# Dumb question about editing a node

**URL:** <https://discourse.nodered.org/t/dumb-question-about-editing-a-node/34434>\
**Category:** General\
**Created:** [18 October 2020 04:20 UTC](https://discourse.nodered.org/t/dumb-question-about-editing-a-node/34434 "2020-10-18T04:20:46Z")\
**Posts on this page:** 20\
**Page:** 1

<div class="post-metadata">

**Author:** ![hepcat72](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/hepcat72/32/8078_2.png) [@hepcat72](https://discourse.nodered.org/u/hepcat72)\
**Post date:** [18 October 2020 04:20 UTC](https://discourse.nodered.org/t/dumb-question-about-editing-a-node/34434/1 "2020-10-18T04:20:46Z")

</div>

Hi,

I installed a node red node the other day and noticed some buggy behavior. I've never worked on a node before, let alone a project in javascript, yet I was able to successfully make changes to the server.js script in the node's directory in `/home/pi/.node-red/node_modules/...`. I have copied those changes to a fork of the node on github.

However, I then set about seeing if I could add a config option to the companion .js and .html file. All I did was try to add a select list. First I tried a dynamic select list using `oneditprepare`, but not only did I not see the list appear in the node's edit panel, I don't even see the label or any indication that I've changed the html file at all.

I restarted my whole raspberry pi and still I see no differences. I understand I'm probably not using a proper development strategy, but is there a way to make changes to the node's edit interface show?

The node is still functioning properly and still reflects the changes I made to server.js.

That asked, what's the best way to tinker with a node's code? Should I create a whole separate copy somehow and give it a different name? How do I deploy changes for testing?

---

<div class="post-metadata">

**Author:** ![hepcat72](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/hepcat72/32/8078_2.png) [@hepcat72](https://discourse.nodered.org/u/hepcat72)\
**Post date:** [18 October 2020 05:49 UTC](https://discourse.nodered.org/t/dumb-question-about-editing-a-node/34434/2 "2020-10-18T05:49:52Z")

</div>

OK. I figured out that I needed to empty my browser cache.

I have another dumb question. I'm trying to add a dynamically populated select list in the node's edit pane (the node's name is `location`) via a `RED.httpAdmin.get('/location/:cmd', RED.auth.needsPermission('location.read'), function(req, res){...` method in location.js, but to get the values, I need to grab them from the configuration node (named `server`).

At first, I got an error when I just tried to access the server via `node.server` (I had guessed it was saved as a member of the location node object based on the constructor code (I'm not well versed in javascript). So I copied the code from the constructor that grabs the server:

`node.server = RED.nodes.getNode(node.config.server);`

However, when that line executes, it yields this error in the node red error log:

`TypeError: Cannot read property 'config' of null`

How do I get data from the configuration node for the select list in the location node's edit panel?

---

<div class="post-metadata">

**Author:** ![BartButenaers](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/bartbutenaers/32/10476_2.png) [@BartButenaers](https://discourse.nodered.org/u/BartButenaers)\
**Post date:** [18 October 2020 06:17 UTC](https://discourse.nodered.org/t/dumb-question-about-editing-a-node/34434/3 "2020-10-18T06:17:24Z")

</div>

> [@hepcat72](#):
>
> How do I get data from the configuration node for the select list in the location node's edit panel?

Hi Robert,  
if you have a look at this [discussion](https://discourse.nodered.org/t/issues-with-loading-async-list-for-drop-down-in-edit-dialogue/33409/2), you can see that the client-side code differs a little bit from the server-side code:

```auto
var configNode = RED.nodes.node(configNodeId);

```

There are other people who had the same questions as you in the past (inclusive me ....).  
It is always useful to search on Discourse when you are stuck, because there are already quite some code snippets available.

Good luck with it!  
Bart

---

<div class="post-metadata">

**Author:** ![hepcat72](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/hepcat72/32/8078_2.png) [@hepcat72](https://discourse.nodered.org/u/hepcat72)\
**Post date:** [18 October 2020 12:19 UTC](https://discourse.nodered.org/t/dumb-question-about-editing-a-node/34434/4 "2020-10-18T12:19:52Z")

</div>

Thanks! I'll take a look. I did search a decent bit for this before asking, but as with my first dumb question, I appear to be completely inept at knowing what terms will reveal the relevant results.

