@themost/jspa v2.0.0

@themost/jspa

@themost web framework JavaScript Persistent API on top of @themost/data ORM.

@themost/jspa is a mimic of Java Persistent API for Node.js environment and provides a set of tools for describing object relational mapping.

The following example describes a Thing class:

import { DataObject } from '@themost/data';
import { Column, Entity, GeneratedValue, GenerationType, Id, Table, Counter, Basic, Formula, ManyToOne, FetchType, ColumnDefault } from '@themost/jspa';

@Entity()
@Table()
class Thing extends DataObject {

    constructor() {
        super();
    }

    @Id()
    @Column()
    @GeneratedValue({
        strategy: GenerationType.Identity
    })
    public id?: Counter;

    @Basic()
    public name?: string;

    @Column()
    public alternateName?: string;

    @Column()
    public description?: string;

    @Column()
    public additionalType?: string;

    @Column()
    public sameAs?: string;

    @Column()
    public url?: string;

    @Column()
    public identifier?: string;

    @Column()
    public image?: string;

    @Column({
        nullable: false,
        updatable: false
    })
    @ColumnDefault(() => new Date())
    public dateCreated?: Date;

    @Column({
        nullable: false
    })
    @Formula(() => new Date())
    public dateModified?: Date;

    @Column({
        nullable: true,
        updatable: false,
        type: 'User'
    })
    @ManyToOne({
        fetchType: FetchType.Lazy
    })
    public createdBy?: any;

    @Column({
        nullable: true,
        type: 'User'
    })
    @ManyToOne({
        fetchType: FetchType.Lazy
    })
    public modifiedBy?: any;
}

export {
    Thing
}

Usage

npm i @themost/jspa

Annotations

@Entity

The basic annotation of a class. Use optional @Entity.name attribute to define the name of this entity if it's different than class name and @Entity.version attribute to allow @themost/data auto-upgrade operations to update database objects after any change.

@Entity({
    version: '1.0.0'
})
class Party extends Thing {
    ...
}

@Entity() annotation includes @Entity.privileges attribute to allow setting the collection of default privileges assigned to a class

@Entity({
    version: '1.0.0',
    privileges: [
        {
            mask: 15,
            type: 'global'
        },
        {
            mask: 15,
            type: 'global',
            account: 'Administrators'
        }
    ]
})
class Party extends Thing {
    ...
}

The previous example defines that Party will be accessible by each user which has permissions defined in data permission storage. It also defines that Administrators have full-access by default.

@Table

The optional @Table annotation allows you to specify the properties of the database objects that will be used to persist the entity in the database.

@Entity({
    version: '1.0.0'
})
@Table(
    name: 'PartyBase'
)
class Party extends Thing {
    ...
}

• @Table.name

  The name of the table that will be used to persist objects. The default value provided by @themost/data is a concatenation of entity's name and word "Base" e.g. PartyBase, PostalAddressBase etc.

• @Table.indexes

  A collection of indexes that should be included while creating or updating database objects.

    @Table(
        indexes: [
            {
                columnList: [
                    'name'
                ]
            },
            {
                columnList: [
                    'email'
                ]
            }
        ]
    )
    class Party extends Thing {
        ...
    }

• @Table.uniqueConstraints

  A collection of unique constraints that should be included while creating or updating database objects based on database engine features.

    @Table(
        uniqueConstraints: [
            {
                columnNames: [
                    'email'
                ]
            }
        ]
    )
    class Party extends Thing {
        ...
    }

@Column

@Column annotation is used to specify the mapped column for a property

@Entity()
@Table()
class Thing extends DataObject {
    ...
    @Column()
    public name?: string;
}

• @Column.name

  (Optional) A string which defines the column name. If @Column.name is missing property name is being used.

    class Thing extends DataObject {
        ...
        @Column({
            name: 'obj_name'
        })
        public name?: string;
    }

• @Column.nullable

  (Optional) A boolean which indicates whether the mapped column is nullable of false. The default value is true.

