# Developing Nodes

**URL:** https://discourse.nodered.org/c/developing-nodes/15.md?page=18

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**Page:** 19

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## [TreeList widget is not visible](https://discourse.nodered.org/t/treelist-widget-is-not-visible/67756)

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**Author:** [@sangwoo](https://discourse.nodered.org/u/sangwoo)\
**Replies:** 3\
**Last updated:** [16 September 2022 03:00 UTC](https://discourse.nodered.org/t/treelist-widget-is-not-visible/67756 "2022-09-16T03:00:47Z")

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I studied the contents of the link, but the treelist is not visible. TreeList Widget : Node-RED node-red/60-link.html at master · node-red/node-red · GitHub Below is my code. \<script type="text/html" data-template-…

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## [How to use TreeList widget in my custom node editor](https://discourse.nodered.org/t/how-to-use-treelist-widget-in-my-custom-node-editor/67735)

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**Author:** [@sangwoo](https://discourse.nodered.org/u/sangwoo)\
**Replies:** 2\
**Last updated:** [15 September 2022 16:06 UTC](https://discourse.nodered.org/t/how-to-use-treelist-widget-in-my-custom-node-editor/67735 "2022-09-15T16:06:21Z")

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I'm looking at Node-RED docs/api/ui/treelist, but I don't know how to apply it. I want to see some basic example of treelist. Please help me!!

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## [Creating nodes in node-red containers](https://discourse.nodered.org/t/creating-nodes-in-node-red-containers/67643)

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**Author:** [@elvisj007](https://discourse.nodered.org/u/elvisj007)\
**Replies:** 4\
**Last updated:** [13 September 2022 16:16 UTC](https://discourse.nodered.org/t/creating-nodes-in-node-red-containers/67643 "2022-09-13T16:16:30Z")

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I want to create new nodes and install them to the "node\_modules" in a node-red docker container running on my system. How can i do this? I am familiar with creating and packaging new nodes in Node-red installed locally…

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## [Wires not showing in UI after being saved from API Call](https://discourse.nodered.org/t/wires-not-showing-in-ui-after-being-saved-from-api-call/67409)

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**Author:** [@jdonkinMotiv](https://discourse.nodered.org/u/jdonkinMotiv)\
**Replies:** 5\
**Last updated:** [12 September 2022 14:34 UTC](https://discourse.nodered.org/t/wires-not-showing-in-ui-after-being-saved-from-api-call/67409 "2022-09-12T14:34:38Z")

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I build my flows dynamically using the POST /flow to save them into Node Red. If I view the saved node after the call in the UI I am missing the wires for the created node. If I keep node red closed I can run my workfl…

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## [Where to define class to use in multiple nodes](https://discourse.nodered.org/t/where-to-define-class-to-use-in-multiple-nodes/15808)

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**Author:** [@undef](https://discourse.nodered.org/u/undef)\
**Replies:** 11\
**Last updated:** [11 September 2022 21:46 UTC](https://discourse.nodered.org/t/where-to-define-class-to-use-in-multiple-nodes/15808 "2022-09-11T21:46:30Z")

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Hi, I'm using node-red for some time now and just started to create custom nodes. Because of good documentation I was able to get pretty far up till now. I created 3 custom nodes so far. These are passing json objects…

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## [What is a node-red registry?](https://discourse.nodered.org/t/what-is-a-node-red-registry/67425)

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**Author:** [@elvisj007](https://discourse.nodered.org/u/elvisj007)\
**Replies:** 1\
**Last updated:** [7 September 2022 08:07 UTC](https://discourse.nodered.org/t/what-is-a-node-red-registry/67425 "2022-09-07T08:07:20Z")

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I am quite new to the development background. I do not understand what a 'node-red registry' is and how to use it while you are creating your own nodes. can someone give me a valuable source of information or examples …

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## [Packaged subflows show up as sf:undefined in the pallette](https://discourse.nodered.org/t/packaged-subflows-show-up-as-sf-undefined-in-the-pallette/67375)

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**Author:** [@sg26565](https://discourse.nodered.org/u/sg26565)\
**Replies:** 0\
**Last updated:** [6 September 2022 06:59 UTC](https://discourse.nodered.org/t/packaged-subflows-show-up-as-sf-undefined-in-the-pallette/67375 "2022-09-06T06:59:53Z")

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I have some subflows that I want to share with other projects and therefore, I tried to package them as a module. I followed the documentation about subflow modules in the "Creating Nodes" guide. I was able to package on…

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## [Is there an editor event on wiring up two nodes?](https://discourse.nodered.org/t/is-there-an-editor-event-on-wiring-up-two-nodes/66445)

