Components

JSON-UI includes 26 built-in component types organized into six groups. Every component serializes to JSON with a "type" discriminant and is wrapped in a ComponentNode that adds a unique key, an optional action binding, and optional visibility rules.

Component Overview

ComponentNode

Every component is wrapped in a ComponentNode:

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, Component, CardProps};

ComponentNode {
    key: "my-card".to_string(),          // unique identifier on the page
    component: Component::Card(CardProps { /* ... */ }),
    action: None,                         // optional Action binding
    visibility: None,                     // optional Visibility condition
}
}

Convenience constructors are available for common components:

#![allow(unused)]
fn main() {
// Equivalent to the struct literal above, but more concise
let node = ComponentNode::card("my-card", CardProps {
    title: "Hello".to_string(),
    description: None,
    children: vec![],
    footer: vec![],
});
}

Shared Types

Size

Controls sizing for Button, Avatar, and other components.

ButtonVariant

Visual styles for the Button component (aligned to shadcn/ui).

AlertVariant

Visual styles for Alert and Toast components.

BadgeVariant

Visual styles for the Badge component (aligned to shadcn/ui).

ColumnFormat

Display format for Table columns and DescriptionList items.

TextElement

Semantic HTML element for the Text component.

ToastVariant

Visual styles for the Toast component. Mirrors AlertVariant.

Layout Components

Card

Container with title, optional description, nested children, and footer.

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, CardProps, ButtonProps, ButtonVariant, Size};

let node = ComponentNode::card("user-card", CardProps {
    title: "User Details".to_string(),
    description: Some("Account information".to_string()),
    children: vec![
        ComponentNode::button("edit-btn", ButtonProps {
            label: "Edit".to_string(),
            variant: ButtonVariant::Outline,
            size: Size::Default,
            disabled: None,
            icon: None,
            icon_position: None,
        }),
    ],
    footer: vec![],
});
}

JSON output:

{
  "key": "user-card",
  "type": "Card",
  "title": "User Details",
  "description": "Account information",
  "children": [
    { "key": "edit-btn", "type": "Button", "label": "Edit", "variant": "outline", "size": "default" }
  ]
}

Tabs

Tabbed content with multiple panels. Each tab contains its own set of child components.

Tab defines a tab panel:

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, Component, TabsProps, Tab};

ComponentNode {
    key: "settings-tabs".to_string(),
    component: Component::Tabs(TabsProps {
        default_tab: "general".to_string(),
        tabs: vec![
            Tab {
                value: "general".to_string(),
                label: "General".to_string(),
                children: vec![/* ... */],
            },
            Tab {
                value: "security".to_string(),
                label: "Security".to_string(),
                children: vec![/* ... */],
            },
        ],
    }),
    action: None,
    visibility: None,
}
}

JSON output:

{
  "key": "settings-tabs",
  "type": "Tabs",
  "default_tab": "general",
  "tabs": [
    { "value": "general", "label": "General", "children": [] },
    { "value": "security", "label": "Security", "children": [] }
  ]
}

Separator

Visual divider between content sections.

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, Component, SeparatorProps};

ComponentNode {
    key: "divider".to_string(),
    component: Component::Separator(SeparatorProps {
        orientation: None, // defaults to horizontal
    }),
    action: None,
    visibility: None,
}
}

JSON output:

{ "key": "divider", "type": "Separator" }

Modal

Dialog overlay with title, content, footer, and trigger button.

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, Component, ModalProps, ButtonProps, ButtonVariant, Size, Action};

ComponentNode {
    key: "delete-modal".to_string(),
    component: Component::Modal(ModalProps {
        title: "Delete Item".to_string(),
        description: Some("This action cannot be undone.".to_string()),
        children: vec![],
        footer: vec![
            ComponentNode {
                key: "delete-btn".to_string(),
                component: Component::Button(ButtonProps {
                    label: "Delete".to_string(),
                    variant: ButtonVariant::Destructive,
                    size: Size::Default,
                    disabled: None,
                    icon: None,
                    icon_position: None,
                }),
                action: Some(Action::delete("items.destroy").confirm_danger("Confirm deletion")),
                visibility: None,
            },
        ],
        trigger_label: Some("Delete".to_string()),
    }),
    action: None,
    visibility: None,
}
}

JSON output:

{
  "key": "delete-modal",
  "type": "Modal",
  "title": "Delete Item",
  "description": "This action cannot be undone.",
  "trigger_label": "Delete",
  "children": [],
  "footer": [{ "key": "delete-btn", "type": "Button", "label": "Delete", "variant": "destructive", "size": "default" }]
}

Skeleton

Loading placeholder with configurable dimensions for content that is still loading.

