Support chat for http://getprooph.org/ - official announcement: https://www.sasaprolic.com/2018/08/the-future-of-prooph-components.html
Every service has it's own local event store and then there is a shared event store with each service having a public stream in that shared store. There was some trouble with projections consuming too much resources but this was mainly caused by the set up of the docker containers and K8s cluster.
For prooph board we use AWS SQS as an event-driven transport.
DS-UUID1[xxxx]
For our client this was more of a problem and one reason they decided to use persistent public streams. A team can set up a new service without coordinating that activity with other teams. They just consume all public streams they need and that's it. Definitely a huge advantage, but it's not for free.
Also all teams use prooph board to design their services and document the events available in the public streams.
They have bi-weekly architecture meetings with all team leads on prooph board to discuss public event changes in the streams: like new event versions, new available event types, new consumers and sometimes even new stream versions.
They found a very good way (with our help ;)) to handle their architecture, but without proper collaboration and documentation you can end up in a mess.
https://github.com/prooph/pdo-event-store/releases/tag/v1.14.0
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Hey, I'm thinking about a revival of prooph/event-sourcing but in a totally new way and it would be nice to get some feedback regarding the idea:
@sandrokeil had the idea to create a plugin for Cody (https://youtu.be/0FAgsPNqUV4) that generates framework agnostic domain model code: aggregates, value objects, messages, handlers, ... from a prooph board event map.
One reason to abandon prooph/event-sourcing was that it creates a framework dependency in your business logic. Something you don't really want. So instead you should use the package as inspiration only. But what if you could have a code generator, that generates all the glue code for you in the namespace of your choice?
- Value Objects
- Event Sourced Aggregates
- Commands
- Events
- Repository Interface
One can then connect the result with the framework of their choice. We think about prooph/event-store and Ecotone packages that can be used in combination to also generate framework related glue code (e.g. repository implementation, PHP8 attributes for Ecotone, ...)
Would you be interested in such a package?
Let's try it like this:
Usually developers are lazy. They try to automate repeating tasks and make their life easier. That's the key idea behind Cody as well.
Once you've found rules and conventions how to organize your code base, you'll do the same coding over and over again:
Create this class here, configure message routing there, set up an API endpoint, map data to VOs, define a contract (e.g. OpenAPI/AsyncAPI files) and so on. Isn't that boring?
Why not automate the boring parts? Writing the automation logic is a purely technical and depending on how crazy you want it to be also a challenging task. Something developers usually like. If you write and maintain the logic yourself would you still say it's magic?
@darrylhein good point. The context is super important. For companies with multiple teams all working with the same basic set up and maintaining software over a long period of time, framework decoupling is much more important than for smaller single team projects. A framework often influence the way how problems are solved in code. what works good today, can become a huge problem tomorrow when you want to scale (technically and in teams size)
Another good reason for decoupling is much cleaner business logic that is easier to understand and change over time.
But a framework agnostic domain model means:
more glue code required to make it work with your current framework of choice. But if you automate glue code generation as well as parts of the domain model code itself then you have a win-win situation.
if it is possible to have a generator that can update the code with my changes mixed in later, I'd probably be more interested
that's actually the case. It works like rector or a code sniffer. In rector you have those rules to upgrade parts of the code to a new PHP version. It also modifies your code without destroying it. Cody can do the same. If a VO exists already, Cody does not touch it! But if you want to add a new interface and/or method to all VOs, Cody can easily do that while keeping the original implementation in place.
we are maintaining a single low-time project (ever since starting to use prooph :)), so no need to upgrade multiple things, just making sure things keep on running / evolve with least effort :) ( Also, no hostility meant, I am being honest but not judging, there absolutely is a value of what you suggest)
when I talk about magic, I mean magic in code. I like stupid code. I like obvious code. I spent way too much time of my life debugging / figuring out why something magically does not work (any kind of magic routing / loading / ... ). I prefer repetitive over magic.
When we (team) implement new features, the basic setup is the stuff that takes the least time. Setting up read models / projections is what takes the most time (although repetitive but way more time consuming). That's the place where I personally would like to cut effort (esp since we use json functions and these are a PITA).
