Class EagerLoader

Exposes the methods for storing the associations that should be eager loaded for a table once a query is provided and delegates the job of creating the required joins and decorating the results so that those associations can be part of the result set.

Namespace: Cake\ORM

Property Summary

$_aliasList protected

array

Contains a list of the association names that are to be eagerly loaded
$_autoFields protected

bool

Controls whether or not fields from associated tables will be eagerly loaded. When set to false, no fields will be loaded from associations.
$_containOptions protected

array

List of options accepted by associations in contain() index by key for faster access
$_containments protected

array

Nested array describing the association to be fetched and the options to apply for each of them, if any
$_joinsMap protected

array

A map of table aliases pointing to the association objects they represent for the query.
$_loadExternal protected

array

A list of associations that should be loaded with a separate query
$_matching protected

Cake\ORM\EagerLoader

Another EagerLoader instance that will be used for 'matching' associations.
$_normalized protected

array

Contains a nested array with the compiled containments tree This is a normalized version of the user provided containments array.

Method Summary

_collectKeys() protected

Helper function used to return the keys from the query records that will be used to eagerly load associations.
_correctStrategy() protected

Changes the association fetching strategy if required because of duplicate under the same direct associations chain
_fixStrategies() protected

Iterates over the joinable aliases list and corrects the fetching strategies in order to avoid aliases collision in the generated queries.
_groupKeys() protected

Helper function used to iterate a statement and extract the columns defined in $collectKeys
_normalizeContain() protected

Auxiliary function responsible for fully normalizing deep associations defined using contain()
_reformatContain() protected

Formats the containments array so that associations are always set as keys in the array. This function merges the original associations array with the new associations provided
_resolveJoins() protected

Helper function used to compile a list of all associations that can be joined in the query.
addToJoinsMap() public

Registers a table alias, typically loaded as a join in a query, as belonging to an association. This helps hydrators know what to do with the columns coming from such joined table.
associationsMap() public

Returns an array having as keys a dotted path of associations that participate in this eager loader. The values of the array will contain the following keys
attachAssociations() public

Modifies the passed query to apply joins or any other transformation required in order to eager load the associations described in the contain array. This method will not modify the query for loading external associations, i.e. those that cannot be loaded without executing a separate query.
attachableAssociations() public

Returns an array with the associations that can be fetched using a single query, the array keys are the association aliases and the values will contain an array with Cake\ORM\EagerLoadable objects.
autoFields() public

Set whether or not contained associations will load fields automatically.
contain() public

Sets the list of associations that should be eagerly loaded along for a specific table using when a query is provided. The list of associated tables passed to this method must have been previously set as associations using the Table API.
externalAssociations() public

Returns an array with the associations that need to be fetched using a separate query, each array value will contain a Cake\ORM\EagerLoadable object.
loadExternal() public

Decorates the passed statement object in order to inject data from associations that cannot be joined directly.
matching() public

Adds a new association to the list that will be used to filter the results of any given query based on the results of finding records for that association. You can pass a dot separated path of associations to this method as its first parameter, this will translate in setting all those associations with the matching option.
normalized() public

Returns the fully normalized array of associations that should be eagerly loaded for a table. The normalized array will restructure the original array by sorting all associations under one key and special options under another.

Method Detail

_collectKeys() ¶ protected

_collectKeys(array $external, Cake\ORM\Query $query, BufferedStatement $statement): array

Helper function used to return the keys from the query records that will be used to eagerly load associations.

Parameters

array $external: the list of external associations to be loaded
Cake\ORM\Query $query: The query from which the results where generated
BufferedStatement $statement: The statement to work on

Returns

array

_correctStrategy() ¶ protected

_correctStrategy(Cake\ORM\EagerLoadable $loadable): void

Changes the association fetching strategy if required because of duplicate under the same direct associations chain

Parameters

Cake\ORM\EagerLoadable $loadable: The association config

Returns

void

_fixStrategies() ¶ protected

_fixStrategies(): void

Iterates over the joinable aliases list and corrects the fetching strategies in order to avoid aliases collision in the generated queries.

This function operates on the array references that were generated by the _normalizeContain() function.

