abstract CloudObject
A CloudObject is the base class for all objects that can be persisted and exchanged between Olympe applications.
In essence, it represents a remote reference to an object in the data cloud.
It is identified by its unique ID, or tag. From a CloudObject you can access related CloudObjects.
A CloudObject can be instantiated via the InstanceOrTag of its model, and it can be instantiated multiple times with different properties values.
Data types defined in DRAW are such CloudObjects, instances of Data types are also CloudObjects.
Example:
const dcObject = CloudObject.get(tag);
Extended by
Implements
HasTag
Constructors
new CloudObject()
new CloudObject(): CloudObject
Returns
CloudObject
Properties
containsRel
static containsRel: Relation<CloudObject, CloudObject>;
Relation between a container (a CloudObject) that has children (other CloudObjects)
For example, from a folder to the contained elements or from a function to the elements needed for that function to run.
extendedByRel
static extendedByRel: Relation<CloudObject, CloudObject>;
Inverse relation of extendRel
extendRel
static extendRel: Relation<CloudObject, CloudObject>;
Model CloudObjects can inherit relations and properties
from another CloudObject model to mimic their behaviour.
Relation from a model to the CloudObject model it extends.
A --extendRel-> B
A inherits B's properties and relations.
instancesRel
static instancesRel: Relation<CloudObject, CloudObject>;
Inverse relation of modelRel between a model and its instances
Equivalent to modelRel.getInverse()
modelRel
static modelRel: Relation<CloudObject, CloudObject>;
Relation between a CloudObjectand its model
instance --modelRel-> model
nameProp
static nameProp: Property<string>;
Name property for all CloudObjects
propertyRel
static propertyRel: Relation<CloudObject, PropertyModel>;
Relation between a model and the properties it defines.
Methods
asInstance()
static asInstance<T>(this): T
Get this CloudObject class as a CloudObject instance.
Type Parameters
| Type Parameter |
|---|
T |
Parameters
| Parameter | Type |
|---|---|
this | Class<T> |
Returns
T
the current data type class as a CloudObject instance.
createWith()
static createWith<T>(
this,
properties,
model?,
source?): T
Create an instance of the specified data type (or model)
in the local datacloud (not persisted) with the specified property values.
If the model is not specified, it uses this DataType.
Type Parameters
| Type Parameter |
|---|
T |
Parameters
| Parameter | Type | Description |
|---|---|---|
this | Class<T> | - |
properties | Map<InstanceOrTag, any> | mappings of (propertyTag -> propertyValue) |
model? | InstanceOrTag | tag of the model of the CloudObject you want to create. |
source? | string |
Returns
T
newly created CloudObject
exists()
static exists(tag): boolean
Checks whether a CloudObject exists or not.
Parameters
| Parameter | Type | Description |
|---|---|---|
tag | InstanceOrTag | tag of the CloudObject |
Returns
boolean
true if tag is valid and references a CloudObject.
Static
get()
static get<T>(tag): T
Get the CloudObject whose tag is specified.
This only works if the CloudObject is already present in the local datacloud cache.
(NB: you can use a Query to retrieve a distant CloudObject)
Type Parameters
| Type Parameter |
|---|
T extends CloudObject |
Parameters
| Parameter | Type | Description |
|---|---|---|
tag | InstanceOrTag | tag of the CloudObject |
Returns
T
CloudObject specified by the tag
Static
getProperties()
static getProperties(): Property<any>[]
The attributes of a CloudObject are called properties. Properties can be of different types,
e.g. Property<string>, Property<number>, Property<Date>.
If a Person CloudObject has an age property, all the instances of Person can access
the age property using the same tag, the tag of the age property. This method returns all
properties defined by the Data Type associated to this class.
Returns
Property<any>[]
All properties defined for a data type
getRelations()
static getRelations<O, D>(this): (Relation<O, D> | Relation<D, O>)[]
Return all the relations whose origin OR destination is the CloudObject associated to this class.
Type Parameters
| Type Parameter |
|---|
O extends CloudObject |
D extends CloudObject |
Parameters
| Parameter | Type |
|---|---|
this | Class<O> |
Returns
(Relation<O, D> | Relation<D, O>)[]
All relations defined on the current data type. It can be the destination or the origin of the relations.
instancesOf()
static instancesOf<T>(model): Query<T, never>
Return a query starting from all instances of this Data Type.
Type Parameters
| Type Parameter |
|---|
T extends CloudObject |
Parameters
| Parameter | Type | Description |
|---|---|---|
model | InstanceOrTag | Class<T> | data type to get instances of |
Returns
Query<T, never>
A query starting from the instances of the specified model.
equals()
equals(object): boolean
Compare this CloudObject and the given one and return whether they are identical or not.
