4.2.1.1. Client

Warning

WIP

The openEHR Client is the foundation of all following functionalities. It needs to be created and set up before the endpoints can be used.

4.2.1.1.1. Interface and implementation

All compatible clients need to implement the OpenEhrClient Interface.

Standard operation is possible with the included DefaultRestClient implementation.

4.2.1.1.2. Client setup

To set up a default client it is necessary to create a new instance, which requires the following components as parameters:

• OpenEhrClientConfig containing the base URI of the openEHR REST API backend server
• Optional (if not given, templates will be queried from the remote system) add a TemplateProvider (see below)

Together a typical setup might look like:

DefaultRestClient client = new DefaultRestClient(
    new OpenEhrClientConfig(new URI("http://localhost:8080/ehrbase/")),
    templateProvider);

4.2.1.1.3. Template provider

The TemplateProvider interface needs an implementation that gives the SDK access to the templates used.

Technically, it needs to provide a function Optional<OPERATIONALTEMPLATE> find(String s) which returns an object representation of a given template ID.

An example is the TestDataTemplateProvider from the SDK’s own integration tests:

@Override
public Optional<OPERATIONALTEMPLATE> find(String templateId) {
    return Optional.ofNullable(OperationalTemplateTestData.findByTemplateId(templateId))
            .map(OperationalTemplateTestData::getStream)
            .map(s -> {
                try {
                    return TemplateDocument.Factory.parse(s);
                } catch (XmlException | IOException e) {
                    throw new RuntimeException(e.getMessage(), e);
                }
            })
            .map(TemplateDocument::getTemplate);
}

Please also see the used OperationalTemplateTestData enum to understand how actual .opt files can be made accessible.

4.2.1.1.4. Additional steps

Now the client is set up and ready to be used. Before going on it might make sense to sync your backend with the templates used by your client.

The template provider could have a listTemplateIds() method for that purpose. So the following would use this method and the template endpoint (see Template endpoint) to make sure all templates of this clients scope are available in the backend.

templateProvider.listTemplateIds().forEach(
        t -> client.templateEndpoint().ensureExistence(t)
);