我想写一个像时钟应用程序的东西.状态基本上是一个重复递增的数字.这里可以看到一种做法.
(ns chest-example.core
(:require [om.core :as om :include-macros true]
[om.dom :as dom :include-macros true]
[cljs.core.async :as async])
(:require-macros [cljs.core.async.macros :refer [go]]))
(defonce app-state (atom {:time 0}))
(defn clock-view [data owner]
(reify
om/IRender
(render [_]
(dom/div nil (pr-str data)))))
(go (while true
(async/<! (async/timeout 1000))
(om/transact! (om/root-cursor app-state) :time inc)))
(defn main []
(om/root
clock-view
app-state
{ :target (. js/document (getElementById "clock"))}))
我遇到的问题是这不是可重新加载的代码.一旦我通过无花果轮刷新代码,增量变得更快,因为有几件事情更新状态.
我试图尝试各种想法(基本上使用不同的组件来拥有go语句代码)但我无法想出一些可行的东西.
有没有人对此有一个简洁的解决方案,或者我只是必须坚持在开发过程中?
最佳答案 你必须告诉goroutine何时停止运行.最简单的方法是发送关闭!告诉goroutine:
(ns myproject.core
;; imports
)
(def my-goroutine
(go-loop []
(when (async/<! (async/timeout 1000))
(om/transact! (om/root-cursor app-state) :time inc)
(recur)))))
;; put in your on-reload function for figwheel
(defn on-reload []
(async/close! my-goroutine))
任何在循环中运行的goroutine都需要发出信号以在重新加载时停止(通过figwheel:on-jsload config).
;; project.clj
(defproject ;; ...
:figwheel {:on-jsload "myproject.core/on-reload"}
)
最好将长期运行的goroutine视为需要管理的资源.在golang中,将长期运行的goroutine视为流程/墓碑以确保正确拆卸是一种常见模式.同样应该应用于core.async的goroutines.