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UI guidelines


UI design

The whole web UI is designed following PatternFly patterns. Please, read carefully PatternFly documentation before starting the design of a new web page.

The main goal is to have a consistent design and behavior across all modules.

All web page should guide the user to well-defined and specific task like:

  • bad task example: "The user must choose the correct account provider"
  • good task example: "The user must choose Active Directory provider if ACLs on shared folders are a functional requirements"

Left menu

The left menu should be considered fixed: modules shouldn't add items inside the left menu. When a module needs to add a new feature, the web page should be added inside exiting sections like "System".


The Applications page is a container of each new module which implements new features, like mail server, nextcloud, etc. Each new application web page should display:

  • the status of the application status on the top
  • a list of common actions just below the status
  • all configuration parameters (forms, table, etc.) in the center

On first run, the application must display a modal wizard if the module can't be configured with a reasonable defaults.

Also the web page should display suggestions to help the user to follow best practices. For example, inside the "Certificate page", the interface should display a suggestion to enable Let's Encrypt if a self-signed certificate is used as default.

Each application must be described by a JSON manifest inspired to AppData format.


A configuration form should always display the minimum number of fields needed to configure the feature. Extra parameters should be hidden inside an Advanced panel with reasonable defaults.

For example, when creating a user you need at least the user name, the full name and the password; but you could hide extra details like street address or phone number.

Also it is a good practice to add a "Description" when creating records inside tables.


NethServer Cockpit provides multiple toast notification. Each notification can have one of these states:

  • success: everything is ok. Transient: it stays on the screen for 3 seconds.
  • error: something went wrong. Not transient: it stays on the screen until the user explicitly close it. May require an action link.

Finally there also is a task notification, it stays on the screen until the task has been completed. This kind of notification can be created only by signal-event.


// success - hide notifications after 3 seconds
parent.ns.$children[0] = true;
parent.ns.$children[0].notifications.success.message = "Your success message";
setTimeout(function() {
    parent.ns.$children[0] = false;
}, 3000);

// error
parent.ns.$children[0] = true;
parent.ns.$children[0].notifications.error.message = "Your error message";

// event
parent.ns.$children[0] = true;
parent.ns.$children[0] = "Your event name";
parent.ns.$children[0].notifications.event.message = "Your action-name";
parent.ns.$children[0].notifications.event.progress = 50;
/* */

Call API

Using Cockpit API you can easily call NethServer API or your own module API in this way:

// Definition
    ["<api-name>/<action>"], // action can be: read | validate | update
    null, // used for input in JSON format -> { "key": "value" }
    null, // used for strem output, for actions the print on STDOUT
    function(success) {
        success = JSON.parse(success);
        return success;
    function(error) {
        return error;
    true   // set to `false` if you do not want to launch the API with the sudo command

// Example
// define method
function validate(obj, callback) {
        function(success) {
            var success = JSON.parse(success);
        function(error, data) {
            var errorData = JSON.parse(data);

// call it
var validateObj = {}
    validate(validateObj, function (result) {
        // check errors
        // if(result) { ... }

        // if no errors
        // update value
        // ...


Modal overlay should be provided any time the user needs to enter data on a form and press "Save" button to change system configuration.

See also Modal Overlay for extra use cases.

Help on forms

There are many ways to provide additional help to users when filling forms. The UI can display inline documentation or add links to external documentation.


The field should have the help icon as described in PatternFly. On click, a pop-over can give context about the field or describe the syntax. Pop-over can contain HTML syntax but it should be avoided to ease the string translation.

HTML5 placeholder can be used to suggest actions like: "Type a word to start searching".

A link pointing to external documentation should be added on complex sections which requires a general explanation. Some use cases are:

  • wizards where the user should be guided to make a decision, like the backup configuration
  • sections using NethServer-related terminology, like the "Trusted network" page


We need to evaluate how PatternFly copes with people suffering of low vision, who need to access most features using the keyboard shortcuts.



Start an asynchronous call that fetches the localized strings. The current Cockpit language is automatically detected from the current session settings.

If the remote call completes successfully callback is invoked.

Return value

a jQuery jqXHR object.


  • callback(data), a function that accepts an argument data containing the language.json file contents

The actual localization is performed by the Cockpit server process, according to its content-negotiation rules. See also


In a VueJS main.js, using vue-i18n plugin:

const i18n = new VueI18n();
nethserver.fetchTranslatedStrings(function (data, lang) {
    i18n.setLocaleMessage('cockpit', data);
    i18n.locale = 'cockpit';
    app.$mount('#app'); // Start VueJS application after language strings are loaded