title: how to add parameter in gql query
body: <p>I would like to add parameter in gql query :</p>
  
  <pre><code> onSubmit() {
      console.log(this.contact);
  
      let SendEmailQuery = gql`
      { 
        sendemail(contactorFirstname:"",
                  contactorLastname:"",
                  contactorEmail:"",
                  contacteeFirstname:"firstname",
                  contacteeLastname:"",
                  contacteeEmail:"") 
  
      }
      `;
  
      this.apollo.watchQuery({ query: SendEmailQuery 
  }).valueChanges.subscribe(({data, loading}) =&gt; {
  
        this.data = data;
        this.loading = loading;
      });
  </code></pre>
  
  <p>rather to add "firstname" hardcoded, I would like to pass a parameter ? anyone have an idea how to do it ?</p>
  
  <p>thank you for your feedback,</p>
  
  <p>best regards,</p>
  
  <p>Nicolas Maujean</p>