Parameters
| Parameter | Type | Description |
|---|---|---|
object | any | the object to compare |
Returns
boolean
true if the specified object is the same CloudObject
follow()
follow<D>(relation): Query<D, never>
Start a query from this instance and follow the relation given as argument. The query starts from this single instance, and follows a relation to an arbitrary number of destination instances. See Query.follow | Query.follow(relation)
The following are equivalent:
myCloudObject.follow(relation);
myCloudObject.query().follow(relation);
Type Parameters
| Type Parameter |
|---|
D extends CloudObject |
Parameters
| Parameter | Type | Description |
|---|---|---|
relation | Relation<CloudObject, D> | the relation to follow from the starting instance (this) |
Returns
Query<D, never>
query starting from this and following the relation relation as first step of the query
followSingle()
followSingle<D>(relation): QuerySingle<D>
Start a querySingle from this instance that follows 0..1 relations
The query starts from this instance, and follow the relation to a single
destination instance. It is equivalent to QuerySingle.from(this).follow(relation).
Type Parameters
| Type Parameter |
|---|
D extends CloudObject |
Parameters
| Parameter | Type | Description |
|---|---|---|
relation | Relation<CloudObject, D> | to follow from this starting instance |
Returns
QuerySingle<D>
a query following 0-1 relations
get()
get<T>(property): T
Get the current value of the specified property for this CloudObject instance
Type Parameters
| Type Parameter |
|---|
T |
Parameters
| Parameter | Type | Description |
|---|---|---|
property | InstanceOrTag | Property<T> | property or property's tag |
Returns
T
property value
getModel()
getModel(): CloudObject
Every CloudObject has a model which defines relations and properties its instances may have.
Returns
CloudObject
the model of this CloudObject instance as a CloudObject instance
getModelTag()
getModelTag(): string
Every CloudObject has a model which defines relations and properties its instances may have.
Returns
string
the tag of the model of this CloudObject instance
getSource()
getSource(): string
Return the source id that owns this cloud object.
Returns
string
getTag()
getTag(): string
Every CloudObject has a unique tag.
Returns
string
tag of the CloudObject
Implementation of
HasTag.getTag
isPersisted()
isPersisted(): boolean
Return the persistence state of this instance.
CloudObjects can either be volatile, and only live in the local cache. In this case,
the CloudObject instance is not persisted. If a CloudObjectis persisted, it is stored in an external data store.
This means that the instance can be accessible through other Olympe VMs in the same environment.
Returns
boolean
a boolean indicating if this object is persisted in a non-volatile way.
name()
name(): string
Every CloudObject can define a value for its nameProperty.
This method returns the current value of that property for this instance.
Returns
string
the value of the name property of this
observe()
observe<T>(
context,
property,
waitForValue?): Observable<T>
Get an observable to the current value of the specified property for this CloudObject instance.
The observable gets the new value each time the property gets updated in the datacloud.
The observable gets completed automatically once the specified context is Context.onClear | cleared.
If waitForValue is set to FALSE (TRUE by default), the first value received by the observable is null if there is no value at call time.
Type Parameters
| Type Parameter |
|---|
T |
Parameters
| Parameter | Type | Description |
|---|---|---|
context | Context | context to which the Observable is attached |
property | InstanceOrTag | Property<T> | property or property's tag to observe |
waitForValue? | boolean | whether the observable wait for a first value to get a value. (Default = true) |
Returns
Observable<T>
Observable of property values
observeProperties()
observeProperties<T>(context): Observable<[Property<T>, T]>
Get an observable to pair [property, value] for this CloudObject instance.
The observable gets the new value each time any property gets updated in the datacloud. The observable gets completed automatically once the specified context is Context.onClear | cleared.
Type Parameters
| Type Parameter |
|---|
T |
Parameters
| Parameter | Type | Description |
|---|---|---|
context | Context | Context to which the Observable will be attached |
Returns
Observable<[Property<T>, T]>
Observable of property values
query()
query(): Query<CloudObject, never>
Create and return a query starting from this instance
Returns
Query<CloudObject, never>
a query starting at this CloudObject instance
toJSON()
toJSON(): Object
Create a Javascript object from this CloudObject current state, including its tag and property values. It provides the same result as toObject called with nameAsKey = true and inheritedProperties = false.
Returns
Object
toObject()
toObject(namesAsKey?, inheritedProperties?): Object
Create a Javascript object from this CloudObject current state.
Parameters
| Parameter | Type | Description |
|---|---|---|
namesAsKey? | boolean | If true, use the property name instead of the property tag as keys of the generated object. |
inheritedProperties? | boolean | If false, do not including inherited property. By default, it includes them. |
Returns
Object