Custom Pipelines

[NicolajDK]

Hi,

I would like to have a pipeline for when the checkout has been completed, I have been looking into creating my own pipeline, but I am having some trouble executing / starting the pipeline. I can only find documentation about injection new tasks into existing pipelines, but I dont see an existing pipeline that matches what i need.

Is this a viable solution (to create my own pipeline) or should i be looking into another solution ?

Thanks for the help!

[mattbrailsford]

The pipeline solution in Umbraco Commerce is really only intended for our own pipelines. They might be reusable, but it's not our intention that others would so ideally you'd form your own solution for what you need.

We have plenty of events that you can hook into though to be able to react to changes in an order so hopefully those will be a good solution.

[mattbrailsford]

No problem.

Expand in what way?

[NicolajDK]

Mostly if you were considering adding new pipelines for certains flows

[mattbrailsford]

Which flows would you like to see?

[nickfrederiksen]

Hi @mattbrailsford I'm taking over for my colleague Nicolaj.

Our use case is that we have a list of different tasks that we want to run in sequence whenever certain events are triggered. Eg. whenever a product is added to the cart.

These tasks will have different responsibilities that depends on the state of the cart and the type of product being added. The main task is setting properties on the order line based on the product type.

It is unclear how events are being triggered. Are they sequential, or are they run in parallel? Having a single handler to do all the tasks seems like a bad way of doing things with regards to separation of concern. Hence the pipeline approach.

If I were to implement multiple handlers, I would also have to create, and execute, multiple unit of works. This would go against the best practices outlined in this document: https://docs.umbraco.com/umbraco-commerce/key-concepts/unit-of-work. This will also open up for potential situations where the cart will end up in a partially modified state. Which I would like to avoid.

Currently I've implemented custom pipelines based on the PipelineTaskCollection class and executing them on the relevant events. It seems to be working all right.

My biggest issue, currently, is that I have no way to prevent an order line to be added. Say I want to add a product that is not allowed in the cart because it would be in conflict with another product, I cannot prevent the product to be added without throwing an exception.

And a few quick questions, why are event handlers, (and pipeline tasks), singletons? Am I right to inject the IFactory service, or should I use the built-in IServiceProvider instead?

[mattbrailsford]

Handlers and tasks were generally singletons as they shouldn't really change so seemed like no point constantly instantiating them, but I do wonder if that was the right decision. RE IFactory or IServiceProvider that's up to you. IFactory is just an abstraction layer, it uses IServiceProvider under the hood.