sdk-javascript/lib/bindings/http/receiver_binary.js

138 lines
3.8 KiB
JavaScript

const Constants = require("./constants.js");
const Commons = require("./commons.js");
const Cloudevent = require("../../cloudevent.js");
const {
isDefinedOrThrow,
isStringOrObjectOrThrow
} = require("../../utils/fun.js");
function validateArgs(payload, attributes) {
Array.of(payload)
.filter((p) => isDefinedOrThrow(p,
{message: "payload is null or undefined"}))
.filter((p) => isStringOrObjectOrThrow(p,
{message: "payload must be an object or a string"}))
.shift();
Array.of(attributes)
.filter((a) => isDefinedOrThrow(a,
{message: "attributes is null or undefined"}))
.shift();
}
function BinaryHTTPReceiver(
parsersByEncoding,
setterByHeader,
allowedContentTypes,
requiredHeaders,
Spec,
specversion,
extensionsPrefix,
checkDecorator) {
this.parsersByEncoding = parsersByEncoding;
this.setterByHeader = setterByHeader;
this.allowedContentTypes = allowedContentTypes;
this.requiredHeaders = requiredHeaders;
this.Spec = Spec;
this.spec = new Spec();
this.specversion = specversion;
this.extensionsPrefix = extensionsPrefix;
this.checkDecorator = checkDecorator;
}
BinaryHTTPReceiver.prototype.check = function(payload, headers) {
// Validation Level 0
validateArgs(payload, headers);
if(this.checkDecorator) {
this.checkDecorator(payload, headers);
}
// Clone and low case all headers names
var sanityHeaders = Commons.sanityAndClone(headers);
// Validation Level 1
if(!this.allowedContentTypes
.includes(sanityHeaders[Constants.HEADER_CONTENT_TYPE])){
throw {
message: "invalid content type",
errors: [sanityHeaders[Constants.HEADER_CONTENT_TYPE]]
};
}
this.requiredHeaders
.filter((required) => !sanityHeaders[required])
.forEach((required) => {
throw {message: "header '" + required + "' not found"};
});
if(sanityHeaders[Constants.DEFAULT_SPEC_VERSION_HEADER] !== this.specversion){
throw {
message: "invalid spec version",
errors: [sanityHeaders[Constants.DEFAULT_SPEC_VERSION_HEADER]]
};
}
// No erros! Its contains the minimum required attributes
};
function parserFor(parsersByEncoding, cloudevent, headers){
let encoding = cloudevent.spec.payload["datacontentencoding"];
return parsersByEncoding[encoding][headers[Constants.HEADER_CONTENT_TYPE]];
}
BinaryHTTPReceiver.prototype.parse = function(payload, headers) {
this.check(payload, headers);
// Clone and low case all headers names
var sanityHeaders = Commons.sanityAndClone(headers);
var processedHeaders = [];
var cloudevent = new Cloudevent(this.Spec);
// dont worry, check() have seen what was required or not
Array.from(Object.keys(this.setterByHeader))
.filter((header) => sanityHeaders[header])
.forEach((header) => {
var setterName = this.setterByHeader[header].name;
var parserFun = this.setterByHeader[header].parser;
// invoke the setter function
cloudevent[setterName](parserFun(sanityHeaders[header]));
// to use ahead, for extensions processing
processedHeaders.push(header);
});
// Parses the payload
let parsedPayload =
parserFor(this.parsersByEncoding, cloudevent, sanityHeaders)
.parse(payload);
// Every unprocessed header can be an extension
Array.from(Object.keys(sanityHeaders))
.filter((value) => !processedHeaders.includes(value))
.filter((value) =>
value.startsWith(this.extensionsPrefix))
.map((extension) =>
extension.substring(this.extensionsPrefix.length)
).forEach((extension) =>
cloudevent.addExtension(extension,
sanityHeaders[this.extensionsPrefix+extension])
);
// Sets the data
cloudevent.data(parsedPayload);
// Checks the event spec
cloudevent.format();
// return the result
return cloudevent;
};
module.exports = BinaryHTTPReceiver;