Custom methods

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Custom methods
Custom methods can be added to entities instances through their Schemas.
schema.methods.<methodName> = function(){ ... }
Make sure not to use arrow function as you would lose the scope of the entity instance.
const blogPostSchema = new Schema({ title: {} });
​
// Custom method to retrieve all children Text entities
blogPostSchema.methods.texts = function getTexts() {
    // the scope (this) is the entity instance
    const query = this.model('Text')
                        .query()
                        .hasAncestor(this.entityKey);
​
    return query.run();
};
​
// In your Controller
// You can then call it on an entity instance of BlogPost
​
const BlogPost = require('../models/blogpost.model');
BlogPost.get(123)
    .then((blogEntity) => {
        blogEntity.texts()
            .then((response) => {
                const texts = response[0].entities;
            });
        });
Note how entities instances can access other models through entity.model('MyModel'). Denormalization can then easily be done with a custom method:
// Add custom "profilePict()" method on the User Schema
userSchema.methods.profilePicture = function profilePicture() {
    // Any type of query can be done here
    return this.model('Image').get(this.imageIdx);
};
​
// In your controller
const User = require('../models/user.model');
​
const user = new User({ name: 'John', imageIdx: 1234 });
user.profilePicture()
    .then((imageEntity) => {
        user.profilePicture = imageEntity.url;
        user.save()
            .then(() { ... });
    });
​
// Or with a callback
userSchema.methods.profilePict = function(cb) {
    return this.model('Image').get(this.imageIdx, cb);
};
...
​
const user = new User({ name:'John', imageIdx:1234 });
​
// Call custom Method 'getImage'
user.profilePict(function onProfilePict(err, imageEntity) {
    user.profilePict = imageEntity.url;
    user.save().then(() { ... });
});
virtual()
Model
Last modified 3yr ago
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