Class ResultSet
Represents the results obtained after executing a query for a specific table This object is responsible for correctly nesting result keys reported from the query, casting each field to the correct type and executing the extra queries required for eager loading external associations.
Property Summary
-
$_autoFields protected
bool|null
Tracks value of $_autoFields property of $query passed to constructor.
-
$_containMap protected
array
List of associations that should be eager loaded.
-
$_count protected
int
Holds the count of records in this result set
-
$_current protected
object|array
Last record fetched from the statement
-
$_defaultAlias protected
string
The default table alias
-
$_defaultTable protected
Cake\ORM\Table
Default table instance
-
$_driver protected
Cake\Database\DriverInterface
The Database driver object.
-
$_entityClass protected
string
The fully namespaced name of the class to use for hydrating results
-
$_hydrate protected
bool
Whether to hydrate results into objects or not
-
$_index protected
int
Points to the next record number that should be fetched
-
$_map protected
array<string, mixed>
Map of fields that are fetched from the statement with their type and the table they belong to
-
$_matchingMap protected
array<string, mixed>
List of associations that should be placed under the
_matchingData
result key. -
$_matchingMapColumns protected
array<string, mixed>
List of matching associations and the column keys to expect from each of them.
-
$_results protected
SplFixedArray|array
Results that have been fetched or hydrated into the results.
-
$_statement protected
Cake\Database\StatementInterface
Database statement holding the results
-
$_useBuffering protected
bool
Whether to buffer results fetched from the statement
Method Summary
-
__construct() public
Constructor
-
__debugInfo() public
Returns an array that can be used to describe the internal state of this object.
-
__serialize() public
Serializes a resultset.
-
__unserialize() public
Unserializes a resultset.
-
_calculateAssociationMap() protected
Calculates the list of associations that should get eager loaded when fetching each record
-
_calculateColumnMap() protected
Creates a map of row keys out of the query select clause that can be used to hydrate nested result sets more quickly.
-
_createMatcherFilter() protected
Returns a callable that receives a value and will return whether it matches certain condition.
-
_extract() protected
Returns a column from $data that can be extracted by iterating over the column names contained in $path. It will return arrays for elements in represented with
{*}
-
_fetchResult() protected
Helper function to fetch the next result from the statement or seeded results.
-
_groupResult() protected
Correctly nests results keys including those coming from associations
-
_propertyExtractor() protected
Returns a callable that can be used to extract a property or column from an array or object based on a dot separated path.
-
_simpleExtract() protected
Returns a column from $data that can be extracted by iterating over the column names contained in $path
-
append() public
Returns a new collection as the result of concatenating the list of elements in this collection with the passed list of elements
-
appendItem() public
Append a single item creating a new collection.
-
avg() public
Returns the average of all the values extracted with $path or of this collection.
-
buffered() public
Returns a new collection where the operations performed by this collection. No matter how many times the new collection is iterated, those operations will only be performed once.
-
cartesianProduct() public
Create a new collection that is the cartesian product of the current collection
-
chunk() public
Breaks the collection into smaller arrays of the given size.
-
chunkWithKeys() public
Breaks the collection into smaller arrays of the given size.
-
combine() public
Returns a new collection where the values extracted based on a value path and then indexed by a key path. Optionally this method can produce parent groups based on a group property path.
-
compile() public
Iterates once all elements in this collection and executes all stacked operations of them, finally it returns a new collection with the result. This is useful for converting non-rewindable internal iterators into a collection that can be rewound and used multiple times.
-
contains() public
Returns true if $value is present in this collection. Comparisons are made both by value and type.
-
count() public
Gives the number of rows in the result set.
-
countBy() public
Sorts a list into groups and returns a count for the number of elements in each group. Similar to groupBy, but instead of returning a list of values, returns a count for the number of values in that group.
-
countKeys() public
Returns the number of unique keys in this iterator. This is the same as the number of elements the collection will contain after calling
toArray()
-
current() public
Returns the current record in the result iterator
-
each() public
Applies a callback to the elements in this collection.
-
every() public
Returns true if all values in this collection pass the truth test provided in the callback.
-
extract() public
Returns a new collection containing the column or property value found in each of the elements.
-
filter() public
Looks through each value in the collection, and returns another collection with all the values that pass a truth test. Only the values for which the callback returns true will be present in the resulting collection.
-
first() public
Get the first record from a result set.
-
firstMatch() public
Returns the first result matching all the key-value pairs listed in conditions.
-
groupBy() public
Splits a collection into sets, grouped by the result of running each value through the callback. If $callback is a string instead of a callable, groups by the property named by $callback on each of the values.
-
indexBy() public
Given a list and a callback function that returns a key for each element in the list (or a property name), returns an object with an index of each item. Just like groupBy, but for when you know your keys are unique.
