Posted 2021-04-10 鎺ㄥ晩鍓嶇鍥㈤槦

鍓嶈█

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涓句釜 馃尠

杈撳嚭灏变笉鍐欎簡锛岃繕涓嶆竻妤氱殑鍚屽鑷灏濊瘯涓?/p>

app.use鍋氫簡浠€涔?/h2>

杩囨护鎺変竴浜涙殏鏃剁敤涓嶅埌鐨勪唬鐮?/p>

callback

compose() 杩欎釜鏂规硶锛屽氨灏嗘垜浠紶鍏ョ殑涓棿浠舵暟缁勫叧鑱旇捣鏉ヤ簡锛屾渶鍚?callback() 杩斿洖 this.handleRequest() 鐨勬墽琛岀粨鏋滐紝鏆備笉绠¤繑鍥炰粈涔堝惂锛屽厛鐪嬬湅杩欎釜绁炲鐨?compose() 鏂规硶鍋氫簡浠€涔堜娇寰楁枃绔犳渶寮€濮嬬殑渚嬪瓙鍙互閭ｆ牱鎵ц

compose

1. 棣栧厛浼氶粯璁ゆ墽琛岀涓€涓腑闂翠欢锛岃繑鍥?Promise锛岃 Koa 鐩戝惉锛屾墽琛屽搴旈€昏緫

2. 鍦ㄦ墽琛岀涓€涓腑闂翠欢鐨勯€昏緫鏃讹紝閬囧埌 await next()鏃讹紝浼氱户缁墽琛?dispatch(i+1)锛屼篃灏辨槸鎵ц dispatch(1)锛屼細鎵嬪姩瑙﹀彂鎵ц绗簩涓腑闂翠欢銆傝繖鏃跺€欙紝绗竴涓腑闂翠欢 await next() 鍚庨潰鐨勪唬鐮佸氨浼氳 pending锛岀瓑寰?await next() 杩斿洖 Promise锛屾墠浼氱户缁墽琛岀涓€涓腑闂翠欢 await next() 鍚庨潰鐨勪唬鐮併€?/span>

3. 浠ユ绫绘帹锛屽鏋滄湁澶氫釜涓棿浠剁殑鏃跺€欙紝浼氫緷鐓т笂闈㈢殑閫昏緫涓嶆柇鎵ц锛屽厛鎵ц绗竴涓腑闂翠欢锛屽湪 await next() 鍑?pending锛岀户缁墽琛岀浜屼釜涓棿浠讹紝缁х画鍦?await next() 鍑?pending锛岀户缁墽琛岀涓変釜涓棿锛岀洿鍒版渶鍚庝竴涓腑闂翠欢鎵ц瀹岋紝鐒跺悗杩斿洖 Promise锛岀劧鍚庡€掓暟绗簩涓腑闂翠欢鎵嶆墽琛屽悗缁殑浠ｇ爜骞惰繑鍥濸romise锛岀劧鍚庢槸鍊掓暟绗笁涓腑闂翠欢锛屾帴鐫€涓€鐩翠互杩欑鏂瑰紡鎵ц鐩村埌绗竴涓腑闂翠欢鎵ц瀹岋紝骞惰繑鍥?Promise锛屼粠鑰屽疄鐜板紑澶翠緥瀛愮殑鎵ц椤哄簭锛屽氨濂芥瘮涓嬮潰缃戜笂寰堢伀鐨勪竴寮犳磱钁卞浘

鎬荤粨

koa 鐪熼锛岃繖 compose() 鍑芥暟鐪熼獨锛屾墍浠ヨ璇勪环涓€涓ソ鐨勭▼搴忓憳涓嶆槸鐢变唬鐮侀噺鍐冲畾鐨?/p>