added on nodes for rtdb and firestore andmade nodes pass through msg objects with as little changes as possible

firestore/firestore-on.js

@@ -0,0 +1,51 @@
+
+let msgin
+let unsub
+
+module.exports = function(RED) {
+  function FirebaseAdmin(config) {
+    RED.nodes.createNode(this, config);
+    var node = this;
+
+    if(config.cred){
+      let c = RED.nodes.getNode(config.cred)
+      this.admin = c.admin
+    }
+
+    const setup = ()=>{
+      if(unsub){
+        unsub()
+      }
+      this.admin.firestore().doc(path).onSnapshot(cb)
+    }
+
+    const cb = (res)=>{
+      console.log('firestore get result '+res)
+      console.dir(res)
+      let val = res.data()
+      console.log('val='+val)
+      if(msgin){
+        msgin.payload = val
+        node.send(msgin)
+      } else {
+        node.send({payload: val})
+      }
+    }
+
+    node.on('input', function(msg) {
+      if(msg && msg.payload){
+        msgin = msg
+        const path = msg.payload.path
+        setup(path)
+
+      }
+    }.bind(this));
+
+    if(config.path){
+      setup(config.path)
+    }
+
+
+  }
+  RED.nodes.registerType("firestore-on", FirebaseAdmin);
+}