Observables – concatMap

Our list of boards is currently using data from the /api/boards REST endpoint, and therefore has access to the general information relating to a board, such as its name, short_description, and manufacturer logo. Remember that most windsurfing boards come in a range of sizes, with each size having a slightly different volume, width, and length, in order to support different sail sizes. What we have here, then, is a one-to-many relationship between a board and its sizes, as a single board may have many sizes.

Our REST endpoints, however, do not return the sizes of a board within the JSON structure for a single board. This means that for each board in our list, we will need to make a secondary call to the REST endpoints ...

Get Mastering TypeScript 3 - Third Edition now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.