Issue with SetVariable and GetVariable method calls from DWT

Question

I have written a DWT which is creating an XML as below:-

<?xml version="1.0" encoding="utf-8"?><episodes><episode>
<episode_id>EPS_7208_7205_56</episode_id>
<title>Episode 56</title>
<media_links>
  <media_link>
    <asset_id></asset_id>
    <media_filepath>\Entertainment\TV Shows\TV Show 56.mp4</media_filepath>
    <media_type>mp4</media_type>
  </media_link>
</media_links></episode><episode><episode_id>EPS_7208_7205_57</episode_id>
<title>Episode 2</title>
<media_links>
  <media_link>
    <asset_id>Asset_EPS_56</asset_id>
    <media_filepath>\Entertainment\TV Shows\TV Show 1.mp4</media_filepath>
    <media_type>mp4</media_type>
  </media_link>
</media_links></episode><episode><episode_id>EPS_7208_7205_58</episode_id>
<title>Episode 2</title>
<media_links>
  <media_link>
    <asset_id>Asset_EPS_57</asset_id>
    <media_filepath>\Entertainment\TV Shows\TV Show 1.mp4</media_filepath>
    <media_type>mp4</media_type>
  </media_link>
</media_links></episode></episodes>

DWT Code:-

<?xml version="1.0" encoding="utf-8"?><episodes><!-- TemplateBeginRepeat name="episodes" --><episode>   <episode_id>EPS_@@GetIdFromTcmUri(Component.ID)@@_@@episode_number@@</episode_id>
@@SetVariable('EpisodeNumber', episode_number)@@
<title>@@title@@</title>
<media_links>
  <!-- TemplateBeginRepeat name="media_links" -->
  <media_link>
    <asset_id>Asset_EPS_@@GetVariable('EpisodeNumber')@@</asset_id>
    <media_filepath>@@media_filepath@@</media_filepath>
    <media_type>@@media_type@@</media_type>
  </media_link>
  <!-- TemplateEndRepeat -->
</media_links></episode><!-- TemplateEndRepeat --></episodes>

I calling template callable methods:-

/// <summary>
    /// Sets a varialbe in the package to the name and value specifed. Also removes any other variable that was set with the same name before.
    /// </summary>
    /// <param name="variableName">Name of the varialbet</param>
    /// <param name="value">Value of the variable</param>
    [TemplateCallable()]
    public string SetVariable(string variableName, string value)
    {
        //Remove the old variable and set the new variable
        m_engine.PublishingContext.RenderContext.ContextVariables.Remove(variableName);
        m_engine.PublishingContext.RenderContext.ContextVariables.Add(variableName, value);

        return String.Empty;
    }

    /// <summary>
    /// Gets a variable from the publishing context.
    /// </summary>
    /// <param name="variableName">Name of the variable</param>
    [TemplateCallable()]
    public string GetVariable(string variableName)
    {
        //Get the variable
        try
        {
            return m_engine.PublishingContext.RenderContext.ContextVariables[variableName].ToString();
        }
        catch
        {
            return String.Empty;
        }
    }

IN the asset_id node I want the value of episode number which was set initially as soon as episodes loop started. But the value which I am expecting for asset_id node of an episode is getting written in the asset_id node of episode which is next to it in xml. Can you please tell where I am wrong?

Answer 1

I am confused as to why you cannot directly use the field @@episode_number@@ rather than using built-in function in your DWT. If it is in the component it should be accessible. Otherwise I would recommend posting your component xml to give a better idea. And, indeed as @Eric mentions the DWT is evaluated inside to outside, so the innermost repeating region is evaluated before evaluating outer repeat regions or any references.

<?xml version="1.0" encoding="utf-8"?><episodes><!-- TemplateBeginRepeat name="episodes" --><episode>   <episode_id>EPS_@@GetIdFromTcmUri(Component.ID)@@_@@episode_number@@</episode_id>
<title>@@title@@</title>
<media_links>
  <!-- TemplateBeginRepeat name="media_links" -->
  <media_link>
    <asset_id>Asset_EPS_@@episode_number@@</asset_id>
    <media_filepath>@@media_filepath@@</media_filepath>
    <media_type>@@media_type@@</media_type>
  </media_link>
  <!-- TemplateEndRepeat -->
</media_links></episode><!-- TemplateEndRepeat --></episodes>

Component xml

<Content xmlns="uuid:01cee2f6-035c-4ced-b225-abde4ceded5e">
    <episodes>
        <episode_number>5</episode_number>
        <media_links>
            <Link>Link5.1</Link>
        </media_links>
        <media_links>
            <Link>Link5.2</Link>
        </media_links>
    </episodes>
    <episodes>
        <episode_number>6</episode_number>
            <media_links>
            <Link>Link6.1</Link>
        </media_links>
    </episodes>
</Content>

Series DWTBB

<?xml version="1.0" encoding="utf-8"?>
<episodes>
<!-- TemplateBeginRepeat name="episodes" -->
<episode>
    <episode_id>EPS__@@episode_number@@</episode_id>
    <title>@@title@@</title>
    <media_links>
        <!-- TemplateBeginRepeat name="media_links" -->
        <media_link>
            <asset_id>Asset_EPS_@@episode_number@@</asset_id>
            <media_filepath>@@Link@@</media_filepath>
            <media_type>@@FieldPath@@</media_type>
        </media_link>
        <!-- TemplateEndRepeat -->
    </media_links>
</episode>
<!-- TemplateEndRepeat -->
</episodes>

Answer 2

DWTs are executed from inside to outside, it means that the repeat section and GetVariable are executed before SetVariable so that your episode number is not set yet.

Try to set the variable in the repeat section (i know it would be extra processing), it will ensure the variable is available when you execute GetVariable

Other option would be of course to move the logic to C# TBBs and create a Dummy Array including the episode titles include the episode number