title: How to define link text different in Odoo widget=url
body: <p>I have made read only computed URL-field  based on invoice number. It works nicely but I would like to produce text part  only itself like 400:</p>
  
  <pre><code>&lt;a href="https://external_site_invoice?num=400"&gt;400&lt;/a&gt;
  </code></pre>
  
  <p>Now it's producing whole link as text which is quite ugly</p>
  
  <pre><code>&lt;a href="https://external_site_invoice?num=400"&gt;https://external_site_invoice?num=400&lt;/a&gt;
  </code></pre>
  
  <p>My Odoo fields are defined this way...</p>
  
  <pre><code>ext_invoice_number= fields.Integer(string="Ext number")
  
  def _showlink(self):
      for rec in self:
          if rec.ext_invoice_number:
              if  rec.ext_invoice_number&gt;0:
                  rec.ext_link="https://external site/invoice?num=%d" % (rec.ext_invoice_number,)
  
  
  ext_link = fields.Char(string="Link",compute=_showlink,)
  </code></pre>
  
  <p>How can I define text part of URL in Odoo to be different than link? This is poorly documented or it's not possible?</p>