Call order for itemtypes Page with multiple storage types

Question

I'm using SDL Tridion 2013 SP1.

I want to make a REST call for each Page item that's being deployed with a few page metadata values. For that I'm thinking about three options:

1. Creating a Storage Extension for the item type Page (JPAPageDAOImpl as the example page in Tridion online documentation) and inside make call to an external URL. My concern is if I can access page metadata in Storage Extension, if not, I'll need another approach.

2. Creating a new Storage Type (which wouldn't be storing anything just making the REST call. In this way I can keep clean the storing of the page in the database and in the configuration file add the new storage type to make the REST call. Again, my concern is if I can access page metadata in Storage Extension, if not, I'll need another approach.

For this one (2)...Can I have something like this?

<Item typeMapping="Page" storageId="database" />
<Item typeMapping="Page" storageId="MyCustomStorageId" />

So, for each page call both of those Storages. And if so, Will the second one (MyCustomStorageId) being called after to commit was completed in the database (in the previous step)?

3. Creating a Deployer Extension (instead of Storage Extension). This options is less atomic than the previous two, so probably not the best one, again, my concern is if I can access page metadata in Storage Extension, if not, I'll need to go this approach.

UPDATE

I can see in the create method of JPABaseDAO that the commit is being called in there, so if I inherit from JPABaseDAO and call super in create method, I can be sure that the transaction was already committed (or an exception will be thrown).

Answer 1

Not sure what you wanted to do with the REST call after accessing the meta-data, but if you are not doing anything on the Storage Layer of CD (e.g. making something related to storage), I would recommend using the Deployer Extension.

Please note, Storage Extension is invoked in-transaction and if need to to retrieve anything post transaction commit; you wont be able to access that in Storage Extension.

However, the deployer extension, you can execute in pre-commit and post-commit phase.

One more issue with Storage Extension is that if you want to retrieve more details on the page like accessing the Components and Component Templates associated on the page, then it might not be possible but in Deployer Extension you.

Further, I am not very sure and tried this; but my understanding is that you can only access the Page Presentation with in the storage extension. I could not access the Components on the page and I am not sure about the Page Meta data but you can do a quick test.

On the other hand, if you need to access the meta-data, manipulate with it and store that somewhere or such that you need to interact with Storage Layers, then the advise is to use the Storage Extension.