Relation behavior is a controller modifier used for easily managing complex model relationships on a page. Not to be confused with List relation columns or Form relation fields that only provide simple management.
Relation behavior depends on relation definitions. In order to use the relation behavior you should add the Backend.Behaviors.RelationController definition to the $implement field of the controller class. Also, the $relationConfig class property should be defined and its value should refer to the YAML file used for configuring the behavior options.
namespace Acme\Projects\Controllers;
class Projects extends Controller
{
public $implement = [
'Backend.Behaviors.FormController',
'Backend.Behaviors.RelationController',
];
public $formConfig = 'config_form.yaml';
public $relationConfig = 'config_relation.yaml';
}
Note: Very often the relation behavior is used together with the form behavior.
The configuration file referred in the $relationConfig property is defined in YAML format. The file should be placed into the controller's views directory. The required configuration depends on the relationship type between the target model and the related model.
The first level field in the relation configuration file defines the relationship name in the target model. For example:
class Invoice {
public $hasMany = [
'items' => ['Acme\Pay\Models\InvoiceItem'],
];
}
An Invoice model with a relationship called items should define the first level field using the same relationship name:
# ===================================
# Relation Behavior Config
# ===================================
items:
label: Invoice Line Item
view:
list: $/acme/pay/models/invoiceitem/columns.yaml
toolbarButtons: create|delete
manage:
form: $/acme/pay/models/invoiceitem/fields.yaml
recordsPerPage: 10
The following options are then used for each relationship name definition:
| Option | Description |
|---|---|
| label | a label for the relation, in the singular tense, required. |
| view | configuration specific to the view container, see below. |
| manage | configuration specific to the management popup, see below. |
| pivot | a reference to form field definition file, used for relations with pivot table data. |
| emptyMessage | a message to display when the relationship is empty, optional. |
| readOnly | disables the ability to add, update, delete or create relations. default: false |
| deferredBinding | defers all binding actions using a session key when it is available. default: false |
These configuration values can be specified for the view or manage options, where applicable to the render type of list, form or both.
| Option | Type | Description |
|---|---|---|
| form | Form | a reference to form field definition file, see backend form fields. |
| list | List | a reference to list column definition file, see backend list columns. |
| showSearch | List | display an input for searching the records. Default: false |
| showSorting | List | displays the sorting link on each column. Default: true |
| defaultSort | List | sets a default sorting column and direction when user preference is not defined. Supports a string or an array with keys column and direction. |
| recordsPerPage | List | maximum rows to display for each page. |
These configuration values can be specified only for the view options.
| Option | Type | Description |
|---|---|---|
| showCheckboxes | List | displays checkboxes next to each record. |
| recordUrl | List | link each list record to another page. Eg: users/update/:id. The :id part is replaced with the record identifier. |
| recordOnClick | List | custom JavaScript code to execute when clicking on a record. |
| toolbarPartial | Both | a reference to a controller partial file with the toolbar buttons. Eg: _relation_toolbar.htm. This option overrides the toolbarButtons option. |
| toolbarButtons | Both | the set of buttons to display, can be an array or a pipe separated string. Set to false to show no buttons. Available options are: add, create, update, delete, remove, link, unlink. Eg: add|remove |
These configuration values can be specified only for the manage options.
| Option | Type | Description |
|---|---|---|
| title | Both | a popup title, can refer to a localization string. |
| context | Form | context of the form being displayed. Can be a string or an array with keys: create, update. |
| conditions | List | specifies a raw where query statement to apply to the list model query. |
| scope | List | specifies a query scope method defined in the related form model to apply to the list query always. |
How the relation manager is displayed depends on the relationship definition in the target model. The relationship type will also determine the configuration requirements, these are shown in bold. The following relationship types are available:
- Related records are displayed as a list (view.list).
- Clicking a record will display an update form (manage.form).
- Clicking Add will display a selection list (manage.list).
- Clicking Create will display a create form (manage.form).
- Clicking Delete will destroy the record(s).
- Clicking Remove will orphan the relationship.
