Questions tagged [command-message]

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2answers
128 views

A command as the intended effect of POST versus as the side effect of PUT

The intended effect (semantics) of the POST method is resource specific, e.g. executing a command with arguments: POST /command HTTP/1.1 {"parameter-1": "argument-1", "...
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1answer
134 views

Message bus: should an event handler trigger other commands?

Given I have a message bus that can handle commands and events. A command handler can dispatch an event. But should an event handler be able to dispatch another command? Or should event handlers only ...
3
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1answer
187 views

Message Mapper Design Considerations

Long question context, skip to tl;dr for the meat of it. I am designing an integration between two web applications, and have come to the conclusion that a message pattern would be an appropriate ...
1
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1answer
462 views

Passing Meta info from Command through Aggregate to Event

I have a CQRS system in development that passes the Command to a CommandHandler, which gets an Aggregate from a Repository, and calls a method with the properties of the Command (converted to ...
10
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2answers
2k views

Where should you validate the state of "other" aggregates?

Scenario: A customer places an order, then, after receiving the product, provides feedback on the order process. Assume the following aggregate roots: Customer Order Feedback Here are the business ...
1
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1answer
109 views

How to implement format-complying logging system?

We have a system that generates lots of logs and we have to somehow maintain logging workflow in a project. The 'strict' (let's assume it's strict) requirement is that there should be a document ...
1
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2answers
2k views

Reading the result of your command with the Command Pattern

I am currently looking into developing a new system utilizing hexagonal architecture and the commandpattern facilitated by a commandbus like tactician (it's a PHP system). Now I really like the idea ...
14
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3answers
13k views

In CQRS/ES, can a command create another command?

In CQRS/ES, a command is sent from the client to the server and routed to the appropriate command handler. That command handler loads an aggregate from its repository, and calls some method on it, and ...
1
vote
1answer
35 views

Does my Remote Procedure and Event Protocol complete?

I recently wrote a protocol I call RPEP (https://github.com/Tixit/RPEP), partially in response to the unfortunately named WAMP protocol. I'm looking for feedback as to whether the protocol is ...
13
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2answers
6k views

How to determine if a message should be a command message or event message?

Two enterprise integration patterns are the command message and the event message. I am working on a system in which we use messaging not only for integration with other systems, but for internal ...
2
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2answers
2k views

Building a string parser for user command and control?

My goal is to build a command parser that has basic syntax and multiple possible branches at each point. These commands come from users of the system and are text input (no GUI). The basic syntax is ...
1
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1answer
286 views

MVC Communication Pattern

This is kind of a follow up question to this https://stackoverflow.com/questions/23743285/model-view-controller-and-callbacks, but I wanted to post it separately, because its kind of a different topic....