Descriptor Files

One YAML file describes one resource: the table, where it mounts, who may reach it, and its list and form.

# descriptors/posts.yaml
entity: posts
path: /posts
title: Posts
permission: acme.blog.manage_posts
list:
  creatable: true
  deletable: true
  order_by: created_at
  order_dir: desc
  no_records_message: No posts yet.
  search: { prompt: Search posts }
  columns:
    title:      { searchable: true }
    status:     { type: status_pill, width: 10% }
    created_at: { type: datetime, align: right }
  filters:
    status: { type: select, options: [{ value: draft, label: Draft }] }
form:
  title: Post
  fields:
    title:  { span: 2/3, rules: [required, { max_length: 120 }] }
    status: { span: 1/3, type: select, options: [{ value: draft, label: Draft }] }
    body:   { type: textarea, rows: 8 }

Register it from your module:

registry.add_resource(laterite_admin::resource!("descriptors/posts.yaml"));

The path is relative to your Cargo.toml. The file is read at compile time: a missing or malformed one fails the build.

Resource keys

entity, path and id_field reach both screens.

Naming

Columns, fields and filters are maps. The key is the name, and they render in the order written:

columns:
  title: {}
  created_at: { type: datetime }

A missing label is made from the key: created_at becomes “Created at”. It is still translatable, and lat i18n extract finds it, as it finds the label of every entry under a column’s labels.

Type keys

An entry carries its own keys and its type’s, side by side:

fields:
  body:   { type: textarea, rows: 8, placeholder: Write here }
  price:  { input: number, min: 0, step: 0.01 }
  status: { type: select, options: [{ value: draft, label: Draft }] }
filters:
  status: { type: select, options: [{ value: draft, label: Draft }] }

A key the type does not read is refused, naming the entry and the keys it accepts.

Checklist

Boxes in groups. The column holds the ticked values as a JSON array of text.

fields:
  topics:
    type: checklist
    rules: [required]        # a box must be ticked
    options:
      - { value: news, label: News }
      - group: Sport
        options:
          - { value: football, label: Football, note: Every league }
          - { value: cricket, label: Cricket }
    select_all: auto
    search: auto
    expand: auto

A value listed twice stops the boot, naming it.

Form keys

form:
  enter: off
  confirm_leave: false
  focus: off
  fields:
    title: { rules: [{ max_length: 80 }], counter: true }
    body:  { type: textarea, rows: 8, grow: false }
    token: { type: password, reveal: false }

A max_length rule also sets the control’s maxlength.

Dependencies

fields:
  title: {}
  slug:  { preset: title }
  path:  { preset: { field: title, type: url } }
  is_delayed: { type: switch, label: Send later }
  send_at:
    type: date
    trigger: { action: show, field: is_delayed, condition: checked }
  format: { type: select, options: [{ value: csv }, { value: xml }] }
  delimiter:
    trigger: { action: show|empty, field: format, condition: "value[csv]" }
  topics: { type: checklist, options: [{ value: news }, { value: sport }] }
  region:
    trigger: { action: enable, field: "topics[]", condition: "value[sport]" }

A field that follows or watches one the form does not have stops the boot. An action or condition the page does not know is refused when the file is read.

Layout

Fields lay out on a twelve-column row and wrap as it fills.

Under 1100px a quarter becomes a half; under 768px every field takes the row.

Errors

A key the framework does not know is refused with its line:

error: line 11 column 19: unknown field `searchabel`, expected one of
label, type, sortable, invisible, width, align, permission, searchable

Write only the keys you set; everything else takes its default.

lat doctor parses every descriptors/**/*.yaml in the application and its plugins, so a typo is named without a build.

Read a descriptor at run time

resource! embeds a file. For YAML you loaded yourself, call the function behind it:

let resource = laterite_admin::descriptor::from_yaml(&yaml, "posts.yaml")?;