Added gateway-specific Q-Apps handler. For now, just show a warning alert if an app requires authentication / interactive features.

src/main/java/org/qortal/api/HTMLParser.java

@@ -7,6 +7,8 @@ import org.jsoup.nodes.Document;
 import org.jsoup.select.Elements;
 import org.qortal.arbitrary.misc.Service;
 
+import java.util.Objects;
+
 public class HTMLParser {
 
     private static final Logger LOGGER = LogManager.getLogger(HTMLParser.class);
@@ -43,6 +45,12 @@ public class HTMLParser {
             String qAppsScriptElement = String.format("<script src=\"/apps/q-apps.js?time=%d\">", System.currentTimeMillis());
             head.get(0).prepend(qAppsScriptElement);
 
+            // Add q-apps gateway script tag if in gateway mode
+            if (Objects.equals(this.qdnContext, "gateway")) {
+                String qAppsGatewayScriptElement = String.format("<script src=\"/apps/q-apps-gateway.js?time=%d\">", System.currentTimeMillis());
+                head.get(0).prepend(qAppsGatewayScriptElement);
+            }
+
             // Escape and add vars
             String service = this.service.toString().replace("\"","\\\"");
             String name = this.resourceId != null ? this.resourceId.replace("\"","\\\"") : "";

src/main/java/org/qortal/api/resource/AppsResource.java

@@ -54,4 +54,30 @@ public class AppsResource {
         }
     }
 
+    @GET
+    @Path("/q-apps-gateway.js")
+    @Hidden // For internal Q-App API use only
+    @Operation(
+            summary = "Gateway-specific interface for Q-Apps",
+            responses = {
+                    @ApiResponse(
+                            description = "javascript",
+                            content = @Content(
+                                    mediaType = MediaType.TEXT_PLAIN,
+                                    schema = @Schema(
+                                            type = "string"
+                                    )
+                            )
+                    )
+            }
+    )
+    public String getQAppsGatewayJs() {
+        URL url = Resources.getResource("q-apps/q-apps-gateway.js");
+        try {
+            return Resources.toString(url, StandardCharsets.UTF_8);
+        } catch (IOException e) {
+            throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FILE_NOT_FOUND);
+        }
+    }
+
 }

src/main/resources/q-apps/q-apps-gateway.js

@@ -0,0 +1,38 @@
+console.log("Gateway mode");
+
+window.addEventListener("message", (event) => {
+    if (event == null || event.data == null || event.data.length == 0) {
+        return;
+    }
+    if (event.data.action == null || event.data.requestedHandler == null) {
+        return;
+    }
+    if (event.data.requestedHandler != "UI") {
+        // Gateway mode only cares about requests that were intended for the UI
+        return;
+    }
+
+    let response;
+    let data = event.data;
+
+    switch (data.action) {
+        case "GET_USER_ACCOUNT":
+        case "PUBLISH_QDN_RESOURCE":
+        case "SEND_CHAT_MESSAGE":
+        case "JOIN_GROUP":
+        case "DEPLOY_AT":
+        case "GET_WALLET_BALANCE":
+        case "SEND_COIN":
+            const errorString = "Authentication was requested, but this is not yet supported when viewing via a gateway. To use interactive features, please access using the Qortal UI desktop app. More info at: https://qortal.org";
+            alert(errorString);
+            response = "{\"error\": \"" + errorString + "\"}"
+            break;
+
+        default:
+            console.log('Unhandled gateway message: ' + JSON.stringify(data));
+            return;
+    }
+
+    handleResponse(event, response);
+
+}, false);