包装 javascript fetch 以添加自定义功能
Wrap javascript fetch to add custom functionality
我想知道是否可以这样做，因为我不确定是我错了还是不可能。基本上，我想做的是为原生 fetch javascript 函数创建一个包装函数。这个包装函数将实现令牌验证过程，如果给定的过期则请求一个新的 accessToken 并再次请求所需的资源。这是我到目前为止所达到的：
customFetch.js
// 'url' and 'options' parameters are used strictely as you would use them in fetch. 'authOptions' are used to configure the call to refresh the access token
window.customFetch = (url, options, authOptions) => {
const OPTIONS = {
url: '',
unauthorizedRedirect: '',
storage: window.sessionStorage,
tokenName: 'accessToken'
}
// Merge options passed by user with the default auth options
let opts = Object.assign({}, OPTIONS, authOptions);
// Try to update 'authorizarion's header in order to send always the proper one to the server
options.headers = options.headers || {};
options.headers['Authorization'] = `Bearer ${opts.storage.getItem(opts.tokenName)}`;
// Actual server request that user wants to do.
const request = window.fetch(url, options)
.then((d) => {
if (d.status === 401) {
// Unauthorized
console.log('not authorized');
return refreshAccesToken();
}
else {
return d.json();
}
});
// Auxiliar server call to get refresh the access token if it is expired. Here also check if the
// cookie has expired and if it has expired, then we should redirect to other page to login again in
// the application.
const refreshAccesToken = () => {
window.fetch(opts.url, {
method: 'get',
credentials: 'include'
}).then((d) => {
// For this example, we can omit this, we can suppose we always receive the access token
if (d.status === 401) {
// Unauthorized and the cookie used to validate and refresh the access token has expired. So we want to login in to the app again
window.location.href = opts.unauthorizedRedirect;
}
return d.json();
}).then((json) => {
const jwt = json.token;
if (jwt) {
// Store in the browser's storage (sessionStorage by default) the refreshed token, in order to use it on every request
opts.storage.setItem(opts.tokenName, jwt);
console.log('new acces token: ' + jwt);
// Re-send the original request when we have received the refreshed access token.
return window.customFetch(url, options, authOptions);
}
else {
console.log('no token has been sent');
return null;
}
});
}
return request;
}
consumer.js
const getResourcePrivate = () => {
const url = MAIN_URL + '/resource';
customFetch(url, {
method: 'get'
},{
url: AUTH_SERVER_TOKEN,
unauthorizedRedirect: AUTH_URI,
tokenName: TOKEN_NAME
}).then((json) => {
const resource = json ? json.resource : null;
if (resource) {
console.log(resource);
}
else {
console.log('No resource has been provided.');
}
});
}
我会尝试更好地解释上面的代码：我想让用户对令牌验证透明，以便让他们只担心请求他们想要的资源。当 accessToken 仍然有效时，这种方法工作正常，因为 return request 指令向消费者提供 fetch 请求的承诺。
当然，当 accessToken 过期并且我们向 auth 服务器请求一个新的时，这是行不通的。刷新令牌并请求私有资源，但 consumer.js 看不到它。
对于最后一个场景，是否可以修改程序流程，以便刷新accessToken并执行服务器调用以再次获取私有资源？消费者不应该意识到这个过程；在这两种情况下（accessToken 有效并且 accessToken 已过期并已刷新）consumer.js 应该在其 then 函数中获得私有请求的资源。
好吧，我终于找到了解决方案。我尝试使用 Promise 来解决它并且它有效。这是 customFetch.js 文件的方法：
window.customFetch = (url, options, authOptions) => {
const OPTIONS = {
url: '',
unauthorizedRedirect: '',
storage: window.sessionStorage,
tokenName: 'accessToken'
}
// Merge options passed by user with the default auth options
let opts = Object.assign({}, OPTIONS, authOptions);
const requestResource = (resolve) => {
// Try to update 'authorizarion's header in order to send always the proper one to the server
options.headers = options.headers || {};
options.headers['Authorization'] = `Bearer ${opts.storage.getItem(opts.tokenName)}`;
window.fetch(url, options)
.then((d) => {
if (d.status === 401) {
// Unauthorized
console.log('not authorized');
return refreshAccesToken(resolve);
}
else {
resolve(d.json());
}
});
}
// Auxiliar server call to get refresh the access token if it is expired. Here also check if the
// cookie has expired and if it has expired, then we should redirect to other page to login again in
// the application.