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**Author:** [@kakyoism](https://discourse.nodered.org/u/kakyoism)\
**Replies:** 13\
**Last updated:** [3 September 2022 13:34 UTC](https://discourse.nodered.org/t/is-there-an-editor-event-on-wiring-up-two-nodes/66445 "2022-09-03T13:34:49Z")

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I'd like to create a port-validation mechanism so that some nodes can reject certain nodes upon connection attempts. AFAIK, this would require an editor event that fires up when connecting ports. Is there an event like …

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## [nodesDir crashes Node-RED 3.0?](https://discourse.nodered.org/t/nodesdir-crashes-node-red-3-0/67227)

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**Author:** [@lhp](https://discourse.nodered.org/u/lhp)\
**Replies:** 7\
**Last updated:** [2 September 2022 08:46 UTC](https://discourse.nodered.org/t/nodesdir-crashes-node-red-3-0/67227 "2022-09-02T08:46:40Z")

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Hello, I’m developing custom nodes in a directory specified with the nodesDir property in the settings.js file. This set-up used to work up to Node-RED 2.2.2. However, I’ve just upgraded to Node-RED 3.0.2 and now the se…

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## [Disabled button still clickable](https://discourse.nodered.org/t/disabled-button-still-clickable/67060)

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**Author:** [@nileio](https://discourse.nodered.org/u/nileio)\
**Replies:** 0\
**Last updated:** [29 August 2022 11:43 UTC](https://discourse.nodered.org/t/disabled-button-still-clickable/67060 "2022-08-29T11:43:56Z")

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Hi team, I noticed a behaviour while developing a new node and using the button attribute https://nodered.org/docs/creating-nodes/appearance#buttons the node has a button defined like this visible: function () { ret…

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## [Call C++ from Node-Red, suggestion for examples ? :)](https://discourse.nodered.org/t/call-c-from-node-red-suggestion-for-examples/66492)

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**Author:** [@iiot2k](https://discourse.nodered.org/u/iiot2k)\
**Replies:** 17\
**Last updated:** [27 August 2022 07:45 UTC](https://discourse.nodered.org/t/call-c-from-node-red-suggestion-for-examples/66492 "2022-08-27T07:45:06Z")

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Hi guys, I see that many node developers calls Python from Node-Red. But JavaScript has the possibilities to call C++ functions directly. Some parts of JavaScript are written in C++. This has advantages and disadvant…

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## [Call C++ from Node.js (Node-Red), A tutorial](https://discourse.nodered.org/t/call-c-from-node-js-node-red-a-tutorial/66979)

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**Author:** [@iiot2k](https://discourse.nodered.org/u/iiot2k)\
**Replies:** 0\
**Last updated:** [26 August 2022 16:02 UTC](https://discourse.nodered.org/t/call-c-from-node-js-node-red-a-tutorial/66979 "2022-08-26T16:02:25Z")

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Hi guys, I write a litte tutorial how C++ is called from Node.js (Node-Red). The tutorial isn't finished and I hope understandable and helpful for you. If I add more chapters and examples, I inform this here. Than…

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## [Store and Restore dynamic node UI properties](https://discourse.nodered.org/t/store-and-restore-dynamic-node-ui-properties/66831)

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**Author:** [@mbenson](https://discourse.nodered.org/u/mbenson)\
**Replies:** 4\
**Last updated:** [24 August 2022 08:45 UTC](https://discourse.nodered.org/t/store-and-restore-dynamic-node-ui-properties/66831 "2022-08-24T08:45:49Z")

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I wrote a node that has a dropdown list property (field?) that is used to basically define the function of the Node. Some of the functions have additional properties. So I wrote the node to dynamically add the labels a…

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## [How does the UI access global “config” data](https://discourse.nodered.org/t/how-does-the-ui-access-global-config-data/66737)

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**Author:** [@mbenson](https://discourse.nodered.org/u/mbenson)\
**Replies:** 10\
**Last updated:** [24 August 2022 05:39 UTC](https://discourse.nodered.org/t/how-does-the-ui-access-global-config-data/66737 "2022-08-24T05:39:01Z")

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I’m writing a plugin that has a global “config” component that contains IP, port, username, and password for a remote server. The user then sets an ID in the node which corresponds to data supplied by the server. The s…

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## [Node restriction from multiple nodes](https://discourse.nodered.org/t/node-restriction-from-multiple-nodes/66790)

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**Author:** [@Techie](https://discourse.nodered.org/u/Techie)\
**Replies:** 8\
**Last updated:** [23 August 2022 14:12 UTC](https://discourse.nodered.org/t/node-restriction-from-multiple-nodes/66790 "2022-08-23T14:12:36Z")

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can we restrict the input of a node from a specific node , or is there any way we can make 2 nodes dependent to each other

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## [Can we secure a single node in node red](https://discourse.nodered.org/t/can-we-secure-a-single-node-in-node-red/66611)

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**Author:** [@Techie](https://discourse.nodered.org/u/Techie)\
**Replies:** 3\
**Last updated:** [23 August 2022 06:04 UTC](https://discourse.nodered.org/t/can-we-secure-a-single-node-in-node-red/66611 "2022-08-23T06:04:19Z")

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i want to secure a single node in my node red flow so that no one can acess that. is this possible. if yes, how?

