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1 change: 1 addition & 0 deletions CHANGELOG.md
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Expand Up @@ -19,6 +19,7 @@ Special thanks to: @rejas, @sdetweil, @MagMar94
- Added css class names "today" and "tomorrow" for default calendar
- Added Collaboration.md
- Added new github action for dependency review (#2862)
- Added Yr as a weather provider
- Added config options "ignoreXOriginHeader" and "ignoreContentSecurityPolicy"

### Removed
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147 changes: 147 additions & 0 deletions modules/default/utils.js
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/**
* A function to make HTTP requests via the server to avoid CORS-errors.
*
* @param {string} url the url to fetch from
* @param {string} type what contenttype to expect in the response, can be "json" or "xml"
* @param {boolean} useCorsProxy A flag to indicate
* @param {Array.<{name: string, value:string}>} requestHeaders the HTTP headers to send
* @param {Array.<string>} expectedResponseHeaders the expected HTTP headers to recieve
* @returns {Promise} resolved when the fetch is done. The response headers is placed in a headers-property (provided the response does not allready contain a headers-property).
*/
async function performWebRequest(url, type = "json", useCorsProxy = false, requestHeaders = undefined, expectedResponseHeaders = undefined) {
const request = {};
if (useCorsProxy) {
url = getCorsUrl(url, requestHeaders, expectedResponseHeaders);
} else {
request.headers = getHeadersToSend(requestHeaders);
}
const response = await fetch(url, request);
const data = await response.text();

if (type === "xml") {
return new DOMParser().parseFromString(data, "text/html");
} else {
if (!data || !data.length > 0) return undefined;

const dataResponse = JSON.parse(data);
if (!dataResponse.headers) {
dataResponse.headers = getHeadersFromResponse(expectedResponseHeaders, response);
}
return dataResponse;
}
}

/**
* Gets a URL that will be used when calling the CORS-method on the server.
*
* @param {string} url the url to fetch from
* @param {Array.<{name: string, value:string}>} requestHeaders the HTTP headers to send
* @param {Array.<string>} expectedResponseHeaders the expected HTTP headers to recieve
* @returns {string} to be used as URL when calling CORS-method on server.
*/
const getCorsUrl = function (url, requestHeaders, expectedResponseHeaders) {
if (!url || url.length < 1) {
throw new Error(`Invalid URL: ${url}`);
} else {
let corsUrl = `${location.protocol}//${location.host}/cors?`;

const requestHeaderString = getRequestHeaderString(requestHeaders);
if (requestHeaderString) corsUrl = `${corsUrl}sendheaders=${requestHeaderString}`;

const expectedResponseHeadersString = getExpectedResponseHeadersString(expectedResponseHeaders);
if (requestHeaderString && expectedResponseHeadersString) {
corsUrl = `${corsUrl}&expectedheaders=${expectedResponseHeadersString}`;
} else if (expectedResponseHeadersString) {
corsUrl = `${corsUrl}expectedheaders=${expectedResponseHeadersString}`;
}

if (requestHeaderString || expectedResponseHeadersString) {
return `${corsUrl}&url=${url}`;
}
return `${corsUrl}url=${url}`;
}
};

/**
* Gets the part of the CORS URL that represents the HTTP headers to send.
*
* @param {Array.<{name: string, value:string}>} requestHeaders the HTTP headers to send
* @returns {string} to be used as request-headers component in CORS URL.
*/
const getRequestHeaderString = function (requestHeaders) {
let requestHeaderString = "";
if (requestHeaders) {
for (const header of requestHeaders) {
if (requestHeaderString.length === 0) {
requestHeaderString = `${header.name}:${encodeURIComponent(header.value)}`;
} else {
requestHeaderString = `${requestHeaderString},${header.name}:${encodeURIComponent(header.value)}`;
}
}
return requestHeaderString;
}
return undefined;
};

/**
* Gets headers and values to attatch to the web request.
*
* @param {Array.<{name: string, value:string}>} requestHeaders the HTTP headers to send
* @returns {object} An object specifying name and value of the headers.
*/
const getHeadersToSend = (requestHeaders) => {
const headersToSend = {};
if (requestHeaders) {
for (const header of requestHeaders) {
headersToSend[header.name] = header.value;
}
}

return headersToSend;
};

/**
* Gets the part of the CORS URL that represents the expected HTTP headers to recieve.
*
* @param {Array.<string>} expectedResponseHeaders the expected HTTP headers to recieve
* @returns {string} to be used as the expected HTTP-headers component in CORS URL.
*/
const getExpectedResponseHeadersString = function (expectedResponseHeaders) {
let expectedResponseHeadersString = "";
if (expectedResponseHeaders) {
for (const header of expectedResponseHeaders) {
if (expectedResponseHeadersString.length === 0) {
expectedResponseHeadersString = `${header}`;
} else {
expectedResponseHeadersString = `${expectedResponseHeadersString},${header}`;
}
}
return expectedResponseHeaders;
}
return undefined;
};

/**
* Gets the values for the expected headers from the response.
*
* @param {Array.<string>} expectedResponseHeaders the expected HTTP headers to recieve
* @param {Response} response the HTTP response
* @returns {string} to be used as the expected HTTP-headers component in CORS URL.
*/
const getHeadersFromResponse = (expectedResponseHeaders, response) => {
const responseHeaders = [];

if (expectedResponseHeaders) {
for (const header of expectedResponseHeaders) {
const headerValue = response.headers.get(header);
responseHeaders.push({ name: header, value: headerValue });
}
}

return responseHeaders;
};

if (typeof module !== "undefined")
module.exports = {
performWebRequest
};
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