Object-Data-Relational-Mapping
Like mongoose, RxDB has ORM-capabilities which can be used to add specific behavior to documents and collections.
staticsβ
Statics are defined collection-wide and can be called on the collection.
Add statics to a collectionβ
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-methodsβ
Instance-methods are defined collection-wide. They can be called on the RxDocuments of the collection.
Add instance-methods to a collectionβ
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-methodsβ
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!!'