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, Component, SkeletonProps};

ComponentNode {
    key: "loading-placeholder".to_string(),
    component: Component::Skeleton(SkeletonProps {
        width: Some("100%".to_string()),
        height: Some("40px".to_string()),
        rounded: Some(true),
    }),
    action: None,
    visibility: None,
}
}

JSON output:

{ "key": "loading-placeholder", "type": "Skeleton", "width": "100%", "height": "40px", "rounded": true }

Data Display Components

Table

Data table with column definitions, row actions, and sorting support. Rows are loaded from handler data via data_path.

Column defines a table column:

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, TableProps, Column, ColumnFormat, Action};

let node = ComponentNode::table("users-table", TableProps {
    columns: vec![
        Column { key: "name".to_string(), label: "Name".to_string(), format: None },
        Column { key: "email".to_string(), label: "Email".to_string(), format: None },
        Column {
            key: "created_at".to_string(),
            label: "Created".to_string(),
            format: Some(ColumnFormat::Date),
        },
    ],
    data_path: "/data/users".to_string(),
    row_actions: Some(vec![
        Action::get("users.edit"),
        Action::delete("users.destroy").confirm_danger("Delete this user?"),
    ]),
    empty_message: Some("No users found.".to_string()),
    sortable: Some(true),
    sort_column: None,
    sort_direction: None,
});
}

JSON output:

{
  "key": "users-table",
  "type": "Table",
  "data_path": "/data/users",
  "columns": [
    { "key": "name", "label": "Name" },
    { "key": "email", "label": "Email" },
    { "key": "created_at", "label": "Created", "format": "date" }
  ],
  "sortable": true
}

DescriptionList

Key-value pairs displayed as a description list. Reuses ColumnFormat for value formatting.

DescriptionItem defines a key-value pair:

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, Component, DescriptionListProps, DescriptionItem, ColumnFormat};

ComponentNode {
    key: "user-info".to_string(),
    component: Component::DescriptionList(DescriptionListProps {
        items: vec![
            DescriptionItem { label: "Name".to_string(), value: "Alice Johnson".to_string(), format: None },
            DescriptionItem {
                label: "Joined".to_string(),
                value: "2026-01-15".to_string(),
                format: Some(ColumnFormat::Date),
            },
            DescriptionItem {
                label: "Active".to_string(),
                value: "true".to_string(),
                format: Some(ColumnFormat::Boolean),
            },
        ],
        columns: Some(2),
    }),
    action: None,
    visibility: None,
}
}

JSON output:

{
  "key": "user-info",
  "type": "DescriptionList",
  "columns": 2,
  "items": [
    { "label": "Name", "value": "Alice Johnson" },
    { "label": "Joined", "value": "2026-01-15", "format": "date" },
    { "label": "Active", "value": "true", "format": "boolean" }
  ]
}

DetailForm

Split-mode detail page with inline edit. Renders the same description-list-style scaffold in two modes — View and Edit — driven by a URL query parameter.

When to use. Use DetailForm instead of a pair of DescriptionList (for viewing) + Form (for editing) when you want the view and edit states to share a single structural container, so the user sees the same layout whether they are reading or editing. The mode toggle is URL-driven (?mode=edit); there is no client-side JavaScript state.

DetailField defines one row:

EditMode controls which mode to render:

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, Component, DetailForm, DetailFormProps, DetailField,
            EditMode, InputProps, InputType, Action, HttpMethod};

let mode = EditMode::from_query(req.query("mode").as_deref());

let node = ComponentNode::detail_form(
    "user-detail",
    DetailFormProps {
        mode,
        action: Action::new("users.update"),
        fields: vec![
            DetailField::new(
                "Name",
                user.name.clone(),
                // Option A: input label must be "" — the <dt> provides the visible label.
                ComponentNode::input("name", InputProps {
                    field: "name".to_string(),
                    label: "".to_string(),
                    input_type: InputType::Text,
                    default_value: Some(user.name.clone()),
                    ..Default::default()
                }),
            ),
            DetailField::new(
                "Email",
                user.email.clone(),
                ComponentNode::input("email", InputProps {
                    field: "email".to_string(),
                    label: "".to_string(),
                    input_type: InputType::Email,
                    default_value: Some(user.email.clone()),
                    ..Default::default()
                }),
            ),
        ],
        edit_url: format!("/users/{}?mode=edit", user.id),
        cancel_url: format!("/users/{}", user.id),
        edit_label: None,
        save_label: None,
        cancel_label: None,
        method: Some(HttpMethod::Put),
    },
);
}

