# Developing Nodes

**URL:** https://discourse.nodered.org/c/developing-nodes/15.md?page=46

[Latest](https://discourse.nodered.org/latest.md) · [Categories](https://discourse.nodered.org/categories.md) · [Tags](https://discourse.nodered.org/tags.md)

**Page:** 47

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## [Grouping subflows - renaming category](https://discourse.nodered.org/t/grouping-subflows-renaming-category/9215)

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**Author:** [@mvidhya86](https://discourse.nodered.org/u/mvidhya86)\
**Replies:** 7\
**Last updated:** [21 March 2019 13:38 UTC](https://discourse.nodered.org/t/grouping-subflows-renaming-category/9215 "2019-03-21T13:38:32Z")

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Hi I have 5 subflows, i want to group them in various categories , say. 2 in one group and other 3 in another group, i noticed that we can use categorize option, is there a way to rename the created category ?

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## [Custom function node with auto filled code](https://discourse.nodered.org/t/custom-function-node-with-auto-filled-code/9119)

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**Author:** [@mvidhya86](https://discourse.nodered.org/u/mvidhya86)\
**Replies:** 3\
**Last updated:** [20 March 2019 04:13 UTC](https://discourse.nodered.org/t/custom-function-node-with-auto-filled-code/9119 "2019-03-20T04:13:35Z")

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Can i create a custom function node with auto filled code in it ? How do i achieve this? I would like to drag-drop this custom node, and when i double click, the code(which is pre-configured or pre-defined) has to appea…

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## [Making a custom node and getting ERROR : Waiting for missing types to be registered](https://discourse.nodered.org/t/making-a-custom-node-and-getting-error-waiting-for-missing-types-to-be-registered/8964)

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**Author:** [@rb2594](https://discourse.nodered.org/u/rb2594)\
**Replies:** 6\
**Last updated:** [14 March 2019 11:18 UTC](https://discourse.nodered.org/t/making-a-custom-node-and-getting-error-waiting-for-missing-types-to-be-registered/8964 "2019-03-14T11:18:37Z")

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On my machine, nodejs version : 8.15.1 npm version : 6.4.1 I have made a simple node that generates any random number. I'm sharing the sequence of steps that I did so that it becomes simple and easy for you to unders…

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## [Set intial date for node input with type date](https://discourse.nodered.org/t/set-intial-date-for-node-input-with-type-date/8629)

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**Author:** [@Callmoon](https://discourse.nodered.org/u/Callmoon)\
**Replies:** 1\
**Last updated:** [5 March 2019 13:31 UTC](https://discourse.nodered.org/t/set-intial-date-for-node-input-with-type-date/8629 "2019-03-05T13:31:40Z")

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Hi folks, I try to create my own node which contains a input object with the type of date where this input object has as initial value the date of today (like if you use new Date()). I've already tried something like t…

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## [Select form with tree structure in custom node](https://discourse.nodered.org/t/select-form-with-tree-structure-in-custom-node/8348)

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**Author:** [@germancmartinez](https://discourse.nodered.org/u/germancmartinez)\
**Replies:** 9\
**Last updated:** [26 February 2019 13:53 UTC](https://discourse.nodered.org/t/select-form-with-tree-structure-in-custom-node/8348 "2019-02-26T13:53:35Z")

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Hi! I need to create a select form with tree structure for my custom node edit display. I'm wondering if it's possible to use this: https://mbraak.github.io/jqTree/#demo Can I use jqTree in the html file? or do I have t…

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## [Div height 0 after deploy](https://discourse.nodered.org/t/div-height-0-after-deploy/8336)

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**Author:** [@BartButenaers](https://discourse.nodered.org/u/BartButenaers)\
**Replies:** 1\
**Last updated:** [25 February 2019 21:14 UTC](https://discourse.nodered.org/t/div-height-0-after-deploy/8336 "2019-02-25T21:14:42Z")

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Hi folks, I would like to publish my node-red-contrib-ui-heatmap node on npm, but @dceejay reported that it raises following exception: DOMException: Failed to execute 'getImageData' on 'CanvasRenderingContext2D': The…

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## [Custom UI node - layout problems](https://discourse.nodered.org/t/custom-ui-node-layout-problems/7731)

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**Author:** [@BartButenaers](https://discourse.nodered.org/u/BartButenaers)\
**Replies:** 25\
**Last updated:** [16 February 2019 14:15 UTC](https://discourse.nodered.org/t/custom-ui-node-layout-problems/7731 "2019-02-16T14:15:39Z")

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Hi folks, It has become very clear that I will never receive a Nobel Prize in styling, layouting, CSS, ... :woozy\_face: For my new contribution node-red-contrib-ui-camera, I want a 'canvas' tag that displays my camera …

