daily-email: add 2023-05-09

src/content/daily-email/2023-05-09.md

@@ -0,0 +1,20 @@
+---
+title: >
+  The single responsibility principle
+pubDate: 2023-05-09
+permalink: >
+  archive/2023/05/09/the-single-responsibility-principle
+tags: []
+---
+
+Today, I added a new feature to a project that allows a member to search for a node based on either its title or a specified field on that node, select a result from an autocomplete list and then be redirected to their selected node.
+
+I've already implemented this for other node types but needed to do the same for this node type.
+
+There are some differences, such as the node type to query for; the additional field depends on which node type as does the text shown in the autocomplete list.
+
+To do this, I needed to add a custom block and form, update the `AutocompleteController`, create a new instance of a `NodeQuery` class (a custom class within the custom module), register it as a service and update the `SearchQueryFactory` class.
+
+A principle that I follow as much as possible is the single responsibility principle, or SRP (the 'S' in SOLID), where each function or class only has one responsibility - such as returning a response for the autocomplete list, determining the correct node query to use based on the search being run or building the query itself - these are separated and split into their own files.
+
+Although more files and functions are created when coding in this way, though they are smaller and more straightforward to work with - which makes them easier to read, debug and maintain. It also makes code like the node query classes reusable as they aren't embedded within a larger class and are easier to test.