Skip to main content

Passing PageUri to a DCP for Dynamic Linking

We should all know by now that passing an empty (aka Null TcmUri) as PageUri when resolving a Component Link is very bad practice. The reason -- this kind of link resolving is not cached. So, in case you are using a Content Delivery DB, you will make a trip to the DB for every single Component Link resolving.

I have written an older article available here on SDLTridionWorld, about solving these issues, but that's about old school templating. This post presents the mechanism to use when writing Compound Templates.

So, I have a DWT TBB that generates some output for an RTF field. Something like @@Component.Fields.Paragraph@@. I have some ComponentLinks in the RTF field.

The templates runs on a DCP and it generates a TCDL link like this:
<tcdl:Link type="Component" origin="tcm:0-0-0" destination="tcm:37-968" templateURI="tcm:0-0-0" linkAttributes="" textOnFail="true" addAnchor="false" variantId="">Read more</tcdl:Link>.

The problem is the origin is tcm:0-0-0. I want to have my own value/variable here. In JSP, I can use a JSTL variable like this:
<tridion:ComponentLink pageURI="${PageUri}" componentURI="tcm:37-969" templateURI="tcm:0-0-0" addAnchor="false" linkText="Read more" linkAttributes="" textOnFail="true"/>

Where ${PageUri} is some JSTL variable set with the following code in the ‘calling’ JSP:
<%@ taglib prefix="c" uri="" %>
<c:set var="PageUri" value="tcm:37-986-64" scope="request"/>

But anyway, the problem for me is how to get that PageURI attribute (or origin) assigned to my actual value?

The solution I used in this case is the following:
  • C# TBB that parses the <tcdl:Link origin="tcm:0-0-0"… and replaces the NullUri with ${PageUri}
    • Only does that for ‘Publish’, not for preview;
  • Add this TBB at the bottom of the Dynamic CT (after DefaultFinishActions, or after LinkResolver);
Code sample:

private static Regex ComponentLinkRegex = new Regex(@"<tcdl:Link type=""Component"" origin=""tcm:0-0-0""");

public void Transform(Engine engine, Package package)
    if (!engine.RenderMode.Equals(RenderMode.Publish))
        Logger.Debug("Render mode not Publish. Do not perform any replacements");

    Item OutputItem = package.GetByName(Package.OutputName);
    String OutputText = OutputItem.GetAsString();

    // Component Links with null origin
    Match match = ComponentLinkRegex.Match(OutputText);
    while (match.Success)
        String ReplaceLink = match.Value.Replace("tcm:0-0-0", inputParam);
        // inputParam is the value to replace with. e.g. "${PageUri}"
        OutputText = OutputText.Replace(match.Value, ReplaceLink);
        match = match.NextMatch();



Nuno said…
Awesome, I needed this code just now. :)

Popular posts from this blog

Running sp_updatestats on AWS RDS database

Part of the maintenance tasks that I perform on a MSSQL Content Manager database is to run stored procedure sp_updatestats . exec sp_updatestats However, that is not supported on an AWS RDS instance. The error message below indicates that only the sa  account can perform this: Msg 15247 , Level 16 , State 1 , Procedure sp_updatestats, Line 15 [Batch Start Line 0 ] User does not have permission to perform this action. Instead there are several posts that suggest using UPDATE STATISTICS instead: I stumbled upon the following post from 2008 (!!!), , which describes a way to wrap the call to sp_updatestats and execute it under a different user: create procedure dbo.sp_updstats with execute as 'dbo' as

Content Delivery Monitoring in AWS with CloudWatch

This post describes a way of monitoring a Tridion 9 combined Deployer by sending the health checks into a custom metric in CloudWatch in AWS. The same approach can also be used for other Content Delivery services. Once the metric is available in CloudWatch, we can create alarms in case the service errors out or becomes unresponsive. The overall architecture is as follows: Content Delivery service sends heartbeat (or exposes HTTP endpoint) for monitoring Monitoring Agent checks heartbeat (or HTTP health check) regularly and stores health state AWS lambda function: runs regularly reads the health state from Monitoring Agent pushes custom metrics into CloudWatch I am running the Deployer ( installation docs ) and Monitoring Agent ( installation docs ) on a t2.medium EC2 instance running CentOS on which I also installed the Systems Manager Agent (SSM Agent) ( installation docs ). In my case I have a combined Deployer that I want to monitor. This consists of an Endpoint and a

Debugging a Tridion 2011 Event System

OK, so you wrote your Tridion Event System. Now it's time to debug it. I know this is a hypothetical situtation -- your code never needs any kind of debugging ;) but indulge me... Recently, Alvin Reyes ( @nivlong ) blogged about being difficult to know how exactly to debug a Tridion Event System. More exactly, the question was " What process do I attach to for debugging even system code? ". Unfortunately, there is no simple or generic answer for it. Different events are fired by different Tridion CM modules. These modules run as different programs (or services) or run inside other programs (e.g. IIS). This means that you will need to monitor (or debug) different processes, based on which events your code handles. So the usual suspects are: dllhost.exe (or dllhost3g.exe ) - running as the MTSUser is the SDL Tridion Content Manager COM+ application and it fires events on generic TOM objects (e.g. events based on Tridion.ContentManager.Extensibility.Events.CrudEven