Docs for hooks and model

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Anatoliy Chakkaev 2013-03-26 23:34:20 +04:00
parent 5e24bd960f
commit 895c2d6bf7
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jugglingdb-hooks(3) - Hooks and object lifecycle. jugglingdb-hooks(3) - Hooks and object lifecycle.
================== ===================
## DESCRIPTION
Hook is a class method called on object when some event happens. List of events:
* initialize - called after `new Model` called
* create - called before and after create
* update - called before and after save (except create)
* save - called before and after save (including both create and update)
* validate - called before and after validations
* destroy - called before and after destroy on instance
Each hook except `initialize` accepts callback as first argument. This callback
should be called when hook done. All hooks called on object instance, but it's
not recommended to use `this` for updating in all hooks where data argument
available (second arguments for all data-related before-hooks: save, update,
create).
## INITIALIZE
Initialize hook called when new object created after all setters and default
being applied.
Model.afterInitialize = function() {
this.property = 'some value;
console.log('afterInitialize called');
};
new Model; // afterInitialize called
## CREATE
Create hooks called when object created.
The `beforeCreate` hook accepts data as second arguments.
Model.beforeCreate = function(next, data) {
// use data argument to update object
data.createdAt = new Date();
console.log('before');
next();
};
Model.afterCreate = function(next) {
this.notifySocialNetworks();
this.sendEmailNotifications();
console.log('after');
next();
};
Model.create({foo: 'bar'}, function(err, model) {
console.log('callback');
});
Example output will be:
before
after
callback
## UPDATE
Update hooks called on each save except create.
The `beforeUpdate` hook accepts data as second arguments.
Data argument only containing actual data for update, not full object data.
Model.beforeUpdate = function(next, data) {
// use data argument to update object
// in update hook data argumen only contains data for update (not
// full object)
data.updatedAt = new Date();
console.log('before');
next();
};
Model.afterUpdate = function(next) {
this.scheduleFulltextIndexUpdate();
console.log('after');
next();
};
model.updateAttributes({foo: 'bar'}, function(err, model) {
console.log('callback');
});
Example output will be:
before
after
callback
## SAVE
Save hooks called on each save, both update and create.
The `beforeSave` hook accepts data as second arguments.
For before save hook data argument is the same as this.
Model.beforeSave = function(next, data) {
data.tags = JSON.parse(data.tags);
next();
};
Model.afterSave = function(next) {
next();
};
## DESTROY
Destroy hooks called when `model.destroy()` called. Please note that
`destroyAll` method doesn't call destroy hooks.
## VALIDATE
Validate hooks callen before and after validation and should be used for data
modification and not for validation. Use custom validation described in
jugglingdb-validations(3) man section.
## SEE ALSO
jugglingdb-model(3)
jugglingdb-validations(3)

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console.log(count); // count of approved users stored in database console.log(count); // count of approved users stored in database
}); });
## ESSENTIALS ## RELATIONS
### Default values ### hasMany
Define all necessary stuff for "one to many" relation:
* foreign key in "many" model
* named scope in "one" model
Example:
var Book = db.define('Book');
var Chapter = db.define('Chapters');
// syntax 1 (old):
Book.hasMany(Chapter);
// syntax 2 (new):
Book.hasMany('chapters');
Syntax 1 and 2 does same things in different ways: adds `chapters` method to
`Book.prototype` and add `bookId` property to `Chapter` model. Foreign key name
(`bookId`) could be specified manually using second param:
Book.hasMany('chapters', {foreignKey: `chapter_id`});
When using syntax 2 jugglingdb looking for model with singularized name:
'chapters' => 'chapter' => 'Chapter'
But it's possible to specify model manually using second param:
Book.hasMany('stories', {model: Chapter});
Syntax 1 allows to override scope name using `as` property of second param:
Book.hasMany(Chapter, {as: 'stories'});
**Scope methods** created on BaseClass by hasMany allows to build, create and
query instances of other class. For example:
Book.create(function(err, book) {
// using 'chapters' scope for build:
var c = book.chapters.build({name: 'Chapter 1'});
// same as:
c = new Chapter({name: 'Chapter 1', bookId: book.id});
// using 'chapters' scope for create:
book.chapters.create();
// same as:
Chapter.create({bookId: book.id});
// using scope for querying:
book.chapters(function() {/* all chapters with bookId = book.id */ });
book.chapters({where: {name: 'test'}, function(err, chapters) {
// all chapters with bookId = book.id and name = 'test'
});
});
### belongsTo
TODO: document
### hasAndBelongsToMany
TODO: implement and document
## SEE ALSO ## SEE ALSO