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## [Developing a custom ui node for Flexdash](https://discourse.nodered.org/t/developing-a-custom-ui-node-for-flexdash/66704)

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**Author:** [@BartButenaers](https://discourse.nodered.org/u/BartButenaers)\
**Replies:** 16\
**Last updated:** [21 August 2022 15:38 UTC](https://discourse.nodered.org/t/developing-a-custom-ui-node-for-flexdash/66704 "2022-08-21T15:38:21Z")

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Hi @tve, I would like to experiment with audio in the Node-RED dashboard, for another discussion to assist @nhiennguyenhuy. Would like the dashboard to be able to support an infinite stream of audio segments via the pc…

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## [Issue with the TypedInput widget ("Select multiple items from a list of options" variant)](https://discourse.nodered.org/t/issue-with-the-typedinput-widget-select-multiple-items-from-a-list-of-options-variant/66476)

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**Author:** [@MoonDev](https://discourse.nodered.org/u/MoonDev)\
**Replies:** 6\
**Last updated:** [17 August 2022 10:09 UTC](https://discourse.nodered.org/t/issue-with-the-typedinput-widget-select-multiple-items-from-a-list-of-options-variant/66476 "2022-08-17T10:09:14Z")

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Hello, I'm having an issue with the TypedInput widget in the "Select multiple items from a list of options" variant. The Problem is when I initially open the edit page of my node the dropdown shows e.g. "4 Selected" whi…

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## [Wanted: Curated list of "great" nodes (preferably a pinned post or in the documentation somewhere)](https://discourse.nodered.org/t/wanted-curated-list-of-great-nodes-preferably-a-pinned-post-or-in-the-documentation-somewhere/66512)

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**Author:** [@Laro88](https://discourse.nodered.org/u/Laro88)\
**Replies:** 15\
**Last updated:** [17 August 2022 08:02 UTC](https://discourse.nodered.org/t/wanted-curated-list-of-great-nodes-preferably-a-pinned-post-or-in-the-documentation-somewhere/66512 "2022-08-17T08:02:30Z")

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I have a simple yet difficult request for beginners like me. My desire is for the ninjas to put up a list of Nodes that are well laid out and structured - simply to have a "look at these nodes on github for inspiration"…

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## [Multiple send(msg) in custom nodes](https://discourse.nodered.org/t/multiple-send-msg-in-custom-nodes/66437)

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**Author:** [@omrid](https://discourse.nodered.org/u/omrid)\
**Replies:** 2\
**Last updated:** [15 August 2022 11:33 UTC](https://discourse.nodered.org/t/multiple-send-msg-in-custom-nodes/66437 "2022-08-15T11:33:38Z")

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Hi, Sorry if a repost (please point me in case this was already discusses) I am developing a custom node which needs to do multiple sends from within its input handler. I see a difference between custom & function node…

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## [Trying to fill msg more efficient but gives errors](https://discourse.nodered.org/t/trying-to-fill-msg-more-efficient-but-gives-errors/66372)

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**Author:** [@WesleyFranken](https://discourse.nodered.org/u/WesleyFranken)\
**Replies:** 4\
**Last updated:** [12 August 2022 22:43 UTC](https://discourse.nodered.org/t/trying-to-fill-msg-more-efficient-but-gives-errors/66372 "2022-08-12T22:43:44Z")

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Dear community, I couldn't find the answer so I've to ask it. I would like to send the following messages. But it gives an error. What am I doing wrong? The error given at msg+d is "Bad assignment" The error given at…

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## [Fill editor values from node function](https://discourse.nodered.org/t/fill-editor-values-from-node-function/65982)

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**Author:** [@dionmes](https://discourse.nodered.org/u/dionmes)\
**Replies:** 5\
**Last updated:** [7 August 2022 08:21 UTC](https://discourse.nodered.org/t/fill-editor-values-from-node-function/65982 "2022-08-07T08:21:31Z")

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Hi, I am building a node with bluetooth connectivity. And this all works fine. But to connect to the bluetooth device you need to enter a bluetooth address, and also first find out what that address is. This can be quit…

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## [How to read node properties on deployment](https://discourse.nodered.org/t/how-to-read-node-properties-on-deployment/66127)

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**Author:** [@mbenson](https://discourse.nodered.org/u/mbenson)\
**Replies:** 0\
**Last updated:** [7 August 2022 00:49 UTC](https://discourse.nodered.org/t/how-to-read-node-properties-on-deployment/66127 "2022-08-07T00:49:33Z")

