Transform Your Angular HTTP Service Response with rxjs скачать в хорошем качестве

Transform Your Angular HTTP Service Response with rxjs

Learn how to modify an HTTP service response in Angular using `rxjs` operators to add properties to objects in a response array. --- This video is based on the question https://stackoverflow.com/q/64280242/ asked by the user 'user1608841' ( https://stackoverflow.com/u/1608841/ ) and on the answer https://stackoverflow.com/a/64280520/ provided by the user 'vitaliy kotov' ( https://stackoverflow.com/u/11900833/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions. Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Transform http service response in Angular using rxjs Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l... The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license. If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com. --- Transforming HTTP Service Response in Angular Using RxJS In today's development world, dealing with API responses is an essential skill. In an Angular application, managing responses efficiently using rxjs can enhance job performance and maintainability. This guide will guide you through a common problem: how to transform an HTTP service response by adding new properties to each object of an array. The Use Case Imagine you've got an Angular service that performs HTTP calls, and you need to manipulate the response. Your current process looks like this: Fetching an ID using one HTTP method. Using that ID to call another method which fetches an array of objects for processing. Example Response For our illustration, let's consider the following sample response you might get from the server: [[See Video to Reveal this Text or Code Snippet]] Now, your goal is to add an isEditable property set to false for every object in that response array. The Challenge You attempted to implement this by using the concatMap and mergeAll operators from RxJS, but you ended up only modifying the first object of the array. This is a common hurdle developers face when transforming array data in a stream. Your Attempt Here’s the code you started with: [[See Video to Reveal this Text or Code Snippet]] The Result You Need The expected output is to have every object in your array look like this: [[See Video to Reveal this Text or Code Snippet]] The Solution To correctly modify all objects in the array returned from your HTTP call, you can utilize the map operator effectively. The map operator allows you to modify the stream and is perfectly suited for transforming array data. Step-by-Step Implementation Use the map operator on the stream of data. Return a new array where each object includes the isEditable property. Here’s how you can achieve that: [[See Video to Reveal this Text or Code Snippet]] Explanation of the Code concatMap: This operator ensures that the HTTP requests are made sequentially. It subscribes to the inner observable and waits for it to complete before moving to the next one. map: After receiving the data array from the second HTTP call, we use map to transform each item in the array. Spread Operator: The {...item, isEditable: false} syntax creates a new object that includes all existing properties from item while adding isEditable: false. Conclusion By leveraging RxJS operators like map, you can elegantly and efficiently manipulate HTTP service responses in Angular applications. This approach not only makes your code cleaner and more maintainable but also enhances the overall performance of your application. Feel free to experiment with different transformations as required by your application, and happy coding!