title: Dart: convert map into query string
body: <p>I have a situation where I need to turn a <code>Map</code> into a query String (after the first <code>?</code>). For instance if I have the following map:</p>
  
  
  
  <pre class="lang-dart prettyprint-override"><code>Map json = {
      "email":  eml,
      "password": passwd
  };
  </code></pre>
  
  <p>And a base URL:</p>
  
  <pre class="lang-dart prettyprint-override"><code>String baseURL = "http://localhost:8080/myapp";
  </code></pre>
  
  <p>Then I need something that converts the json <code>Map</code> into the query string of the base URL:</p>
  
  <pre class="lang-dart prettyprint-override"><code>String fullURL = parameterizeURL(baseURL, json);
  
  // Prints: http://localhost:8080/myapp?email=blah&amp;password=meh
  // (if "blah" was entered as the email, and "meh" was entered as the password)
  print(fullURL);
  </code></pre>
  
  <p>I found <a href="https://github.com/kaisellgren/QueryString" rel="noreferrer">this query String-to-map library</a> on Git, but I need the <strong>inverse</strong> of this! It would be great to get URL encoding in there as well.</p>
  
  <p><strong>I'm happy to make something homegrown but being so new to Dart I was wondering if there's anything on <code>pub</code>/Github/the etherspehere that does this already.</strong></p>