Question

I am trying to print out documents in various different orders. Right now I have a collection of print objects and an XML document where each node has attributes associated with a print object in the collection. I want to sort these objects by sorting the XML document based on these attributes.

Right now I am using a series of collections that i am cycling through and adding the node into a new collection based on the sorting i need done. The problem is 3 or 4 sorts in it gets messy. I am sure there has to be a better way to sort this collection of print objects, using XML or not.

Here are some attributes that my XML has that i am sorting on:

• # of pages
• Zip Code listed on document
• Name of Document

Does anyone have a better idea?

thanks,

EDIT –

my document will look something like

<xml>
<claim key="1" att1="wd" att2="de"/>
<claim key="2" att1="wd" att2="de"/>
<claim key="3" att1="wd" att2="de"/>
<claim key="4" att1="wd" att2="de"/>
</xml>

The key value is associated with a spot in the print object collection. The claim nodes may have more child nodes but i do not think that is relevant at this point. I would just like to be able to sort based on the attributes, there will be at least 3 attributes but more may be added. Also this needs to be versatile so if I need to switch the sorting order it should be somewhat easy to rearrange. Once I have the XML in the correct order I want, then i use a cycle through the XML in order putting the key into a list and then print out the Print objects by the keys in that list.

thanks,

Answer 1

I tried this example out in LINQPad and it seems to do what you’re asking.

var root = XDocument.Parse("<xml><claim>...</claim></xml>").Element("xml");

var query = from claim in root.Elements("claim")
            let key = claim.Attributes("key").First().Value
            let att1 = claim.Attributes("att1").First().Value
            let att2 = claim.Attributes("att2").First().Value
            orderby key, att1, att2
            select claim;

It finds the <claim> nodes in your XML, selects the attributes on which you’d like to sort, sorts them, and then returns an IEnumerable<XElement> collection representing the sorted <claim> nodes.

You can then use the query result to build your Print objects, or you could change the above to have it do it for you:

var query2 = from claim in root.Elements("claim")
            let key = claim.Attributes("key").First().Value
            let att1 = claim.Attributes("att1").First().Value
            let att2 = claim.Attributes("att2").First().Value
            orderby key, att1, att2
            select new Print {
                        Property1 = key, // do type conversion if needed
                        Property2 = att1,
                        Property3 = att2
                    };

I think it fits the maintainability requirements you mentioned — you just have to change add/remove/change the attribute names in the LINQ query if you need to sort differently.

EDIT: To get the key into a list of ints, as per your comment below:

var printKeys = (from claim in query
                select Integer.Parse(claim.Attributes("key").First().Value)).ToList();