Ytukyg

Can any one help me to sort the XmlDocument based on attribute value.

I have given a sample xml having few attr elements. So I want to sort it based on "value" attribute of elements having attribute Name="from" I am trying to achieve this using linq to xml.

Here is one sample code I tried. But it is retaining only the "from" attributes in sorted order. I want all the attributes as shown below under expected xml.

container.ReplaceNodes(

            from childEl in container.Elements().Elements()

            where childEl.Attribute("Name")?.Value == "from"

            orderby childEl.Attribute("Value")?.Value descending

            select childEl

        );

        foreach (XElement childEl in container.Elements().Where(e => e.HasElements))

    {

        SortByName(childEl);

    }

Input XML:

`<Attrs>

  <Attr Name="zddressprevious" isVerified="false">

    <Attr Name="from" Value="2014-01-01" isVerified="false" />

    <Attr Name="house" Value="3" isVerified="false" />

    <Attr Name="street" Value="Test Street" isVerified="false" />

  </Attr>

  <Attr Name="addressprevious" isVerified="false">

    <Attr Name="from" Value="2015-01-01" isVerified="false" />

    <Attr Name="house" Value="1" isVerified="false" />

    <Attr Name="street" Value="Acacia Avenue" isVerified="false" />

  </Attr>

  <Attr Name="addressprevious" isVerified="false">

    <Attr Name="from" Value="2016-01-01" isVerified="false" />

    <Attr Name="house" Value="1" isVerified="false" />

    <Attr Name="street" Value="Test Street" isVerified="false" />

   </Attr>

</Attrs>`

Expected output:

`<?xml version="1.0" encoding="utf-8"?>

<Attrs>

  <Attr <Attr Name="addressprevious" isVerified="false">

    <Attr Name="from" Value="2016-01-01" isVerified="false" />

    <Attr Name="house" Value="1" isVerified="false" />

    <Attr Name="street" Value="Test Street" isVerified="false" />

   </Attr>

   <Attr Name="addressprevious" isVerified="false">

    <Attr Name="from" Value="2015-01-01" isVerified="false" />

    <Attr Name="house" Value="1" isVerified="false" />

    <Attr Name="street" Value="Acacia Avenue" isVerified="false" />

  </Attr>

  <Attr Name="zddressprevious" isVerified="false">

    <Attr Name="from" Value="2014-01-01" isVerified="false" />

    <Attr Name="house" Value="3" isVerified="false" />

    <Attr Name="street" Value="Test Street" isVerified="false" />

  </Attr>

</Attrs>`

Your LINQ statement has to return the parent element (of the one containing the from-attribute) via childEl.Parent.

From your question is not completely clear whether your container is an XDocumentor an XElement.

In case of an XElement the LINQstatement looks like:

var q =

    from childEl in container.Elements("Attr").Elements("Attr")                

    where childEl.Attribute("Name")?.Value == "from"

    orderby childEl.Attribute("Value")?.Value descending

    select childEl.Parent

    ;

and the replace as:

container.ReplaceNodes(q);

Note that the LINQ statement without explicitly specifying the Attrelement names will also do the job:

var q =

    from childEl in container.Elements().Elements()                

    where childEl.Attribute("Name")?.Value == "from"

    orderby childEl.Attribute("Value")?.Value descending

    select childEl.Parent

    ;

In case of an XDocument your query must look like:

var q =

    from childEl in container.Element("Attrs").Elements("Attr").Elements("Attr")                

    where childEl.Attribute("Name")?.Value == "from"

    orderby childEl.Attribute("Value")?.Value descending

    select childEl.Parent

    ;

and you have to replace the nodes via:

container.Element("Attrs").ReplaceAll(q);