Create, Update, Delete

Creating Records

You can create records by calling the createRecord() method on the datastore:

• The first argument is the type of object you want to create.
• The second is a JSON with the object attributes.

this.datastore.createRecord(Post, {
    title: 'My post',
    content: 'My content'
});

Updating Records

Making changes to records is as simple as setting the attribute you want to change:

this.datastore.findRecord(Post, '1').subscribe(
    (post: Post) => {
        post.title = 'New title';
    }
);

Persisting Records

Records are persisted on a per-instance basis. Call save() on any instance of JsonApiModel and it will make a network request.

The library takes care of tracking the state of each record for you, so that newly created records are treated differently from existing records when saving.

Newly created records will be POSTed:

let post = this.datastore.createRecord(Post, {
    title: 'My post',
    content: 'My content'
});

post.save().subscribe();  // => POST to '/posts'

Records that already exist on the backend are updated using the HTTP PATCH verb:

this.datastore.findRecord(Post, '1').subscribe(
    (post: Post) => {
        post.title = 'New title';
        post.save().subscribe();  // => PATCH to '/posts/1'
    }
);

The save() method will return an Observer that you need to subscribe:

post.save().subscribe(
    (post: Post) => console.log(post)
);

Note: always remember to call the subscribe() method, even if you are not interested in doing something with the response. Since the http method return a cold Observable, the request won't go out until something subscribes to the observable.

You can tell if a record has outstanding changes that have not yet been saved by checking its hasDirtyAttributes property.

At this point, you can either persist your changes via save() or you can roll back your changes. Calling rollbackAttributes() for a saved record reverts all the dirty attributes to their original value.

this.datastore.findRecord(Post, '1').subscribe(
    (post: Post) => {
        console.log(post.title);                // => 'Old title'
        console.log(post.hasDirtyAttributes);   // => false
        post.title = 'New title';
        console.log(post.hasDirtyAttributes);   // => true
        post.rollbackAttributes();
        console.log(post.hasDirtyAttributes);   // => false
        console.log(post.title);                // => 'Old title'
    }
);

Deleting Records

For deleting a record, just call the datastore's method deleteRecord(), passing the type and the id of the record:

this.datastore.deleteRecord(Post, '1').subscribe(() => {
    // deleted!
});