JSON output (mode = Edit):

{
  "key": "user-detail",
  "type": "DetailForm",
  "mode": "edit",
  "action": { "handler": "users.update", "method": "PUT" },
  "fields": [
    {
      "label": "Name",
      "value": "Ada Lovelace",
      "input": { "type": "Input", "field": "name", "label": "", "input_type": "text", "default_value": "Ada Lovelace" }
    },
    {
      "label": "Email",
      "value": "ada@example.com",
      "input": { "type": "Input", "field": "email", "label": "", "input_type": "email", "default_value": "ada@example.com" }
    }
  ],
  "edit_url": "/users/1?mode=edit",
  "cancel_url": "/users/1",
  "method": "PUT"
}

Authoring rule (Option A). When a DetailField.input is an Input, Select, Textarea, Checkbox, or Switch component, the caller MUST set its label prop to the empty string "". The <dt> already provides the visible label; a non-empty input label produces duplicate UI text. DetailForm does not mutate caller-supplied props. For accessibility, callers SHOULD also set aria-label on each input derived from the field's label value so screen readers retain the field name.

Not included in v1. Client-side mode toggle (no JS). Optimistic updates. Per-field mode override. Custom action buttons beyond Modifica/Salva/Annulla. Top-level error banner. i18n binding for default labels (currently Italian literals).

Badge

Small label with variant-based styling.

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, Component, BadgeProps, BadgeVariant};

ComponentNode {
    key: "status".to_string(),
    component: Component::Badge(BadgeProps {
        label: "Active".to_string(),
        variant: BadgeVariant::Default,
    }),
    action: None,
    visibility: None,
}
}

JSON output:

{ "key": "status", "type": "Badge", "label": "Active", "variant": "default" }

Avatar

User avatar with image source, fallback text, and size variants.

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, Component, AvatarProps, Size};

ComponentNode {
    key: "user-avatar".to_string(),
    component: Component::Avatar(AvatarProps {
        src: Some("/images/alice.jpg".to_string()),
        alt: "Alice Johnson".to_string(),
        fallback: Some("AJ".to_string()),
        size: Some(Size::Lg),
    }),
    action: None,
    visibility: None,
}
}

JSON output:

{ "key": "user-avatar", "type": "Avatar", "alt": "Alice Johnson", "src": "/images/alice.jpg", "fallback": "AJ", "size": "lg" }

Image

Renders a bounded visual asset — either an external image via URL, or a server-constructed inline SVG.

Props

Exactly one of src or svg must be set. Backward-compatibility note: existing JSON sending {"type":"Image","src":"…","alt":"…"} continues to work unchanged.

Safety note — svg variant: The svg value is emitted verbatim without HTML escaping. Intended for server-constructed SVG (charts, sparklines, icons). Not suitable for user-supplied strings. Callers that incorporate user data into the SVG output are responsible for sanitization before constructing the svg variant. The alt attribute is HTML-escaped on both variants.

Rust

#![allow(unused)]
fn main() {
use ferro_json_ui::{ComponentNode, ImageProps};

// URL variant
let url_node = ComponentNode::image(
    "hero",
    ImageProps::url("/img/hero.png", "Hero image"),
);

// SVG variant — server-constructed chart (e.g. from a Rust helper)
let svg = bar_chart_svg(&weekly_data, 800, 300);
let chart_node = ComponentNode::image(
    "revenue-chart",
    ImageProps::inline_svg(svg, "Incassi settimanali: 150€ lun, 320€ mar, …"),
);
}

JSON

URL variant:

{
  "type": "Image",
  "src": "/img/hero.png",
  "alt": "Hero image",
  "aspect_ratio": "16/9"
}

SVG variant:

{
  "type": "Image",
  "svg": "<svg viewBox=\"0 0 800 300\">…</svg>",
  "alt": "Incassi settimanali: 150€ lun, 320€ mar, …"
}

Use cases for the SVG variant

• Server-rendered charts (bar, line, sparkline)
• Diagrams assembled from typed data on the server
• Decorative vector assets constructed by Rust code
• Server-rendered icon sets

No generic HTML escape hatch. For rendering HTML (not SVG), no generic HtmlEmbed-style component exists — by design. If a real use-case demands HTML embedding, author a narrower component scoped to the specific content shape rather than a generic string-to-HTML escape hatch.

