80 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
			
		
		
	
	
			80 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
var _ = require('lodash')
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var logger = require('./logger').getInstance()
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var ERRORS = require('./errors')
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module.exports = {
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  create: createPathRewriter
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}
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/**
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 * Create rewrite function, to cache parsed rewrite rules.
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 *
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 * @param {Object} rewriteConfig
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 * @return {Function} Function to rewrite paths; This function should accept `path` (request.url) as parameter
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 */
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function createPathRewriter(rewriteConfig) {
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  var rulesCache
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  if (!isValidRewriteConfig(rewriteConfig)) {
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    return
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  }
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  if (_.isFunction(rewriteConfig)) {
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    var customRewriteFn = rewriteConfig
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    return customRewriteFn
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  } else {
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    rulesCache = parsePathRewriteRules(rewriteConfig)
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    return rewritePath
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  }
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  function rewritePath(path) {
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    var result = path
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    _.forEach(rulesCache, function(rule) {
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      if (rule.regex.test(path)) {
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        result = result.replace(rule.regex, rule.value)
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        logger.debug('[HPM] Rewriting path from "%s" to "%s"', path, result)
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        return false
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      }
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    })
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    return result
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  }
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}
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function isValidRewriteConfig(rewriteConfig) {
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  if (_.isFunction(rewriteConfig)) {
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    return true
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  } else if (!_.isEmpty(rewriteConfig) && _.isPlainObject(rewriteConfig)) {
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    return true
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  } else if (
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    _.isUndefined(rewriteConfig) ||
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    _.isNull(rewriteConfig) ||
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    _.isEqual(rewriteConfig, {})
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  ) {
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    return false
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  } else {
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    throw new Error(ERRORS.ERR_PATH_REWRITER_CONFIG)
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  }
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}
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function parsePathRewriteRules(rewriteConfig) {
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  var rules = []
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  if (_.isPlainObject(rewriteConfig)) {
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    _.forIn(rewriteConfig, function(value, key) {
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      rules.push({
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        regex: new RegExp(key),
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        value: rewriteConfig[key]
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      })
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      logger.info(
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        '[HPM] Proxy rewrite rule created: "%s" ~> "%s"',
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        key,
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        rewriteConfig[key]
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      )
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    })
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  }
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  return rules
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}
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