const Spec = require("./specs/spec_1.js");
const Formatter = require("./formats/json/formatter.js");
/**
* An instance of a CloudEvent.
*/
class CloudEvent {
/**
* Creates a new CloudEvent instance
* @param {Spec} [UserSpec] A CloudEvent version specification
* @param {Formatter} [UserFormatter] Converts the event into a readable string
*/
constructor(UserSpec, UserFormatter) {
this.spec = (UserSpec) ? new UserSpec(CloudEvent) : new Spec(CloudEvent);
this.formatter = (UserFormatter) ? new UserFormatter() : new Formatter();
// The map of extensions
this.extensions = {};
}
/**
* Get the formatters available to this CloudEvent
* @returns {Object} a JSON formatter
*/
getFormats() {
return { json: Formatter };
}
/**
* Format the CloudEvent as JSON. Validates the event according
* to the CloudEvent specification and throws an exception if
* it's invalid.
* @returns {JSON} the CloudEvent in JSON form
*/
format() {
// Check the constraints
this.spec.check();
// To run asData()
this.getData();
// Then, format
return this.formatter.format(this.spec.payload);
}
/**
* Formats the CLoudEvent as JSON. No specification validation
* is performed.
* @returns {JSON} the CloudEvent in JSON form
*/
toString() {
return this.formatter.toString(this.spec.payload);
}
/**
* Sets the event type
* @see https://github.com/cloudevents/spec/blob/master/spec.md#type
* @param {string} type the type of event related to the originating source
* @returns {CloudEvent} this CloudEvent
*/
type(type) {
this.spec.type(type);
return this;
}
/**
* Gets the event type
* @see https://github.com/cloudevents/spec/blob/master/spec.md#type
* @returns {String} the type of event related to the originating source
*/
getType() {
return this.spec.getType();
}
// TODO: The fact that this is exposed is problematic, given that it's
// immutable and this method will have no effect. The specification
// version is determined via the constructor - specifically the use
// of cloud event creator functions in /v03 and /v1. By default this
// object is created as a version 1.0 CloudEvent. Not documenting.
specversion(version) {
return this.spec.specversion(version);
}
/**
* Gets the CloudEvent specification version
* @see https://github.com/cloudevents/spec/blob/master/spec.md#specversion
* @returns {string} The CloudEvent version that this event adheres to
*/
getSpecversion() {
return this.spec.getSpecversion();
}
/**
* Sets the origination source of this event.
* @see https://github.com/cloudevents/spec/blob/master/spec.md#source-1
* @param {URI} source the context in which the event happened
* @returns {CloudEvent} this CloudEvent instance
*/
source(source) {
this.spec.source(source);
return this;
}
/**
* Gets the origination source of this event.
* @see https://github.com/cloudevents/spec/blob/master/spec.md#source-1
* @returns {string} the event source
*/
getSource() {
return this.spec.getSource();
}
/**
* Sets the event id. Source + id must be unique for each distinct event.
* @see https://github.com/cloudevents/spec/blob/master/spec.md#id
* @param {string} id source+id must be unique for each distinct event
* @returns {CloudEvent} this CloudEvent instance
*/
id(id) {
this.spec.id(id);
return this;
}
/**
* Gets the event id.
* @returns {string} the event id
*/
getId() {
return this.spec.getId();
}
/**
* Sets the timestamp for this event
* @see https://github.com/cloudevents/spec/blob/master/spec.md#time
* @param {Date} time timestamp when the event occurred
* @returns {CloudEvent} this CloudEvent instance
*/
time(time) {
// TODO: Ensure that this is represented as a Date internally,
// or update the JSDoc
this.spec.time(time);
return this;
}
/**
* Gets the timestamp for this event
* @see https://github.com/cloudevents/spec/blob/master/spec.md#time
* @returns {Date} the timestamp for this event
*/
getTime() {
// TODO: Ensure that this is represented as a Date internally,
// or update the JSDoc
return this.spec.getTime();
}
// TODO: Deprecated in 1.0
schemaurl(schemaurl) {
this.spec.schemaurl(schemaurl);
return this;
}
// TODO: Deprecated in 1.0
getSchemaurl() {
return this.spec.getSchemaurl();
}
/**
* Sets the content type of the data value for this event
* @see https://github.com/cloudevents/spec/blob/master/spec.md#datacontenttype
* @param {string} contenttype per https://tools.ietf.org/html/rfc2046
* @returns {CloudEvent} this CloudEvent instance
*/
dataContenttype(contenttype) {
this.spec.dataContenttype(contenttype);
return this;
}
/**
* Gets the content type of the data value for this event
* @see https://github.com/cloudevents/spec/blob/master/spec.md#datacontenttype
* @returns {string} the content type for the data in this event
*/
getDataContenttype() {
return this.spec.getDataContenttype();
}
/**
* Sets the data for this event
* @see https://github.com/cloudevents/spec/blob/master/spec.md#event-data
* @param {*} data any data associated with this event
* @returns {CloudEvent} this CloudEvent instance
*/
data(data) {
this.spec.data(data);
return this;
}
/**
* Gets any data that has been set for this event
* @see https://github.com/cloudevents/spec/blob/master/spec.md#event-data
* @returns {*} any data set for this event
*/
getData() {
return this.spec.getData();
}
/**
* Adds an extension attribute to this CloudEvent
* @see https://github.com/cloudevents/spec/blob/master/spec.md#extension-context-attributes
* @param {*} key the name of the exteneion attribute
* @param {*} value the value of the extension attribute
* @returns {CloudEvent} this CloudEvent instance
*/
addExtension(key, value) {
this.spec.addExtension(key, value);
// Stores locally
this.extensions[key] = value;
return this;
}
/**
* Gets the extension attributes, if any, associated with this event
* @see https://github.com/cloudevents/spec/blob/master/spec.md#extension-context-attributes
* @returns {Object} the extensions attributes - if none exist will will be {}
* // TODO - this should return null or undefined if no extensions
*/
getExtensions() {
return this.extensions;
}
}
module.exports = CloudEvent;