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@tecmaverick
Created April 11, 2018 08:57
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## convert HTML POST data or HTTP GET query string to JSON
## get the raw post data from the AWS built-in variable and give it a nicer name
#if ($context.httpMethod == "POST")
#set($rawAPIData = $input.path("$"))
#elseif ($context.httpMethod == "GET")
#set($rawAPIData = $input.params().querystring)
#set($rawAPIData = $rawAPIData.toString())
#set($rawAPIDataLength = $rawAPIData.length() - 1)
#set($rawAPIData = $rawAPIData.substring(1, $rawAPIDataLength))
#set($rawAPIData = $rawAPIData.replace(", ", "&"))
#else
#set($rawAPIData = "")
#end
## first we get the number of "&" in the string, this tells us if there is more than one key value pair
#set($countAmpersands = $rawAPIData.length() - $rawAPIData.replace("&", "").length())
## if there are no "&" at all then we have only one key value pair.
## we append an ampersand to the string so that we can tokenise it the same way as multiple kv pairs.
## the "empty" kv pair to the right of the ampersand will be ignored anyway.
#if ($countAmpersands == 0)
#set($rawPostData = $rawAPIData + "&")
#end
## now we tokenise using the ampersand(s)
#set($tokenisedAmpersand = $rawAPIData.split("&"))
## we set up a variable to hold the valid key value pairs
#set($tokenisedEquals = [])
## now we set up a loop to find the valid key value pairs, which must contain only one "="
#foreach( $kvPair in $tokenisedAmpersand )
#set($countEquals = $kvPair.length() - $kvPair.replace("=", "").length())
#if ($countEquals == 1)
#set($kvTokenised = $kvPair.split("="))
#if ($kvTokenised[0].length() > 0)
## we found a valid key value pair. add it to the list.
#set($devNull = $tokenisedEquals.add($kvPair))
#end
#end
#end
## next we set up our loop inside the output structure "{" and "}"
{
#foreach( $kvPair in $tokenisedEquals )
## finally we output the JSON for this pair and append a comma if this isn't the last pair
#set($kvTokenised = $kvPair.split("="))
##define vars for JSON keyname and keyvalue
#set($keyName = "$util.urlDecode($kvTokenised[0])")
#set($keyValue = "")
#set($idxPosition = $kvPair.indexOf("="))
#set($strLen = $kvPair.length())
#set($strLen = $strLen - 1)
##check value exists for the key
#if($idxPosition != $strLen)
#set($ValExists = true)
#else
#set($ValExists = false)
#end
#if($ValExists && $kvTokenised[1].length() > 0)
#set($keyValue = "$util.urlDecode($kvTokenised[1])")
#end
#if($keyName.toUpperCase() == "DATA")
#set($keyValue = "$util.base64Encode($kvTokenised[1])")
#end
"$keyName" : "$keyValue" #if( $foreach.hasNext ),#end
#end
##Append the StreamName
,"StreamName": "$input.params('stream-name')"
}
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