Listener on Schema
Listeners allow us to execute actions when an event occurs in the ORM. \ events are set to the "on" property. \ And the events that can be listened to are select, insert, bulkInsert, update and delete. \ The "condition" property allows you to define an expression that is evaluated to determine if the listener is executed. \ The expressions to be executed can be defined in the "before", "after" and "error" properties. \
The parameters that we have to use in the expressions are:
| Parameter | Description |
|---|---|
| query | The query expression that was executed |
| data | The data that was sent when the expression was executed |
| options | The options that were sent when the expression was executed |
| result | It is only available in the after event and contains the result of the expression execution |
| action | The action that was executed (select, insert, update, delete, upsert, merge, bulkInsert, bulkUpdate, bulkMerge) |
| type | The type of sentence that was executed (dql, ddl, dml) |
| category | The category of the sentence that was executed (select, insert, update, delete, upsert) |
| sentence | The sentence that was executed |
| dialect | The dialect of the source where the sentence was executed |
| source | The source where the sentence was executed |
| entity | The entity that was affected by the sentence |
| error | It is only available in the error event and contains the error that occurred |
Listener Example
In this example we see how a Listener is declared to synchronize data in Insights. \ When a record is inserted, updated or deleted in the default or cqrs stages, the listener is executed. \ In this case, the expression is defined in the after property, which executes the same expression with the same data but in the stage insights.
Part of the schema where the listener is defined:
...
application:
listeners:
- name: syncInsights
on: [insert, bulkInsert, update, delete]
condition: options.stage.in("default","cqrs")
after: orm.execute(query,data,{stage:"insights"})
Schema Complete:
domain:
enums:
entities:
- name: Address
abstract: true
indexes:
- name: postalCode
fields: ["postalCode"]
- name: region
fields: ["region", "country"]
- name: city
fields: ["city"]
properties:
- name: address
- name: city
- name: region
- name: postalCode
length: 20
- name: country
- name: Categories
primaryKey: ["id"]
uniqueKey: ["name"]
properties:
- name: id
type: integer
required: true
autoIncrement: true
- name: name
required: true
- name: Customers
extends: Address
primaryKey: ["id"]
indexes:
- name: name
fields: ["name"]
properties:
- name: id
length: 5
required: true
- name: name
required: true
- name: Products
primaryKey: ["id"]
uniqueKey: ["name", "supplierId"]
properties:
- name: id
type: integer
required: true
autoIncrement: true
- name: name
required: true
- name: categoryId
type: integer
- name: quantity
- name: price
type: decimal
default: 0
relations:
- name: category
from: categoryId
entity: Categories
to: id
target: products
- name: Orders
primaryKey: ["id"]
indexes:
- name: orderDate
fields: ["orderDate"]
properties:
- name: id
type: integer
required: true
autoIncrement: true
- name: customerId
required: true
length: 5
- name: orderDate
type: dateTime
relations:
- name: customer
from: customerId
entity: Customers
to: id
target: orders
- name: Orders.details
primaryKey: ["orderId", "productId"]
properties:
- name: orderId
required: true
type: integer
- name: productId
required: true
type: integer
- name: unitPrice
type: decimal
- name: quantity
type: decimal
relations:
- name: order
from: orderId
entity: Orders
to: id
target: details
- name: product
from: productId
entity: Products
to: id
target: orderDetails
infrastructure:
views:
- name: default
mappings:
- name: default
entities:
- name: Address
abstract: true
properties:
- name: address
mapping: Address
- name: city
mapping: City
- name: region
mapping: Region
- name: postalCode
mapping: PostalCode
- name: country
mapping: Country
- name: Categories
mapping: Categories
properties:
- name: id
mapping: CategoryID
- name: name
mapping: CategoryName
- name: Customers
extends: Address
mapping: Customers
properties:
- name: id
mapping: CustomerID
- name: name
mapping: CompanyName
- name: Products
mapping: Products
properties:
- name: id
mapping: ProductID
- name: name
mapping: ProductName
- name: categoryId
mapping: CategoryID
- name: quantity
mapping: QuantityPerUnit
- name: price
mapping: UnitPrice
- name: Orders
mapping: Orders
properties:
- name: id
mapping: OrderID
- name: customerId
mapping: CustomerID
- name: orderDate
mapping: OrderDate
- name: Orders.details
mapping: Order Details
properties:
- name: orderId
mapping: OrderID
- name: productId
mapping: ProductID
- name: unitPrice
mapping: UnitPrice
- name: quantity
mapping: Quantity
- name: mongoDb
extends: default
entities:
- name: Orders
sequence: SQ_ORDERS
properties:
- name: id
mapping: _id
sources:
- name: Catalog
dialect: MySQL
mapping: default
connection: ${CNN_MYSQL}
- name: Crm
dialect: PostgreSQL
mapping: default
connection: ${CNN_POSTGRES}
- name: Ordering
dialect: MongoDB
mapping: mongoDb
connection: ${CNN_MONGODB}
- name: Insights
dialect: PostgreSQL
mapping: default
connection: ${CNN_INSIGHTS}
stages:
- name: default
sources:
- name: Catalog
condition: entity.in(["Categories","Products"])
- name: Crm
condition: entity.in(["Address","Customers"])
- name: Ordering
condition: entity.in(["Orders","Orders.details"])
- name: insights
sources:
- name: Insights
- name: cqrs
sources:
- name: Insights
condition: action == "select"
- name: Catalog
condition: entity.in(["Categories","Products"])
- name: Crm
condition: entity.in(["Address","Customers"])
- name: Ordering
condition: entity.in(["Orders","Orders.details"])
application:
listeners:
- name: syncInsights
on: [insert, bulkInsert, update, delete ]
condition: options.stage.in("default","cqrs")
after: orm.execute(query,data,{stage:"insights"})