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Object-Data-Relational-Mapping

Like mongoose, RxDB has ORM-capabilities which can be used to add specific behavior to documents and collections.

statics

Statics are defined collection-wide and can be called on the collection.

Add statics to a collection

To add static functions, pass a statics-object when you create your collection. The object contains functions, mapped to their function-names.

const heroes = await myDatabase.addCollections({
heroes: {
schema: mySchema,
statics: {
scream: function(){
return 'AAAH!!';
}
}
}
});

console.log(heroes.scream());
// 'AAAH!!'

You can also use the this-keyword which resolves to the collection:

const heroes = await myDatabase.addCollections({
heroes: {
schema: mySchema,
statics: {
whoAmI: function(){
return this.name;
}
}
}
});
console.log(heroes.whoAmI());
// 'heroes'

instance-methods

Instance-methods are defined collection-wide. They can be called on the RxDocuments of the collection.

Add instance-methods to a collection

const heroes = await myDatabase.addCollections({
heroes: {
schema: mySchema,
methods: {
scream: function(){
return 'AAAH!!';
}
}
}
});
const doc = await heroes.findOne().exec();
console.log(doc.scream());
// 'AAAH!!'

Here you can also use the this-keyword:

const heroes = await myDatabase.addCollections({
heroes: {
schema: mySchema,
methods: {
whoAmI: function(){
return 'I am ' + this.name + '!!';
}
}
}
});
await heroes.insert({
name: 'Skeletor'
});
const doc = await heroes.findOne().exec();
console.log(doc.whoAmI());
// 'I am Skeletor!!'

attachment-methods

Attachment-methods are defined collection-wide. They can be called on the RxAttachments of the RxDocuments of the collection.

const heroes = await myDatabase.addCollections({
heroes: {
schema: mySchema,
attachments: {
scream: function(){
return 'AAAH!!';
}
}
}
});
const doc = await heroes.findOne().exec();
const attachment = await doc.putAttachment({
id: 'cat.txt',
data: 'meow I am a kitty',
type: 'text/plain'
});
console.log(attachment.scream());
// 'AAAH!!'