Layout

<Layout> arranges the form declared by <EditorFields>. Controls nest; if the top-level controls are <Tab>s the form renders as a wizard/stepper.

Element	Attributes	Holds
<Tab>	Title, Page, Validate	sections / grids / items
<Section>	Label, IsAccordian, IsExpanded	items / lines / grids
<Item>	Name (field), Width (1–12), ViewOnlyLabel	— (a single field)
<Line>	Render	— (a separator / new row)
<Sub>	Name (a SubView), Width	— (embeds a child grid; for cart line-items use CartTable SubView="…" instead)
<Grid> → <Row> → <Column>	Column Span (1–12, default 12)	explicit 12-column grid; columns hold items / nested grids / subs

<Item Name="…"> references an editor field by name; Width controls its span within the enclosing section (1–12). Use a <Grid>/<Row>/<Column> block when you need an explicit 12-column layout — each <Column Span="…"> holds items or nested grids.

<Layout>
  <Section Label="Identity">
    <Item Name="Name" Width="6" />
    <Item Name="CategoryId" Width="6" />
  </Section>
  <Section Label="Pricing">
    <Grid>
      <Row>
        <Column Span="4"><Item Name="UnitPrice" Width="12" /></Column>
        <Column Span="4"><Item Name="UnitCost" Width="12" /></Column>
        <Column Span="4"><Item Name="Margin" Width="12" /></Column>
      </Row>
    </Grid>
  </Section>
  <Section Label="Movements">
    <Sub Name="ProductStockMovements" Width="12" />
  </Section>
</Layout>

• <Sub Name="…"> embeds a child grid — see Sub-views. For cart line-items, prefer <CartTable SubView="…"> (see CartTable) over a standalone <Sub>.
• Placing a <CartTable> in the layout uses a single <Item Name="{cart}" /> — the cart drives all three modes itself (see the CartTable page).

Worked example: sample/Inventory/models/views/Products.view.xml (<Tab>/<Section> with a nested <Grid>/<Row>/<Column> and a <Sub> child grid).