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## [Show table in custom node config screen](https://discourse.nodered.org/t/show-table-in-custom-node-config-screen/7897)

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**Author:** [@BartButenaers](https://discourse.nodered.org/u/BartButenaers)\
**Replies:** 5\
**Last updated:** [12 February 2019 22:07 UTC](https://discourse.nodered.org/t/show-table-in-custom-node-config-screen/7897 "2019-02-12T22:07:11Z")

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Hi folks, I have added a table to my config screen: \<div class="form-row"\> \<label for="node-input-areas"\>\<i class="fa fa-table"\>\</i\> Area's\</label\> \<div id="node-input-areas" style="background-color…

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## [URL link to specific node instance in the admin ui](https://discourse.nodered.org/t/url-link-to-specific-node-instance-in-the-admin-ui/7579)

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**Author:** [@TotallyInformation](https://discourse.nodered.org/u/TotallyInformation)\
**Replies:** 2\
**Last updated:** [4 February 2019 17:06 UTC](https://discourse.nodered.org/t/url-link-to-specific-node-instance-in-the-admin-ui/7579 "2019-02-04T17:06:43Z")

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Hi, I'm thinking to build an index webpage that contains links to all of the implemented uibuilder endpoints (each node instance in you flows). That is easy to to by putting something like the following inside the modu…

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## [Property value saved as string to flow.json instead of number](https://discourse.nodered.org/t/property-value-saved-as-string-to-flow-json-instead-of-number/7363)

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**Author:** [@janoslaszlo](https://discourse.nodered.org/u/janoslaszlo)\
**Replies:** 2\
**Last updated:** [3 February 2019 14:46 UTC](https://discourse.nodered.org/t/property-value-saved-as-string-to-flow-json-instead-of-number/7363 "2019-02-03T14:46:28Z")

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Hi, I added an option list to an existing node to enable selecting an existing property. The value of the property is saved as string (e.g. "address":"72") to the flow.json instead of "address":72. Actually I copied t…

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## [Initializing config screen based on new config node](https://discourse.nodered.org/t/initializing-config-screen-based-on-new-config-node/7327)

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**Author:** [@BartButenaers](https://discourse.nodered.org/u/BartButenaers)\
**Replies:** 12\
**Last updated:** [1 February 2019 00:08 UTC](https://discourse.nodered.org/t/initializing-config-screen-based-on-new-config-node/7327 "2019-02-01T00:08:40Z")

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Hi folks, In my new node-red-contrib-onvif-nodes, I have a config node that contains all the logic to communicate with an Onvif-compliant IP camera. So all my other nodes can get data from the IP camera (via their corr…

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## [How can I 'delete' via the Admin API Methods?](https://discourse.nodered.org/t/how-can-i-delete-via-the-admin-api-methods/7332)

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**Author:** [@Simo219h](https://discourse.nodered.org/u/Simo219h)\
**Replies:** 8\
**Last updated:** [30 January 2019 13:27 UTC](https://discourse.nodered.org/t/how-can-i-delete-via-the-admin-api-methods/7332 "2019-01-30T13:27:49Z")

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Hi, I am using the Admin API Methods to get information about the configuration of a node. Specifically which pins are in use on some digital outputs. In the .js file: RED.httpAdmin.get('/Digital-output/node-input-pin…

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## [Anyway to have a map (key/value pairs) on the config for a node?](https://discourse.nodered.org/t/anyway-to-have-a-map-key-value-pairs-on-the-config-for-a-node/7225)

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**Author:** [@ScottChapman](https://discourse.nodered.org/u/ScottChapman)\
**Replies:** 1\
**Last updated:** [25 January 2019 20:24 UTC](https://discourse.nodered.org/t/anyway-to-have-a-map-key-value-pairs-on-the-config-for-a-node/7225 "2019-01-25T20:24:50Z")

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I'm creating a new node. And I need to be able to enter in a map of key/value pairs as part of the configuration. They should be able to add/remove the pairs. Is there such an animal in the available input types?

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## [Simple example of typedInput with type JSON?](https://discourse.nodered.org/t/simple-example-of-typedinput-with-type-json/7248)

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**Author:** [@ScottChapman](https://discourse.nodered.org/u/ScottChapman)\
**Replies:** 1\
**Last updated:** [25 January 2019 17:11 UTC](https://discourse.nodered.org/t/simple-example-of-typedinput-with-type-json/7248 "2019-01-25T17:11:45Z")

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I'm building (one of) my first nodes, and I want to have a configuration property that accepts valid JSON. I know I need to use the typedInput mechanism for this, but I am having difficulty finding a simple example of i…

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## [Can node functions return promises?](https://discourse.nodered.org/t/can-node-functions-return-promises/7050)