-
insert() public
Returns a new collection containing each of the elements found in
$values
as a property inside the corresponding elements in this collection. The property where the values will be inserted is described by the$path
parameter. -
isEmpty() public
Returns whether there are elements in this collection
-
jsonSerialize() public
Returns the data that can be converted to JSON. This returns the same data as
toArray()
which contains only unique keys. -
key() public
Returns the key of the current record in the iterator
-
last() public
Returns the last result in this collection
-
lazy() public
Returns a new collection where any operations chained after it are guaranteed to be run lazily. That is, elements will be yielded one at a time.
-
listNested() public
Returns a new collection with each of the elements of this collection after flattening the tree structure. The tree structure is defined by nesting elements under a key with a known name. It is possible to specify such name by using the '$nestingKey' parameter.
-
map() public
Returns another collection after modifying each of the values in this one using the provided callable.
-
match() public
Looks through each value in the list, returning a Collection of all the values that contain all of the key-value pairs listed in $conditions.
-
max() public
Returns the top element in this collection after being sorted by a property. Check the sortBy method for information on the callback and $sort parameters
-
median() public
Returns the median of all the values extracted with $path or of this collection.
-
min() public
Returns the bottom element in this collection after being sorted by a property. Check the sortBy method for information on the callback and $sort parameters
-
nest() public
Returns a new collection where the values are nested in a tree-like structure based on an id property path and a parent id property path.
-
newCollection() protected
Returns a new collection.
-
next() public
Advances the iterator pointer to the next record
-
optimizeUnwrap() protected
Unwraps this iterator and returns the simplest traversable that can be used for getting the data out
-
prepend() public
Prepend a set of items to a collection creating a new collection
-
prependItem() public
Prepend a single item creating a new collection.
-
reduce() public
Folds the values in this collection to a single value, as the result of applying the callback function to all elements. $zero is the initial state of the reduction, and each successive step of it should be returned by the callback function. If $zero is omitted the first value of the collection will be used in its place and reduction will start from the second item.
-
reject() public
Looks through each value in the collection, and returns another collection with all the values that do not pass a truth test. This is the opposite of
filter
. -
rewind() public
Rewinds a ResultSet.
-
sample() public
Returns a new collection with maximum $length random elements from this collection
-
serialize() public
Serializes a resultset.
-
shuffle() public
Returns a new collection with the elements placed in a random order, this function does not preserve the original keys in the collection.
-
skip() public
Returns a new collection that will skip the specified amount of elements at the beginning of the iteration.
-
some() public
Returns true if any of the values in this collection pass the truth test provided in the callback.
-
sortBy() public
Returns a sorted iterator out of the elements in this collection, ranked based on the results of applying a callback function to each value. The parameter $path can also be a string representing the column or property name.
-
stopWhen() public
Creates a new collection that when iterated will stop yielding results if the provided condition evaluates to true.
-
sumOf() public
Returns the total sum of all the values extracted with $matcher or of this collection.
-
take() public
Returns a new collection with maximum $length elements in the internal order this collection was created. If a second parameter is passed, it will determine from what position to start taking elements.
-
takeLast() public
Returns the last N elements of a collection
-
through() public
Passes this collection through a callable as its first argument. This is useful for decorating the full collection with another object.
-
toArray() public
Returns an array representation of the results
-
toList() public
Returns an numerically-indexed array representation of the results. This is equivalent to calling
toArray(false)
-
transpose() public
Transpose rows and columns into columns and rows
-
unfold() public
Creates a new collection where the items are the concatenation of the lists of items generated by the transformer function applied to each item in the original collection.
-
unserialize() public
Unserializes a resultset.
-
unwrap() public
Returns the closest nested iterator that can be safely traversed without losing any possible transformations. This is used mainly to remove empty IteratorIterator wrappers that can only slowdown the iteration process.
-
valid() public
Whether there are more results to be fetched from the iterator
-
zip() public
Combines the elements of this collection with each of the elements of the passed iterables, using their positional index as a reference.
-
zipWith() public
Combines the elements of this collection with each of the elements of the passed iterables, using their positional index as a reference.
Method Detail
__construct() ¶ public
__construct(Cake\ORM\Query $query, Cake\Database\StatementInterface $statement)
Constructor
Parameters
-
Cake\ORM\Query
$query Query from where results come
-
Cake\Database\StatementInterface
$statement The statement to fetch from
__debugInfo() ¶ public
__debugInfo(): array<string, mixed>
Returns an array that can be used to describe the internal state of this object.
Returns
array<string, mixed>
__unserialize() ¶ public
__unserialize(array $data): void
Unserializes a resultset.
Parameters
-
array
$data Data array.
Returns
void
_calculateAssociationMap() ¶ protected
_calculateAssociationMap(Cake\ORM\Query $query): void
Calculates the list of associations that should get eager loaded when fetching each record
Parameters
-
Cake\ORM\Query
$query The query from where to derive the associations
Returns
void
_calculateColumnMap() ¶ protected
_calculateColumnMap(Cake\ORM\Query $query): void
Creates a map of row keys out of the query select clause that can be used to hydrate nested result sets more quickly.