Returns

void

_groupKeys() ¶ protected

_groupKeys(Cake\Database\StatementInterface $statement, array $collectKeys): array

Helper function used to iterate a statement and extract the columns defined in $collectKeys

Parameters

Cake\Database\StatementInterface $statement: The statement to read from.
array $collectKeys: The keys to collect

Returns

array

_normalizeContain() ¶ protected

_normalizeContain(Table $parent, string $alias, array $options, array $paths): array

Auxiliary function responsible for fully normalizing deep associations defined using contain()

Parameters

Table $parent: owning side of the association
string $alias: name of the association to be loaded
array $options: list of extra options to use for this association
array $paths: An array with two values, the first one is a list of dot separated strings representing associations that lead to this $alias in the chain of associations to be loaded. The second value is the path to follow in entities' properties to fetch a record of the corresponding association.

Returns

array

Throws

InvalidArgumentException
When containments refer to associations that do not exist.

_reformatContain() ¶ protected

_reformatContain(array $associations, array $original): array

Formats the containments array so that associations are always set as keys in the array. This function merges the original associations array with the new associations provided

Parameters

array $associations: user provided containments array
array $original: The original containments array to merge with the new one

Returns

array

_resolveJoins() ¶ protected

_resolveJoins(array $associations, array $matching = []): array

Helper function used to compile a list of all associations that can be joined in the query.

Parameters

array $associations: list of associations from which to obtain joins.
array $matching optional: list of associations that should be forcibly joined.

Returns

array

addToJoinsMap() ¶ public

addToJoinsMap(string $alias, Cake\ORM\Association $assoc, bool $asMatching = false): void

Registers a table alias, typically loaded as a join in a query, as belonging to an association. This helps hydrators know what to do with the columns coming from such joined table.

Parameters

string $alias: The table alias as it appears in the query.
Cake\ORM\Association $assoc: The association object the alias represents; will be normalized
bool $asMatching optional: Whether or not this join results should be treated as a 'matching' association.

Returns

void

associationsMap() ¶ public

associationsMap(Cake\ORM\Table $table): array

Returns an array having as keys a dotted path of associations that participate in this eager loader. The values of the array will contain the following keys

alias: The association alias
instance: The association instance
canBeJoined: Whether or not the association will be loaded using a JOIN
entityClass: The entity that should be used for hydrating the results
nestKey: A dotted path that can be used to correctly insert the data into the results.
matching: Whether or not it is an association loaded through matching().

Parameters

Cake\ORM\Table $table: The table containing the association that will be normalized

Returns

array

attachAssociations() ¶ public

attachAssociations(Cake\ORM\Query $query, Cake\ORM\Table $repository, bool $includeFields): void

Modifies the passed query to apply joins or any other transformation required in order to eager load the associations described in the contain array. This method will not modify the query for loading external associations, i.e. those that cannot be loaded without executing a separate query.

Parameters

Cake\ORM\Query $query: The query to be modified
Cake\ORM\Table $repository: The repository containing the associations
bool $includeFields: whether to append all fields from the associations to the passed query. This can be overridden according to the settings defined per association in the containments array

Returns

void

attachableAssociations() ¶ public

attachableAssociations(Cake\ORM\Table $repository): array

Returns an array with the associations that can be fetched using a single query, the array keys are the association aliases and the values will contain an array with Cake\ORM\EagerLoadable objects.

Parameters

Cake\ORM\Table $repository: The table containing the associations to be attached

Returns

array

autoFields() ¶ public

autoFields(bool $value = null): bool

Set whether or not contained associations will load fields automatically.

Parameters

bool $value optional: The value to set.

Returns

bool

contain() ¶ public

contain(array|string $associations = []): array

Sets the list of associations that should be eagerly loaded along for a specific table using when a query is provided. The list of associated tables passed to this method must have been previously set as associations using the Table API.

Associations can be arbitrarily nested using dot notation or nested arrays, this allows this object to calculate joins or any additional queries that must be executed to bring the required associated data.

