Missing PATCH request for REST

[Avit]

I’m using KNIME in combination with MS PowerBI and trying to publish reports from KNIME using the PowerBI REST API. Unfortunately the PATCH request is not available as a node (unlike the more regular GET, POST, PUT and DELETE). In order to update e.g. a data source for the report PowerBI uses PATCH, and I did not find a way around it with other commands.

Also tried falling back to the Java node and use an HTTPConnection, but I run into the same issue: request type is not supported.

Does anyone have suggestions how to proceed?
(any change the PATCH request node will be added to the REST-set?)

[Avit]

Found a work-around in Java’s HTTPURLConnection… using reflection classes to change final fields at runtime

HttpURLConnection http = (HttpURLConnection) url.openConnection();
//http.setRequestMethod(“PATCH”);

final Object target;
if (http instanceof HttpsURLConnectionImpl) {
	final Field delegate = HttpsURLConnectionImpl.class.getDeclaredField("delegate");
	delegate.setAccessible(true);
	target = delegate.get(http);
} else {
	target = http;
}
final Field f = HttpURLConnection.class.getDeclaredField("method");
f.setAccessible(true);
f.set(target, "PATCH");

[marten_kose]

Thanks for sharing your workaround. I think a PATCH Request node would be a good extension for our REST Web Services, therefore I’ve opened a feature request for a dedicated PATCH Request node.

[David_Ko]

Yes please, we need a PATCH request with a triple store running datalog rules that does not accept any other way to delete the rules.

Do you have a timeline for creating a PATCH node?

David

[David_Ko]

we have a similar problem, would it be possible to share the workaround as a workflow? not sure how to get the java approach to work.

Best

David

[kkam]

I found a workaround by writing a custom REST PATCH API call using Okhttp ->
https://square.github.io/okhttp/.

JAR file download -> https://jar-download.com/artifacts/com.squareup.okhttp3/okhttp/4.2.1/source-code

The actual code from my java snippet, feel free to make changes as needed

// imports for input and output fields
import javax.json.JsonValue;

// Your custom imports:
import okhttp3.Headers;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;
import okhttp3.MediaType;
import java.io.IOException;
// system variables
public class JSnippet extends AbstractJSnippet {
// Fields for input columns
/** Input column: “json_body” /
public JsonValue c_json_body;
/* Input column: “patch_url” /
public String c_patch_url;
// Fields for input flow variables
/* Input flow variable: “auth header” */
public String v_authheader;

// Fields for output columns
/** Output column: “okHeader” /
public String[] out_okHeader;
/* Output column: “okResponse” /
public String out_okResponse;
/* Output column: “out_okError” /
public String out_okError;
/* Output column: “okMessage” */
public String out_okMessage;

// Your custom variables:

// expression start

// Enter your code here:
OkHttpClient httpClient = new OkHttpClient();
String json = c_json_body.toString();
MediaType JSON = MediaType.parse(“application/json; charset=utf-8”);

RequestBody body = RequestBody.create(json, JSON);

Request request = new Request.Builder()
.url(c_patch_url)
.addHeader(“Authorization”, v_authheader) // add request headers
.addHeader(“Content-Type”, “application/json”)
.patch(body)
.build();

try (Response response = httpClient.newCall(request).execute()) {

if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);




// Get response headers
Headers responseHeaders = response.headers();
out_okHeader = new String[responseHeaders.size()];
for (int i = 0; i < responseHeaders.size(); i++) {
 out_okHeader[i] = responseHeaders.name(i) + ": " + responseHeaders.value(i);
}

// Get response body

out_okResponse = response.body().string();

out_okMessage = response.message();
out_okError = "None";

} catch (IOException e) {
out_okError = e.getMessage();
}

[rjrumsey]

Hello,

Has there been any movement on the creation of an actual PATCH node? I would like to avoid creating any special logic. Thank you. @Marten_Pfannenschmidt

[DennisHandt]

Hey @Iris,
same here, a PATCH Request Node would be really useful.
Thanks

[Iris]

Hi @DennisHandt and all,

we have the node already ready for the 4.3. release, which will be released on sunday

Best, Iris