Mailspring/docs/DatabaseView.html

---
layout: docs
title: DatabaseView
edit_url: "https://github.com/nylas/N1/blob/master/src/flux/stores/database-view.coffee"
---

<h2>Summary</h2>

<div class="markdown-from-sourecode">
  <p><p>DatabaseView abstracts away the process of paginating a query
and loading ranges of data. It&#39;s very smart about deciding when
results need to be refreshed. There are a few core concepts that
make it flexible:</p>
<p>metadataProvider: For each item loaded, you can provide a promise
that resolves with additional data for that item. The DatabaseView
will not consider the page of data &quot;loaded&quot; until all the metadata
promises have resolved.  (Used for message metadata on threads)</p>
<p>retainedRange: The retained range ({start, end}) represents the
objects currently being displayed. React components displaying the
view can alter the retained range as the user scrolls.</p>
<p>Note: Do not make the retainedRange larger than you need. The
DatabaseView may internally keep a larger set of items loaded
for performance.</p>
</p>
</div>

<ul>
</ul>





    <h3>Instance Methods</h3>

    <h4 id=invalidate class="function-name">
      invalidate(<span class="args"><span class="arg">options</span></span>) <a href="#invalidate" class="link"></a>
    </h4>

    <div class="function-description markdown-from-sourecode">
      <p><p>Call this method when the DatabaseStore triggers and will impact the
    data maintained by this DatabaseView. In the future, the DatabaseView will
    probably observe the DatabaseView directly.</p>
    <p>TODO: In order for the DatabaseView to monitor the DatabaseStore directly,
    it needs to have some way of detatching it&#39;s listener when it&#39;s no longer needed!
    Need a destructor...</p>
    </p>
    </div>

        <strong>Parameters</strong>
        <table class="arguments">
            <tr>
              <th>Argument</th>
              <th>Description</th>
            </tr>
            <tr>
              <td style="width:15%;">
                <em>options</em>
              </td>
              <td class="markdown-from-sourecode">

                <p>an Object with the following optional keys which can be used to optimize the behavior of the DatabaseView:</p>

              </td>
            </tr>
        </table>