---

<div class="post-metadata">

**Author:** ![hepcat72](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/hepcat72/32/8078_2.png) [@hepcat72](https://discourse.nodered.org/u/hepcat72)\
**Post date:** [18 October 2020 19:25 UTC](https://discourse.nodered.org/t/dumb-question-about-editing-a-node/34434/5 "2020-10-18T19:25:34Z")

</div>

OK. So I tried out how I interpreted that thread, but it seems I don't have it quite right. When I tried this:

```
var configNode = RED.nodes.getNode(req.params.config_node_id);
var server = RED.nodes.getNode(configNode.server);
let circles = server.updateLife360();

```

I got this:

```
TypeError: Cannot read property 'server' of null

```

So I guessed maybe `configNode` _was_ server and tried this:

```
var server = RED.nodes.getNode(req.params.config_node_id);
//var server = RED.nodes.getNode(configNode.server);
let circles = server.updateLife360();

```

and got this:

```
TypeError: Cannot read property 'updateLife360' of null

```

How do I get back the server node so that I can use its methods to retrieve data? Is there a good documentation source for this type of thing?

---

<div class="post-metadata">

**Author:** ![BartButenaers](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/bartbutenaers/32/10476_2.png) [@BartButenaers](https://discourse.nodered.org/u/BartButenaers)\
**Post date:** [18 October 2020 20:06 UTC](https://discourse.nodered.org/t/dumb-question-about-editing-a-node/34434/6 "2020-10-18T20:06:55Z")

</div>

I don't completely understand the entire setup at the moment. Are my assumptions correct:

1. You are building a node-red-contrib-location node.
2. In the node's edit panel you have a dropdown, which you want to fill automatically by getting the values from your http admin endpoint on the server.
3. In the node you also have a config node, which is named "server".
4. You call the endpoint from the edit panel, and you pass the config node id as input parameter.
5. On the server side you want to get the config node instance, and call its updateLife360 function.

Is that correct?

---

<div class="post-metadata">

**Author:** ![hepcat72](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/hepcat72/32/8078_2.png) [@hepcat72](https://discourse.nodered.org/u/hepcat72)\
**Post date:** [18 October 2020 20:23 UTC](https://discourse.nodered.org/t/dumb-question-about-editing-a-node/34434/7 "2020-10-18T20:23:22Z")

</div>

It seems that even setting the node returns null:

```
RED.httpAdmin.get('/location/:cmd', RED.auth.needsPermission('location.read'), function(req, res){
    var node = RED.nodes.getNode(req.params.id);
    node.warn("Does this work?");

```

I get:

```
TypeError: Cannot read property 'warn' of null

```

I was typing up the above and got your response, so here are the answers:

1. You are building a node-red-contrib-location node.

I'm adding features to an existing disto (fork with testing on my NR instance). It doesn't currently have dynamically populated options in the location node edit panel. I am attempting to add options.

1. In the node's edit panel you have a dropdown, which you want to fill automatically by getting the values from your http admin endpoint on the server.

I am not sure I understand the question because I don't know this topic deeply enough to be precise about where things are happening. This is my first node red project to mess with the underlying code. So let me point you to my fork: [https://github.com/hepcat72/node-red-contrib-life/tree/invld\_null\_loc\_names](https://github.com/hepcat72/node-red-contrib-life/tree/invld_null_loc_names)

My fork has successful edits in it. This attempt to add the dynamic content is only on my laptop.

1. In the node you also have a config node, which is named "server".

The location node has a member named server, which I understand is the config node defined in server.js.

1. You call the endpoint from the edit panel, and you pass the config node id as input parameter.

Not sure I understand. The location.html has this call:

```
    oneditprepare: function() {
        var node = this;

        // Load the available categories from the server
        $.getJSON('location/circles', function(data) {
            // The response is a json hash, containing all the available circles

            $("<option value='sanity'> check </option>").appendTo("#node-input-circle");

            // Show all available circles in the dropdown
            let selectedCircle = "";
            for (const [circleId, circleName] of Object.entries(data)) {
                selectedCircle = circleId;
                $("<option value='" + circleId + "'> " + circleName + "</option>").appendTo("#node-input-circle");
            }

            // When a circle is available, make sure it is selected in the dropdown
            if (selectedCircle) {
                $("#node-input-circle").val(selectedCircle);
                $('#node-input-circle').trigger('change');
            }
        });

