节点/表达如何在req.header上拆分

Question

I am trying to check if an item exists in a req.headers I have here to decide what to send back to the user. So I have this -

function serveAppData(req, res) {
console.log("CHECKME", req.headers);
//var headerSSo = req.headers).... .split("#canSend")
//if (headerSSo)
var data = require('../static/app-data.json');
res.status(200).json(data);
}

The log works fine - however I am wondering how I can wrap a conditional around this data so I can check if the '#canSend' string is inside that header object and use it as a conditional. Do I have to turn it to json or something first to check it?

I tried flat out doing

  req.headers.split("#canSend");

So doing this gives me "TypeError: Illegal invocation" in the dev console and , "TypeError: undefined is not a function" in the shell.

Which caused some errors so I think I'm missing a step here to do this correctly. My desired result is to check if a string is in the key of 'user-tokens' in side that header object. Maybe I have to approach this different entirely? Would much appreciate any input. Thanks!

Answer 1

req.headers in express is a key-value JavaScript object where key are name of header, and value is value. So to check if item exist, you can use native method:

req.header.hasOwnProperty('#canSend');

If #canSend is value of HTTP Header, than you need to iterate and find it like this:

for( var prop in req.header ) {
    if( req.header.hasOwnProperty( prop ) ) {
         if( req.header[ prop ] === '#canSend' )
             return true;
    }
}