const refreshAccesToken = (resolve) => {
window.fetch(opts.url, {
method: 'get',
credentials: 'include'
}).then((d) => {
if (d.status === 401) {
// Unauthorized
window.location.href = opts.unauthorizedRedirect;
}
return d.json();
}).then((json) => {
const jwt = json.token;
if (jwt) {
// Store in the browser's storage (sessionStorage by default) the refreshed token, in order to use it on every request
opts.storage.setItem(opts.tokenName, jwt);
console.log('new acces token: ' + jwt);
// Re-send the original request when we have received the refreshed access token.
requestResource(resolve);
}
else {
console.log('no token has been sent');
return null;
}
});
}
let promise = new Promise((resolve, reject) => {
requestResource(resolve);
});
return promise;
}
基本上，我创建了一个 Promise 并在其中调用了调用服务器以获取资源的函数。我对 request（现在称为 requestResource）和 refreshAccessToken 进行了一些修改，以使它们成为参数化函数。我已经将 resolve 函数传递给他们，以便在我收到新令牌后 "resolve" 任何函数。
可能解决方案可以改进和优化，但作为第一种方法，它按我预期的方式工作，所以我认为这是一个有效的解决方案。
编辑：正如@Dennis 向我建议的那样，我在最初的方法中犯了一个错误。我只需要 return refreshAccessToken 函数中的承诺，它就可以正常工作。这是 customFetch.js 文件的外观（这与我第一次发布的代码更相似。事实上，我只是在函数中添加了一条 return 指令，尽管删除了开始和结束括号也可以）：
// 'url' and 'options' parameters are used strictely as you would use them in fetch. 'authOptions' are used to configure the call to refresh the access token
window.customFetch = (url, options, authOptions) => {
const OPTIONS = {
url: '',
unauthorizedRedirect: '',
storage: window.sessionStorage,
tokenName: 'accessToken'
}
// Merge options passed by user with the default auth options
let opts = Object.assign({}, OPTIONS, authOptions);
// Try to update 'authorizarion's header in order to send always the proper one to the server
options.headers = options.headers || {};
options.headers['Authorization'] = `Bearer ${opts.storage.getItem(opts.tokenName)}`;
// Actual server request that user wants to do.
const request = window.fetch(url, options)
.then((d) => {
if (d.status === 401) {
// Unauthorized
console.log('not authorized');
return refreshAccesToken();
}
else {
return d.json();
}
});
// Auxiliar server call to get refresh the access token if it is expired. Here also check if the
// cookie has expired and if it has expired, then we should redirect to other page to login again in
// the application.
const refreshAccesToken = () => {
return window.fetch(opts.url, {
method: 'get',
credentials: 'include'
}).then((d) => {
// For this example, we can omit this, we can suppose we always receive the access token
if (d.status === 401) {
// Unauthorized and the cookie used to validate and refresh the access token has expired. So we want to login in to the app again
window.location.href = opts.unauthorizedRedirect;
}
return d.json();
}).then((json) => {
const jwt = json.token;
if (jwt) {
// Store in the browser's storage (sessionStorage by default) the refreshed token, in order to use it on every request
opts.storage.setItem(opts.tokenName, jwt);
console.log('new acces token: ' + jwt);
// Re-send the original request when we have received the refreshed access token.