```

And the location.js has this code, which does seem to work. I just can't seem to call the updateLife360 method in server.js:

```
// Make all the available circle info accessible for the node's config screen
RED.httpAdmin.get('/location/:cmd', RED.auth.needsPermission('location.read'), function(req, res){
    //Does not work:
    var node = RED.nodes.getNode(req.params.id);

    //Does not work:
    node.warn("Does this work?");

    //These static tests work when I use them to update the select list in the edit dialog
    let test = {};
    test['sanity2'] = 'check2';
    let circles_select = {};

    //These to not work:
    var server = RED.nodes.getNode(req.params.config_node_id);
    //var server = RED.nodes.getNode(configNode.server);
    let circles = server.updateLife360();

```

1. On the server side you want to get the config node instance, and call its updateLife360 function.

Yes

---

<div class="post-metadata">

**Author:** ![hepcat72](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/hepcat72/32/8078_2.png) [@hepcat72](https://discourse.nodered.org/u/hepcat72)\
**Post date:** [18 October 2020 21:10 UTC](https://discourse.nodered.org/t/dumb-question-about-editing-a-node/34434/8 "2020-10-18T21:10:49Z")

</div>

Corrections: the changes only exist on my rPi. Whenever I get something working my trial and error, I update my repo.

By "this topic", I mean node development and JavaScript in general. My only prior experiences with JavaScript other than some simple function nodes lately was With form validation in the early 2000s.

My goal with these edits is to basically reproduce these IFTTT triggers in its Life360 service (which is going away on Nov 2): first circle member to arrive and last circle member to leave a named place.

I ultimately need to query the server node in 2 contexts: once to get the circles and a second time to get the places in the selected circle.

---

<div class="post-metadata">

**Author:** ![BartButenaers](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/bartbutenaers/32/10476_2.png) [@BartButenaers](https://discourse.nodered.org/u/BartButenaers)\
**Post date:** [18 October 2020 21:13 UTC](https://discourse.nodered.org/t/dumb-question-about-editing-a-node/34434/9 "2020-10-18T21:13:17Z")

</div>

> [@hepcat72](#):
>
> `req.params.id`

When do this:

```auto
RED.httpAdmin.get('/location/:cmd', RED.auth.needsPermission('location.read'), function(req, res){
   console.log("req.params.id = " + req.params.id);
   ...

```

Does it write to your log the correct config node id that you expect?

---

<div class="post-metadata">

**Author:** ![hepcat72](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/hepcat72/32/8078_2.png) [@hepcat72](https://discourse.nodered.org/u/hepcat72)\
**Post date:** [18 October 2020 21:15 UTC](https://discourse.nodered.org/t/dumb-question-about-editing-a-node/34434/10 "2020-10-18T21:15:13Z")

</div>

I don't know what the config node ID should be, but I will report back what it says...

Will that output to `~/.pm2/logs/node-red-out.txt`?

---

<div class="post-metadata">

**Author:** ![hepcat72](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/hepcat72/32/8078_2.png) [@hepcat72](https://discourse.nodered.org/u/hepcat72)\
**Post date:** [18 October 2020 21:20 UTC](https://discourse.nodered.org/t/dumb-question-about-editing-a-node/34434/11 "2020-10-18T21:20:10Z")

</div>

> [@BartButenaers](#):
>
> `console.log("req.params.id = " + req.params.id);`

It says:

`req.params.id = undefined`

Ugh. Must be something fundamental wrong.

---

<div class="post-metadata">

**Author:** ![BartButenaers](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/bartbutenaers/32/10476_2.png) [@BartButenaers](https://discourse.nodered.org/u/BartButenaers)\
**Post date:** [18 October 2020 21:22 UTC](https://discourse.nodered.org/t/dumb-question-about-editing-a-node/34434/12 "2020-10-18T21:22:02Z")

</div>

> [@hepcat72](#):
>
> Will that output to `~/.pm2/logs/node-red-out.txt` ?

Don't know about pm2. Should appear where all your other Node-RED logs appear...

> [@hepcat72](#):
>
> I don't know what the config node ID should be

When you look e.g. at the mqtt nodes, you will see how a config node input element looks like:

![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/4/3/4361d5863638bea0dbbf6b3f93b91d2f5f8f4199.png)

As soon as you create such a config node (via the dropdown):

![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/0/c/0ca0b7c37167ef7d9863acc91eeb2d1350ebbe58.png)

You can see the node id of that config node in the sidebar:

![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/4/7/478411c69a180aad9676da8cd6a801485a1d2076.png)

---

<div class="post-metadata">

**Author:** ![BartButenaers](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/bartbutenaers/32/10476_2.png) [@BartButenaers](https://discourse.nodered.org/u/BartButenaers)\
**Post date:** [18 October 2020 21:25 UTC](https://discourse.nodered.org/t/dumb-question-about-editing-a-node/34434/13 "2020-10-18T21:25:35Z")

</div>

> [@hepcat72](#):
>
> Ugh. Must be something fundamental wrong.

