WF4 questions (current state & compilation) - workflow-foundation-4

We're currently trying to see if we should use WF4 for a project and I have 2 questions since I don't really know that much about the latest WF version:
If a create a state machine workflow, is there a way to know the current state of a workflow instance? I.e: I have a complaint state machine WF and I would like to know the current state of one complaint, can I do it without loading the WF instance?
Whenever there is a change in a workflow definition (i.e: the process changed), will it generate a new DLL (assembly)?
Thanks a lot.

Not out of the box but that is quite easy to do using a TrackingParticipant
It depends on how you define you workflows. A XAML file can be compiled into a CLR type and in that case you would need to recompile. You can also load them dynamically from disk, or some other store, if you want and execute them that way. And finally a workflow service (XAMLX file) is always loaded as a file and never compiled.

Related

Tridion 2011 SP1 HR1 - which extension to use?

We have a requirement that on a page publish, we need to:
Find a component presentation that has a component based upon a particular schema.
Extract certain field vales from that component and store them in a custom database table that's available to our .NET application (on the Content Delivery side).
I think this is a good candidate for either a Deployer extension or a Storage extension - but I'm a little unclear which and why having never written either?
I've ruled out the Event System as this kind of code would be located on the CM, which seems like the wrong "side" to me - my focus is on extending what happens on the CD-side after a page is published.
Read a few articles on Tridion World (this, this, this and this) and I think a storage extension would be the better choice?
Mihai's article seems to be very close to what we need, where he uses a new item type mapping:
<ItemTypes defaultStorageId="brokerdb" cached="true">
<Item typeMapping="PublishAction" cached="false" storageId="searchdb" /></ItemTypes>
But how does Tridion "know" to use this new item type when content is published, (its not one of the defined TYPE_NAMEs, which is kind of the point)?
I should clarify I'm a .NET/C# dev not a Java dev so this is probably really obvious to Java people - apologies if it is!
Cheers
Tridion will not know by default how to deploy your new entity. My advise is to create a Deployer Module (your links should give you enough information about how you can do that) that executes in post-processing phase (of the deployment process), that processes all components from the deployment/transport package, extracts the needed information and uses a custom Storage Extension to store the needed information.
Be careful: you need to set-up in config your new type but you also need to use it yourself from that Deployer Module.
Hope this helps.

Need to get the XML of a component's that version which is published

We are iterating the components in a folder in Tridion 2011 and creating our custom XML to be used on CDS on the basis of the publishing status of component. I am giving below example to make you understand the problem.
Supppose we have 10 components in a folder which are all published and we publish our XML then the XML gets generated for 10 items.
Now we make change in one of the component and don't publish it.
After modification of component, we publish the XML again. then the XML get updated for the modified component also. So it creates the difference between the published version of that component and the that is in our XML.
So I want to publish the custom XML in such a way that it should only contain that data which is in sync with published version of component.
So you want to:
determine the XML of the Component that was last published
determine the changes between that XML and the current XML of the Component
only publish the changes
Tridion doesn't keep track of the version that was published (on the Content Manager at least). So the closest you can do is find out when the Component was last published and retrieve the XML of that time. This question is a great starting point for more information on that approach. Based on that XML you can then do steps 2 and 3 above.
Alternatively you can keep a snapshot of the XML that you published "somewhere" (for example in Application Data) when you're rendering the Component. Then when the Component gets published next time, you can retrieve that XML and do steps 2 and 3 above.
Note that with any of those solutions you should really wonder if you should be implementing it to begin with. You are overriding some of Tridion's default rendering behavior and circumventing part of its architecture (a clear, explicit disconnect between Content Management and Content Delivery, with the former knowing "nothing" about the latter) and anything you do will come back to haunt you in time. In this use-case you have to wonder what will happen when the CDS and TCM get out of sync. Simply republishing the content suddenly won't be good enough anymore, since your code will be in there deciding that "nothing changed since last publish, so we'll publish nothing".
Please forgive me if I jump to conclusions, but I strongly feel this question has arisen from a lack of understanding of Tridion. Publishing in Tridion does more than just raise a flag to indicate the item is 'published', in other words ready to be shown to the outside world. I know this is how some (many) content management systems operate (which may explain why you are asking this question).
In Tridion, however, publishing means that the item is actually - physically - transferred from the content management environment to the content delivery environment. This environment always contains versions of your content that represent the state when the item was last published - simply because it was the very act of publishing that created them.
In my opinion, what you are really asking is how to rebuild this publishing functionality. This is never a good idea. Instead, you should take Bart's comment seriously and look at one of the content delivery APIs that Tridion has on offer (the broker API or the OData web service). Optionally you might want to look into DD4T, which is built on top of the broker and exposes the full Tridion data model.
Then your solution is to
Write an event handler on the Publish Transaction Save event
Which saves the publish info (version data) to Application Data of the published Component
I'm mentioning the Publish Transaction Save event because from there you can ensure that the publish info is only saved when the transaction is successfull.
Also be aware that this publish info can go out of sync when the event handler fails to execute, and you might loose all of the application data when moving to another environment.
So when this information is absolutely crucial I would save it to a separate database, and not to Application Data.