return window.customFetch(url, options, authOptions);
}
else {
console.log('no token has been sent');
return null;
}
});
}
return request;
}
我想知道是否可以这样做，因为我不确定是我错了还是不可能。基本上，我想做的是为原生 fetch javascript 函数创建一个包装函数。这个包装函数将实现令牌验证过程，如果给定的过期则请求一个新的 accessToken 并再次请求所需的资源。这是我到目前为止所达到的：
customFetch.js
// 'url' and 'options' parameters are used strictely as you would use them in fetch. 'authOptions' are used to configure the call to refresh the access token
window.customFetch = (url, options, authOptions) => {
const OPTIONS = {
url: '',
unauthorizedRedirect: '',
storage: window.sessionStorage,
tokenName: 'accessToken'
}
// Merge options passed by user with the default auth options
let opts = Object.assign({}, OPTIONS, authOptions);
// Try to update 'authorizarion's header in order to send always the proper one to the server
options.headers = options.headers || {};
options.headers['Authorization'] = `Bearer ${opts.storage.getItem(opts.tokenName)}`;
// Actual server request that user wants to do.
const request = window.fetch(url, options)
.then((d) => {
if (d.status === 401) {
// Unauthorized
console.log('not authorized');
return refreshAccesToken();
}
else {
return d.json();
}
});
// Auxiliar server call to get refresh the access token if it is expired. Here also check if the
// cookie has expired and if it has expired, then we should redirect to other page to login again in
// the application.
const refreshAccesToken = () => {
window.fetch(opts.url, {
method: 'get',
credentials: 'include'
}).then((d) => {
// For this example, we can omit this, we can suppose we always receive the access token
if (d.status === 401) {
// Unauthorized and the cookie used to validate and refresh the access token has expired. So we want to login in to the app again
window.location.href = opts.unauthorizedRedirect;
}
return d.json();
}).then((json) => {
const jwt = json.token;
if (jwt) {
// Store in the browser's storage (sessionStorage by default) the refreshed token, in order to use it on every request
opts.storage.setItem(opts.tokenName, jwt);
console.log('new acces token: ' + jwt);
// Re-send the original request when we have received the refreshed access token.
return window.customFetch(url, options, authOptions);
}
else {
console.log('no token has been sent');
return null;
}
});
}
return request;
}
consumer.js
const getResourcePrivate = () => {
const url = MAIN_URL + '/resource';
customFetch(url, {
method: 'get'
},{
url: AUTH_SERVER_TOKEN,
unauthorizedRedirect: AUTH_URI,
tokenName: TOKEN_NAME
}).then((json) => {
const resource = json ? json.resource : null;
if (resource) {
console.log(resource);
}
else {
console.log('No resource has been provided.');
}
});
}
我会尝试更好地解释上面的代码：我想让用户对令牌验证透明，以便让他们只担心请求他们想要的资源。当 accessToken 仍然有效时，这种方法工作正常，因为 return request 指令向消费者提供 fetch 请求的承诺。
当然，当 accessToken 过期并且我们向 auth 服务器请求一个新的时，这是行不通的。刷新令牌并请求私有资源，但 consumer.js 看不到它。
对于最后一个场景，是否可以修改程序流程，以便刷新accessToken并执行服务器调用以再次获取私有资源？消费者不应该意识到这个过程；在这两种情况下（accessToken 有效并且 accessToken 已过期并已刷新）consumer.js 应该在其 then 函数中获得私有请求的资源。
好吧，我终于找到了解决方案。我尝试使用 Promise 来解决它并且它有效。这是 customFetch.js 文件的方法：
window.customFetch = (url, options, authOptions) => {
const OPTIONS = {
url: '',
unauthorizedRedirect: '',
storage: window.sessionStorage,
tokenName: 'accessToken'
}
// Merge options passed by user with the default auth options
let opts = Object.assign({}, OPTIONS, authOptions);
const requestResource = (resolve) => {
// Try to update 'authorizarion's header in order to send always the proper one to the server
options.headers = options.headers || {};
options.headers['Authorization'] = `Bearer ${opts.storage.getItem(opts.tokenName)}`;
window.fetch(url, options)
.then((d) => {
if (d.status === 401) {
// Unauthorized
console.log('not authorized');
return refreshAccesToken(resolve);
}
else {
resolve(d.json());
}
});
}
// Auxiliar server call to get refresh the access token if it is expired. Here also check if the
// cookie has expired and if it has expired, then we should redirect to other page to login again in
// the application.