Then you need to add some debugging code in your edit panel client side code:

```auto
oneditprepare: function() {
     debugger;
}

```

By adding a `debugger` statement, you can open the developer tools of your browser (where the flow editor is being displayed) and debug your code. You should pass the correct config node id to your endpoint on the server, otherwise it will never work ...

---

<div class="post-metadata">

**Author:** ![hepcat72](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/hepcat72/32/8078_2.png) [@hepcat72](https://discourse.nodered.org/u/hepcat72)\
**Post date:** [18 October 2020 21:43 UTC](https://discourse.nodered.org/t/dumb-question-about-editing-a-node/34434/14 "2020-10-18T21:43:40Z")

</div>

I suspect that when you say anything to do or is happening "client side", you're referring to code that's in the node's HTML file, e.g. location.html. Assuming that's correct, I then interpret "pass the correct config node id" to mean that in this call in the oneditprepare section: `$.getJSON('location/circles', function(data) {`, I need to pass the server's ID.

I believe that call (above) is calling this in `location.js`?: `RED.httpAdmin.get('/location/:cmd', RED.auth.needsPermission('location.read'), function(req, res){`. I'm not sure where it goes in the call, but even then, I'm not sure:

1. whether there's some alias to that ID
2. If I'm passing the actual ID as a string, what the ID is. Because I don't see a correlating "flow" section:

 ![lts-server](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/6/d/6d707fc707c21ee046f315389c88bd2672a6022c.png)

I also assume that "to your endpoint on the server" refers to what's in that location.js code. If I click on the server edit button, I assume this contains the ID I need?:

 ![lts-server-edit-redacted](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/7/5/75dc5541959f8a80f6101feb89513433ff7f8f86.png)

BTW, I really appreciate your patience and help.

---

<div class="post-metadata">

**Author:** ![BartButenaers](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/bartbutenaers/32/10476_2.png) [@BartButenaers](https://discourse.nodered.org/u/BartButenaers)\
**Post date:** [18 October 2020 21:57 UTC](https://discourse.nodered.org/t/dumb-question-about-editing-a-node/34434/15 "2020-10-18T21:57:07Z")

</div>

> [@hepcat72](#):
>
> suspect that when you say anything to do or is happening "client side", you're referring to code that's in the node's HTML file, e.g. location.html. Assuming that's correct, I then interpret "pass the correct config node id" to mean that in this call in the oneditprepare section: `$.getJSON('location/circles', function(data) {` , I need to pass the server's ID.

Yes `server` is the node field that refers to your config node. So I assume you need to pass your config node id as an url parameter:

```auto
$.getJSON('location/circles/' + configNodeId, function(data) {

```

Remark: I assume configNodeId is server.id ....

And then you need to intercept that in your endpoint url:

```auto
RED.httpAdmin.get('/location/:cmd/:config_node_id', RED.auth.needsPer... {

```

Then you should be able to use it in your endpoint as ´req.params.config\_node\_id´.

I now see that you use in your endpoint code both `req.params.id` and `req.params.config_node_id`. But if you don't define them in your url (as `:id` and `:config_node_id`) and pass those parameters via getJSON, those values can never be passed to your endpoint on the server ...

My time is up for today ...

---

<div class="post-metadata">

**Author:** ![hepcat72](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/hepcat72/32/8078_2.png) [@hepcat72](https://discourse.nodered.org/u/hepcat72)\
**Post date:** [18 October 2020 21:59 UTC](https://discourse.nodered.org/t/dumb-question-about-editing-a-node/34434/16 "2020-10-18T21:59:43Z")

</div>

THANK YOU! If you have a venmo, I'll buy you a beer! You've been so helpful.

---

<div class="post-metadata">

**Author:** ![hepcat72](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/hepcat72/32/8078_2.png) [@hepcat72](https://discourse.nodered.org/u/hepcat72)\
**Post date:** [18 October 2020 23:00 UTC](https://discourse.nodered.org/t/dumb-question-about-editing-a-node/34434/17 "2020-10-18T23:00:02Z")

</div>

Well, I now have access to the updateLife360 method, but now I have a new problem. It doesn't return the circles. It updates the circles and triggers changes when a member's location has changed. It just doesn't return the circles... I'll ruminate on this via google for awhile.

