45 lines
1.4 KiB
JavaScript
45 lines
1.4 KiB
JavaScript
'use strict';
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module.exports = function setLastModifiedHeader () {
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return function setLastModifiedHeaderMiddleware (req, res, next) {
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if (req.method !== 'GET') {
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return next();
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}
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const { mapConfigProvider, cache_buster: cacheBuster, logger } = res.locals;
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if (cacheBuster) {
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const cacheBusterTimestamp = parseInt(cacheBuster, 10);
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const lastModifiedDate = Number.isFinite(cacheBusterTimestamp) && cacheBusterTimestamp !== 0
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? new Date(cacheBusterTimestamp)
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: new Date();
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res.set('Last-Modified', lastModifiedDate.toUTCString());
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return next();
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}
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mapConfigProvider.getAffectedTables((err, affectedTables) => {
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if (err) {
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logger.warn(err, 'ERROR generating Last Modified Header');
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return next();
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}
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if (!affectedTables) {
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res.set('Last-Modified', new Date().toUTCString());
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return next();
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}
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const lastUpdatedAt = affectedTables.getLastUpdatedAt();
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const lastModifiedDate = Number.isFinite(lastUpdatedAt) ? new Date(lastUpdatedAt) : new Date();
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res.set('Last-Modified', lastModifiedDate.toUTCString());
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res.locals.cache_buster = lastUpdatedAt;
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next();
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});
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};
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};
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