const refreshAccesToken = (resolve) => {
window.fetch(opts.url, {
method: 'get',
credentials: 'include'
}).then((d) => {
if (d.status === 401) {
// Unauthorized
window.location.href = opts.unauthorizedRedirect;
}
return d.json();
}).then((json) => {
const jwt = json.token;
if (jwt) {
// Store in the browser's storage (sessionStorage by default) the refreshed token, in order to use it on every request
opts.storage.setItem(opts.tokenName, jwt);
console.log('new acces token: ' + jwt);
// Re-send the original request when we have received the refreshed access token.
requestResource(resolve);
}
else {
console.log('no token has been sent');
return null;
}
});
}
let promise = new Promise((resolve, reject) => {
requestResource(resolve);
});
return promise;
}
基本上，我创建了一个 Promise 并在其中调用了调用服务器以获取资源的函数。我对 request（现在称为 requestResource）和 refreshAccessToken 进行了一些修改，以使它们成为参数化函数。我已经将 resolve 函数传递给他们，以便在我收到新令牌后 "resolve" 任何函数。
可能解决方案可以改进和优化，但作为第一种方法，它按我预期的方式工作，所以我认为这是一个有效的解决方案。
编辑：正如@Dennis 向我建议的那样，我在最初的方法中犯了一个错误。我只需要 return refreshAccessToken 函数中的承诺，它就可以正常工作。这是 customFetch.js 文件的外观（这与我第一次发布的代码更相似。事实上，我只是在函数中添加了一条 return 指令，尽管删除了开始和结束括号也可以）：
// 'url' and 'options' parameters are used strictely as you would use them in fetch. 'authOptions' are used to configure the call to refresh the access token
window.customFetch = (url, options, authOptions) => {
const OPTIONS = {
url: '',
unauthorizedRedirect: '',
storage: window.sessionStorage,
tokenName: 'accessToken'
}
// Merge options passed by user with the default auth options
let opts = Object.assign({}, OPTIONS, authOptions);
// Try to update 'authorizarion's header in order to send always the proper one to the server
options.headers = options.headers || {};
options.headers['Authorization'] = `Bearer ${opts.storage.getItem(opts.tokenName)}`;
// Actual server request that user wants to do.
const request = window.fetch(url, options)
.then((d) => {
if (d.status === 401) {
// Unauthorized
console.log('not authorized');
return refreshAccesToken();
}
else {
return d.json();
}
});
// Auxiliar server call to get refresh the access token if it is expired. Here also check if the
// cookie has expired and if it has expired, then we should redirect to other page to login again in
// the application.
const refreshAccesToken = () => {
return window.fetch(opts.url, {
method: 'get',
credentials: 'include'
}).then((d) => {
// For this example, we can omit this, we can suppose we always receive the access token
if (d.status === 401) {
// Unauthorized and the cookie used to validate and refresh the access token has expired. So we want to login in to the app again
window.location.href = opts.unauthorizedRedirect;
}
return d.json();
}).then((json) => {
const jwt = json.token;
if (jwt) {
// Store in the browser's storage (sessionStorage by default) the refreshed token, in order to use it on every request
opts.storage.setItem(opts.tokenName, jwt);
console.log('new acces token: ' + jwt);
// Re-send the original request when we have received the refreshed access token.
return window.customFetch(url, options, authOptions);
}
else {
console.log('no token has been sent');
return null;
}
});
}
return request;
}