• @Column.type

  A string which defines the type of the column. Column may be one of the primitive column types of @themost/data or an object type

    class Thing extends DataObject {
        ...
        @Column({
            type: ColumnType.Text
        })
        public name;
  
        @Column({
            type: 'User'
        })
        public createdBy;
    }

• @Column.length

  (Optional) The column length

    class Thing extends DataObject {
        ...
        @Column({
            type: ColumnType.Text,
            length: 100
        })
        public name;
    }

• @Column.scale

  (Optional) The scale for a numeric column

• @Column.precision

  (Optional) The precision for a numeric column

• @Column.insertable

  (Optional) A boolean which indicates whether the column will be included while inserting objects or not

• @Column.updatable

  (Optional) A boolean which indicates whether the column will be included while updating objects or not

@Id()

@Id is used to specify identity columns

@Entity()
@Table()
class Thing extends DataObject {
    
    @Id()
    @Column({
        type: ColumnType.Counter
    })
    @GeneratedValue({
        strategy: GenerationType.Identity
    })
    public id;
    ...
}

@GeneratedValue()

@GeneratedValue annotation is used to specify generation strategy for identity columns

@Entity()
@Table()
class Thing extends DataObject {
    
    @Id()
    @Column({
        type: ColumnType.Counter
    })
    @GeneratedValue({
        strategy: GenerationType.Identity
    })
    public id;
    ...
}

The available generation strategies are:

• GenerationType.Auto: Based on the database’s support for primary key generation framework decides which generator type to be used.

• GenerationType.Identity: In this case database is responsible for determining and assigning the next primary key.

• GenerationType.Sequence: A sequence specify a database object that can be used as a source of primary key values.

• GenerationType.Table: It keeps a separate table with the primary key values

@Formula

@Formula annotation is used to specify calculated values.

class Thing extends DataObject {

    ...
    @Formula((event) => {
        const context = event.context as any;
        let user: { name?: string } =context.interactiveUser;
        if (user && user.name) {
            return {
                name: user.name
            };
        }
        user = context.user;
        if (user && user.name) {
            return {
                name: user.name
            };
        }
        return null;
    })
    public createdBy?: any;

}

@Formula closure has event parameter of type FormulaArgs

• FormulaArgs.context The current data context

• Formula.model An instance of DataModel class which represents the current entity type

• Formula.target The current object

@ColumnDefault

@ColumnDefault annotation defines the default value of the mapped column

@Entity()
@Table()
class Thing extends DataObject {
    ...
    @ColumnDefault(() => new Date())
    public dateCreated?: Date;
}

@ColumnDefault can be a simple closure which returns a single value or a closure which has event parameter of type ColumnDefaultArgs

• ColumnDefaultArgs.context The current data context

• ColumnDefaultArgs.model An instance of DataModel class which represents the current entity type

• ColumnDefaultArgs.target The current object

@Embedded

@Embedded annotation is used to embed type into another type. An embedded type will be inserted, updated or deleted as result of an operation made on parent object.

@Entity()
class Place extends Thing {
    ...
    @Embedded()
    public address?: PostalAddress;
}

e.g. Place entity type embeds PostalAddress into address property.

@ManyToOne

@ManyToOne annotation defined a foreign-key association between two entity types

@Entity()
class Party extends Thing {

    ...
    @Column({
        nullable: false,
        updatable: false,
        type: 'User'
    })
    @ManyToOne({
        fetchType: FetchType.Lazy
    })
    public createdBy?: User;
}

e.g. Party.createdBy defines a foreign-key association between Party and User

• @ManyToOne.optional A boolean which whether the association is optional or not.
• @ManyToOne.fetchType Defines that data can be lazily or eagerly fetched

@OneToMany

@OneToMany annotation is used to implement one-to-many relationship between two entity types.

@Entity()
class Place extends Thing {

    ...
    @OneToMany({
        cascadeType: CascadeType.Detach,
        fetchType: FetchType.Lazy,
        mappedBy: 'containedIn',
        targetEntity: 'Place'
    })
    public containsPlace?: Place;

}

e.g. Place has a collection of places based on property containedIn

@OneToMany annotation has the following properties

• @ManyToOne.fetchType Defines that data can be lazily or eagerly fetched
• @ManyToOne.cascadeType Defines the cascade operation that will be used while removing an object.
• @ManyToOne.mappedBy The target column that holds the association between the current entity type and the target entity type.
• @ManyToOne.targetEntity The type of the target entity

@ManyToMany

@OneToMany annotation is used to implement many-to-many relationship between two entity types.