Parameters
-
Cake\ORM\Query
$query The query from where to derive the column map
Returns
void
_createMatcherFilter() ¶ protected
_createMatcherFilter(array $conditions): Closure
Returns a callable that receives a value and will return whether it matches certain condition.
Parameters
-
array
$conditions A key-value list of conditions to match where the key is the property path to get from the current item and the value is the value to be compared the item with.
Returns
Closure
_extract() ¶ protected
_extract(ArrayAccess|array $data, array<string> $parts): mixed
Returns a column from $data that can be extracted
by iterating over the column names contained in $path.
It will return arrays for elements in represented with {*}
Parameters
-
ArrayAccess|array
$data Data.
-
array<string>
$parts Path to extract from.
Returns
mixed
_fetchResult() ¶ protected
_fetchResult(): mixed
Helper function to fetch the next result from the statement or seeded results.
Returns
mixed
_groupResult() ¶ protected
_groupResult(array $row): Cake\Datasource\EntityInterface|array
Correctly nests results keys including those coming from associations
Parameters
-
array
$row Array containing columns and values or false if there is no results
Returns
Cake\Datasource\EntityInterface|array
_propertyExtractor() ¶ protected
_propertyExtractor(callable|string $path): callable
Returns a callable that can be used to extract a property or column from an array or object based on a dot separated path.
Parameters
-
callable|string
$path A dot separated path of column to follow so that the final one can be returned or a callable that will take care of doing that.
Returns
callable
_simpleExtract() ¶ protected
_simpleExtract(ArrayAccess|array $data, array<string> $parts): mixed
Returns a column from $data that can be extracted by iterating over the column names contained in $path
Parameters
-
ArrayAccess|array
$data Data.
-
array<string>
$parts Path to extract from.
Returns
mixed
append() ¶ public
append(iterable $items): self
Returns a new collection as the result of concatenating the list of elements in this collection with the passed list of elements
Parameters
-
iterable
$items
Returns
self
appendItem() ¶ public
appendItem(mixed $item, mixed $key = null): self
Append a single item creating a new collection.
Parameters
-
mixed
$item -
mixed
$key optional
Returns
self
avg() ¶ public
avg(callable|string|null $path = null): float|int|null
Returns the average of all the values extracted with $path or of this collection.
Example:
$items = [
['invoice' => ['total' => 100]],
['invoice' => ['total' => 200]]
];
$total = (new Collection($items))->avg('invoice.total');
// Total: 150
$total = (new Collection([1, 2, 3]))->avg();
// Total: 2
The average of an empty set or 0 rows is null
. Collections with null
values are not considered empty.
Parameters
-
callable|string|null
$path optional
Returns
float|int|null
buffered() ¶ public
buffered(): self
Returns a new collection where the operations performed by this collection. No matter how many times the new collection is iterated, those operations will only be performed once.
This can also be used to make any non-rewindable iterator rewindable.
Returns
self
cartesianProduct() ¶ public
cartesianProduct(callable|null $operation = null, callable|null $filter = null): Cake\Collection\CollectionInterface
Create a new collection that is the cartesian product of the current collection
In order to create a cartesian product a collection must contain a single dimension of data.
Example
$collection = new Collection([['A', 'B', 'C'], [1, 2, 3]]);
$result = $collection->cartesianProduct()->toArray();
$expected = [
['A', 1],
['A', 2],
['A', 3],
['B', 1],
['B', 2],
['B', 3],
['C', 1],
['C', 2],
['C', 3],
];
Parameters
-
callable|null
$operation optional A callable that allows you to customize the product result.
-
callable|null
$filter optional A filtering callback that must return true for a result to be part of the final results.
Returns
Cake\Collection\CollectionInterface
Throws
LogicException
chunk() ¶ public
chunk(int $chunkSize): self
Breaks the collection into smaller arrays of the given size.
Example:
$items [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11];
$chunked = (new Collection($items))->chunk(3)->toList();
// Returns [[1, 2, 3], [4, 5, 6], [7, 8, 9], [10, 11]]
Parameters
-
int
$chunkSize
Returns
self
chunkWithKeys() ¶ public
chunkWithKeys(int $chunkSize, bool $keepKeys = true): self
Breaks the collection into smaller arrays of the given size.
Example:
$items ['a' => 1, 'b' => 2, 'c' => 3, 'd' => 4, 'e' => 5, 'f' => 6];
$chunked = (new Collection($items))->chunkWithKeys(3)->toList();
// Returns [['a' => 1, 'b' => 2, 'c' => 3], ['d' => 4, 'e' => 5, 'f' => 6]]
Parameters
-
int
$chunkSize -
bool
$keepKeys optional
Returns
self
combine() ¶ public
combine(callable|string $keyPath, callable|string $valuePath, callable|string|null $groupPath = null): self
Returns a new collection where the values extracted based on a value path and then indexed by a key path. Optionally this method can produce parent groups based on a group property path.
