apollo-link-batch-http

---

title: Batch Http Link

Note: This package will be updated to remove the dependency on apollo-fetch an use the same options / API as the http-link

Purpose

An Apollo Link to allow batching of multiple operations into a single http request. Instead of sending a single operation, it sends an array of operations to the server.

Installation

npm install apollo-link-batch-http --save

Usage

import { BatchHttpLink } from "apollo-link-batch-http";

const link = new BatchHttpLink({ uri: "/graphql" });

Options

Batch HTTP Link takes an object with four options on it to customize the behavior of the link. The possible keys on this configuration object are:

• uri: a string of the server or a default of "/graphql"
• batchMax: a max number of items to batch, defaults at 10
• batchInterval: the interval at which to batch (in ms), defaults to 10
• fetch: an instance of ApolloFetch

By default, this link uses the Apollo Fetch library for the HTTP transport.

Context

The Batch HTTP Link uses the headers field on the context to allow passing headers to the HTTP request.

• headers: an object to be converted to headers for the http request

import { BatchHttpLink } from "apollo-link-batch-http";
import ApolloClient from "apollo-client";
import InMemoryCache from "apollo-cache-inmemory";

const client = new ApolloClient({
  link: new BatchHttpLink({ uri: "/graphql" }),
  cache: new InMemoryCache()
});

// a query with apollo-client that will be batched
client.query({
  query: MY_QUERY,
  context: {
    // example of setting the headers with context per operation
    headers: {
      authoriztion: Meteor.userId()
    }
  }
})

Changelog

apollo-link-dedup 1.0.18

• Fixes an issue introduced in #984 where subscriber next and/or error calls might have already deleted the key the new dedupe changes were intended to help with. <br/> @JoviDeCroock in #988

2019-03-13