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**Author:** [@ScottChapman](https://discourse.nodered.org/u/ScottChapman)\
**Replies:** 2\
**Last updated:** [25 January 2019 00:11 UTC](https://discourse.nodered.org/t/can-node-functions-return-promises/7050 "2019-01-25T00:11:27Z")

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Sorry for the noob question, I did poke around but couldn't find anything specific (might not have really known where to look exactly). Anyway, I am writing my first node, and it looks like I basically create a module a…

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## [How does a custom node pass json data from js to HTML](https://discourse.nodered.org/t/how-does-a-custom-node-pass-json-data-from-js-to-html/7126)

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**Author:** [@JiChen](https://discourse.nodered.org/u/JiChen)\
**Replies:** 8\
**Last updated:** [24 January 2019 08:30 UTC](https://discourse.nodered.org/t/how-does-a-custom-node-pass-json-data-from-js-to-html/7126 "2019-01-24T08:30:22Z")

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\*Everybody is good!Does anyone know how a custom node passes json data from js to HTML

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## [RED.httpAdmin.get not refreshing JSON](https://discourse.nodered.org/t/red-httpadmin-get-not-refreshing-json/7113)

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**Author:** [@germancmartinez](https://discourse.nodered.org/u/germancmartinez)\
**Replies:** 2\
**Last updated:** [22 January 2019 02:09 UTC](https://discourse.nodered.org/t/red-httpadmin-get-not-refreshing-json/7113 "2019-01-22T02:09:00Z")

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Hi, I´m using httpAdmin.get to send a json from the runtime js to the html. The problem I have is that the json is only updated the first time the code runs. I can see in the console that data variable is being updated,…

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## [Share property information](https://discourse.nodered.org/t/share-property-information/6912)

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**Author:** [@Simo219h](https://discourse.nodered.org/u/Simo219h)\
**Replies:** 2\
**Last updated:** [17 January 2019 09:14 UTC](https://discourse.nodered.org/t/share-property-information/6912 "2019-01-17T09:14:47Z")

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Hi, I am trying to make a node to control some digital outputs. I am facing a problem, because my digital outputs have the possibility to use external voltage reference. I have made the node, but I cannot seem to find a…

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## [New node property and validation](https://discourse.nodered.org/t/new-node-property-and-validation/6673)

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**Author:** [@Onixarts](https://discourse.nodered.org/u/Onixarts)\
**Replies:** 9\
**Last updated:** [11 January 2019 22:42 UTC](https://discourse.nodered.org/t/new-node-property-and-validation/6673 "2019-01-11T22:42:38Z")

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Hi, What is the right way to add new property to configuration node (in case node exists in production systems)? I've put my new property in defaults section, for example like this below: reconnectPeriod: {value: 1000,…

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## [Custom storage module: credentials not being restored](https://discourse.nodered.org/t/custom-storage-module-credentials-not-being-restored/6700)

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**Author:** [@BGoll](https://discourse.nodered.org/u/BGoll)\
**Replies:** 0\
**Last updated:** [11 January 2019 14:54 UTC](https://discourse.nodered.org/t/custom-storage-module-credentials-not-being-restored/6700 "2019-01-11T14:54:09Z")

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Hey there, my team develops/modifies a custom storage module which uses MongoDB to store the Node-RED runtime data. The reason for this is that we deploy Node-RED to Cloud Foundry which leads to a lost state if Node-RED…

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## [Adding extra development documentation](https://discourse.nodered.org/t/adding-extra-development-documentation/6223)

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**Author:** [@BartButenaers](https://discourse.nodered.org/u/BartButenaers)\
**Replies:** 25\
**Last updated:** [7 January 2019 19:35 UTC](https://discourse.nodered.org/t/adding-extra-development-documentation/6223 "2019-01-07T19:35:10Z")

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Hey folks, When you want to start developing your custom Node-RED nodes, there is currently already a LOT of useful information available in the official documentation: But I would like to add some extra stuff to it: …

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## [How to find the root cause of a Node error/warning when node-red is starting](https://discourse.nodered.org/t/how-to-find-the-root-cause-of-a-node-error-warning-when-node-red-is-starting/6395)

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**Author:** [@germancmartinez](https://discourse.nodered.org/u/germancmartinez)\
**Replies:** 5\
**Last updated:** [6 January 2019 04:14 UTC](https://discourse.nodered.org/t/how-to-find-the-root-cause-of-a-node-error-warning-when-node-red-is-starting/6395 "2019-01-06T04:14:12Z")

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Hi, I´m trying to create my own MongoDB connector using the MongoDB node.js driver. To do that I'm creating a node with its corresponding configuration node. I don't get any error when installing my library using npm in…

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## [Custom UI Node Not Appearing In Group In Dashboard SideTab](https://discourse.nodered.org/t/custom-ui-node-not-appearing-in-group-in-dashboard-sidetab/6347)