Examples:
$items = [
['id' => 1, 'name' => 'foo', 'parent' => 'a'],
['id' => 2, 'name' => 'bar', 'parent' => 'b'],
['id' => 3, 'name' => 'baz', 'parent' => 'a'],
];
$combined = (new Collection($items))->combine('id', 'name');
// Result will look like this when converted to array
[
1 => 'foo',
2 => 'bar',
3 => 'baz',
];
$combined = (new Collection($items))->combine('id', 'name', 'parent');
// Result will look like this when converted to array
[
'a' => [1 => 'foo', 3 => 'baz'],
'b' => [2 => 'bar'],
];
Parameters
-
callable|string
$keyPath -
callable|string
$valuePath -
callable|string|null
$groupPath optional
Returns
self
compile() ¶ public
compile(bool $keepKeys = true): self
Iterates once all elements in this collection and executes all stacked operations of them, finally it returns a new collection with the result. This is useful for converting non-rewindable internal iterators into a collection that can be rewound and used multiple times.
A common use case is to re-use the same variable for calculating different data. In those cases it may be helpful and more performant to first compile a collection and then apply more operations to it.
Example:
$collection->map($mapper)->sortBy('age')->extract('name');
$compiled = $collection->compile();
$isJohnHere = $compiled->some($johnMatcher);
$allButJohn = $compiled->filter($johnMatcher);
In the above example, had the collection not been compiled before, the
iterations for map
, sortBy
and extract
would've been executed twice:
once for getting $isJohnHere
and once for $allButJohn
You can think of this method as a way to create save points for complex calculations in a collection.
Parameters
-
bool
$keepKeys optional
Returns
self
contains() ¶ public
contains(mixed $value): bool
Returns true if $value is present in this collection. Comparisons are made both by value and type.
Parameters
-
mixed
$value
Returns
bool
count() ¶ public
count(): int
Gives the number of rows in the result set.
Part of the Countable interface.
Returns
int
countBy() ¶ public
countBy(callable|string $path): self
Sorts a list into groups and returns a count for the number of elements in each group. Similar to groupBy, but instead of returning a list of values, returns a count for the number of values in that group.
When $callback is a string it should be a property name to extract or a dot separated path of properties that should be followed to get the last one in the path.
Example:
$items = [
['id' => 1, 'name' => 'foo', 'parent_id' => 10],
['id' => 2, 'name' => 'bar', 'parent_id' => 11],
['id' => 3, 'name' => 'baz', 'parent_id' => 10],
];
$group = (new Collection($items))->countBy('parent_id');
// Or
$group = (new Collection($items))->countBy(function ($e) {
return $e['parent_id'];
});
// Result will look like this when converted to array
[
10 => 2,
11 => 1
];
Parameters
-
callable|string
$path
Returns
self
countKeys() ¶ public
countKeys(): int
Returns the number of unique keys in this iterator. This is the same as the number of
elements the collection will contain after calling toArray()
This method comes with a number of caveats. Please refer to CollectionInterface::count()
for details.
Returns
int
current() ¶ public
current(): object|array
Returns the current record in the result iterator
Part of Iterator interface.
Returns
object|array
each() ¶ public
each(callable $callback): $this
Applies a callback to the elements in this collection.
Example:
$collection = (new Collection($items))->each(function ($value, $key) {
echo "Element $key: $value";
});
Parameters
-
callable
$callback
Returns
$this
every() ¶ public
every(callable $callback): bool
Returns true if all values in this collection pass the truth test provided in the callback.
The callback is passed the value and key of the element being tested and should return true if the test passed.
Example:
$overTwentyOne = (new Collection([24, 45, 60, 15]))->every(function ($value, $key) {
return $value > 21;
});
Empty collections always return true.
Parameters
-
callable
$callback
Returns
bool
extract() ¶ public
extract(callable|string $path): self
Returns a new collection containing the column or property value found in each of the elements.
The matcher can be a string with a property name to extract or a dot separated path of properties that should be followed to get the last one in the path.
If a column or property could not be found for a particular element in the collection, that position is filled with null.
Example:
Extract the user name for all comments in the array:
$items = [
['comment' => ['body' => 'cool', 'user' => ['name' => 'Mark']],
['comment' => ['body' => 'very cool', 'user' => ['name' => 'Renan']]
];
$extracted = (new Collection($items))->extract('comment.user.name');
// Result will look like this when converted to array
['Mark', 'Renan']
It is also possible to extract a flattened collection out of nested properties
$items = [
['comment' => ['votes' => [['value' => 1], ['value' => 2], ['value' => 3]]],
['comment' => ['votes' => [['value' => 4]]
];
$extracted = (new Collection($items))->extract('comment.votes.{*}.value');
// Result will contain
[1, 2, 3, 4]
Parameters
-
callable|string
$path
Returns
self
filter() ¶ public
filter(callable|null $callback = null): self
Looks through each value in the collection, and returns another collection with all the values that pass a truth test. Only the values for which the callback returns true will be present in the resulting collection.