Accepted options per passed association:

foreignKey: Used to set a different field to match both tables, if set to false no join conditions will be generated automatically
fields: An array with the fields that should be fetched from the association
queryBuilder: Equivalent to passing a callable instead of an options array
matching: Whether to inform the association class that it should filter the main query by the results fetched by that class.
joinType: For joinable associations, the SQL join type to use.
strategy: The loading strategy to use (join, select, subquery)

Parameters

array|string $associations optional: list of table aliases to be queried. When this method is called multiple times it will merge previous list with the new one.

Returns

array

externalAssociations() ¶ public

externalAssociations(Cake\ORM\Table $repository): array

Returns an array with the associations that need to be fetched using a separate query, each array value will contain a Cake\ORM\EagerLoadable object.

Parameters

Cake\ORM\Table $repository: The table containing the associations to be loaded

Returns

array

loadExternal() ¶ public

loadExternal(Cake\ORM\Query $query, Cake\Database\StatementInterface $statement): CallbackStatement

Decorates the passed statement object in order to inject data from associations that cannot be joined directly.

Parameters

Cake\ORM\Query $query: The query for which to eager load external associations
Cake\Database\StatementInterface $statement: The statement created after executing the $query

Returns

CallbackStatement

matching() ¶ public

matching(string|null $assoc = null, callable|null $builder = null): array

Adds a new association to the list that will be used to filter the results of any given query based on the results of finding records for that association. You can pass a dot separated path of associations to this method as its first parameter, this will translate in setting all those associations with the matching option.

If called with no arguments it will return the current tree of associations to be matched.

Parameters

string|null $assoc optional: A single association or a dot separated path of associations.
callable|null $builder optional: the callback function to be used for setting extra options to the filtering query

Returns

array

normalized() ¶ public

normalized(Cake\ORM\Table $repository): array

Returns the fully normalized array of associations that should be eagerly loaded for a table. The normalized array will restructure the original array by sorting all associations under one key and special options under another.

Each of the levels of the associations tree will converted to a Cake\ORM\EagerLoadable object, that contains all the information required for the association objects to load the information from the database.

Additionally it will set an 'instance' key per association containing the association instance from the corresponding source table

Parameters

Cake\ORM\Table $repository: The table containing the association that will be normalized

Returns

array

Contains a nested array with the compiled containments tree This is a normalized version of the user provided containments array.

Type

array

Namespaces

Class EagerLoader

Property Summary

Method Summary

_collectKeys() protected

_correctStrategy() protected

_fixStrategies() protected

_groupKeys() protected

_normalizeContain() protected

_reformatContain() protected

_resolveJoins() protected

addToJoinsMap() public

associationsMap() public

attachAssociations() public

attachableAssociations() public

autoFields() public

contain() public

externalAssociations() public

loadExternal() public

matching() public

normalized() public

Method Detail

_collectKeys() ¶ protected

Parameters

Returns

_correctStrategy() ¶ protected

Parameters

Returns

_fixStrategies() ¶ protected

Returns

_groupKeys() ¶ protected

Parameters

Returns

_normalizeContain() ¶ protected

Parameters

Returns

Throws

_reformatContain() ¶ protected

Parameters

Returns

_resolveJoins() ¶ protected

Parameters

Returns

addToJoinsMap() ¶ public

Parameters

Returns

associationsMap() ¶ public

Parameters

Returns

attachAssociations() ¶ public

Parameters

Returns

attachableAssociations() ¶ public

Parameters

Returns

autoFields() ¶ public

Parameters

Returns

contain() ¶ public

Parameters

Returns

externalAssociations() ¶ public

Parameters

Returns

loadExternal() ¶ public

Parameters

Returns

matching() ¶ public

Parameters

Returns

normalized() ¶ public

Parameters

Returns

Property Detail

$_aliasList ¶ protected

Type

$_autoFields ¶ protected

Type

$_containOptions ¶ protected

Type

`$_aliasList` ¶ protected

`$_autoFields` ¶ protected

`$_containOptions` ¶ protected

`$_containments` ¶ protected

`$_joinsMap` ¶ protected

`$_loadExternal` ¶ protected

`$_matching` ¶ protected

`$_normalized` ¶ protected