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I have an idea for a node and successfully prototyped it using existing primitives. I have a data source that required I subscribe to specific parameters. I send a single JSON message to the server containing a list of…

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## [UDP OUT - no output on wireshark](https://discourse.nodered.org/t/udp-out-no-output-on-wireshark/66032)

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**Author:** [@RBSI](https://discourse.nodered.org/u/RBSI)\
**Replies:** 4\
**Last updated:** [6 August 2022 06:26 UTC](https://discourse.nodered.org/t/udp-out-no-output-on-wireshark/66032 "2022-08-06T06:26:29Z")

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Hello everyone. I am trying to send a network variable list to a device (WAGO-PFC200) on port 1000, however i do not see any data transmission or receive on port 1000 via wireshark and here is more details on my form…

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## [Migrating configuration to a configuration node (or, programmatically instantiating a config node)](https://discourse.nodered.org/t/migrating-configuration-to-a-configuration-node-or-programmatically-instantiating-a-config-node/61154)

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**Author:** [@sverre](https://discourse.nodered.org/u/sverre)\
**Replies:** 2\
**Last updated:** [3 August 2022 20:01 UTC](https://discourse.nodered.org/t/migrating-configuration-to-a-configuration-node-or-programmatically-instantiating-a-config-node/61154 "2022-08-03T20:01:37Z")

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I'm considering moving some configuration fields from an existing node to a (new) config node, but would like to avoid a breaking change if possible. Is there a way to instantiate a config node programmatically? If there…

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## [Using of SemVer](https://discourse.nodered.org/t/using-of-semver/65965)

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**Author:** [@FStefanni](https://discourse.nodered.org/u/FStefanni)\
**Replies:** 13\
**Last updated:** [3 August 2022 14:44 UTC](https://discourse.nodered.org/t/using-of-semver/65965 "2022-08-03T14:44:57Z")

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Hi, this is a sort of issue for custom nodes creators, related to node-red not following SemVer. TL;DR @node-red developers, please use SemVer The long explanation I found that node-red does not use SemVer for trackin…

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## [Dynamically adapting editor based on selected properties](https://discourse.nodered.org/t/dynamically-adapting-editor-based-on-selected-properties/65789)

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**Author:** [@OsamaAlAhmadieh](https://discourse.nodered.org/u/OsamaAlAhmadieh)\
**Replies:** 10\
**Last updated:** [1 August 2022 12:45 UTC](https://discourse.nodered.org/t/dynamically-adapting-editor-based-on-selected-properties/65789 "2022-08-01T12:45:52Z")

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Hello, I am looking to create a node that is similar to the filter node, from a dynamically changing editor perspective. My end goal is to have attributes change depending on what I have previously chosen. For example…

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## [Saving node parameter in an variable in the html file](https://discourse.nodered.org/t/saving-node-parameter-in-an-variable-in-the-html-file/65576)

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**Author:** [@OsamaAlAhmadieh](https://discourse.nodered.org/u/OsamaAlAhmadieh)\
**Replies:** 6\
**Last updated:** [25 July 2022 12:52 UTC](https://discourse.nodered.org/t/saving-node-parameter-in-an-variable-in-the-html-file/65576 "2022-07-25T12:52:44Z")

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I have a node for which i am setting different attributes (Name, fruit, vegetable) from a typedInput. For further processing, I want to get the values that I set for each parameter into my html file in which i define th…

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## [Editable List: How to limit editable list widget](https://discourse.nodered.org/t/editable-list-how-to-limit-editable-list-widget/65571)

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**Author:** [@namph-sgn](https://discourse.nodered.org/u/namph-sgn)\
**Replies:** 1\
**Last updated:** [25 July 2022 11:10 UTC](https://discourse.nodered.org/t/editable-list-how-to-limit-editable-list-widget/65571 "2022-07-25T11:10:01Z")

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Hi all, is there any way to limit the amount of items users can create in the list? I'm currently creating a nodes with editable list and I want to limit the items in the list to only 3. I have checked the document: Edi…

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## [How to create custom ui node for getting user input](https://discourse.nodered.org/t/how-to-create-custom-ui-node-for-getting-user-input/65174)

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**Author:** [@fuad\_rock](https://discourse.nodered.org/u/fuad_rock)\
**Replies:** 1\
**Last updated:** [16 July 2022 08:36 UTC](https://discourse.nodered.org/t/how-to-create-custom-ui-node-for-getting-user-input/65174 "2022-07-16T08:36:57Z")

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Hi, I want to create a custom UI node so that my client drags and drops the node in his flows. The node will contain a small part of this simulation. I know it's possible with the dashboard's template node but I wa…

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