深入淺出Apple響應式框架Combine

{"type":"doc","content":[{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"一、引言"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"Combine.framework 是Apple在2019 WWDC 上基於Swift推出的函數響應框架（Functional Reactive Programming）,支持Apple全平臺的操作系統（iOS13+，macOS 10.15+等）。函數式響應框架無論在哪個平臺早已流行氾濫，開源的"},{"type":"link","attrs":{"href":"http:\/\/reactivex.io\/","title":"","type":null},"content":[{"type":"text","text":"Rx"}]},{"type":"text","text":"更是實現了各種語言的響應式編程框架。Apple在這個時候推出響應式框架，無疑是對自己護城河的進一步鞏固。事實上SwiftUI的數據驅動就是依賴Combine。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"本文將深入淺出地介紹Combine的基本概念和原理，然後通過具體demo詳細闡述其在實際編碼中的應用。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"二、什麼是Combine"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"Combine is Swift declarative framework for processing values over time"}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"Combine 爲處理隨着時間變化的值的一種聲明式框架。Combine 作用是將異步事件通過組合事件處理操作符進行自定義處理。關注如何處理變化的值，正是響應式編程的核心。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"Combine可以概述爲一種聲明式的函數響應式編程，簡潔用下圖表示："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https:\/\/static001.infoq.cn\/resource\/image\/f3\/33\/f3cf70f3fe6ea57a01c8316d8c7fe433.png","alt":null,"title":null,"style":null,"href":null,"fromPaste":true,"pastePass":false}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"通過此圖，我們可以總結Combine是什麼："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"Combine = Publishers + Operators + Subscribers"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":"2.1 Publishers"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"Publisher sends sequences of values over time to one or more Subscribers."}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}}]}