Table node (using Tabulator) for Node-RED Dashboard 2.0

A short summary of the node's design concepts, functionality & configuration options. Complete, detailed usage reference is provided in the node's on-line help, available in the Node-RED editor.

ui-tabulator

The ui-tabulator custom node uses the popular Tabulator JavaScript package, for updating, presenting & querying UI tables.

Note: the node comes in addition to, not replacing, dashboard V2.0's native vue-based table node.

General Overview

• The node serves as a smart wrapper containing a Tabulator (table) object. For the most part, it calls the Tabulator API as-is (as defined in the Tabulator Documentation).
• The node enables automatic instantiation of the table (with user-defined configuration & initial data), as well as to dynamically create/modify/destroy tables in runtime.
• Interface to the node is through messages (regular Node-red msg objects). The msg specifies a command (and arguments), and returns the table's response
• The table accepts data-setting commands (e.g. setData, addData, updateData, deleteData etc.) as well as data-query commands (getData, searchData etc.), as well as in-cell data edit (from the UI).
• In addition, the table can send unsolicited event messages for selected table events (cell & row click/double-click, cell edit etc.)
• By default, the table operates in shared mode, i.e. a common table image (data + styling) in all concurrent dashboard clients. The table image is also cached in the Node-RED datastore, and reloaded upon browser open, refresh etc.
  The node also supports a Multi-User mode, which maintains independent, client-specific table data with "private" messaging.

Message Examples

• Data-setting command example

  msg.tbCmd  = "addData";
  msg.tbArgs = [
  [
    {id:1, name:"bob", gender:"male"},
    {id:2, name:"Jenny", gender:"female"}
  ],
  true
  ];

• Data-retrieval command example

  msg.tbCmd  = "searchData";
  msg.tbArgs = [ "age", ">", 12 ];

• Event example

  {
  topic: "tbNotification",
  event: "cellEdited",
  payload: {
      id: 2,
      field: "name",
      newValue: "Jack Brown",
      oldValue: "John Doe"
  },
  _client: {
      socketId: "uXRxjY9yO-Hya1vtAAAB"
  },
  _msgid:"6d9d7a97666f2783"
  }

  Node Configuration

  The node configuration properties (in the editor):

• Name, Group, Size: - same as in all dashboard 2.0 nodes
• Initial Table Configuration: JSON object with all table & column definitions, and (optional) initial data
• Max Width: sets the visible width of the table
• Notifications: selection of table events which trigger notification messages
• Multi-user mode: (Y/N)
• Row-Id validation/duplication check (Y/N)
• CSS theme: selection of an optional tabulator CSS Stylesheet (e.g. Midnight, Modern etc.)
• DIV Override: optional: enables to specify a specific HTML DIV Id in which the table will be created, overriding the default DIV, auto-allocated by the Vue framework

Architectural Concepts in Multi-Client Environment

Tables are created as widgets on the client (browser) page. Hence, in case of multiple dashboard clients, a single ui-tabulator node is associated to multiple table widgets. Per Node-RED's framework, every message sent to a ui-tabulator node in a flow, is replicated to all of its widgets. If the table object responds, the flow will receive multiple, identical responses (one per client). To enable a Shared mode, where all table widgets are synchronized and have a common data image, we do the following:

• Data-setting & styling commands sent from the ui-tabulator node in flow to all table widgets in parallel, thus applying the same changes on the widgets
• The (identical) table responses to command messages are grouped by msgid, and only a single response is returned to the flow
• When a user changes table data directly on the UI of any client, an update notification is automatically sent to all other clients
• The current table data image is always saved in the Node-RED datastore, automatically restoring the table image upon client open/refresh.

Having said the above, some table presentation aspects (on top of the common data image) are user-related by nature, and are not synchronized. For example, users may want to set their own filtering/sorting, or select specific rows for further actions. In such cases, each client table may return a different response to data query commands. For this, the command should be scoped to a specific table widget (by specifying the client Id, or initiating the command from a dashboard objet, e.g. button, on the same client)

Known Issues

Upon server restart, deploy and reconnect, sometimes the client's socket listeners in the Node-RED framework are not restored properly. As a temporary workaround, until this is fixed in Node-RED, each client page automatically reloads itself once upon reconnection (showing a little "flicker").

Node Dependencies

• Node-JS version >= 18
• Node-red version >= 3.10
• Node-red dashboard 2.0, version >= 1.17.1
• Tabulator version >= 6.2 (comes bundled in the node installation)