Restful Datasource with url parameter replacement

[fbdo]

Hi all!

I'm new to the SmartClient and to SmartGWT, and I don't know how obvious my information is, but for I needed to do a lot of research to get a good solution, and take a piece off the puzzle here and there to accomplish my objective, and I want to contribute.
In my project, we are using a Restful architecture, and I extended the RestDataSource setting all the properties to use GET, PUT, POST and DELETE verbs, and to do parameter replacement in case like http://server/resources/order/{id}/orderitem{id}.

The code follows:

public class RestfulDataSource extends RestDataSource {

    private OperationBinding[] operationBindings;

    public RestfulDataSource(String id, String fetchUrl, String addUrl, String updateUrl, String removeUrl) {
        super();
        this.setID(id);
        Map<String, String> headers = new HashMap<String, String>();
        headers.put("Accept", "text/xml");

        setDataFormat(DSDataFormat.XML);
        setJsonRecordXPath("data");


        OperationBinding fetch = new OperationBinding();
        fetch.setOperationType(DSOperationType.FETCH);
        fetch.setDataProtocol(DSProtocol.GETPARAMS);
        fetch.setDataURL(fetchUrl);
        DSRequest fetchRequest = new DSRequest();
        fetchRequest.setHttpHeaders(headers);
        fetch.setRequestProperties(fetchRequest);

        OperationBinding add = new OperationBinding();
        add.setOperationType(DSOperationType.ADD);
        add.setDataProtocol(DSProtocol.POSTMESSAGE);
        add.setDataURL(addUrl);
        DSRequest addRequest = new DSRequest();
        addRequest.setHttpHeaders(headers);
        add.setRequestProperties(fetchRequest);

        OperationBinding update = new OperationBinding();
        update.setOperationType(DSOperationType.UPDATE);
        update.setDataProtocol(DSProtocol.GETPARAMS);
        DSRequest updateRequest = new DSRequest();
        updateRequest.setHttpMethod("PUT");
        updateRequest.setHttpHeaders(headers);
        update.setRequestProperties(updateRequest);
        update.setDataURL(updateUrl);

        OperationBinding remove = new OperationBinding();
        remove.setOperationType(DSOperationType.REMOVE);
        remove.setDataProtocol(DSProtocol.GETPARAMS);
        DSRequest removeRequest = new DSRequest();
        removeRequest.setHttpMethod("DELETE");
        removeRequest.setHttpHeaders(headers);
        remove.setRequestProperties(removeRequest);
        remove.setDataURL(removeUrl);

        operationBindings = new OperationBinding[]{fetch, add, update, remove};

        this.setOperationBindings(operationBindings);
    }

    
    @Override
    protected Object transformRequest(DSRequest dsRequest) {

        for (OperationBinding operationBinding : operationBindings) {
            if (dsRequest.getOperationType().equals(operationBinding.getOperationType())) {
                String url = operationBinding.getDataURL();
                int start = url.indexOf('{');
                int end = url.indexOf('}');
                while (start != -1 && end != -1) {
                    String parametro = url.substring(start + 1, end);
                    url = url.replace("{" + parametro + "}",
                            JSOHelper.getAttribute(dsRequest.getData(), parametro));
                    start = url.indexOf('{');
                    end = url.indexOf('}');
                }
                dsRequest.setActionURL(url);
                return super.transformRequest(dsRequest);
            }
        }

        return super.transformRequest(dsRequest);
    }
}

Please, if you know how to do this better, send the code and show how miserable I am.

Thanks!

[jlanza]

I have to do the same thing and I have recently found that gwt includes or is gonna include RegExp support.

Have a look at
http://code.google.com/p/google-web-toolkit/issues/detail?id=1727
http://code.google.com/p/google-web-toolkit/source/browse/trunk/user/src/#src/com/google/gwt/regexp/

[davidj6]

I have been watching the following internet draft with an intention to add support to DataSource in the future: URI Template. The intent will be to expand the template based on the record contents automatically.