{"id":1157,"date":"2023-07-07T05:00:00","date_gmt":"2023-07-07T12:00:00","guid":{"rendered":"https:\/\/www.angulartraining.com\/daily-newsletter\/?p=1157"},"modified":"2023-06-30T16:00:28","modified_gmt":"2023-06-30T23:00:28","slug":"use-functions-for-readable-rxjs-operator-chains","status":"publish","type":"post","link":"https:\/\/www.angulartraining.com\/daily-newsletter\/use-functions-for-readable-rxjs-operator-chains\/","title":{"rendered":"Use functions for readable RxJs operator chains"},"content":{"rendered":"\n

When you have complex RxJs operator chains, a good idea is to refactor them into simple functions. This can also favor code reuse for simple scenarios such as the following example.<\/p>\n\n\n\n

Say we have a User<\/code> object with the following shape:<\/p>\n\n\n

\n
\"\"<\/figure>\n<\/div>\n\n\n

<\/p>\n\n\n\n

We receive that object through an Observable; all we want from it is the user’s age. Using Rxjs (and date-fns<\/a><\/code>), we could do something like this:<\/p>\n\n\n

\n
\"\"<\/figure>\n<\/div>\n\n\n

<\/p>\n\n\n\n

This works, but it’s not instantly apparent that we’re computing the age of the user, and if we need similar code elsewhere, we’d have to copy-paste that line of code, which is terrible.<\/p>\n\n\n\n

Instead, we could create a function with an explicit name:<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

<\/p>\n\n\n\n

And then use it as our new custom operator function:<\/p>\n\n\n

\n
\"\"<\/figure>\n<\/div>\n\n\n

<\/p>\n\n\n\n

We can improve the signature of our function for type safety purposes, too:<\/p>\n\n\n

\n
\"\"<\/figure>\n<\/div>\n\n\n

<\/p>\n\n\n\n

You can see that code in action on Stackblitz here<\/a>.<\/p>\n\n\n\n

Obviously, the approach makes even more sense when you have several operators, and you can even combine such operator functions with other operator functions:<\/p>\n\n\n

\n
\"\"<\/figure>\n<\/div>\n\n\n

<\/p>\n\n\n\n

Now we have beautiful, maintainable code that can be read without documentation.<\/p>\n","protected":false},"excerpt":{"rendered":"

When you have complex RxJs operator chains, a good idea is to refactor them into simple functions. This can also favor code reuse for simple scenarios such as the following example. Say we have a User object with the following shape: We receive that object through an Observable; all we want from it is the […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12,10],"tags":[],"class_list":["post-1157","post","type-post","status-publish","format-standard","hentry","category-operators","category-rxjs"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.angulartraining.com\/daily-newsletter\/wp-json\/wp\/v2\/posts\/1157","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.angulartraining.com\/daily-newsletter\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.angulartraining.com\/daily-newsletter\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.angulartraining.com\/daily-newsletter\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.angulartraining.com\/daily-newsletter\/wp-json\/wp\/v2\/comments?post=1157"}],"version-history":[{"count":2,"href":"https:\/\/www.angulartraining.com\/daily-newsletter\/wp-json\/wp\/v2\/posts\/1157\/revisions"}],"predecessor-version":[{"id":1165,"href":"https:\/\/www.angulartraining.com\/daily-newsletter\/wp-json\/wp\/v2\/posts\/1157\/revisions\/1165"}],"wp:attachment":[{"href":"https:\/\/www.angulartraining.com\/daily-newsletter\/wp-json\/wp\/v2\/media?parent=1157"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.angulartraining.com\/daily-newsletter\/wp-json\/wp\/v2\/categories?post=1157"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.angulartraining.com\/daily-newsletter\/wp-json\/wp\/v2\/tags?post=1157"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}