Question

I’m working on a .NET application (VB 2008) that gets all of its data from a web-based Django application.

I’m using Linq-to-XML and Linq-to-objects in the app.

One API call is giving me XML data in the following format that I am loading into an XDocument.

<django-objects version='1.0'>     <object pk='1' model='app.person'>         <field type='CharField' name='reference_num'>001</field>         <field to='app.office' name='office' rel='ManyToOneRel'>2</field>         <field type='DateField' name='date'>2008-09-03</field>         <field type='CharField' name='surname'></field>         <field type='CharField' name='name'>Sandra</field>         <field type='DateField' name='birthdate'>1988-11-03</field>         <field type='CharField' name='sex'>F</field>         <field type='CharField' name='marital_status'>S</field>         <field type='TextField' name='special_interests'>Biking</field>         <field type='CharField' name='identity_proof'></field>         <field type='CharField' name='identity_proof_number'></field>         <field type='BooleanField' name='is_active'>0</field>         <field type='DateTimeField' name='created'>2008-09-03 12:46:39</field>         <field type='DateTimeField' name='modified'>2008-09-03 12:46:39</field>         <field type='DateField' name='important_date'><None></None></field>         <field type='DateField' name='archive_date'><None></None></field>         <field type='CharField' name='process_status'></field>         <field type='FileField' name='image'></field>         <field to='auth.user' name='self_user' rel='OneToOneRel'>13</field>     </object>     <object pk='2' model='app.person'>     .     <!-- more similar xml //-->     .     </object>     .     .     . </django-objects> 

This is the format, the API call returns several <object> elements like this one. This XML contains <None></None> to represent Null values, for example, towards the bottom in the code block above, in <field type='DateField' name='archive_date'><None></None></field> . The <None></None> tells me that in the database this field has a null value. Other <object> elements in this XDocument may have valid dates or <None></None> . What I would like to do is: for all <object> where <field type='DateField' name='archive_date'> contains <None></None> replace this null representation with 1899-01-01.

How would I go about achieving this?

Thanks.

Answer 1

What about something like this?

XElement djangoElement = XElement.Load(@'c:\django.xml');  IEnumerable<XElement> archiveDateElements = from fieldElement in djangoElement.Elements('object').Elements('field')                                             where fieldElement.Attribute('type') != null &&                                                  fieldElement.Attribute('type').Value == 'DateField' &&                                                 fieldElement.Attribute('name') != null &&                                                 fieldElement.Attribute('name').Value == 'archive_date'                                         select fieldElement;  foreach (var archiveDateElement in archiveDateElements) {     XElement noneElement = archiveDateElement.Element('None');      if (noneElement != null)     {         noneElement.ReplaceWith('1899-01-01');     } } 

P.S. Sorry – just noticed it was VB.NET you were after. But I guess the similarities are such that it may point you in the right direction.