Book Image

Python Geospatial Development - Third Edition

By : Erik Westra
Book Image

Python Geospatial Development - Third Edition

By: Erik Westra

Overview of this book

Geospatial development links your data to locations on the surface of the Earth. Writing geospatial programs involves tasks such as grouping data by location, storing and analyzing large amounts of spatial information, performing complex geospatial calculations, and drawing colorful interactive maps. In order to do this well, you’ll need appropriate tools and techniques, as well as a thorough understanding of geospatial concepts such as map projections, datums, and coordinate systems. This book provides an overview of the major geospatial concepts, data sources, and toolkits. It starts by showing you how to store and access spatial data using Python, how to perform a range of spatial calculations, and how to store spatial data in a database. Further on, the book teaches you how to build your own slippy map interface within a web application, and finishes with the detailed construction of a geospatial data editor using the GeoDjango framework. By the end of this book, you will be able to confidently use Python to write your own geospatial applications ranging from quick, one-off utilities to sophisticated web-based applications using maps and other geospatial data.
Table of Contents (20 chapters)
Python Geospatial Development Third Edition
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

Deleting features


We next want to let the user delete an existing feature. To do this, we'll add a Delete Feature button to the "Edit Feature" view. Clicking on this button will redirect the user to the "Delete Feature" view for that feature.

Edit the edit_feature.html template, and add the following highlighted lines to the <form> section of the template:

  <form method="POST" action="">
    <table>
      <tr>
        <td></td>
        <td align="right">
          <input type="submit" name="delete"
                 value="Delete Feature"/>
        </td>
      </tr>
      {{ form.as_table }}
      ...

Notice that we've used <input type="submit"> for this button. This will submit the form with an extra POST parameter named delete. Now, go back to the shapefiles.views module and add the following to the top of the edit_feature() function:

  if request.method == "POST" and "delete" in request.POST:
    return HttpResponseRedirect...