Read XML file with LINQ and create object with IEnumerable propety

Question

Here is my problem:

I have this XML file:

<?xml version="1.0" encoding="utf-8" ?>
<settings>
  <app name="Application1">
    <log name="Log1" path="d:\paths\" filename="Log1File"/>
    <log name="Log2" path="d:\paths\"/>
    <log name="log3" path="d:\paths\" filename="Log3File"/>
  </app>
</settings>

And I'm trying to read it with LINQ and create object of this class:

  public class Apps
  {
    public string Name { get; set; }
    public IEnumerable<Logs> Logs { get; set; }
  }

  public class Logs
  {
    public string Name { get; set; }
    public string Path { get; set; }
    public string Filename { get; set; }
  }

So far I managed to create this bit of code however looks like it only gets first log element mean time I need all log elements for each app element:

   public static IEnumerable<Apps> GetAllApps()
    {
      var items = from a in db.Descendants("app")
                  orderby a.Attribute("name").Value
                  select new Apps
                  {
                    Name = a.Attribute("name").Value,
                    Logs = from b in a.Descendants("log")
                           select new Logs 
                           { 
                            Name = b.Attribute("name").Value,
                            Path = b.Attribute("path").Value,
                            Filename = b.Attribute("filename").Value
                           }
                  };

      return items;
    }

L.B · Accepted Answer · 2012-06-05 12:49:00Z

3

I would use serialization here

XmlSerializer ser = new XmlSerializer(typeof(Settings));
var result = (Settings)ser.Deserialize(stream);

[XmlRoot("settings")]
public class Settings
{
    [XmlElement("app")]
    public Apps[] apps;
}


public class Apps
{
    [XmlAttribute("name")]
    public string Name { get; set; }
    [XmlElement("log")]
    public Logs[] Logs { get; set; }
}

public class Logs
{
    [XmlAttribute("name")]
    public string Name { get; set; }
    [XmlAttribute("path")]
    public string Path { get; set; }
    [XmlAttribute("filename")]
    public string Filename { get; set; }
}

answered Jun 5, 2012 at 12:49

L.B

116k20 gold badges189 silver badges229 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

mbx Over a year ago

This is usually the better solution. If you have a stable/proper xml schema, you can even generate your boilerplate code with xsd.exe. As it generates partial classes by default, you can have them implement you domain interfaces and thus further reduce the dependencies from the actual xml code.

Raphaël Althaus · Accepted Answer · 2012-06-05 13:02:58Z

I used fluent API, but let you adapt as you prefer...

Problem is a NullReferenceException, as one of your Logs in xml has no "filename" attribute. And when you use "Value" on a null, you get a NRE.

So, check if the Attribute exists before trying to get it's value.

var it = db.Descendants("app")
                    .OrderBy(app => app.Attribute("name").Value)
                    .Select(app => new Apps() {
                        Name = app.Attribute("name").Value,
                        Logs = app.Descendants("log").Select(a =>
                            new Logs() {
                                Name = a.Attribute("name") != null ? a.Attribute("name").Value : null,
                                Path = a.Attribute("path") != null ? a.Attribute("path").Value : null,
                                Filename = a.Attribute("filename") != null ? a.Attribute("filename").Value : null
                            }).ToList()
                    }).ToList();

Collectives™ on Stack Overflow

Read XML file with LINQ and create object with IEnumerable propety

2 Answers 2

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related