Child records configuration

The "children" property is used to create nested structures, generally MM tables where additional information needs to be stored.

Note

This corresponds to inline-type ("IRRE") fields with MM tables having a primary key field ("uid").

See the Mapping data chapter for an overview of import scenarios which may help understand this feature.

Example:

$GLOBALS['TCA']['tx_externalimporttest_product']['columns']['pictures']['external'] = [
   'base' => [
        'field' => 'Pictures', // remote db field
        'transformations' => [
            10 => [
                'userFunction' => [
                    'class' => \Cobweb\ExternalImport\Transformation\ImageTransformation::class,
                    'method' => 'saveImageFromUri',
                    'parameters' => [
                        'storage' => '1:importedpictures', // local folder for files
                    ]
                ]
            ]
        ],
        'children' => [
            'table' => 'sys_file_reference',
            'columns' => [
                'uid_local' => [
                    'field' => 'pictures'
                ],
                'uid_foreign' => [
                    'field' => '__parent.id__'
                ],
                'title' => [
                    'field' => 'picture_title'
                ],
                'tablenames' => [
                    'value' => 'tx_externalimporttest_product'
                ],
                'fieldname' => [
                    'value' => 'pictures'
                ],
                'table_local' => [
                    'value' => 'sys_file'
                ]
            ],
            'sorting' => [
                'source' => 'picture_order',
                'target' => 'sorting_foreign'
            ],
            'controlColumnsForUpdate' => 'uid_local, uid_foreign, tablenames, fieldname, table_local',
            'controlColumnsForDelete' => 'uid_foreign, tablenames, fieldname, table_local'
        ]
       ...
   ]
]

Properties

Property	Data type	Step/Scope
columns	array	Store data
controlColumnsForUpdate	string	Store data
controlColumnsForDelete	string	Store data
disabledOperations	string	Store data
sorting	array	Store data
table	string	Store data

table

Type: string
Description: Name of the nested table. This information is mandatory.
Scope: Store data

columns

Type

array

Description

List of columns (database fields) needed for the nested table. This is an associative array, using the column name as the key. Then each column must have one of two properties:

value

This is a simple value that will be used for each entry into the nested table. Use it for invariants like the "tablenames" field of a MM table.

field

This is the name of a field that is available in the imported data. The value is copied from the current record. Note that such fields can be any of the mapped columns, any of the additionalFields or any of the substructureFields.

The special value __parent.id__ refers to the primary key of the current record and will typically be used for "uid_local" or "uid_foreign" fields in MM tables, depending on how the relation is built.

Scope

Store data

controlColumnsForUpdate

Type

string

Description

Comma-separated list of columns that need to be used for checking if a child record already exists. All these columns must exist in the list of columns defined above. Defining this property ensures that existing relations are updated instead of being created anew.

This list should contain all columns that are significant for identifying a child record without ambiguity. In the example above, we have:

'controlColumnsForUpdate' => 'uid_local, uid_foreign, tablenames, fieldname, table_local',

These are all the columns that need to be queried in the "sys_file_reference" table to be sure that we are targeting the right record in the database. Any missing information might mean retrieving another record (for a different table or field, or whatever).

Note

If this property is not defined, all children records will be considered to be new. If controlColumnsForDelete is defined and the "delete" operation is not disabled, all existing child relations will be deleted upon each import.

Scope

Store data

controlColumnsForDelete

Type: string
Description: This is similar to controlColumnsForUpdate but for finding out which existing relations are no longer relevant and need to be deleted. It is not the same list of fields as you need to leave out the field which references the relation on the "other side". In the case of "sys_file_reference", you would leave out "uid_local", which is the reference to the "sys_file" table.

Note

If this property is not defined, existing children records will not be checked and thus never be deleted.
Scope: Store data

sorting

Type

array

Description

External Import stores child records in the order in which they appear, which is generally the order in which they are in the external data source. It may be needed to sort the child records differently, according to some other data available in the in the external source.

This property allows this. It is defined by two elements:

source

The name of the column containing the sorting value in the external data source. This column should ideally contain numerical values. If that is not the case, the values are cast to integer when they are used, so you need to make sure that the values contained in this column can be cast safely.

If the sorting value is missing for some records, a value of 0 will be used instead, putting those child records at the top of the list.

target

The name of the sorting field in the child record table.

Both elements are mandatory. Configuration validation will fail otherwise.

'sorting' => [
    'source' => 'picture_order',
    'target' => 'sorting_foreign'
],

Scope

Store data

disabledOperations

Type: string
Description: Comma-separated list of operations which should not take place. This can be "insert" (no new child records), "update" (no update to existing child records) and/or "delete" (no removal of existing child records).

Note

This applies only when a parent record is being updated. When a parent record is being created, it does not make sense to forbid creation of its child records.
Scope: Store data