Content Types

View content items are the maps, charts, tables, stat-cards, forms, and info-panels that make up a view's layout. They are defined under views[].content: in folia.yaml.

Content items are per-tab: they exist only within their view. When the user switches tabs, the content changes. This is distinct from workspace panels (layers, terminal, catalog) which persist across tabs.

Decided in ADR-0015 D4.

map - Interactive Map

The primary spatial content type. Renders an interactive map with data layers. Supports nested components: for canvas overlays and per-layer interactions:.

Fields

Field	Type	Required	Description
map	object	MAY	Map state: engine, style, center, zoom, pitch, bearing, bounds
layers	list	MAY	Layer subset for this map. Overrides view-level layers:.
style	object	MAY	Per-layer style overrides keyed by layer path
interactions	object	MAY	Per-layer interaction config (see Interactions)
components	list	MAY	Map canvas components (see Components)
label	string	MAY	Label shown in grid layouts to identify this map

When a map content item omits layers:, it MUST inherit the view-level layers: list.

Map State Object

Field	Type	Required	Description
engine	enum	MAY	Map renderer: maplibre (default), mapbox, deckgl, leaflet
style	string	MAY	Basemap style name or URL
center	[lng, lat]	MAY	Initial map center
zoom	number	MAY	Initial zoom level
pitch	number	MAY	Camera tilt in degrees (0-85)
bearing	number	MAY	Camera rotation in degrees
bounds	[w, s, e, n]	MAY	Bounding box. Alternative to center/zoom.

Example

- type: map
  position: [0, 0, 2, 2]
  map:
    engine: maplibre
    style: terrain
    center: [-111.6, 40.6]
    zoom: 12
    pitch: 45
    bearing: -30
  layers: [terrain/slope, boundaries/counties]
  style:
    terrain/slope: { opacity: 0.7, palette: avalanche }
  interactions:
    terrain/slope:
      click: sample
      hover: value-tooltip
    boundaries/counties:
      click: popup
      hover: highlight
  components:
    - type: legend
      anchor: bottom-right
    - type: scale-bar
      anchor: bottom-left

chart - Data Visualization

Renders charts from layer data or analysis results.

Fields

Field	Type	Required	Description
chartType	enum	MUST	bar, line, scatter, histogram, pie, area
title	string	MAY	Chart title
data	string	MUST	Layer path providing the data
xAxis	object	MUST (except pie)	{ field, label } - field name and axis label
yAxis	object	MUST (except pie, histogram)	{ field, label } - field name and axis label
color	string or object	MAY	Fixed color string, or { field, map } for categorical coloring

Supported Chart Types

Type	Use Case	Required Fields
bar	Category comparison	xAxis.field, yAxis.field
line	Time series, trends	xAxis.field, yAxis.field
scatter	Correlation	xAxis.field, yAxis.field
histogram	Distribution	xAxis.field (binned automatically)
pie	Proportions	field, valueField
area	Cumulative trends	xAxis.field, yAxis.field

Example

- type: chart
  position: [2, 0, 2, 1]
  chartType: bar
  title: Avalanches by Terrain Class
  data: analysis/terrain_avy_join
  xAxis:
    field: terrain_class
    label: ATES Classification
  yAxis:
    field: avalanche_count
    label: Number of Avalanches
  color:
    field: terrain_class
    map:
      simple: "#4caf50"
      challenging: "#ff9800"
      complex: "#f44336"

table - Data Table

Sortable, filterable data grid from vector data or analysis results.

Fields

Field	Type	Required	Description
data	string	MUST	Layer path to render
columns	list	MAY	Column definitions. Each item: { field, label, format, width }. Defaults to all fields.
sortBy	string	MAY	Default sort column field name
sortOrder	enum	MAY	asc or desc. Defaults to asc.
pageSize	number	MAY	Rows per page. Defaults to 25.
filterable	boolean	MAY	Enable column filter UI. Defaults to false.