Text

Renders text content with semantic HTML element selection.

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, Component, TextProps, TextElement};

ComponentNode {
    key: "heading".to_string(),
    component: Component::Text(TextProps {
        content: "Welcome to the dashboard".to_string(),
        element: TextElement::H1,
    }),
    action: None,
    visibility: None,
}
}

JSON output:

{ "key": "heading", "type": "Text", "content": "Welcome to the dashboard", "element": "h1" }

Progress

Progress bar with percentage value.

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, Component, ProgressProps};

ComponentNode {
    key: "upload-progress".to_string(),
    component: Component::Progress(ProgressProps {
        value: 75,
        max: Some(100),
        label: Some("Uploading...".to_string()),
    }),
    action: None,
    visibility: None,
}
}

JSON output:

{ "key": "upload-progress", "type": "Progress", "value": 75, "max": 100, "label": "Uploading..." }

Breadcrumb

Navigation breadcrumb trail. The last item typically has no URL (current page).

BreadcrumbItem defines a breadcrumb entry:

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, Component, BreadcrumbProps, BreadcrumbItem};

ComponentNode {
    key: "breadcrumbs".to_string(),
    component: Component::Breadcrumb(BreadcrumbProps {
        items: vec![
            BreadcrumbItem { label: "Home".to_string(), url: Some("/".to_string()) },
            BreadcrumbItem { label: "Users".to_string(), url: Some("/users".to_string()) },
            BreadcrumbItem { label: "Edit User".to_string(), url: None },
        ],
    }),
    action: None,
    visibility: None,
}
}

JSON output:

{
  "key": "breadcrumbs",
  "type": "Breadcrumb",
  "items": [
    { "label": "Home", "url": "/" },
    { "label": "Users", "url": "/users" },
    { "label": "Edit User" }
  ]
}

Pagination

Page navigation for paginated data. Computes page count from total and per_page.

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, Component, PaginationProps};

ComponentNode {
    key: "users-pagination".to_string(),
    component: Component::Pagination(PaginationProps {
        current_page: 1,
        per_page: 25,
        total: 150,
        base_url: Some("/users".to_string()),
    }),
    action: None,
    visibility: None,
}
}

JSON output:

{ "key": "users-pagination", "type": "Pagination", "current_page": 1, "per_page": 25, "total": 150, "base_url": "/users" }

StatCard

Live-updatable metric card with an optional SSE target for real-time value updates. Used in dashboards to display KPIs, counts, and monetary totals.

The sse_target field connects this card to the JS runtime's SSE listener. When the server emits a Server-Sent Event with a matching key, the runtime updates the displayed value without a page reload:

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, StatCardProps};

let node = ComponentNode::stat_card("revenue", StatCardProps {
    label: "Total Revenue".to_string(),
    value: "€12,345".to_string(),
    icon: Some("currency-euro".to_string()),
    subtitle: Some("This month".to_string()),
    sse_target: Some("revenue_total".to_string()),
});
}

The server sends updates via SSE as JSON:

event: live-value
data: {"target": "revenue_total", "value": "€13,210"}

JSON output:

{
  "key": "revenue",
  "type": "StatCard",
  "label": "Total Revenue",
  "value": "€12,345",
  "icon": "currency-euro",
  "subtitle": "This month",
  "sse_target": "revenue_total"
}

Forms Components

Form

Form container with action binding and field components. The action defines the submit endpoint.

