Services working using on-demand class definitions (from .srv files)

Author: chfritz

example.js

@@ -5,7 +5,8 @@ let rosnodejs = require('./index.js');
 // const SetBool = rosnodejs.require('std_srvs').srv.SetBool;
 
 // aspirational:
-rosnodejs.use(['std_msgs/String'], function() {
+rosnodejs.use(['std_msgs/String'], 
+              ['std_srvs/SetBool'], function() {
 
   const msg = new (rosnodejs.message('std_msgs/String'))(
     { data: "howdy" });
@@ -18,36 +19,48 @@ rosnodejs.use(['std_msgs/String'], function() {
   rosnodejs.initNode('/my_node')
     .then((rosNode) => {
       // EXP 1) Service Server
-      // let service = rosNode.advertiseService({
-      //   service: '/set_bool',
-      //   type: 'std_srvs/SetBool'
-      // }, (req, resp) => {
-      //   console.log('Handling request! ' + JSON.stringify(req));
-      //   resp.success = !req.data;
-      //   resp.message = 'Inverted!';
-      //   return true;
-      // });
+      let service = rosNode.advertiseService({
+        service: '/set_bool',
+        type: 'std_srvs/SetBool'
+      }, (req, resp) => {
+        console.log('Handling request! ' + JSON.stringify(req));
+        resp.success = !req.data;
+        resp.message = 'Inverted!';
+        return true;
+      });
 
       // // EXP 2) Service Client
-      // let serviceClient = rosNode.serviceClient({
-      //   service: '/set_bool',
-      //   type: 'std_srvs/SetBool'
-      // });
-      // rosNode.waitForService(serviceClient.getService(), 2000)
-      // .then((available) => {
-      //   if (available) {
-      //     const request = new SetBool.Request();
-      //     request.data = true;
-      //     serviceClient.call(request, (resp) => {
-      //       console.log('Service response ' + JSON.stringify(resp));
-      //     });
-      //   }
-      // });
+      setTimeout(function() {
+        let serviceClient = rosNode.serviceClient({
+          service: '/set_bool',
+          type: 'std_srvs/SetBool'
+        });
+        rosNode.waitForService(serviceClient.getService(), 2000)
+          .then((available) => {
+            if (available) {
+              console.log('Service available');     
+              // const request = new SetBool.Request();
+              // request.data = true;
+              // #HERE
+              const request = 
+                new (rosnodejs.serviceRequest('std_srvs/SetBool'))({ 
+                  data: true });
+              console.log("call service", request);
+              serviceClient.call(request, (resp) => {
+                console.log('Service response ' + JSON.stringify(resp));
+              });
+            } else {
+              console.log('Service not available');     
+            }
+          });
+      }, 1000); // wait a second before calling our service
 
-      // // EXP 3) Params
-      // rosNode.setParam('~junk', {'hi': 2}).then(() => {
-      //   rosNode.getParam('~junk').then((val) => { console.log('Got Param!!! ' + JSON.stringify(val)); });
-      // });
+      // EXP 3) Params
+      rosNode.setParam('~junk', {'hi': 2}).then(() => {
+        rosNode.getParam('~junk').then((val) => { 
+          console.log('Got Param!!! ' + JSON.stringify(val)); 
+        });
+      });
 
       // // EXP 4) Publisher
       let pub = rosNode.advertise({

index.js

@@ -137,22 +137,17 @@ let Rosnodejs = {
     return pack;
   },
 
-  /** get new object of the message class type for the given ROS
-   * message type
-   */
-  getMessage(type, cb) {
-    messages.getMessage(type, function(error, Message) {
-      // console.log(error, Message);
-      if (error) {
-        cb(error, null);
-      } else {
-        cb(null, new Message());
-      }
+  /** create message classes and services classes for all the given
+   * types before calling callback */
+  use(messages, services, callback) {
+    const self = this;
+    this._useMessages(messages, function() {
+      self._useServices(services, callback);
     });
   },
 
   /** create message classes for all the given types */
-  use(types, callback) {
+  _useMessages(types, callback) {
     var Messages = [];
     types.forEach(function(type) { 
       messages.getMessage(type, function(error, Message) {
@@ -164,12 +159,34 @@ let Rosnodejs = {
     });
   },
 
+  /** create message classes for all the given types */
+  _useServices(types, callback) {
+    var count = types.length;
+    types.forEach(function(type) { 
+      messages.getServiceRequest(type, function() {
+        messages.getServiceResponse(type, function() {
+          if (--count == 0) {
+            callback();
+          }
+        });
+      });
+    });
+  },
+
   /** get message definition class from registry. Do not generate it
    * from .msg file if it doesn't already exist. This is mostly
    * because that would need to be async right now and we want a sync
    * method. */
   message(type) {
-    return messages.getMessageFromRegistry(type);
+    return messages.getFromRegistry(type, "message");
+  },
+
+  serviceRequest(type) {
+    return messages.getFromRegistry(type, "request");
+  },
+
+  serviceResponse(type) {
+    return messages.getFromRegistry(type, "response");
   },
 
   /**

utils/message_utils.js

@@ -208,7 +208,7 @@ let MessageUtils = {
       return messagePackage.msg[type];
     } else {
       // console.log("get message from registry");
-      let type = messages.getMessageFromRegistry(rosDataType);
+      let type = messages.getFromRegistry(rosDataType, "message");
       if (type) {
         // console.log("got message from registry", type);
         return new type();
@@ -226,10 +226,21 @@ let MessageUtils = {
     if (messagePackage) {
       let type = parts[1];
       return messagePackage.srv[type];
-    }
-    else {
-      console.error('Unable to find message package ' + msgPackage);
-      throw new Error();
+    } else {
+      // console.log("get service from registry");
+      let request = messages.getFromRegistry(rosDataType, "request");
+      let response = messages.getFromRegistry(rosDataType, "response");
+      if (request && response) {
+        return { 
+          // Request: new request(),
+          // Response: new response()
+          Request: request,
+          Response: response
+        };
+      } else {
+        console.error('Unable to find message package ' + msgPackage);
+        throw new Error();
+      }
     }
   }
 };

utils/messages.js

@@ -14,8 +14,8 @@ messages.getMessage = function(messageType, callback) {
   this.getMessageFromPackage(messageType, "message", callback);
 }
 
-messages.getMessageFromRegistry = function(messageType) {
-  return getMessageFromRegistry(messageType, "message");
+messages.getFromRegistry = function(messageType, type) {
+  return getMessageFromRegistry(messageType, type);
 }
 
 messages.getServiceRequest = function(messageType, callback) {

utils/xmlrpc_utils.js

@@ -23,6 +23,7 @@ module.exports = {
         }
         else if (err || resp[0] !== 1) {
           log.warn('Some other error during %s: %s, %j', method, err, resp);
+          log.warn((new Error()).stack);
           reject(err, resp);
         }
         else {