Each time the callback is executed it will receive the value of the element in the current iteration, the key of the element and this collection as arguments, in that order.
Example:
Filtering odd numbers in an array, at the end only the value 2 will be present in the resulting collection:
$collection = (new Collection([1, 2, 3]))->filter(function ($value, $key) {
return $value % 2 === 0;
});
Parameters
-
callable|null
$callback optional
Returns
self
first() ¶ public
first(): object|array|null
Get the first record from a result set.
This method will also close the underlying statement cursor.
Returns
object|array|null
firstMatch() ¶ public
firstMatch(array $conditions): mixed
Returns the first result matching all the key-value pairs listed in conditions.
Parameters
-
array
$conditions
Returns
mixed
groupBy() ¶ public
groupBy(callable|string $path): self
Splits a collection into sets, grouped by the result of running each value through the callback. If $callback is a string instead of a callable, groups by the property named by $callback on each of the values.
When $callback is a string it should be a property name to extract or a dot separated path of properties that should be followed to get the last one in the path.
Example:
$items = [
['id' => 1, 'name' => 'foo', 'parent_id' => 10],
['id' => 2, 'name' => 'bar', 'parent_id' => 11],
['id' => 3, 'name' => 'baz', 'parent_id' => 10],
];
$group = (new Collection($items))->groupBy('parent_id');
// Or
$group = (new Collection($items))->groupBy(function ($e) {
return $e['parent_id'];
});
// Result will look like this when converted to array
[
10 => [
['id' => 1, 'name' => 'foo', 'parent_id' => 10],
['id' => 3, 'name' => 'baz', 'parent_id' => 10],
],
11 => [
['id' => 2, 'name' => 'bar', 'parent_id' => 11],
]
];
Parameters
-
callable|string
$path
Returns
self
indexBy() ¶ public
indexBy(callable|string $path): self
Given a list and a callback function that returns a key for each element in the list (or a property name), returns an object with an index of each item. Just like groupBy, but for when you know your keys are unique.
When $callback is a string it should be a property name to extract or a dot separated path of properties that should be followed to get the last one in the path.
Example:
$items = [
['id' => 1, 'name' => 'foo'],
['id' => 2, 'name' => 'bar'],
['id' => 3, 'name' => 'baz'],
];
$indexed = (new Collection($items))->indexBy('id');
// Or
$indexed = (new Collection($items))->indexBy(function ($e) {
return $e['id'];
});
// Result will look like this when converted to array
[
1 => ['id' => 1, 'name' => 'foo'],
3 => ['id' => 3, 'name' => 'baz'],
2 => ['id' => 2, 'name' => 'bar'],
];
Parameters
-
callable|string
$path
Returns
self
insert() ¶ public
insert(string $path, mixed $values): self
Returns a new collection containing each of the elements found in $values
as
a property inside the corresponding elements in this collection. The property
where the values will be inserted is described by the $path
parameter.
The $path can be a string with a property name or a dot separated path of properties that should be followed to get the last one in the path.
If a column or property could not be found for a particular element in the collection as part of the path, the element will be kept unchanged.
Example:
Insert ages into a collection containing users:
$items = [
['comment' => ['body' => 'cool', 'user' => ['name' => 'Mark']],
['comment' => ['body' => 'awesome', 'user' => ['name' => 'Renan']]
];
$ages = [25, 28];
$inserted = (new Collection($items))->insert('comment.user.age', $ages);
// Result will look like this when converted to array
[
['comment' => ['body' => 'cool', 'user' => ['name' => 'Mark', 'age' => 25]],
['comment' => ['body' => 'awesome', 'user' => ['name' => 'Renan', 'age' => 28]]
];
Parameters
-
string
$path -
mixed
$values
Returns
self
isEmpty() ¶ public
isEmpty(): bool
Returns whether there are elements in this collection
Example:
$items [1, 2, 3];
(new Collection($items))->isEmpty(); // false
(new Collection([]))->isEmpty(); // true
Returns
bool
jsonSerialize() ¶ public
jsonSerialize(): array
Returns the data that can be converted to JSON. This returns the same data
as toArray()
which contains only unique keys.
Part of JsonSerializable interface.
Returns
array
key() ¶ public
key(): int
Returns the key of the current record in the iterator
Part of Iterator interface.
Returns
int
lazy() ¶ public
lazy(): self
Returns a new collection where any operations chained after it are guaranteed to be run lazily. That is, elements will be yielded one at a time.
