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Flow

When you use Flow Components to build something that involves use of a multiple components, your implementation may become a bit cluttered. To ease these use cases, we added a ComponentFlow that can hook multiple component executions together as a “flow”.spring-doc.cn

The following listings show examples of flows and their output in a shell:spring-doc.cn

static class FlowSampleComplex {

	@Autowired
	private ComponentFlow.Builder componentFlowBuilder;

	public void runFlow() {
		List<SelectItem> single1SelectItems = Arrays.asList(SelectItem.of("key1", "value1"),
				SelectItem.of("key2", "value2"));
		List<SelectItem> multi1SelectItems = Arrays.asList(SelectItem.of("key1", "value1"),
				SelectItem.of("key2", "value2"), SelectItem.of("key3", "value3"));
		ComponentFlow flow = componentFlowBuilder.clone().reset()
				.withStringInput("field1")
					.name("Field1")
					.defaultValue("defaultField1Value")
					.and()
				.withStringInput("field2")
					.name("Field2")
					.and()
				.withConfirmationInput("confirmation1")
					.name("Confirmation1")
					.and()
				.withPathInput("path1")
					.name("Path1")
					.and()
				.withSingleItemSelector("single1")
					.name("Single1")
					.selectItems(single1SelectItems)
					.and()
				.withMultiItemSelector("multi1")
					.name("Multi1")
					.selectItems(multi1SelectItems)
					.and()
				.build();
		flow.run();
	}

}

Normal execution order of a components is same as defined with a builder. It’s possible to conditionally choose where to jump in a flow by using a next function and returning target component id. If this returned id is aither null or doesn’t exist flow is essentially stopped right there.spring-doc.cn

static class FlowSampleConditional {

	@Autowired
	private ComponentFlow.Builder componentFlowBuilder;

	public void runFlow() {
		Map<String, String> single1SelectItems = new HashMap<>();
		single1SelectItems.put("Field1", "field1");
		single1SelectItems.put("Field2", "field2");
		ComponentFlow flow = componentFlowBuilder.clone().reset()
				.withSingleItemSelector("single1")
					.name("Single1")
					.selectItems(single1SelectItems)
					.next(ctx -> ctx.getResultItem().get().getItem())
					.and()
				.withStringInput("field1")
					.name("Field1")
					.defaultValue("defaultField1Value")
					.next(ctx -> null)
					.and()
				.withStringInput("field2")
					.name("Field2")
					.defaultValue("defaultField2Value")
					.next(ctx -> null)
					.and()
				.build();
		flow.run();
	}

}
The result from running a flow returns ComponentFlowResult, which you can use to do further actions.