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**Author:** [@seth350](https://discourse.nodered.org/u/seth350)\
**Replies:** 7\
**Last updated:** [4 January 2019 15:47 UTC](https://discourse.nodered.org/t/custom-ui-node-not-appearing-in-group-in-dashboard-sidetab/6347 "2019-01-04T15:47:50Z")

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Good morning, I have recently come up with two ui nodes that are both experiencing the same problem. If you look at this picture, I have 19 linear-gauges in a group on the dashboard. This picture shows none of the l…

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## [Need advice on node-red node design](https://discourse.nodered.org/t/need-advice-on-node-red-node-design/6216)

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**Author:** [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)\
**Replies:** 9\
**Last updated:** [30 December 2018 21:49 UTC](https://discourse.nodered.org/t/need-advice-on-node-red-node-design/6216 "2018-12-30T21:49:33Z")

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Hi all. I'm after some advice on developing nodes. Firstly I have read the guidelines however most of the info is unfinished. I am creating some nodes that are essentially PLC Read and PLC Write nodes. These nodes sha…

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## [Storing variable number of username/password credentials in configuration node](https://discourse.nodered.org/t/storing-variable-number-of-username-password-credentials-in-configuration-node/5575)

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**Author:** [@varadi](https://discourse.nodered.org/u/varadi)\
**Replies:** 0\
**Last updated:** [7 December 2018 23:26 UTC](https://discourse.nodered.org/t/storing-variable-number-of-username-password-credentials-in-configuration-node/5575 "2018-12-07T23:26:14Z")

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I need to connect to a large number of authenticated sources of the same type (say, 100). I have a node that can communicate with one source, but using one authenticated node per source makes the flow completely unreadab…

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## [Questions about persistent context](https://discourse.nodered.org/t/questions-about-persistent-context/5547)

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**Author:** [@drmibell](https://discourse.nodered.org/u/drmibell)\
**Replies:** 4\
**Last updated:** [7 December 2018 15:08 UTC](https://discourse.nodered.org/t/questions-about-persistent-context/5547 "2018-12-07T15:08:39Z")

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I want to use persistent context in one of my contributed nodes, but I have a few questions about how it works. First, when using the localfilesystem module, the documentation says the default flushInterval is 30 second…

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## [Show select option text as label](https://discourse.nodered.org/t/show-select-option-text-as-label/5130)

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**Author:** [@BartButenaers](https://discourse.nodered.org/u/BartButenaers)\
**Replies:** 11\
**Last updated:** [29 November 2018 18:51 UTC](https://discourse.nodered.org/t/show-select-option-text-as-label/5130 "2018-11-29T18:51:06Z")

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Hi folks, The config screen of my custom node contains a dropdown: \<script type="text/x-red" data-template-name="math"\> \<div class="form-row"\> \<label for="node-input-operation"\>\<i class="fa fa-calculator"\>\</…

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## [Remote syslog input node](https://discourse.nodered.org/t/remote-syslog-input-node/5144)

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**Author:** [@damoclark](https://discourse.nodered.org/u/damoclark)\
**Replies:** 0\
**Last updated:** [23 November 2018 13:08 UTC](https://discourse.nodered.org/t/remote-syslog-input-node/5144 "2018-11-23T13:08:39Z")

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Hi Everyone, TL;DR Working on a syslog node that remotely receives syslog messages Input and feedback welcome So I was looking for a simple way to have my NUT UPS monitoring software send event data into node-red so I…

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## [Error in Node shown in Palette view; how to debug?](https://discourse.nodered.org/t/error-in-node-shown-in-palette-view-how-to-debug/5081)

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**Author:** [@RaimondB](https://discourse.nodered.org/u/RaimondB)\
**Replies:** 7\
**Last updated:** [21 November 2018 13:39 UTC](https://discourse.nodered.org/t/error-in-node-shown-in-palette-view-how-to-debug/5081 "2018-11-21T13:39:14Z")

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Hi, I'm am developing a new version of my node; however when I test it via the npm link procedure, it shows up in the Palette Manager, but with a strange error and I have no idea how to debug this. Can anybody provide …

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## [Get property name in custom validator](https://discourse.nodered.org/t/get-property-name-in-custom-validator/4940)

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**Author:** [@BartButenaers](https://discourse.nodered.org/u/BartButenaers)\
**Replies:** 2\
**Last updated:** [17 November 2018 06:07 UTC](https://discourse.nodered.org/t/get-property-name-in-custom-validator/4940 "2018-11-17T06:07:08Z")

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Hi folks, When developing a node, you can apply your own custom validators to validate the node properties. RED.nodes.registerType('myType',{ defaults: { myProperty: {value:'', validate:function(v) { …

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