How to call D2FS method from custom D2 service

Hello,

The "D2 4.X Plugins and Extensions" document explains that for any D2FS service which you want to call via OAH, which doesn't have signature of:


public List<Attribute> methodName(Context context, String id, List<Attribute> parameters


...it will be necessary to create a custom plugin action with a standard signature, as described in the Plugin action section

So, I want to call IBrowserService from my custom D2 service (implementing IPluginAction).

So far the only option that works for me is to use the generated D2FS client and use the GetBrowserContentRequest object.

I'm wondering if it is possible to inject or instantiate the the service somehow, so that I could use the IBrowserService interface instead.

I dug in the D2 source code and I found there is a factory class:


ID2Service service = D2ServiceFactory.getInstance().getService(ID2Service.class, serviceContext);

which takes D2ServiceProfile as an argument later on, but there is no Profile for Browse service.

Any ideas?

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Comments

Walid Boussandel

Hi,

Why do you want to call the IBrowserService from a CustomService action ?

The IBrowserService only contains methods that return the Browser Content.

- The D2FS web service are useful to call D2 Services from external application.

- Custom Service actions are useful to enrich or modify the behaviour of an existing ACTION.

If you want to locate a folder, you just need to use the publish event action in the menu config with D2_ACTION_OPEN_FOLDER event.

KJurkowski

Why do you want to call the IBrowserService from a CustomService action ?

Because writing backend of a widget using CustomService has following benefits:

I don't have to bundle dfc and dfc.properties inside the widget - this way it is environment independent.
I don't have to bother about session management, parse user and ticket form widget url
This way my widget can be a pure JS application using OAH as a gateway to the backend which is managed by D2

And in fact, as I wrote, I don't want to call IBrowserService from CustomService - I'm doing it only because I have to - because calling it from OAH doesn't seem to work.


- Custom Service actions are useful to enrich or modify the behaviour of an existing ACTION.

Not true, you can use it to build something that is not provided OOTB.

In my case, I'm using the list of nodes returned by IBrowserService to generate my own custom tree.

AlvaroRomanFdez

Hi Krzysztof


Because writing backend of a widget using CustomService has following benefits:

Do you achieve this aprox?

How you can connect the CustomService Plugin with the Widget? I mean, The widget can send OAH message to some event, and you can custom native Services like ExportService or SavePropertySevice with a IPuginAction. But I'm not sure how a CustomService Plugin could be work in conjunction with a widget. But it would be great.

KJurkowski

Assume you have a DummyService class that implements IPluginAction, with a method dummyAction:


public class DummyService implements IPluginAction {
     public List dummyAction(D2fsContext context) throws DfException, D2fsException {

          Listresult = new ArrayList();
          Attribute dummyAttr = new Attribute();

          IDfSysObject dummyObject = (IDfSysObject) context.getSession()
                    .getObjectByQualification("dm_document where object_name='My dummy object'");
          dummyAttr.setName("dummy_attribute");
          dummyAttr.setValue(dummyObject.getSubject());
          result.add(dummyAttr);

          return result;
     }
}

To call the dummyAction method from DummyService class via OAH you have to call


var message = new OpenAjaxMessage();
message.put("CHANNEL_EVENT", "D2_ACTION_EXECUTE");
// here you specify the name of the class and method, that you want to call 
message.put("eService", "DummyService"); 
message.put("eMethod", "dummyAction"); 
message.put("eMode", "SINGLE");

// here you specify how you will be notified about the results from the method
message.put("rAction", "D2_EVENT_CUSTOM");
message.put("rType", "EVENT");
     
d2OpenAjaxHub.sendMessage("D2_ACTION_EXECUTE", message);

You can pass any custom or build in attribute inside the message, and this way provide additional parameters for your custom method.To retrieve them you need to call:


context.getParameterParser().getStringParameter("parameter_name")

When dummyAction is executed you will receive D2_EVENT_CUSTOM event with message containing dummy_attribute and it's value.

The only tricky part is when you use multiple services - since you will probably choose that results will arrive wrapped in D2_EVENT_CUSTOM event, you have to prepare a mechanism which will allow you to distinguish to which callback you should dispatch the result.

In the OAH framework for GWT which I prepared and published on I handled it by storing the callback object hashcode, plus storing the eService and eMethod for informational purposes:


// store hashcode to identify the AsynchCallback object to which the response message will be passed
Attribute callbackAttr = new Attribute();
callbackAttr.setName("callback_code");
callbackAttr.setValue(context.getParameterParser().getStringParameter("callback_code", null));
result.add(callbackAttr);

// store the called service (for informational purposes)
Attribute serviceAttr = new Attribute();
serviceAttr.setName("eService");
serviceAttr.setValue(context.getParameterParser().getStringParameter("eService", null));
result.add(serviceAttr);

// store the called method of the service (for informational purposes)
Attribute methodAttr = new Attribute();
methodAttr.setName("eMethod");
methodAttr.setValue(context.getParameterParser().getStringParameter("eMethod", null));
result.add(methodAttr);

In couple of weeks I will publish code and tutorial in my blog series, demonstrating how to build custom Searches widget, which will involve displaying custom Public searches dialogs.