CODEWITHSUNDEEP
springspring-mvcspring-webflowspring-webflow-2
LWK69
LWK69

Reputation: 1080

Spring Webflow 2.4.2 missing start state

I just started adding Webflow to a Spring MVC project and I'm getting this compile error on my flow.xml component:

Start state is missing. Add at least one state to the flow

I found an identical post on SO from a year ago: webflow.xsd - Start state is missing. Add at least one state to the flow. No one responded to this question but I found it in the Jira repository for Spring Webflow: webflow.xsd - Start state is missing. Add at least one state to the flow. It is marked as Cannot Reproduce.

Here is an excerpt from my very simple webflow.xml.

    <?xml version="1.0" encoding="UTF-8"?>
    <flow xmlns="http://www.springframework.org/schema/webflow"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://www.springframework.org/schema/webflow
            http://www.springframework.org/schema/webflow/spring-webflow-2.4.xsd">

    <on-start>
        <evaluate expression="recipeService.createRecipe(currentUser.name)" result="flowScope.recipe" />
    </on-start>

    <view-state id="basics" view="recipe/basics" model="recipe">
        <transition on="proceed" to="ingredients"></transition>
        <transition on="cancel" to="cancel"></transition>
    </view-state>

    ... more states ...

    <end-state id="end" view="recipe/end"/>
    <end-state id="cancel" view="recipe/end"/>

    </flow>

The documentation indicates that start-state is optional - the first view-state will be assumed to be the start. If I change the spring-webflow-2.4.xsd to 2.0 the error goes away, but then I get a different error if I attempt to use validation-hints on any of the view-state entries. "Basic1" and "Basic2" in the example below are validation groups on the recipe model.

<view-state id="basics" view="recipe/basics" model="recipe" validation-hints="'basic1,basic2'">

I'm using

I'm using java-based config for everything, but I don't think that is where the problem lies unless I have a mismatch in the versions that Webflow 2.4.2 requires? I can post my WebMvcConfig and WebFlowConfig or the pom.xml or any other info if that would help.

Any assistance would be greatly appreciated.

EDIT #1: excerpts from java config

    From WebFlowConfig.java: 
    @Bean
    public FlowDefinitionRegistry flowRegistry() {
        return getFlowDefinitionRegistryBuilder(flowBuilderServices())
            .setBasePath("/WEB-INF/views")
            .addFlowLocationPattern("/**/*-flow.xml")
            .build();               
    }

    From WebMvcConfig.java
    @Override
    public void addViewControllers(final ViewControllerRegistry registry) {
        super.addViewControllers(registry);
        registry.addViewController("/recipe/basics.htm");        
        registry.addViewController("/recipe/ingredients.htm");
        registry.addViewController("/recipe/instructions.htm");
        registry.addViewController("/recipe/optional.htm");
        registry.addViewController("/recipe/end.htm");
    }

Using 2.0 all of the pages are executed in the correct order.

EDIT #2

I forgot to mention that even with the 2.4 xsd compile error the webflow does get executed, same as in the post from a year ago. I also found this issue regarding STS: webflow config gives incorrect "Start state definition is missing." error. The indicated fix version is 3.3.0.M1 so I would assume (?) the fix is still included in STS 3.6.4.

Upvotes: 2

Views: 4052

Answers (3)

user7152981
user7152981

Reputation:

I have finally found the solution.

Eclipse think "Start state is missing" because he thinks the XML is a "Spring Web Flow Definition File", but he is wrong. The solution is to tell Eclipse the XML is not a "Spring Web Flow Definition File".

Open "Spring Explorer", you will find the XML shown in "Web Flow", right click and select "Properties", you can see the XML is in "Web Flow Support / Config Files" list. Just remove it.

screenshot

Upvotes: 1

LWK69
LWK69

Reputation: 1080

I spent several hours trying everything I could think of, including replacing nearly everything in the pom.xml with the contents of the pom.xml from the booking-mvc sample project, which was not displaying this error in spite of also being set to version 2.4.2. Since webflow seems to be tied into Thymeleaf and Tiles (which I am not using) I thought there might be a dependency in those projects which would remove the error. There was not.

So I went through the properties of the booking-mvc project and compared them to mine. The only relevant difference I could see was in the Spring | Web Flow Support. My project listed my recipe-flow.xml, but booking-mvc did not display its -flow.xml file. Once I removed my flow.xml file the error disappeared.

enter image description here

I have no idea how the file ended up in this config location and I can't find any documentation on what this property is for, but apparently it's a no-no, at least in my project. It took a while to get my pom.xml back in shape but the app is now working again.

Upvotes: 4

Selwyn
Selwyn

Reputation: 3198

Here are the differences between the 2.0 and 2.4 xsd's

http://diffchecker.com/oqx5rq7t

With the only diffrence being the addition of validation-hints attribute.

Not sure what else can be deduced from that. Maybe this is a bug with eclipse/STS with how it is parsing the xsd files.

As Rossen indicated in the SWF jira ticket every sub element in the xsd is defined with minOccurs="0" https://jira.spring.io/browse/SWF-1646

so I think this isn't a SWF issue but a STS/Eclipse parsing issue.

Upvotes: 1

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