For example, if a Blog Post has many Comments, the target model is set as the blog post and a list of comments is displayed, using columns from the list definition. Clicking on a comment opens a popup form with the fields defined in form to update the comment. Comments can be created in the same way. Below is an example of the relation behavior configuration file:
# ===================================
# Relation Behavior Config
# ===================================
comments:
label: Comment
manage:
form: $/acme/blog/models/comment/fields.yaml
list: $/acme/blog/models/comment/columns.yaml
view:
list: $/acme/blog/models/comment/columns.yaml
toolbarButtons: create|delete
- Related records are displayed as a list (view.list).
- Clicking Add will display a selection list (manage.list).
- Clicking Create will display a create form (manage.form).
- Clicking Delete will destroy the pivot table record(s).
- Clicking Remove will orphan the relationship.
For example, if a User belongs to many Roles, the target model is set as the user and a list of roles is displayed, using columns from the list definition. Existing roles can be added and removed from the user. Below is an example of the relation behavior configuration file:
# ===================================
# Relation Behavior Config
# ===================================
roles:
label: Role
view:
list: $/acme/user/models/role/columns.yaml
toolbarButtons: add|remove
manage:
list: $/acme/user/models/role/columns.yaml
form: $/acme/user/models/role/fields.yaml
- Related records are displayed as a list (view.list).
- Clicking a record will display an update form (pivot.form).
- Clicking Add will display a selection list (manage.list), then a data entry form (pivot.form).
- Clicking Remove will destroy the pivot table record(s).
Continuing the example in Belongs To Many relations, if a role also carried an expiry date, clicking on a role will open a popup form with the fields defined in pivot to update the expiry date. Below is an example of the relation behavior configuration file:
# ===================================
# Relation Behavior Config
# ===================================
roles:
label: Role
view:
list: $/acme/user/models/role/columns.yaml
manage:
list: $/acme/user/models/role/columns.yaml
pivot:
form: $/acme/user/models/role/fields.yaml
Pivot data is available when defining form fields and list columns via the pivot relation, see the example below:
# ===================================
# Relation Behavior Config
# ===================================
teams:
label: Team
view:
list:
columns:
name:
label: Name
pivot[team_color]:
label: Team color
manage:
list:
columns:
name:
label: Name
pivot:
form:
fields:
pivot[team_color]:
label: Team color
Note: Pivot data is not supported by deferred bindings at this time, so the parent model should exist.
- Related record is displayed as a preview form (view.form).
- Clicking Create will display a create form (manage.form).
- Clicking Update will display an update form (manage.form).
- Clicking Link will display a selection list (manage.list).
- Clicking Unlink will orphan the relationship.
- Clicking Delete will destroy the record.
For example, if a Phone belongs to a Person the relation manager will display a form with the fields defined in form. Clicking the Link button will display a list of People to associate with the Phone. Clicking the Unlink button will dissociate the Phone with the Person.
# ===================================
# Relation Behavior Config
# ===================================
person:
label: Person
view:
form: $/acme/user/models/person/fields.yaml
toolbarButtons: link|unlink
manage:
form: $/acme/user/models/person/fields.yaml
list: $/acme/user/models/person/columns.yaml
- Related record is displayed as a preview form (view.form).
- Clicking Create will display a create form (manage.form).
- Clicking Update will display an update form (manage.form).
- Clicking Link will display a selection list (manage.list).
- Clicking Unlink will orphan the relationship.
- Clicking Delete will destroy the record.
For example, if a Person has one Phone the relation manager will display form with the fields defined in form for the Phone. When clicking the Update button, a popup is displayed with the fields now editable. If the Person already has a Phone the fields are update, otherwise a new Phone is created for them.
# ===================================
# Relation Behavior Config
# ===================================
phone:
label: Phone
view:
form: $/acme/user/models/phone/fields.yaml
toolbarButtons: update|delete
manage:
form: $/acme/user/models/phone/fields.yaml
list: $/acme/user/models/phone/columns.yaml
Before relations can be managed on any page, the target model must first be initialized in the controller by calling the initRelation() method.
$post = Post::where('id', 7)->first();
$this->initRelation($post);
Note: The form behavior will automatically initialize the model on its create, update and preview actions.
The relation manager can then be displayed for a specified relation definition by calling the relationRender() method. For example, if you want to display the relation manager on the Preview page, the preview.htm view contents could look like this:
<?= $this->formRenderPreview() ?>
<?= $this->relationRender('comments') ?>
You may instruct the relation manager to render in read only mode by passing the option as the second argument:
<?= $this->relationRender('comments', ['readOnly' => true]) ?>