title: Angular interceptor exclude specific urls
body: <p>I am writing interceptors such that I don't have to handle the headers in every service calling my web api. The problem with this is that 99% of my calls require 1 specific set of headers, but the other 1% only require 1 of the headers and will not work with the others present. With this being known my idea is to make 2 interceptors, the first will add the 1 header that they all use and the second will add the rest of the headers, with the second excluding the 1%. </p>
  
  <p>The following is how I am going about excluding the 1%, which works, but I want to see if there is a better way of going about this: </p>
  
  <pre><code>intercept(request: HttpRequest&lt;any&gt;, next:HttpHandler: Observable&lt;HttpEvent&lt;any&gt;&gt; {
    let position = request.url.indexOf('api/');
    if (position &gt; 0){
      let destination: string = request.url.substr(position + 4);
      let matchFound: boolean = false;
  
      for (let address of this.addressesToUse){
        if (new RegExp(address).test(destination)){
          matchFound = true;
          break;
        }
      }
  
      if (!matchFound){
        ...DO WORK to add the headers
      }
    }
  </code></pre>