A lazy collection can only be iterated once. A second attempt results in an error.
Returns
self
listNested() ¶ public
listNested(string|int $order = 'desc', callable|string $nestingKey = 'children'): self
Returns a new collection with each of the elements of this collection after flattening the tree structure. The tree structure is defined by nesting elements under a key with a known name. It is possible to specify such name by using the '$nestingKey' parameter.
By default all elements in the tree following a Depth First Search will be returned, that is, elements from the top parent to the leaves for each branch.
It is possible to return all elements from bottom to top using a Breadth First Search approach by passing the '$dir' parameter with 'asc'. That is, it will return all elements for the same tree depth first and from bottom to top.
Finally, you can specify to only get a collection with the leaf nodes in the tree structure. You do so by passing 'leaves' in the first argument.
The possible values for the first argument are aliases for the following constants and it is valid to pass those instead of the alias:
- desc: RecursiveIteratorIterator::SELF_FIRST
- asc: RecursiveIteratorIterator::CHILD_FIRST
- leaves: RecursiveIteratorIterator::LEAVES_ONLY
Example:
$collection = new Collection([
['id' => 1, 'children' => [['id' => 2, 'children' => [['id' => 3]]]]],
['id' => 4, 'children' => [['id' => 5]]]
]);
$flattenedIds = $collection->listNested()->extract('id'); // Yields [1, 2, 3, 4, 5]
Parameters
-
string|int
$order optional -
callable|string
$nestingKey optional
Returns
self
map() ¶ public
map(callable $callback): self
Returns another collection after modifying each of the values in this one using the provided callable.
Each time the callback is executed it will receive the value of the element in the current iteration, the key of the element and this collection as arguments, in that order.
Example:
Getting a collection of booleans where true indicates if a person is female:
$collection = (new Collection($people))->map(function ($person, $key) {
return $person->gender === 'female';
});
Parameters
-
callable
$callback
Returns
self
match() ¶ public
match(array $conditions): self
Looks through each value in the list, returning a Collection of all the values that contain all of the key-value pairs listed in $conditions.
Example:
$items = [
['comment' => ['body' => 'cool', 'user' => ['name' => 'Mark']],
['comment' => ['body' => 'very cool', 'user' => ['name' => 'Renan']],
];
$extracted = (new Collection($items))->match(['user.name' => 'Renan']);
// Result will look like this when converted to array
[
['comment' => ['body' => 'very cool', 'user' => ['name' => 'Renan']]]
]
Parameters
-
array
$conditions
Returns
self
max() ¶ public
max(callable|string $path, int $sort = \SORT_NUMERIC): mixed
Returns the top element in this collection after being sorted by a property. Check the sortBy method for information on the callback and $sort parameters
Examples:
// For a collection of employees
$max = $collection->max('age');
$max = $collection->max('user.salary');
$max = $collection->max(function ($e) {
return $e->get('user')->get('salary');
});
// Display employee name
echo $max->name;
Parameters
-
callable|string
$path -
int
$sort optional
Returns
mixed
median() ¶ public
median(callable|string|null $path = null): float|int|null
Returns the median of all the values extracted with $path or of this collection.
Example:
$items = [
['invoice' => ['total' => 400]],
['invoice' => ['total' => 500]]
['invoice' => ['total' => 100]]
['invoice' => ['total' => 333]]
['invoice' => ['total' => 200]]
];
$total = (new Collection($items))->median('invoice.total');
// Total: 333
$total = (new Collection([1, 2, 3, 4]))->median();
// Total: 2.5
The median of an empty set or 0 rows is null
. Collections with null
values are not considered empty.
Parameters
-
callable|string|null
$path optional
Returns
float|int|null
min() ¶ public
min(callable|string $path, int $sort = \SORT_NUMERIC): mixed
Returns the bottom element in this collection after being sorted by a property. Check the sortBy method for information on the callback and $sort parameters
Examples:
// For a collection of employees
$min = $collection->min('age');
$min = $collection->min('user.salary');
$min = $collection->min(function ($e) {
return $e->get('user')->get('salary');
});
// Display employee name
echo $min->name;
Parameters
-
callable|string
$path -
int
$sort optional
Returns
mixed
nest() ¶ public
nest(callable|string $idPath, callable|string $parentPath, string $nestingKey = 'children'): self
Returns a new collection where the values are nested in a tree-like structure based on an id property path and a parent id property path.
Parameters
-
callable|string
$idPath -
callable|string
$parentPath -
string
$nestingKey optional
Returns
self
newCollection() ¶ protected
newCollection(mixed ...$args): Cake\Collection\CollectionInterface
Returns a new collection.
Allows classes which use this trait to determine their own type of returned collection interface
Parameters
-
mixed
...$args Constructor arguments.
Returns
Cake\Collection\CollectionInterface
next() ¶ public
next(): void
Advances the iterator pointer to the next record
Part of Iterator interface.