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, Component, FormProps, InputProps, InputType, Action};

ComponentNode {
    key: "create-form".to_string(),
    component: Component::Form(FormProps {
        action: Action::new("users.store"),
        fields: vec![
            ComponentNode {
                key: "name-input".to_string(),
                component: Component::Input(InputProps {
                    field: "name".to_string(),
                    label: "Name".to_string(),
                    input_type: InputType::Text,
                    placeholder: Some("Enter name".to_string()),
                    required: Some(true),
                    disabled: None,
                    error: None,
                    description: None,
                    default_value: None,
                    data_path: None,
                    step: None,
                }),
                action: None,
                visibility: None,
            },
        ],
        method: None,
    }),
    action: None,
    visibility: None,
}
}

JSON output:

{
  "key": "create-form",
  "type": "Form",
  "action": { "handler": "users.store", "method": "POST" },
  "fields": [
    { "key": "name-input", "type": "Input", "field": "name", "label": "Name", "placeholder": "Enter name", "required": true }
  ]
}

Input

Text input field with type variants, validation error display, and data binding.

InputType variants:

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, Component, InputProps, InputType};

ComponentNode {
    key: "email-input".to_string(),
    component: Component::Input(InputProps {
        field: "email".to_string(),
        label: "Email Address".to_string(),
        input_type: InputType::Email,
        placeholder: Some("user@example.com".to_string()),
        required: Some(true),
        disabled: None,
        error: None,
        description: Some("Your work email".to_string()),
        default_value: None,
        data_path: Some("/data/user/email".to_string()),
        step: None,
    }),
    action: None,
    visibility: None,
}
}

JSON output:

{
  "key": "email-input",
  "type": "Input",
  "field": "email",
  "label": "Email Address",
  "input_type": "email",
  "placeholder": "user@example.com",
  "required": true,
  "description": "Your work email",
  "data_path": "/data/user/email"
}

Select

Dropdown select field with options, validation error, and data binding.

SelectOption defines a value-label pair:

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, Component, SelectProps, SelectOption};

ComponentNode {
    key: "role-select".to_string(),
    component: Component::Select(SelectProps {
        field: "role".to_string(),
        label: "Role".to_string(),
        options: vec![
            SelectOption { value: "admin".to_string(), label: "Administrator".to_string() },
            SelectOption { value: "editor".to_string(), label: "Editor".to_string() },
            SelectOption { value: "viewer".to_string(), label: "Viewer".to_string() },
        ],
        placeholder: Some("Select a role".to_string()),
        required: Some(true),
        disabled: None,
        error: None,
        description: None,
        default_value: None,
        data_path: Some("/data/user/role".to_string()),
    }),
    action: None,
    visibility: None,
}
}

JSON output:

{
  "key": "role-select",
  "type": "Select",
  "field": "role",
  "label": "Role",
  "placeholder": "Select a role",
  "required": true,
  "data_path": "/data/user/role",
  "options": [
    { "value": "admin", "label": "Administrator" },
    { "value": "editor", "label": "Editor" },
    { "value": "viewer", "label": "Viewer" }
  ]
}

Checkbox

Boolean checkbox field with label, description, and data binding.

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, Component, CheckboxProps};

ComponentNode {
    key: "terms-checkbox".to_string(),
    component: Component::Checkbox(CheckboxProps {
        field: "terms".to_string(),
        label: "Accept Terms of Service".to_string(),
        description: Some("You must accept to continue.".to_string()),
        checked: None,
        data_path: None,
        required: Some(true),
        disabled: None,
        error: None,
    }),
    action: None,
    visibility: None,
}
}

JSON output:

{ "key": "terms-checkbox", "type": "Checkbox", "field": "terms", "label": "Accept Terms of Service", "description": "You must accept to continue.", "required": true }

Switch

Toggle switch — a visual alternative to Checkbox with identical props. The frontend renderer handles the visual difference.

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, Component, SwitchProps};

ComponentNode {
    key: "notifications-switch".to_string(),
    component: Component::Switch(SwitchProps {
        field: "notifications".to_string(),
        label: "Enable Notifications".to_string(),
        description: Some("Receive email notifications".to_string()),
        checked: Some(true),
        data_path: Some("/data/user/notifications_enabled".to_string()),
        required: None,
        disabled: None,
        error: None,
    }),
    action: None,
    visibility: None,
}
}

JSON output:

{ "key": "notifications-switch", "type": "Switch", "field": "notifications", "label": "Enable Notifications", "description": "Receive email notifications", "checked": true, "data_path": "/data/user/notifications_enabled" }

Button

Interactive button with visual variants, sizing, and optional icon.

