id'));
if (!count($previousNames) || !count($nextNames)) {
throw new \InvalidArgumentException('missing names of properties virtual node is referencing on');
}
// get names of properties in virtual model to use on referencing
// - try explicitly mentioned names of properties first
$namesOnPrevious = array_values((array) @$referenceToAppend['with']);
$namesOnNext = array_values((array) @$succeedingReference['with']);
// - fall back to implicitly deriving property names from referenced properties
if (!count($namesOnPrevious)) {
$namesOnPrevious = array_map(function ($name) use($previousSetName) {
return "{$previousSetName}_{$name}";
}, $previousNames);
$referenceToAppend['with'] = $namesOnPrevious;
}
if (!count($namesOnNext)) {
$namesOnNext = array_map(function ($name) use($nextSetName) {
return "{$nextSetName}_{$name}";
}, $nextNames);
$succeedingReference['with'] = $namesOnNext;
}
// ensure either reference is working with uniquely named properties
$clashingNames = array_intersect($namesOnPrevious, $namesOnNext);
if (count($clashingNames)) {
throw new \InvalidArgumentException('invalid clash of implicit property names: ' . implode(', ', $clashingNames));
}
// finally compile definition of virtual model's data set
$virtualDefinition = array();
foreach ($namesOnPrevious as $index => $name) {
$relatedName = $previousNames[$index];
$virtualDefinition[$name] = preg_replace('/\\bprimary\\s+key\\b/i', '', $previousDefinition[$relatedName]);
}
foreach ($namesOnNext as $index => $name) {
$relatedName = $nextNames[$index];
$virtualDefinition[$name] = preg_replace('/\\bprimary\\s+key\\b/i', '', $nextDefinition[$relatedName]);
}
/*
* create virtual model basing on description prepared above
*/
$model = model_relation_model::createOnVirtualModel($setName, $virtualDefinition, array_keys($virtualDefinition));
} else {
// next node isn't of type many-to-many
// -> reject implicitly to derive some virtual model
throw new \InvalidArgumentException('definition of relation is missing model of node');
}
}
/*
* create node to append
*/
$nextNode = model_relation_node::createOnModel($model);
if ($referenceToAppend['alias']) {
$nextNode->setAlias($referenceToAppend['alias']);
}
/*
* establish reference between previous and next node as declared
*/
$targetProperty = @$referenceToAppend['on'];
if (!$targetProperty) {
$targetProperty = array('id');
}
if ($toNext) {
// establish reference from previous node to new node
$previousNode->makeReferencingSuccessorIn($referenceToAppend['with']);
$nextNode->makeReferencedByPredecessorOn($targetProperty);
} else {
// establish reference from new node to previous one
$previousNode->makeReferencedBySuccessorOn($targetProperty);
$nextNode->makeReferencingPredecessorIn($referenceToAppend['with']);
}
/*
* append node to relation
*/
if (is_null($relation)) {
// relation hasn't been created before at all
// -> create now
$relation = model_relation::create($previousNode);
}
$expectingAnotherReference = @$referenceToAppend['referencing'] || @$referenceToAppend['referencedBy'];
// append next node to relation
$relation->add($nextNode, $expectingAnotherReference);
/*
* recursively add another node on having declaration
*/
if ($expectingAnotherReference) {
return static::_compileRelation($relation, $referenceToAppend);
}
return $relation;
}