---

<div class="post-metadata">

**Author:** ![hepcat72](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/hepcat72/32/8078_2.png) [@hepcat72](https://discourse.nodered.org/u/hepcat72)\
**Post date:** [19 October 2020 00:26 UTC](https://discourse.nodered.org/t/dumb-question-about-editing-a-node/34434/18 "2020-10-19T00:26:49Z")

</div>

I'm so close! I created a method in server.js to return the circles. It's just returning something else. Here' the method I'm calling from the client that's in server.js:

```
    getCircles() {
        var node = this;
        return node.updateSession(function (session) {
            return life360.circles(session)
                .then(circles => {
                    console.log("this gets called after the end of the main stack. the value received and returned is: " + JSON.stringify(circles));
                    return circles;
                })
        });
    }

```

The data I want is what's printed in that console message, but what the client is receiving is:

```
{"isFulfilled":false,"isRejected":false}

```

This is the console message from the server getCirclesMethod:

```
this gets called after the end of the main stack. the value received and returned is: [{"id":"xxxxxxxx","name":"Rob's Homes","color":"da22d5","type":"basic","createdAt":"1379025809","memberCount":"4","unreadMessages":"0","unreadNotifications":"0","features":{"ownerId":null,"skuId":null,"premium":"0","locationUpdatesLeft":0,"priceMonth":"0","priceYear":"0","skuTier":null}},{"id":"xxxxxxxx","name":"Rob's Family","color":"f05929","type":"basic","createdAt":"1393782349","memberCount":"4","unreadMessages":"0","unreadNotifications":"0","features":{"ownerId":null,"skuId":null,"premium":"0","locationUpdatesLeft":0,"priceMonth":"0","priceYear":"0","skuTier":null}},{"id":"xxxxxxxx","name":"Leach Family","color":"7f26c2","type":"basic","createdAt":"1393785316","memberCount":"6","unreadMessages":"0","unreadNotifications":"0","features":{"ownerId":null,"skuId":null,"premium":"0","locationUpdatesLeft":0,"priceMonth":"0","priceYear":"0","skuTier":null}}]

```

How do I get that data back to the client?

---

<div class="post-metadata">

**Author:** ![BartButenaers](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/bartbutenaers/32/10476_2.png) [@BartButenaers](https://discourse.nodered.org/u/BartButenaers)\
**Post date:** [19 October 2020 19:49 UTC](https://discourse.nodered.org/t/dumb-question-about-editing-a-node/34434/19 "2020-10-19T19:49:02Z")

</div>

> [@hepcat72](#):
>
> How do I get that data back to the client?

Perhaps you have found the answer meanwhile already?  
I assume you need to do this:

```auto
RED.httpAdmin.get('/location/:cmd', RED.auth.needsPermission('location.read'), function(req, res){
   ...
   // Based on the http req(uest) you write your json to the http res(ult)
   res.json(circles);
   ...
})

```

---

<div class="post-metadata">

**Author:** ![hepcat72](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/hepcat72/32/8078_2.png) [@hepcat72](https://discourse.nodered.org/u/hepcat72)\
**Post date:** [19 October 2020 20:27 UTC](https://discourse.nodered.org/t/dumb-question-about-editing-a-node/34434/20 "2020-10-19T20:27:22Z")

</div>

I have not. Still stuck there. I was just speaking with a work colleague about it (who also does not know javascript client/server stuff). He's as baffled as I am, though he did inspire me to question what I thought was the client and what was the server. I think that the problem _might_ be that this whole paradigm I'm following (that the original author created) was for the client being "server.js" and the server being "[Life360.com](http://Life360.com)".

Because clearly, server.js has the data (because I can print it to the raspberry pi's node red log file). Hmmm... location.js also prints to the log file on the rPi. I was about to posit that it was running in the browser on my laptop. The web inspector of my browser does have a copy of that script, but if it's printing to the rPi log, maybe it's running server-side?

I feel fairly confident that the oneditprepare stuff is running on the browser and that's what's calling the method in location.js...

I don't know. My head's kind of spinning. My colleague suggested adding a breakpoint and stepping through things. I've only ever done that with java code before. Maybe that would reveal something. I may try to look up how to do that in javascript tonight. I should also push out what I've got thus far so I can share it.

[Next page](https://discourse.nodered.org/t/dumb-question-about-editing-a-node/34434.md?page=2)