Buttons are typically combined with an action on the ComponentNode to bind click behavior:

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, ButtonProps, ButtonVariant, Size, IconPosition};

let node = ComponentNode::button("save-btn", ButtonProps {
    label: "Save Changes".to_string(),
    variant: ButtonVariant::Default,
    size: Size::Default,
    disabled: None,
    icon: Some("save".to_string()),
    icon_position: Some(IconPosition::Left),
});
}

JSON output:

{ "key": "save-btn", "type": "Button", "label": "Save Changes", "variant": "default", "size": "default", "icon": "save", "icon_position": "left" }

Feedback Components

Alert

Alert message with variant-based styling and optional title.

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, Component, AlertProps, AlertVariant};

ComponentNode {
    key: "warning".to_string(),
    component: Component::Alert(AlertProps {
        message: "Your trial expires in 3 days.".to_string(),
        variant: AlertVariant::Warning,
        title: Some("Trial Ending".to_string()),
    }),
    action: None,
    visibility: None,
}
}

JSON output:

{ "key": "warning", "type": "Alert", "message": "Your trial expires in 3 days.", "variant": "warning", "title": "Trial Ending" }

Toast

Declarative notification intent rendered by the JS runtime. When a Toast component is included in a view, the runtime displays it as an overlay notification (top-right corner) and dismisses it after the configured timeout.

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, Component, ToastProps, ToastVariant};

ComponentNode {
    key: "save-toast".to_string(),
    component: Component::Toast(ToastProps {
        message: "Changes saved successfully.".to_string(),
        variant: ToastVariant::Success,
        timeout: Some(3),
        dismissible: true,
    }),
    action: None,
    visibility: None,
}
}

JSON output:

{ "key": "save-toast", "type": "Toast", "message": "Changes saved successfully.", "variant": "success", "timeout": 3, "dismissible": true }

Navigation Components

Sidebar

Sidebar navigation shell with fixed top items, grouped items, and fixed bottom items. Typically used as a component inside a DashboardLayout. When used standalone it renders as a vertical navigation panel.

SidebarNavItem defines a navigation link:

SidebarGroup defines a labeled, collapsible group:

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, Component, SidebarProps, SidebarNavItem, SidebarGroup};

ComponentNode {
    key: "sidebar".to_string(),
    component: Component::Sidebar(SidebarProps {
        fixed_top: vec![
            SidebarNavItem { label: "Dashboard".to_string(), href: "/".to_string(), icon: Some("home".to_string()), active: true },
        ],
        groups: vec![
            SidebarGroup {
                label: "Management".to_string(),
                collapsed: false,
                items: vec![
                    SidebarNavItem { label: "Users".to_string(), href: "/users".to_string(), icon: Some("users".to_string()), active: false },
                    SidebarNavItem { label: "Orders".to_string(), href: "/orders".to_string(), icon: Some("shopping-bag".to_string()), active: false },
                ],
            },
        ],
        fixed_bottom: vec![
            SidebarNavItem { label: "Settings".to_string(), href: "/settings".to_string(), icon: Some("cog".to_string()), active: false },
        ],
    }),
    action: None,
    visibility: None,
}
}

JSON output:

{
  "key": "sidebar",
  "type": "Sidebar",
  "fixed_top": [{ "label": "Dashboard", "href": "/", "icon": "home", "active": true }],
  "groups": [
    {
      "label": "Management",
      "collapsed": false,
      "items": [
        { "label": "Users", "href": "/users", "icon": "users", "active": false },
        { "label": "Orders", "href": "/orders", "icon": "shopping-bag", "active": false }
      ]
    }
  ],
  "fixed_bottom": [{ "label": "Settings", "href": "/settings", "icon": "cog", "active": false }]
}

Header

Application header shell with business name, user info, notification count, and logout link. Typically used inside DashboardLayout.

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, Component, HeaderProps};

ComponentNode {
    key: "header".to_string(),
    component: Component::Header(HeaderProps {
        business_name: "My App".to_string(),
        notification_count: Some(3),
        user_name: Some("Alice Johnson".to_string()),
        user_avatar: None,
        logout_url: Some("/logout".to_string()),
    }),
    action: None,
    visibility: None,
}
}

JSON output:

{
  "key": "header",
  "type": "Header",
  "business_name": "My App",
  "notification_count": 3,
  "user_name": "Alice Johnson",
  "logout_url": "/logout"
}

NotificationDropdown

A dropdown list of notification items, typically rendered inside a Header. Displays a list of recent notifications with read/unread state, timestamps, and optional action URLs.

