title: React-admin will not properly add id to show view url
body: <p>I am not able to get my show view to work. I am receiving an error that says:</p>
  
  <blockquote>
    <p>Element not found </p>
  </blockquote>
  
  <p>My data within my mongodb for the _id is a string and not an ObjectID. I don't think that is the issue but there are some dashes that are prepended to the beginning of some of the id's in the database. My show component looks like the following:</p>
  
  <pre><code>import React from "react";
     import {Show, SimpleShowLayout,DateField, TextField,BooleanField,NumberField,TabbedShowLayout,Tab
     } from "react-admin";
     import { GridTab } from "../../../common/components/layout/Grid/GridTab";
     import { ReferenceGridTab } from "../../../common/components/layout/Grid/ReferenceGridTab";
  
     export const JssSessionShow = props =&gt; (
         &lt;Show title="Session View" {...props}&gt;
           &lt;SimpleShowLayout&gt;
             &lt;TextField source="session" /&gt;
             &lt;DateField source="expires" /&gt;
             &lt;TextField source="id" /&gt;
          &lt;/SimpleShowLayout&gt;
     &lt;/Show&gt;
   );
  </code></pre>
  
  <p>I don't know how to get my id to be correctly added to the url for my show view. Please someone help me with this. </p>