Column Definition

Field	Type	Required	Description
field	string	MUST	Attribute field name from the data source
label	string	MAY	Display label. Defaults to field name.
format	string	MAY	Format type: number, percent, area_ha, area_km2, degrees, currency_usd
width	number	MAY	Column width in pixels

Example

- type: table
  position: [0, 2, 4, 1]
  title: SNOTEL Stations
  data: sources/snotel_stations
  columns:
    - { field: name, label: Station, width: 200 }
    - { field: elevation, label: "Elev (ft)", format: number }
    - { field: snow_depth, label: "Depth (in)", format: number }
    - { field: air_temp, label: "Temp (F)", format: number }
  sortBy: snow_depth
  sortOrder: desc
  pageSize: 15
  filterable: true

stat-card - Single Metric

Displays a single prominent value with label and optional trend indicator.

Fields

Field	Type	Required	Description
title	string	MUST	Metric label
value	string	MUST	Layer path providing the metric
field	string	MUST	Field name within the layer to display
format	enum	MAY	area_ha, area_km2, percent, number, degrees, currency_usd
precision	number	MAY	Decimal places
icon	string	MAY	Icon name (e.g., mountain, tree, trending-up)
trend	object	MAY	Trend indicator with value, field, format, and positiveIs

Trend Object

Field	Type	Required	Description
value	string	MUST	Layer path providing the trend metric
field	string	MUST	Field name for the trend value
format	enum	MAY	Format type for the trend value
positiveIs	enum	MUST	good or bad. Controls color: green for good, red for bad.

Example

- type: stat-card
  position: [2, 0, 1, 1]
  title: Forest Loss
  value: analysis/forest_loss_total
  field: total_ha
  format: area_ha
  precision: 0
  icon: tree
  trend:
    value: analysis/forest_loss_yoy_change
    field: yoy_percent
    format: percent
    positiveIs: bad

A stat-card can also appear as a component anchored to a map canvas. See Components.

form - User Input

Bidirectional Content

Every other content type is read-only: it consumes data and renders it. The form content type is bidirectional - it renders input controls AND provides parameter values.

Forms change what data is (re-execute compute to produce new results). This is different from controls components, which change how data looks (client-side rendering adjustments).

Decided in ADR-0005.

Form Field Types

Type	Renders as	Value type	Additional config
select	Dropdown	string	source (layer to populate from), sourceField
multi-select	Multi-select	string[]	source, sourceField
slider	Range slider	number	min, max, step, default
number	Number input	number	min, max, default
text	Text input	string	default, placeholder
date	Date picker	date	default, min, max
toggle	Toggle switch	boolean	default

Form vs Controls

	controls component	form content
Defined in	components: on a map content item	content: in a view layout
Binds to	params in the view	:param in a compute: block
Scope	Visual parameters (opacity, filters, thresholds)	Computation inputs (function arguments)
Data flow	Param changes re-render existing data	Param changes re-execute compute, produce new data

Example

- type: form
  position: [0, 0, 1, 1]
  title: Pricing Parameters
  fields:
    - name: instance_type
      type: select
      label: Instance Type
      source: cloud_pricing/ec2
      sourceField: instance_type

    - name: hours
      type: slider
      label: Hours / Month
      min: 0
      max: 730
      step: 1
      default: 730

    - name: count
      type: number
      label: Instance Count
      default: 1
      min: 1
      max: 100

    - name: include_reserved
      type: toggle
      label: Include Reserved Pricing
      default: false

Reactivity

When any form field changes, the computed layer's compute.query MUST re-execute with the new parameter values. All content items referencing that layer MUST update with the new results. The dependency graph determines which downstream layers also recompute.

info-panel - Aggregated Selection Results

Displays query results from map clicks or row selections, aggregated across all queryable layers. Fields are auto-derived from the layer's type and output schema; optionally overridden by the layer's style.info: block.

Decided in ADR-0015 D1.

Fields

Field	Type	Required	Description
trigger	enum	MUST	map-click or row-select

Field Resolution Order

When a user clicks a point on the map, the platform MUST query every visible layer that supports sampling/querying (determined by type:, not manual declaration). Fields are resolved in this order:

1. Compute output schema - if the layer has compute:, the op definition declares output fields
2. Band metadata - if raster source, bands from source metadata
3. Attribute table - if vector source, all fields
4. style.info.fields override - restricts or customizes the auto-derived fields

Results SHOULD be grouped by style.info.section if specified on the layer.

Example

- type: info-panel
  position: [2, 0, 1, 2]
  trigger: map-click