在保留正文的同时,向请求中添加新的标头

时间:2019-02-11 16:11:47

标签: javascript firebase-authentication service-worker progressive-web-apps workbox

我正在为我的公司设置房屋使用PWA。我应该使用哪种方法将承载令牌附加到来自dom或网络工作者的所有请求。

我使用的此方法在发布formjson时可以正常工作,但是我希望使用一种更清洁或更友好的方法,因为我不相信text后备会足够。

我正在Google的workbox.js服务工作程序模块中寻找一个函数,以查看是否可以将拦截器设置为在对服务器发出请求时始终附加Bearer令牌,因为这将解决我最终遇到的问题首先。该代码基于Firebase Service Worker setup。而且没有任何东西可以获取并重新将帖子数据添加到新请求中,从而有效地删除了整个POST正文。

这是我最终得到的代码。

self.addEventListener( 'fetch', ( event ) => {
    const requestProcessor = async ( idToken ) => {

        let req = event.request;

        // For same origin https requests, append idToken to header.
        if ( self.location.origin == getOriginFromUrl( event.request.url ) &&
            ( self.location.protocol == 'https:' ||
                self.location.hostname == 'localhost' ) &&
            idToken ) {


            let contentType = req.headers.get( "Content-Type" );

            // Clone headers as request headers are immutable.
            const headers = new Headers();
            for ( let entry of req.headers.entries() ) {
                headers.append( entry[ 0 ], entry[ 1 ] );
            }
            // Add ID token to header.
            headers.append( 'Authorization', 'Bearer ' + idToken );
            try {

                let tmpReq = req.clone();
                let body = "";

                if ( req.body ) {
                    body = req.body;

                } else if ( req.method === "POST" ) {
                    // get the post data if its json
                    if ( contentType === "application/json" ) {
                        // get JSON data
                        let json = await tmpReq.json();
                        body = JSON.stringify( json );

                    // Get the post data if its a submitted form
                    } else if ( contentType === "application/x-www-form-urlencoded" ) {
                        // get Form-Data
                        body = await tmpReq.formData();

                    // Get the post data as plain text as a fallback
                    } else {
                        body = await tmpReq.text();
                    }

                    console.log( "Content", content );
                }

                // create a new request with the Bearer Token and post body
                req = new Request( req.url, {
                    method: req.method,
                    headers: headers,
                    mode: 'same-origin',
                    credentials: req.credentials,
                    cache: req.cache,
                    redirect: req.redirect,
                    referrer: req.referrer,
                    body: body,
                    bodyUsed: req.bodyUsed,
                    context: req.context
                } );

            } catch ( e ) {
                // This will fail for CORS requests. We just continue with the
                // fetch caching logic below and do not pass the ID token.
            }

        }
        return fetch( req );
    };
    // Fetch the resource after checking for the ID token.
    // This can also be integrated with existing logic to serve cached files
    // in offline mode.
    event.respondWith( getIdToken().then( requestProcessor, requestProcessor ) );
} );

因此,总而言之,我的问题是... 是POST的contentType既不是text()也不是JSON覆盖所有角度或应该覆盖的FormData后备我考虑了一种转移POST正文的新方法

1 个答案:

答案 0 :(得分:1)

如果您要修改Request,保留body但使用新的headers或更新的Request,最简单的方法是将原始请求作为第一个参数传递给{ {1}}类型为RequestInfo的构造函数;它可以是字符串URL,也可以是现有的Request对象。您在第二个参数中输入的RequestInit类型的任何字段都将覆盖原始响应中的字段。

如果您想添加一个附加的标头值,同时保留所有原始请求的标头,则会有些棘手,因为默认情况下,如果仅在headers中提供新值,则会覆盖所有标头原始标题。因此,您需要确保将headers设置为原始标头和新标头的组合。

以下代码说明了这一点:

// This request might be created implicitly by the web app,
// but let's just create it manually as an example:
const originalRequest = new Request('https://example.com', {
  body: 'shared body',
  method: 'POST',
  headers: {
    'x-header': 'my header value'
  },
});

// Start with the original headers as a baseline:
const modifiedHeaders = new Headers(originalRequest.headers);
// Make any changes you want:
modifiedHeaders.set('Authorization', 'Bearer 12345');

// Create a new request based on the original,
// with the modified headers:
const modifiedRequest = new Request(originalRequest, {
  headers: modifiedHeaders,
});

// Everything else in modifiedRequest should be as-is,
// but the headers will be updated.
// Do whatever you want with modifiedRequest at this point.

要注意的一件事是,使用这种方法,当您构造修改后的请求时,原始请求的主体将最终被使用。在您的用例中,这无关紧要,因为只有修改后的请求的body最终会被读取(当您将其传递给fetch()时)。如果由于某种原因您确实需要同时阅读两个body,然后首先在原始请求上调用clone(),例如

const modifiedRequest = new Request(originalRequest.clone(), {...});
// The two requests now have independent bodies.