score:0

Accepted answer

After spending almost a full 2 days on trying to get this solution to work without making big changes elsewhere I finally decided to make a slight design change to the model to make this easier.

How I resolved this was to add each field to the model directly, instead of using a List of custom objects. Due to this I removed the XML Deserialization, and instead looped through all of the elements within the Node using XDocument - then comparing the value of the "Name" attribute to determine which field it was, and assigning the value of the "Value" attribute to the corresponding Property in the model.

A little extra code, and a nice little switch statement with 22 cases to handle the assignments...

Not how I wanted to do it, but at least I can still deliver the service on time and then try to see if there is a better way to do this later...

For the sake of completeness here is what I changed:

public class Bug
{
    public int ID { get; set; }

    public DateTime ChangedDate { get; set; }

    public string State { get; set; }
    public string AreaPath { get; set; }
    public string Title { get; set; }
    public string Status { get; set; }
    public string SubStatus { get; set; }
    public string OpenedBy { get; set; }
    public string ChangedBy { get; set; }
    public DateTime OpenedDate { get; set; }
    public DateTime ResolvedDate { get; set; }
    public string AssignedTo { get; set; }
    public string IssueType { get; set; }
    public string IssueSubtype { get; set; }
    public string Priority { get; set; }
    public string Severity { get; set; }
    public string Keywords { get; set; }
    public string ScreenID { get; set; }
    public string ResolvedBy { get; set; }
    public string Resolution { get; set; }
    public string ReproSteps { get; set; }
    public string HowFound { get; set; }
    public string FullHistory { get; set; }
    public string EverChangedBy { get; set; }


}

and what used to be the deserialization method:

internal static Bug Deserialize(string filePath)
    {
        XDocument doc = XDocument.Load(filePath);
        Bug bug = new Bug();

        bug.ID = int.Parse(doc.Root.Element("ID").Value);
        bug.ChangedDate = DateTime.Parse(doc.Root.Element("ChangedDate").Value);

        foreach (var el in doc.Root.Element("Fields").Elements())
        {
            XAttribute fieldName = el.Attributes("Name").Single();
            XAttribute fieldValue = el.Attributes("Value").Single();

            switch (fieldName.Value.ToString())
            {
                case "State":
                    bug.State = fieldValue.Value.ToString();
                    break;
                case "Area Path":
                    bug.AreaPath = fieldValue.Value.ToString();
                    break;
                case "Title":
                    bug.Title = fieldValue.Value.ToString();
                    break;
                case "Status":
                    bug.Status = fieldValue.Value.ToString();
                    break;
                case "SubStatus":
                    bug.SubStatus = fieldValue.Value.ToString();
                    break;
                case "Opened By":
                    bug.OpenedBy = fieldValue.Value.ToString();
                    break;
                case "ChangedBy":
                    bug.ChangedBy = fieldValue.Value.ToString();
                    break;
                case "Opened Date":
                    bug.OpenedDate = DateTime.Parse(fieldValue.Value.ToString());
                    break;
                case "Resolved Date":
                    bug.ResolvedDate = DateTime.Parse(fieldValue.Value.ToString());
                    break;
                case "Assigned To":
                    bug.AssignedTo = fieldValue.Value.ToString();
                    break;
                case "Issue Type":
                    bug.IssueType = fieldValue.Value.ToString();
                    break;
                case "Issue Subtype":
                    bug.IssueSubtype = fieldValue.Value.ToString();
                    break;
                case "Priority":
                    bug.Priority = fieldValue.Value.ToString();
                    break;
                case "Severity":
                    bug.Severity = fieldValue.Value.ToString();
                    break;
                case "Keywords":
                    bug.Keywords = fieldValue.Value.ToString();
                    break;
                case "ScreenID":
                    bug.ScreenID = fieldValue.Value.ToString();
                    break;
                case "ResolvedBy":
                    bug.ResolvedBy = fieldValue.Value.ToString();
                    break;
                case "Resolution":
                    bug.Resolution = fieldValue.Value.ToString();
                    break;
                case "ReproSteps":
                    bug.State = fieldValue.Value.ToString();
                    break;
                case "HowFound":
                    bug.State = fieldValue.Value.ToString();
                    break;
                case "FullHistory":
                    bug.State = fieldValue.Value.ToString();
                    break;
                case "EverChangedBy":
                    bug.State = fieldValue.Value.ToString();
                    break;
            }
        }

        return bug;
    }

Which allowed me to use the following call to build out the LINQ query:

foreach (KeyValuePair<string, object> field in queryFields)
        {
            itemList = itemList.Where<Bug>(field.Key, field.Value, (FilterOperation)StringEnum.Parse(typeof(FilterOperation), "eq"));                
        }

Cheers!

score:0

I see a couple of approaches to solve that:

1) Have a list of all properties that are available for filtering, match the properties and add them dynamically to your linq query.

The way that would work is that you will accept your json object and iterate through the properties passed with their values. So, say that you get in your controller:

{
Prop[0].Name = "Name" 
Prop[0].Value = "Justin"
Prop[1].Name = "Email"
Prop[1].Value = "j@g.com"
}

In your controller, for example, you will iterate through each key value and dynamicall chain it. Some pseudocode:

foreach(var keyValue in Filters){
  var prop = keyValue.Name;
  var val = keyValue.Value;
  myLinqQuery.AddWhere(c => c.GetType().GetProperty().Name == prop && c.GetValue() == Value);
}

This apprach will work good, but one big disadvantage is that it will try and filter each property in the request with reflection. You would loose some control in that case.

2) Allow only a number of filters and have a filter condition for each of those. In that option you would allow only a list of filters and have some sort of an where action for each of them. Here is a simple example: Say that your controller takes in:

public ActionResult Filter(string name, string email){
 //name and email are the filter values
 var query = ( from c in (List<Bug>)itemList select c);
if(!string.IsNullOrEmpty(name))
  query.AddWhere(c => c.Name == name);

if(!string.IsNullOrEmpty(email))
  query.AddWhere(c => c.Email == email);


}

You can further design that to be more OOP and SOLID by creating a separate class for each filter allowed and exposing its filter action.

Let me know if it helps!

score:1

I know this is old, but here is how I did it without having to type in every possible name:

1) Anonymous IEnumerable coming in, cast as IEnumerable or IList as required
2) On the first element, 

var property = element.GetType().GetProperties(BindingFlags.Instance | BindingFlags.Public)

3) Foreach object in property, add columns to your datatable: 

table.Columns.Add(property.Name, typeof(property.GetValue(element, null));

4) Iterate your collection from the beginning: foreach:

var prop = item.GetType().GetProperties(BindingFlags.Instance | BindingFlags.Public);

dynamic i = new ExpandoObject();
IDictionary<string, object> d = (IDictionary<string, object>)i;
foreach (var p in prop)
{
    d.Add(p.Name, p.GetValue(item));
}
list.Rows.Add(((IDictionary<string, object>)d).Values.ToArray());

This gets the anonymous types, extracts them into an ExpandoObject (which is completely interchangeable with a IDictionary), then adds the row by casting the IDictionary dynamic object as an array.

Scales with any type you can throw at it and allows you to manipulate the data as it is constructed.


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