Returns
void
optimizeUnwrap() ¶ protected
optimizeUnwrap(): iterable
Unwraps this iterator and returns the simplest traversable that can be used for getting the data out
Returns
iterable
prepend() ¶ public
prepend(mixed $items): self
Prepend a set of items to a collection creating a new collection
Parameters
-
mixed
$items
Returns
self
prependItem() ¶ public
prependItem(mixed $item, mixed $key = null): self
Prepend a single item creating a new collection.
Parameters
-
mixed
$item -
mixed
$key optional
Returns
self
reduce() ¶ public
reduce(callable $callback, mixed $initial = null): mixed
Folds the values in this collection to a single value, as the result of applying the callback function to all elements. $zero is the initial state of the reduction, and each successive step of it should be returned by the callback function. If $zero is omitted the first value of the collection will be used in its place and reduction will start from the second item.
Parameters
-
callable
$callback -
mixed
$initial optional
Returns
mixed
reject() ¶ public
reject(callable $callback): self
Looks through each value in the collection, and returns another collection with
all the values that do not pass a truth test. This is the opposite of filter
.
Each time the callback is executed it will receive the value of the element in the current iteration, the key of the element and this collection as arguments, in that order.
Example:
Filtering even numbers in an array, at the end only values 1 and 3 will be present in the resulting collection:
$collection = (new Collection([1, 2, 3]))->reject(function ($value, $key) {
return $value % 2 === 0;
});
Parameters
-
callable
$callback
Returns
self
rewind() ¶ public
rewind(): void
Rewinds a ResultSet.
Part of Iterator interface.
Returns
void
Throws
Cake\Database\Exception\DatabaseException
sample() ¶ public
sample(int $length = 10): self
Returns a new collection with maximum $length random elements from this collection
Parameters
-
int
$length optional
Returns
self
serialize() ¶ public
serialize(): string
Serializes a resultset.
Part of Serializable interface.
Returns
string
shuffle() ¶ public
shuffle(): self
Returns a new collection with the elements placed in a random order, this function does not preserve the original keys in the collection.
Returns
self
skip() ¶ public
skip(int $length): self
Returns a new collection that will skip the specified amount of elements at the beginning of the iteration.
Parameters
-
int
$length
Returns
self
some() ¶ public
some(callable $callback): bool
Returns true if any of the values in this collection pass the truth test provided in the callback.
The callback is passed the value and key of the element being tested and should return true if the test passed.
Example:
$hasYoungPeople = (new Collection([24, 45, 15]))->some(function ($value, $key) {
return $value < 21;
});
Parameters
-
callable
$callback
Returns
bool
sortBy() ¶ public
sortBy(callable|string $path, int $order = \SORT_DESC, int $sort = \SORT_NUMERIC): self
Returns a sorted iterator out of the elements in this collection, ranked based on the results of applying a callback function to each value. The parameter $path can also be a string representing the column or property name.
The callback will receive as its first argument each of the elements in $items, the value returned by the callback will be used as the value for sorting such element. Please note that the callback function could be called more than once per element.
Example:
$items = $collection->sortBy(function ($user) {
return $user->age;
});
// alternatively
$items = $collection->sortBy('age');
// or use a property path
$items = $collection->sortBy('department.name');
// output all user name order by their age in descending order
foreach ($items as $user) {
echo $user->name;
}
Parameters
-
callable|string
$path -
int
$order optional -
int
$sort optional
Returns
self
stopWhen() ¶ public
stopWhen(callable|array $condition): self
Creates a new collection that when iterated will stop yielding results if the provided condition evaluates to true.
This is handy for dealing with infinite iterators or any generator that could start returning invalid elements at a certain point. For example, when reading lines from a file stream you may want to stop the iteration after a certain value is reached.
Example:
Get an array of lines in a CSV file until the timestamp column is less than a date
$lines = (new Collection($fileLines))->stopWhen(function ($value, $key) {
return (new DateTime($value))->format('Y') < 2012;
})
->toArray();
Get elements until the first unapproved message is found:
$comments = (new Collection($comments))->stopWhen(['is_approved' => false]);
Parameters
-
callable|array
$condition
Returns
self
sumOf() ¶ public
sumOf(callable|string|null $path = null): float|int
Returns the total sum of all the values extracted with $matcher or of this collection.
Example:
$items = [
['invoice' => ['total' => 100]],
['invoice' => ['total' => 200]],
];
$total = (new Collection($items))->sumOf('invoice.total');
// Total: 300
$total = (new Collection([1, 2, 3]))->sumOf();
// Total: 6
Parameters
-
callable|string|null
$path optional
Returns
float|int
take() ¶ public
take(int $length = 1, int $offset = 0): self
Returns a new collection with maximum $length elements in the internal order this collection was created. If a second parameter is passed, it will determine from what position to start taking elements.