Debugging SDL Tridion 2011 Custom Resolvers and the GetListPublishItems() method

In one of my C# Template Building Blocks I have the following line of code
publication.GetListPublishItems(uriTarget, false, false,
TDSDefinesInterop.ListColumnFilter.XMLListDefault, listRowFilter);
Before implementing a Custom Resolver, this code executed very quickly. Now that my resolver is implemented for the Publication ItemType the code executes really slowly. From this I conclude that the new Resolver is being called behind the scenes by the GetListPublishItems() method (which makes sense). I assume I need to modify the resolver somehow. However I can't seem to hit a break point in my resolver when the method is called.
I normally attach to the 'TcmTemplateDebugHost' when debugging a template or directly to the publisher process when debugging the resolver. My Resolver only seems to get hit when I first press Publish and not when the GetListPublishItems() method is called.
So this question is twofold:
Do Resolvers get called when the GetListPublishItems() method is used?
Assuming they are called, which process should I attach to when I need to debug it in this scenario?
I don't know for certain, but I can't imagine a sane scenario where a custom resolver wouldn't be involved in GetListPublishItems(). Your evidence seems to back this up, but of course, if we can answer the second part of your question, we'll know it for certain.
I imagine that any normal assumptions you've made about the hosting process are probably correct, so for example, if you are invoking your template during a publish, then the TcmPublisher will be the process. Alternatively, if you were to open up the publish dialog for the publication in the GUI and hit "Show Items To Publish", then it would probably be the COM Surrogate process (dllhost.exe)... and so on. One way to find out for sure, though, is to use Sysinternals Process Explorer, which has a very handy feature that will allow you to search for which processes have a given dll loaded. (Look in the Find menu)
One likely cause for a breakpoint failing to bite is that Visual Studio isn't able to load the symbols correctly. When you're debugging a template building block, Tridion explicitly loads the symbols from a known location, which you can configure (tridion.templating/debugging/#pdbdirectory in the CM config), which is where the template uploader places the PDBs. When the publisher process loads the custom resolver, I doubt if there's any such special mechanism to locate the symbols, so you'll have to fall back to standard .NET methods. The first thing I'd try is to ensure your symbols for the custom resolver class are located in the same place as the assembly (i.e. your bin directory). Failing that you could perhaps configure a symbols path in Visual studio.
The first thing to do is to watch the debug output in Visual Studio. If you start the process and then attach to it, you will see the various assemblies being loaded. If Visual Studio can find the symbols, you will see that the output says "Symbols Loaded".

How to get a compile time error when the database schema changes?

