GetHeader and multiple same key

[BenoitB]

I need to retrieve a cookie after a call to a Rest api.

Not a problem i thought, i'll use aqHttpResponse.GetHeader("Set-Cookie");

But how to retrieve the wanted one if multple Set-Cookie are in the response ?

All headers sent back:

Connection: keep-alive
Date: Mon, 16 Mar 2020 15:36:13 GMT
Content-Length: 3235
Content-Type: text/html;charset=UTF-8
Server: nginx
Set-Cookie: rememberMe=deleteMe; Path=/; Max-Age=0; Expires=Sun, 15-Mar-2020 15:36:13 GMT
Set-Cookie: JSESSIONID=E525712AB14D70C27C8C13F4F063A5B3; Path=/; Secure; HttpOnly
X-Robots-Tag: noindex, nofollow
Strict-Transport-Security: max-age=31536000

I want the JSESSIONID

If i use the GetHeader i have ony the  rememberMe.

I know that a solution is aqHttpResponse.AllHeaders and i parse it to find my JSESSIONID but is there any simplier and more elegant solution to achieve that ?

[AlexKaras]

Hi,

>  is there any simplier and more elegant solution to achieve that ?

Nothing exept this is documented, so I think .AllHeaders is the only way to go.

[BenoitB]

Ok, thanks for confirmation.

So i do the needed function, hope it can help others :

/**
 *  Get a specific header value
 *  @author Biache Benoit
 *  @memberof webtools
 *  @function
 *  @param {string} Headers - The data of the http response headers (usually the <i>aqHttpResponse.AllHeaders</i>)
 *  @param {string} Key - The key to look value for
 *  @returns {string} Return empty string if <i>Key</i> not found or the value of <i>Key</i><br>
 *  If no headers nor key are valid an exception is throw.
 */
function extractKeyValueFromHeaders(Headers = "", Key = "") {
  if (Headers == "")
    throw Error("extractKeyValueFromHeaders() - Header is empty");
  if (Key == "")
    throw Error("extractKeyValueFromHeaders() - Key is missing");
  let headerValue = "";
  let pos1        = aqString.Find(Headers, Key, 0, true);
  if (pos1 != -1) {
    let pos2 = aqString.Find(Headers, ";", pos1, true);
    // The ';' could be missing if it's last value
    // In this case (last value) the caller must clean the value of \r and \n that can be returned
    if (pos2 == -1)
      pos2 = Headers.length;
    // Dont forget the '='
    let len     = pos1 + Key.length + 1;  
    headerValue = Headers.substr(len, pos2 - len);
  }  
  return headerValue;
}

[AlexKaras]

Hi,

I did not execute your code but I hope that it works for you.

Nevertheless, my doubts from just skimming your code:

-- Does it work for your case when you are looking for the second instance of Set-Cookie header?

-- The code searches for ';' as a delimiter, so

  -- for Set-Cookie I expect that it will return just ' rememberMe=deleteMe' (note the space at the start) and will lose Path, Max-Age and all other cookie's fields;

  -- For any other header that does not contain ';' in its value, the result will contain extra characters (for example, for the X-Robots-Tag header I expect ' noindex, nofollow\n\rStrict-Transport-Security: max-age=31536000' to be returned).

[BenoitB]

It works very well for my current need (single value) but you get the point !

Need to make a split instead and then loop into the array to find what we need. I'll post a new revision later.

But about cleansing and tailoring of returned data, it's caller responsability because we don't know in advance what the caller need exactly.

[AlexKaras]

Hi,

> about cleansing and tailoring of returned data

If I am correct with the expectation that

' noindex, nofollow\n\rStrict-Transport-Security: max-age=31536000'

will be returned for the X-Robots-Tag header, than this is not a cleansing case, but the case of incorrect return (more than one header is returned).

I would suggest to consider that by definition:

-- headers section of response is delimited by two CRLFs from the response body (if any); and

-- every header ends with one CRLF and consists of a header name, colon, space and header data (up to CRLF).

You may consider aqString.GetListItem() and related methods to iterate through the list of headers and then use .split(': ') to get the value.

(Or consider regular expressions... Though this may be an overkill 🙂 )

Just my suggestion...

[BenoitB · Accepted solution]

So it's bullet-proof working now ...

On same headers, call of extractKeyValueFromHeaders(aqHttpResponse.AllHeaders, "JSESSIONID")

returns

"5119F6E864B904735B8870DA08215BCD"

Call of extractKeyValueFromHeaders(aqHttpResponse.AllHeaders, "JSESSIONID", true)

returns

"JSESSIONID=5119F6E864B904735B8870DA08215BCD; Path=/; Secure; HttpOnly"

The revised code is (algorithm working, optimization possible) :

function extractKeyValueFromHeaders(Headers = "", Key = "", AllValues = false) {
  if (Headers == "")
    throw Error("extractKeyValueFromHeaders() - Header is empty");
  if (Key == "")
    throw Error("extractKeyValueFromHeaders() - Key is missing");
  let headerValue = "";
  Headers = Headers.replace(/\r/g, '');
  let data = Headers.split("\n");
  let pos1, pos2, len;
  for (let i = 0; i < data.length; i++) {
    if (data[i] != "") {
      pos1 = aqString.Find(data[i], ":");
      if (pos1 != -1) {
        pos1 = aqString.Find(data[i], Key, pos1);
        if (pos1 != -1) {
          if (AllValues) {
            pos2 = data[i].length;
            len = pos1;  
          }
          else {
            pos2 = aqString.Find(data[i], ";", pos1);
            if (pos2 == -1)
              pos2 = data[i].length;
            len = pos1 + Key.length + 1;  
          }
          headerValue = data[i].substr(len, pos2 - len);
          break;
        }  
      }
    }
  }
  return headerValue;
}

[AlexKaras]

> extractKeyValueFromHeaders(aqHttpResponse.AllHeaders, "JSESSIONID")

Ah, now I got your logic... OK then 🙂

[BenoitB]

I noticed that u didnt see my need (only value of the key itself) but thanks to u i improved the code to be more generic..

This is good team work 😉

So do u agree on my last proposal ?

[AlexKaras]

> do u agree on my last proposal ?

Yep 🙂