Parameters
-
int
$length optional -
int
$offset optional
Returns
self
takeLast() ¶ public
takeLast(int $length): self
Returns the last N elements of a collection
Example:
$items = [1, 2, 3, 4, 5];
$last = (new Collection($items))->takeLast(3);
// Result will look like this when converted to array
[3, 4, 5];
Parameters
-
int
$length
Returns
self
through() ¶ public
through(callable $callback): self
Passes this collection through a callable as its first argument. This is useful for decorating the full collection with another object.
Example:
$items = [1, 2, 3];
$decorated = (new Collection($items))->through(function ($collection) {
return new MyCustomCollection($collection);
});
Parameters
-
callable
$callback
Returns
self
toArray() ¶ public
toArray(bool $keepKeys = true): array
Returns an array representation of the results
Parameters
-
bool
$keepKeys optional
Returns
array
toList() ¶ public
toList(): array
Returns an numerically-indexed array representation of the results.
This is equivalent to calling toArray(false)
Returns
array
transpose() ¶ public
transpose(): Cake\Collection\CollectionInterface
Transpose rows and columns into columns and rows
Example:
$items = [
['Products', '2012', '2013', '2014'],
['Product A', '200', '100', '50'],
['Product B', '300', '200', '100'],
['Product C', '400', '300', '200'],
]
$transpose = (new Collection($items))->transpose()->toList();
// Returns
// [
// ['Products', 'Product A', 'Product B', 'Product C'],
// ['2012', '200', '300', '400'],
// ['2013', '100', '200', '300'],
// ['2014', '50', '100', '200'],
// ]
Returns
Cake\Collection\CollectionInterface
Throws
LogicException
unfold() ¶ public
unfold(callable|null $callback = null): self
Creates a new collection where the items are the concatenation of the lists of items generated by the transformer function applied to each item in the original collection.
The transformer function will receive the value and the key for each of the items in the collection, in that order, and it must return an array or a Traversable object that can be concatenated to the final result.
If no transformer function is passed, an "identity" function will be used. This is useful when each of the elements in the source collection are lists of items to be appended one after another.
Example:
$items [[1, 2, 3], [4, 5]];
$unfold = (new Collection($items))->unfold(); // Returns [1, 2, 3, 4, 5]
Using a transformer
$items [1, 2, 3];
$allItems = (new Collection($items))->unfold(function ($page) {
return $service->fetchPage($page)->toArray();
});
Parameters
-
callable|null
$callback optional
Returns
self
unserialize() ¶ public
unserialize(string $serialized): void
Unserializes a resultset.
Part of Serializable interface.
Parameters
-
string
$serialized Serialized object
Returns
void
unwrap() ¶ public
unwrap(): Traversable
Returns the closest nested iterator that can be safely traversed without losing any possible transformations. This is used mainly to remove empty IteratorIterator wrappers that can only slowdown the iteration process.
Returns
Traversable
valid() ¶ public
valid(): bool
Whether there are more results to be fetched from the iterator
Part of Iterator interface.
Returns
bool
zip() ¶ public
zip(iterable $items): self
Combines the elements of this collection with each of the elements of the passed iterables, using their positional index as a reference.
Example:
$collection = new Collection([1, 2]);
$collection->zip([3, 4], [5, 6])->toList(); // returns [[1, 3, 5], [2, 4, 6]]
Parameters
-
iterable
$items
Returns
self
zipWith() ¶ public
zipWith(iterable $items, callable $callback): self
Combines the elements of this collection with each of the elements of the passed iterables, using their positional index as a reference.
The resulting element will be the return value of the $callable function.
Example:
$collection = new Collection([1, 2]);
$zipped = $collection->zipWith([3, 4], [5, 6], function (...$args) {
return array_sum($args);
});
$zipped->toList(); // returns [9, 12]; [(1 + 3 + 5), (2 + 4 + 6)]
Parameters
-
iterable
$items -
callable
$callback
Returns
self
Property Detail
$_autoFields ¶ protected
Tracks value of $_autoFields property of $query passed to constructor.
Type
bool|null
$_driver ¶ protected
The Database driver object.
Cached in a property to avoid multiple calls to the same function.
Type
Cake\Database\DriverInterface
$_entityClass ¶ protected
The fully namespaced name of the class to use for hydrating results
Type
string
$_map ¶ protected
Map of fields that are fetched from the statement with their type and the table they belong to
Type
array<string, mixed>
$_matchingMap ¶ protected
List of associations that should be placed under the _matchingData
result key.
Type
array<string, mixed>
$_matchingMapColumns ¶ protected
List of matching associations and the column keys to expect from each of them.
Type
array<string, mixed>
$_results ¶ protected
Results that have been fetched or hydrated into the results.
Type
SplFixedArray|array
$_statement ¶ protected
Database statement holding the results
Type
Cake\Database\StatementInterface