NotificationItem defines a single notification:

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, Component, NotificationDropdownProps, NotificationItem};

ComponentNode {
    key: "notifications".to_string(),
    component: Component::NotificationDropdown(NotificationDropdownProps {
        notifications: vec![
            NotificationItem {
                icon: Some("bell".to_string()),
                text: "New order received".to_string(),
                timestamp: Some("5 minutes ago".to_string()),
                read: false,
                action_url: Some("/orders/123".to_string()),
            },
            NotificationItem {
                icon: None,
                text: "Payment processed".to_string(),
                timestamp: Some("1 hour ago".to_string()),
                read: true,
                action_url: None,
            },
        ],
        empty_text: Some("No new notifications".to_string()),
    }),
    action: None,
    visibility: None,
}
}

JSON output:

{
  "key": "notifications",
  "type": "NotificationDropdown",
  "empty_text": "No new notifications",
  "notifications": [
    { "icon": "bell", "text": "New order received", "timestamp": "5 minutes ago", "read": false, "action_url": "/orders/123" },
    { "text": "Payment processed", "timestamp": "1 hour ago", "read": true }
  ]
}

Onboarding Components

Checklist

Step-by-step onboarding or task checklist with dismissal and optional server-side state persistence.

ChecklistItem defines a checklist step:

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, Component, ChecklistProps, ChecklistItem};

ComponentNode {
    key: "setup-checklist".to_string(),
    component: Component::Checklist(ChecklistProps {
        title: "Get Started".to_string(),
        items: vec![
            ChecklistItem { label: "Create your account".to_string(), checked: true, href: None },
            ChecklistItem { label: "Set up billing".to_string(), checked: false, href: Some("/billing".to_string()) },
            ChecklistItem { label: "Invite your team".to_string(), checked: false, href: Some("/team/invite".to_string()) },
        ],
        dismissible: true,
        dismiss_label: Some("Done".to_string()),
        data_key: Some("onboarding_checklist".to_string()),
    }),
    action: None,
    visibility: None,
}
}

JSON output:

{
  "key": "setup-checklist",
  "type": "Checklist",
  "title": "Get Started",
  "dismissible": true,
  "dismiss_label": "Done",
  "data_key": "onboarding_checklist",
  "items": [
    { "label": "Create your account", "checked": true },
    { "label": "Set up billing", "checked": false, "href": "/billing" },
    { "label": "Invite your team", "checked": false, "href": "/team/invite" }
  ]
}

Extensible Components

Plugin

Passes through to a registered plugin component. The plugin_type field selects the plugin from the global registry.

#![allow(unused)]
fn main() {
use ferro::{ComponentNode, Component, PluginProps};

ComponentNode {
    key: "office-map".to_string(),
    component: Component::Plugin(PluginProps {
        plugin_type: "Map".to_string(),
        props: serde_json::json!({
            "center": [51.505, -0.09],
            "zoom": 13,
            "markers": [
                { "lat": 51.505, "lng": -0.09, "popup": "Our office" }
            ]
        }),
    }),
    action: None,
    visibility: None,
}
}

See Plugins for the full plugin guide — how to build, register, and use custom plugin components.

JSON output:

{
  "key": "office-map",
  "type": "Map",
  "center": [51.505, -0.09],
  "zoom": 13,
  "markers": [{ "lat": 51.505, "lng": -0.09, "popup": "Our office" }]
}

JSON Serialization

Every component tree serializes to JSON via serde. The Component enum uses serde's tagged representation, producing a "type" field that identifies the component:

{
  "key": "welcome-card",
  "type": "Card",
  "title": "Welcome",
  "description": "Your dashboard",
  "children": [
    {
      "key": "greeting",
      "type": "Text",
      "content": "Hello, Alice!",
      "element": "h2"
    }
  ]
}

The ComponentNode fields (key, action, visibility) are flattened into the same JSON object alongside the component-specific props. This produces clean, predictable JSON that frontend renderers can consume directly.

Optional fields with None values are omitted from serialization (skip_serializing_if = "Option::is_none"). Default values for enums (e.g., ButtonVariant::Default) are always included.