What method do you use to get a compile time error when the database schema changes occur in an ASP.NET project?
For example, if you have a GridView bound to a DataSource, I can only get runtime errors when a schema change occurs, not a compile time error. Intellisense works fine on the code behind using datasets, LINQ, etc, but I cant seem to get a compile time error on an ASP.NET page when I change the schema.
Any advice?
Create a unit test that verifies the correctness of you data access layer, and make sure it covers all your DB-related code. Not everything can be caught at compile time...
One way I can think of easily achieving this behavior would be to databind to a dynamic DAL. There are some tools that can help do this DAL generation, I'd recommend taking a look at SubSonic.
Once you have something like SubSonic in place you can bind to the resulting business objects. These business objects will automatically change in the case of a schema change in the database and this will break your binding code which will result in a compile time error.
Update
Assaf's recommendation to use Unit Tests is also a good idea. It doesn't solve your stated problem but it is definitely something that should be in place and is a great tool for flagging these type of problems.
We use a modest system (xml to c++) to create schemas from an independent description, this system also creates names for tables and columns that we use inside the code, when there is a change in the schema the names change, as the names we originally used are not there anymore and the compiler will flag an error.
You could probably configure a lot of the DAO generation tools to do something similar.
One solution would be to version your database and map an application build to a specific version (maybe in a properties file). In the entry point of your app, you can compare the expected version to the actual version and handle the error accordingly.
I'm not sure whats the equivalent in ASP.net of Migrations in Rails or dbdeploy in Java for versioning your database. But any DB versioning tool that makes schema changes incremental and versioned and tracks the version in a Version table will suit the purpose.
But if you want a compile time error while building your app, you might as well upgrade your schema to the latest version as part of your build process, avoiding the possibility of schema changes in the first place.

Deploying Flex Projects Leveraging Imported Web Services

I'm sure there's a simple explanation for this, but I haven't had much luck at finding the answer yet, so I figured I'd put the word out to my colleagues, as I'm sure some of you've run into this one before.
In my (simple) dev environment, I'm working with a handful of WCF Web Services, imported into my FB3 project and targeting a local instance of the ASP.NET development Web server. All good, no problems -- but what I'd like to know now is, What's the right way to deploy this project to test, staging and production environments? If my imported proxies all point, say, to http://localhost:1234/service.svc (from which their WSDLs were imported), and all I'm deploying is a compiled SWF, does Flex Builder expect me to "Manage Web Services > Delete", "> Add", recompile and release ever time I want to move my compiled Flex project from development to test, and to staging, and ultimately into production? Is there a simpler workflow for this?
Thanks in advance -- hope my question was clear.
Cheers,
Chris
If you have path names which will change depending on the enviroment then you will likely need to recompile for each environment since these will be compiled in the swf.
I typically use ANT scripts to handle my compile/deployment process when moving from development and production environments. This gives me the ability to dynamically change any path names during the compile. These build files can be integrated into Flex Builder making this process very easy once you have everything set up, and can be done with one click or scheduled.
Thanks Brett. I've been meaning to dig into automating my build processes anyway, so now's probably as good a time as any. :)
You do not need to build a SWF for each environment. Here's a technique I use commonly:
Externalize your configuration properties into an XML file; in this case, it could be a URL for each service or a base URL used by all your services
When the application starts up, make an HTTPService call to load the XML file, parse it, and store your properties onto some bindable "configuration object"
Bind the values from that object against your objects that depend on the URLs
Dispatch an event that indicates your configuration is complete. If you have some kind of singleton event dispatcher used by some components in your app, use that, so that the notification is global
Now proceed with the rest of the initialization of your application
It takes a little work to orchestrate your app such that certain parts won't initialize until steps 1-5 take place. However I think it's good practice to handle a lot of this initialization explicitly rather than in constructors or various initialize or creationComplete events for components. You may need to reinitialize things when a user logs out and a different user logs in; if you already have your app set up to that initialization is something you can control then reinitialization will not be a problem.

Resources