Jira plugin, using WebItemProvider, seeing 'cannot cast exception'

Damon Osgood

Jira 7.2.2

I need to generate some menu items dynamically. From what I've read, it seems that the way to do this is to add a web-section in my atlassian-plugin.xml:

<web-section
        key="create-document-section"
        i18n-name-key="create-document-section.name"
        location="opsbar-operations"
        weight="100">
  <label key="create-document-section.label"/>
</web-section>

And then a web-item-provider stanza:

<web-item-provider key="create-document-menu-item-factory"
                   name="Create Document Menu Item Factory"
                   section="create-document-section"
                   i18n-name-key="create-document-item-factory.name"
                   class="com.blizzard.web.DynamicLinkFactory" />

And then implement WebItemProvider:

package com.blizzard.web;

import com.atlassian.plugin.web.api.WebItem;
import com.atlassian.plugin.web.api.model.WebFragmentBuilder;
import com.atlassian.plugin.web.api.provider.WebItemProvider;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;


public class DynamicLinkFactory implements WebItemProvider {

@Override
 public Iterable<WebItem> getItems(Map<String, Object> context) {

final List<WebItem> links = new ArrayList<WebItem>();

 links.add(new WebFragmentBuilder(10).
 id("create_document_item").
 label("test").
 title("temp").
 webItem("create-document-section").
 url("/browse/").
 build());

 return links;
 }
}

This compiles and loads into Jira, but when a page is rendered, I get:

...DynamicLinkFactory cannot be cast to 
com.atlassian.plugin.web.api.provider.WebItemProvider'.
Web-items provided by this provider will be ignored.

What am I doing wrong?

 

Update:

I have a theory that JIRA and my plugin are both loading DynamicLinkFactory, and the casting problem is a result of the ambiguity between the two. I have jira-api listed as a "provided" dependency:

<dependency>
    <groupId>com.atlassian.jira</groupId>
    <artifactId>jira-api</artifactId>
    <version>${jira.version}</version>
    <scope>provided</scope>
</dependency>

 And I have tried with and without atlassian-plugins-webfragment-api listed:

<dependency>
   <groupId>com.atlassian.plugins</groupId>
   <artifactId>atlassian-plugins-webfragment-api</artifactId>
   <version>4.1.0</version>
   <scope>provided</scope>
</dependency>

 But there has been no effect.

 

Can anyone tell me if I'm on the right track? And if so, maybe how to resolve the issue?

Damon Osgood

I have solved my problem. I iterated on this many times, and in the course of iteration I mistakenly left a duplicate copy of the webfragment-api dependency in my pom, but without the <scope>provided</scope>, like this:

<dependency>
   <groupId>com.atlassian.plugins</groupId>
   <artifactId>atlassian-plugins-webfragment-api</artifactId>
   <version>4.1.0</version>
</dependency>

So the webfragment-api classes were actually being packaged into my jar, causing the ambiguity I described above. Ensuring there was only one reference to this dependency, with <scope>provided</scope>, resolved my issue.

To be completely clear, it needed to look like this:

<dependency>
   <groupId>com.atlassian.plugins</groupId>
   <artifactId>atlassian-plugins-webfragment-api</artifactId>
   <version>4.1.0</version>
   <scope>provided</scope>
</dependency>