Internationalization

If a node is packaged as a proper module, it must include a message catalog in order to provide translated content in the editor.

For each node identified in the module’s package.json, a corresponding set of message catalogs and help files can be included alongside the node’s code file.

Given a node identified as:

"name": "my-node-module",
"node-red": {
    "myNode": "myNode/my-node.js"
}

The following message catalogs may exist:

myNode/locales/__language__/my-node.json
myNode/locales/__language__/my-node.help.html

The __language__ part of the path identifies the language the corresponding files provide. By default, Node-RED uses en-US. For every supported language a 2 letter language code should be added as well (this can be done as soft link). For en-US this would be en.

Message catalog

The message catalog is a JSON file containing any pieces of text that the node may display in the editor.

For example:

{
    "myNode" : {
        "message1": "This is my first message",
        "message2": "This is my second message"
    }
}

The catalog is loaded under a namespace specific to the node. For the node defined above, this catalog would be available under the my-node-module/myNode namespace.

The core nodes use the node-red namespace.

Help text

The help file provides translated versions of the node’s help text that gets displayed within the Info sidebar tab of the editor.

Palette help text

Palette help text is placed within the catalog JSON file using the key paletteHelp:

{
    "myNode" : {
        "message1": "This is my first message",
        "message2": "This is my second message",
        "paletteHelp": "This node is a dummy node to explain where help texts are placed"
    }
}

Using i18n messages

In the editor functions are provided for nodes to look-up messages from the catalogs. These are pre-scoped to the nodes own namespace so it isn’t necessary to include the namespace in the message identifier.

Editor

HTML

Any HTML element provided in the node template can specify a data-i18n attribute to provide the message identify to use. For example:

<span data-i18n="myNode.label.foo"></span>

By default, the text content of an element is replace by the message identified. It is also possible to set attributes of the element, such as the placeholder of an <input>:

<input type="text" data-i18n="[placeholder]myNode.placeholder.foo">

It is possible to combine these to specify multiple substitutions For example, to set both the title attribute and the displayed text:

<a href="#" data-i18n="[title]myNode.label.linkTitle;myNode.label.linkText"></a>

JavaScript

All node definition functions (for example, oneditprepare) can use this._() to retrieve messages:

this._("myNode.label.foo");