Forward to configurable product when opening simple product - magento

Question

I have a Magento shop with 2 simple products
Great Red Cup
Great Blue Cup
and a configurable product
Great Cup
with those cups assigned.
The Red and Blue cups are visible in the search.
If the use clicks one of those simple products, the configurable product should be opened instead, but the right color should be preselected.
I am aware that a simple product can be assigned to multiple configurable products, so I would log an exception if two matching configurable products are found an just take the first one.
I think I have to catch the predispatch event of catalog/product/view and somehow replace the simple product by the configurable one.
How can I now pre-configure the right simple product one?
Is there an elegant solution for this?

Answer 1

I found a solution:
register observer on controller_action_predispatch_catalog_product_view
check if we have a simple product with a parent that is a configurable product
create a array that contains the configuration data of the simple product
pass this data to Mage::helper('catalog/product_view')->prepareAndRender() (third parameter)
stop dispatching by setting the FLAG_NO_DISPATCH on the front action
Full code is available in the Mestrona_ForwardToConfigurable module on github.

Answer 2

To preselect a simple product in a configurable product, the address of a simple product should look like this for example:
/mona-pullover-hoodlie.html#143=167&93=53
where
/mona-pullover-hoodlie.html - configurable product URL
143, 93 - attribute IDs
167, 53 - option IDs.
In order to change the URL of simple products, you can create a Plugin (Interceptor) for Magento\Catalog\Model\Product::getProductUrl(), where to generate the URL as in the example above.
Product selection using URL parameters from example above is already implemented in Magento out of the box.
I made VCT Simple Product URl module on Magento Marketplace that solves this problem with the choice of the first configurable product if there are several.

Answer 3

One idea would be to redirect to the configurable product if the simple products meets somes requirements :
have a new attribute "should_redirect_to_parent" to True (optionnal)
have at least a parent product (for that point, I let you follow the link of Alex)
ps: if you don't want to do a parent product lookup you could add a new attribute like "redirect_sku" or "redirect_product_id" in order to directly make a redirection on that product
For the redirection you should use the event catalog_controller_product_init_after and if the two previous conditions match you redirect the user to the configurable product.
ps: for performance optimisation, you could use instead the catalog_controller_product_init_before which would save an expansive and useless Product::load() but it requires that you build custom SQL queries to search for a parent product
Tell if you want some code examples