@improbable-eng/grpc-web

> Library for making gRPC-Web requests from a browser

This library is intended for both JavaScript and TypeScript usage from a web browser or NodeJS (see Usage with NodeJS).

Note: This only works if the server supports gRPC-Web

A Golang gRPC-Web middleware and a Golang-based gRPC-Web proxy are available here.

Please see the full gRPC-Web README for known limitations.

Installation

@improbable-eng/grpc-web has peer dependencies of google-protobuf and @types/google-protobuf.

npm install google-protobuf @types/google-protobuf @improbable-eng/grpc-web --save

Example Project

There is an example project available here

Usage Overview

* Use ts-protoc-gen with protoc to generate .js and .d.ts files for your request and response classes. ts-protoc-gen can also generate gRPC service definitions with the service=true argument.
* Go to code generation docs
* Make a request using unary(), invoke() or client()

``javascript
import {grpc} from "@improbable-eng/grpc-web";

// Import code-generated data structures.
import {BookService} from "./generated/proto/examplecom/library/book_service_pb_service";
import {GetBookRequest} from "./generated/proto/examplecom/library/book_service_pb";

const getBookRequest = new GetBookRequest();
getBookRequest.setIsbn(60929871);
grpc.unary(BookService.GetBook, {
request: getBookRequest,
host: host,
onEnd: res => {
const { status, statusMessage, headers, message, trailers } = res;
if (status === grpc.Code.OK && message) {
console.log("all ok. got book: ", message.toObject());
}
}
});
`

* Requests can be aborted/cancelled before they complete:

`javascript
const request = grpc.unary(BookService.GetBook, { ... });
request.cancel();
`

Available Request Functions

There are three functions for making gRPC requests:

$3

This is a convenience function for making requests that consist of a single request message and single response message. It can only be used with unary methods.

`protobuf
rpc GetBook(GetBookRequest) returns (Book) {}
`

$3

This is a convenience function for making requests that consist of a single request message and a stream of response messages (server-streaming). It can also be used with unary methods.

`protobuf
rpc GetBook(GetBookRequest) returns (Book) {}
rpc QueryBooks(QueryBooksRequest) returns (stream Book) {}
`

$3


grpc.client returns a client. Dependant upon transport compatibility this client is capable of sending multiple request messages (client-streaming) and receiving multiple response messages (server-streaming). It can be used with any type of method, but will enforce limiting the sending of messages for unary methods.

`protobuf
rpc GetBook(GetBookRequest) returns (Book) {}
rpc QueryBooks(QueryBooksRequest) returns (stream Book) {}
rpc LogReadPages(stream PageRead) returns (google.protobuf.Empty) {}
rpc ListenForBooks(stream QueryBooksRequest) returns (stream Book) {}
``

Usage with NodeJS

Refer to grpc-web-node-http-transport.

All Docs

* unary()
* invoke()
* client()
* Code Generation
* Concepts
* Transport