class Group extends Account {
    ...
    @ManyToMany({
        targetEntity: 'Account',
        fetchType: FetchType.Lazy,
        cascadeType: CascadeType.Detach
    })
    @JoinTable({
        name: 'GroupMembers',
        joinColumns: [
            {
                name: 'object',
                referencedColumnName: 'id'
            }
        ],
        inverseJoinColumns: [
            {
                name: 'value',
                referencedColumnName: 'id'
            }
        ]
    })
    public members?: Account[];
    ...
}

e.g. Every Group has a collection of members of type Account

@ManyToOne annotation has the following properties

• @ManyToOne.fetchType Defines that data can be lazily or eagerly fetched
• @ManyToOne.cascadeType Defines the cascade operation that will be used while removing an object.
• @ManyToOne.targetEntity The type of the target entity

The @JoinTable annotation is being used to define the database object where this relationship will be stored. @JoinTable.joinColumns contains the local property and @JoinTable.inverseJoinColumns contains the foreign property.

e.g. Group.members many-to-many association will be stored in GroupMembers table where GroupMembers.object column will be a Group.id and GroupMembers.value column will be an Account.id.

@ElementCollection

@ElementCollection annotation is used to define a collection of primitive typed values e.g. an array of strings or numbers.

class Account extends Thing {
    ...
    @ManyToMany({
        targetClass: Text,
        fetchType: FetchType.Lazy
    })
    @CollectionTable({
        name: 'AccountTags',
        joinColumns: [
            {
                name: 'object',
                referencedColumnName: 'id'
            }
        ],
        inverseJoinColumns: [
            {
                name: 'value'
            }
        ]
    })
    tags;
    ...
}

e.g. Every Account has a collection of tags of type Text which is a subclass of String

The @CollectionTable annotation is being used to define the database object where this relationship will be stored. @CollectionTable.joinColumns contains the local property and @CollectionTable.inverseJoinColumns may contain the column where each value will be stored.

e.g. Account.tags will be persisted in AccountTags table where object field contains Account.id and value field contains Account.tag value.

@EntityListeners

@EntityListeners annotation defines a collection of classes that contain procedures which are going to be executed before and after CRUD operations.

@Entity()
@EntityListeners(OnUserUpdateListener, OnUserRemoveListener, OnUserInitListener)
class User extends Account {
    ...
}

e.g. OnUserUpdateListener contains PreUpdate and PostUpdate procedures

export class OnUserUpdateListener {
    @PreUpdate()
    async onPreUpdate(event: PreUpdateEvent) {
        //
    }
    @PostUpdate()
    async onPostUpdate(event: PostUpdateEvent) {
        //
    }
}

@PreInit

@PreInit annotation defines an event which will be occured before creating or updating an entity type

@PreInit()
async onPreInit(event: PreInitEvent) {
    //
}

@PostInit

@PostInit annotation defines an event which will be occured after creating or updating an entity type

@PostInit()
async onPostInit(event: PostInitEvent) {
    //
}

@PreLoad

@PreLoad annotation defines an event which will be occured before loading an entity

@PreLoad()
async onPreLoad(event: PreLoadEvent) {
    //
}

@PostLoad

@PostInit annotation defines an event which will be occured after loading an entity

@PostLoad()
async onPostLoad(event: PostLoadEvent) {
    //
}

@PrePersist

@PreLoad annotation defines an event which will be occured before inserting an entity

@PrePersist()
async onPrePersist(event: PrePersistEvent) {
    //
}

@PostPersist

@PostPersist annotation defines an event which will be occured after inserting an entity

@PostPersist()
async onPostPersist(event: PostPersistEvent) {
    //
}

@PreUpdate

@PreUpdate annotation defines an event which will be occured before updating an entity

@PreUpdate()
async onPreUpdate(event: PreUpdateEvent) {
    //
}

@PostUpdate

@PostUpdate annotation defines an event which will be occured after updating an entity

@PostUpdate()
async onPostUpdate(event: PostUpdateEvent) {
    //
}

@PreRemove

@PreRemove annotation defines an event which will be occured before removing an entity

@PreRemove()
async onPreRemove(event: PreRemoveEvent) {
    //
}

@PostUpdate

@PostRemove annotation defines an event which will be occured after removing an entity

@PostRemove()
async onPostRemove(event: PostRemoveEvent) {
    //
}