The good thing about automation is: if it works once, it'll always work for that case. You save time and reduce the risk of silly mistakes made by developers who are bored to do the tasks.
Most bugs I produce are the result of boring work. When I'm 100% focused on the task, my code usually works. With or without tests ...
If I have to map data back and forth, write validation logic by hand etc. it happens more often that a bug slows me down. A spelling mistake for example. Of course most of the time I fix the bug even before committing the code, but it's still a waste of time. You know like wondering for an hour why the hell it's not working just to find out that you did a spelling mistake in a mapping ...
But, yes automation is great – use it all the time. I'm the Rector, CS, etc train.
But, I don't think automation > framework coupling.
There are apparently thousands of companies coupled to, all sorts of things. I don't know that if the team gets larger they're less likely to be coupled. From my experiences (in multi-billion $ companies), they were using an awful lot of coupling. It made it easier for them to hire.
But, in the end, it's a just a choice to decide at what level you uncouple at. If Prooph goes that (code gen) way, I'll have to see how it works and go from there.
@silviuvoicu
maybe not just some opinionated suggestion are what you need, but also an mvp, working example, you know, go to your customer and ask/communicate with them :), either company or developers.
yeah, that's the point.
We're in direct exchange with our customers and we demonstrated one real world result of what is possible with prooph board + Cody in a live demo session at EventSourcing.Live last year. BTW the recording is now available on youtube: https://www.youtube.com/watch?v=lKB8-l9MEvs
There you can see the potential incl. fully working FE and BE code generation.
We could release the Cody implementation used in the live demo as an example. But my fear is that people would think it's the only way to work with Cody:
Cody itself is an API. It gives you access to your design on prooph board. Now it is up to you, what you want to do with that information. Generate some boilerplate code, scenario tests or a fully working low-code platform.
Is this too low-level for developers? Because it requires too much learning effort?
I'd love to share the excitement with you. But I try to figure out what would be the best way to do that.
- how do you handle validation (as it's skipped in the video)?
- how do you handle logic (be it validation, read model logic, aggregate logic) that you cannot define in json (i.e. we have complex internal aggregate states etc..)? obviously I can add it in the generated code later on, but how would later updates on the board (and code re-generation) affect my custom added code?
- how does the board handle "branches", think of different features worked on in parallel? how would branches be merged on the board level?
- as we have to maintain our software for years (current installment for ~10 years), we have seen a lot of these tools come and go ;) not being maintained is one thing as long as they remain in our build chain, but SaaS really breaks away forcing you to look into alternatives.. I know the code generated is on our git, but it still breaks established workflows. any plans to bring the board as a self-hosted / run version? ideally as something I can define as a dependency on the project and start like "any other code generator" (just with a graphical UI instead of CLI).. running locally also would be preferred from a security & confidentiality perspective
Before I answer your questions I'd like to stress the point that the answers related to code generation are specific for the set up shown in the video. That said, you can build your own code generation logic the way you want/need it. @sandrokeil Put a lot of effort into an abstraction layer on top of PHP Parser to simplify code generation. It's organized in libs for specific tasks. Check out the github orga Open Code Modeling
Validation:
We translate metadata on prooph board to JSON Schema. I've skipped validation in the video to save some time but here are two examples from the same app:
{
"shorthand": true,
"ns": "/Common",
"voNamespace": "/Common",
"schema": {
"userId": "string",
"givenName": "string",
"familyName": "string",
"roles": "/Common/Roles",
"email": "string|format:email"
}
}It's metadata for a UserInfo VO. As you can see the shorthand version of json schema is used (our own creation, we have a translator to real json schema) and we can type hint properties with definitions (other VOs in the code) and define json schema validation like "email": "string|format:email"
{
"shorthand": false,
"ns": "/Expose",
"voNamespace": "/Expose",
"schema": {
"type": "string",
"pattern": "^((eigentumswohnung(en)?-)|(condominiums-))[üäöÜÄÖßA-Za-z0-9-]+$"
}
}