work.suroh.tk/node_modules/connect-history-api-fallback/lib/index.js

121 lines
3.1 KiB
JavaScript

'use strict';
var url = require('url');
exports = module.exports = function historyApiFallback(options) {
options = options || {};
var logger = getLogger(options);
return function(req, res, next) {
var headers = req.headers;
if (req.method !== 'GET') {
logger(
'Not rewriting',
req.method,
req.url,
'because the method is not GET.'
);
return next();
} else if (!headers || typeof headers.accept !== 'string') {
logger(
'Not rewriting',
req.method,
req.url,
'because the client did not send an HTTP accept header.'
);
return next();
} else if (headers.accept.indexOf('application/json') === 0) {
logger(
'Not rewriting',
req.method,
req.url,
'because the client prefers JSON.'
);
return next();
} else if (!acceptsHtml(headers.accept, options)) {
logger(
'Not rewriting',
req.method,
req.url,
'because the client does not accept HTML.'
);
return next();
}
var parsedUrl = url.parse(req.url);
var rewriteTarget;
options.rewrites = options.rewrites || [];
for (var i = 0; i < options.rewrites.length; i++) {
var rewrite = options.rewrites[i];
var match = parsedUrl.pathname.match(rewrite.from);
if (match !== null) {
rewriteTarget = evaluateRewriteRule(parsedUrl, match, rewrite.to, req);
if(rewriteTarget.charAt(0) !== '/') {
logger(
'We recommend using an absolute path for the rewrite target.',
'Received a non-absolute rewrite target',
rewriteTarget,
'for URL',
req.url
);
}
logger('Rewriting', req.method, req.url, 'to', rewriteTarget);
req.url = rewriteTarget;
return next();
}
}
var pathname = parsedUrl.pathname;
if (pathname.lastIndexOf('.') > pathname.lastIndexOf('/') &&
options.disableDotRule !== true) {
logger(
'Not rewriting',
req.method,
req.url,
'because the path includes a dot (.) character.'
);
return next();
}
rewriteTarget = options.index || '/index.html';
logger('Rewriting', req.method, req.url, 'to', rewriteTarget);
req.url = rewriteTarget;
next();
};
};
function evaluateRewriteRule(parsedUrl, match, rule, req) {
if (typeof rule === 'string') {
return rule;
} else if (typeof rule !== 'function') {
throw new Error('Rewrite rule can only be of type string or function.');
}
return rule({
parsedUrl: parsedUrl,
match: match,
request: req
});
}
function acceptsHtml(header, options) {
options.htmlAcceptHeaders = options.htmlAcceptHeaders || ['text/html', '*/*'];
for (var i = 0; i < options.htmlAcceptHeaders.length; i++) {
if (header.indexOf(options.htmlAcceptHeaders[i]) !== -1) {
return true;
}
}
return false;
}
function getLogger(options) {
if (options && options.logger) {
return options.logger;
} else if (options && options.verbose) {
return console.log.bind(console);
}
return function(){};
}