问题描述
我正在尝试在Google Apps脚本网络应用程序中重构一些难看的代码，以使其使用async / await。
它使用google.script.url.getLocation客户端来提取URL参数，然后将其发送给其他异步函数。
一定有一种优雅的方法。
var doSomeAsyncShit =()=> {
google.script.url.getLocation(function (location) {
var rid = (location.parameter.rid) ? location.parameter.rid : defaultReportID;
var uid = (location.parameter.uid) ? location.parameter.uid : defaultUserID;
console.log (((location.parameter.rid) ? "Report #" : "Default Report ID #")+rid);
console.log (((location.parameter.uid) ? "User #" : "Default User ID #" )+uid);
google.script.run.withSuccessHandler(paintReport).returnjsON(rid);
google.script.run.withSuccessHandler(getMyReportsList).listMyReports(uid);
});
}
$(function () {
doSomeAsyncShit();
}
解决方法
可以拦截对Google api的请求，并使用Promise直接返回Proxy。
脚本：
/**
* Revives old client facing google api in apps script web applications
* Directly returns promises for `google.scipt.run` and `google.script.url.getLocation`
* @see https://stackoverflow.com/a/63537867/
*/
(function projectAdrenaline_google() {
const lifeline = {
funcList: [],excludeList: [
'withSuccessHandler','withFailureHandler','withUserObject','withLogger',],get: function(target,prop,rec) {
if (this.excludeList.includes(prop))
//return (...rest) => new Proxy(Reflect.apply(target[prop],target,rest),trap);
throw new TypeError(
`${prop}: This method is deprecated in this custom api`
);
if (this.funcList.includes(prop))
return (...rest) =>
new Promise((res,rej) =>
target
.withSuccessHandler(res)
.withFailureHandler(rej)
[prop](...rest)
);
switch (prop) {
case 'run':
this.funcList = Object.keys(target.run);
break;
case 'getLocation':
return () => new Promise(res => target[prop](res));
}
return new Proxy(Reflect.get(target,rec),lifeline);
},};
//const superGoogle = new Proxy(google,trap);
//OR overwrite currently loaded google object:
google = new Proxy(google,lifeline);
})();
示例：
const doSomeAsyncStuff = async () => {
const location = await google.script.url.getLocation();
const rid = location.parameter.rid ? location.parameter.rid : defaultReportID;
const uid = location.parameter.uid ? location.parameter.uid : defaultUserID;
//promise
google.script.run.returnJSON(rid).then(paintReport);
//async-await
const reportsList = await google.script.run.listMyReports(uid);
getMyReportsList(reportsList);
};
或者，可以将功能用作语法糖。但这需要学习新的语法定义：
/**
* Syntactic sugar around old callback api returning a promise
*
* @returns {promise} Promise of call from server
* @param {string[]|string} propertyAccesors Array of properties to access
* @param {object[][]} methodAccesors Array of [method_to_access,arguments[]]
* @param {number[]} resRejIdxs 2 Indexes of methodAccesors corresponding to resolve/success and rejection/failure. If omitted promise is resolved immediately.
*/
const GS = (propertyAccesors,methodAccesors,resRejIdxs) =>
new Promise((res,rej) => {
//Boilerplate for type correction
const nestArray = e => (Array.isArray(e) ? e : [e]);
propertyAccesors = nestArray(propertyAccesors);
methodAccesors = nestArray(methodAccesors);
methodAccesors[0] = nestArray(methodAccesors[0]);
if (typeof resRejIdxs !== 'undefined') {
resRejIdxs = Array.isArray(resRejIdxs) ? resRejIdxs : [resRejIdxs];
resRejIdxs[0] && (methodAccesors[resRejIdxs[0]][1] = res);
resRejIdxs[1] && (methodAccesors[resRejIdxs[1]][1] = rej);
} else {
res('Done');
}
//Access properties and call methods
methodAccesors.reduce(
(acc,[method,methodArg]) =>
Array.isArray(methodArg)
? acc[method](...methodArg)
: acc[method](methodArg),propertyAccesors.reduce(
(acc,currentProp) => acc[currentProp],google.script
)
);
});
//EXAMPLES:
GS(
'run',[
['withSuccessHandler',null],['callServer',[5,4]],//call server function `callServer` with 2 arguments 5 and 4
['withFailureHandler',[0,2] //0 is withSuccessHandler and 2 is withFailureHandler
).then(alert);
GS('history',[['setChangeHandler',e => console.log(e.location.hash)]]);
GS('url','getLocation',0).then(location => console.log(location.hash));
GS(['host','editor'],'focus');
GS('host',['setHeight',50]);,
由于可以使用自定义执行程序函数构造Promise，因此可以将google.script.url包装到其中，并在需要时随时解决或拒绝。如果随后将其设为实用程序功能，请使用await等待其解决。
以下是一个灵活的小型实用程序，用于使google.script.url异步友好：
/**
* @typedef {{
* hash : string,* parameter : Object.<string,string>,* parameters : Object.<string,string[]>
* }} UrlLocationObject
*
* @typedef {{
* callback : function (UrlLocationObject,...any) : any,* params : any[]
* }} AsyncUrlOptions
*
* @summary Promise-friendly google.script.url
* @param {AsyncUrlOptions}
* @returns {Promise}
*/
const asyncLocation = ({
callback,params = [],}) => {
return new Promise((res,rej) => {
google.script.url.getLocation((loc) => {
try {
const result = callback(loc,...params);
res(result);
}
catch(error) {
rej(error);
}
});
});
};
google.script.run也一样：
/**
* @typedef {{
* funcName : string,* onFailure : function,* onSuccess : function,* params : array
* }} AsyncOptions
*
* @summary v2 of async-friendly google.script.run
* @param {AsyncOptions}
* @returns {Promise}
*/
const asyncGAPIv2 = ({
funcName,onFailure = console.error,onSuccess,params = []
}) => {
return new Promise((res,rej) => {
google.script.run
.withSuccessHandler(data => {
typeof onSuccess === "function" && onSuccess(data);
res(data);
})
.withFailureHandler(error => {
typeof onFailure === "function" && onFailure(error);
rej(error);
})
[funcName].apply(null,params);
});
};
这样的事情还不错：
var doSomeAsyncShit = async () => {
let location = await new promise(resolve => google.script.url.getLocation(resolve))
// do stuff with location
}
(async () => {
await doSomeAsyncShit();
// do something after
})()
即使如此，您仍然增加了复杂性，降低了可读性，并且没有很好的重用恕我直言