Event Driven Design is the implementation of requirements through a queue of events that are triggered by user input. Callback functions only create event objects and add them to the queue so state remains unchanged.
Questions tagged [event-driven-design]
241 questions
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Javascript has methods to simulate user interactions like .click(), .focus(), .blur(). But no .hover(). Can JS simulate a hover / mouseover?
Javascript enables user interactions to be simulated.
Any script can simulate a user interaction like click or focus on a specific element on the page, by using the methods .click() and .focus().
Example:
const square =…
Rounin
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REST API command with event driven choreography
I'm trying to design a system in an event-driven architecture style, trying also to expose REST API to send commands/queries. I decided to use Kafka as a message broker.
The choreography I'm trying to design is the following:
The part that is very…
Alessandro Dionisi
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Body of model updated event
Let's imagine we have a user object and we want to sync the state of this object through a service-oriented architecture using events. Regarding the event that is sent when the user is modified, I was wondering which of these options would be better…
Bustikiller
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Topic granularity in event driven architecture
I was wondering what should be the granularity of the topic names in an event-driven service-oriented architecture.
Let's imagine we have a user management system where users can perform different actions like signing up, signing in, modifying some…
Bustikiller
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Handling DB Failure during projection in cqrs
We are creating system using CQRS. Our projections are in mongodb. We are facing some cases. We have an event say OrderCreated. We need to produce a sequential order_no for example #3, #4 etc. We could use a projection and keep a sequence in table…
Rohit Bansal
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Create a VO from a Entity
I'm building a e-commerce with DDD and Event Sourcing, CQRS. My ideia is separate each AR in a microservice.
In my AR ShoppingCart I need a VO Item with productId and a Price, because price doesn't change after add to the cart.
I have another AR…
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should events maintain history or is there a use case for it?
Imagine system A broadcasts an event E that is of interest to system B. As a result of E, B generates its own event E' that also gets broadcast. Should E' contain inside it the event that triggered it (i.e. E) in case it becomes useful at later date…
edu
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Streaming data architecture
I would like to design the best architecture for my following project: I have an application running on any device (desktop, mobile...) where users can publish or receive notifications with other users they share data.
Basically, a user can share…
rico
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Microservices: Service discovery/ circuit breaker for Event-driven architecture
I'm fairly new to Microservices...
I've taken an interest in learning more about two main patterns like service discovery and circuit breaker and I have conducted research on how these could be implemented.
As a Java Developer, I'm using Spring…
rm12345
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Sequential vs multi-threaded Accounting Events Processing
We are working on an event-driven accounting engine and so far we are doing everything in a batch/sequential manner.
Problem is there are thousands of events created per day and processing everything sequentially makes it slow.
Is there a safe way…
code-ninja
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javascript (node.js): unit testing code that fires multiple events
I am attempting to write unit test code (caolan's nodeunit) that will test for multiple event firings.
So, I am testing
function A() {
this.fireaway = function() {
send_message_A_to_queue();
send_message_B_to_a_different_queue();
…
Daniel
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Event-driven architecture - why is there no tool for this?
For a new application I am developing I am interested in creating a microservice that allows for events to be created (for example: New order placed) and other microservices to react to these events (for example the payment system listens to the New…
Ryan
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Notify different parts of application if event is occured
I have an onclick event and I need to update some views on a web page according to server response. What is the best way to implement this using listeners and handlers? I think that I should create clickListener and map it to a button, but I don't…
Sharknado
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When using MDA, should you differentiate between idempotent and non-idempotent event handlers?
The question assumes the use of Event Sourcing.
When rebuilding current state by replaying events, event handlers should be idempotent. For example, when a user successfully updates their username, a UsernameUpdated event might be emitted, the event…
magnus
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Turns issue in java game
I've created a simple game which a player plays against computer.
I've got an issue in the timing of the turns, the computer should be the first to make a move than the real player should make his move by clicking LeftChoice or RightChoice…
gil
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