cellx does not work if map-cells is used

[yoonghm]

I use the following code to render a table. I want to align the heading rows to the center and fill it with different colour. However, it does not k if map-cells is used.

#figure(
  tablex(
    columns: (1fr, 4fr),
    align: left,
    auto-vlines: false,
    header-rows: 1,
    map-cells: cell => {
      if cell.y == 0 {
        cell.align = right  // no effect
        cell.fill = blue    // no effect
        set text(size: 14pt, fill: red)
        strong(cell.content)
      }
      else {
        set text(size: 12pt)
        cell.content
      }
    },
  
    /* Header */
    // cellx(...) also has no effect
    cellx(fill: blue, align: center)[Index], cellx(fill: blue, align: center)[Example],
    [`A`  ], [Apple],
    [`B`  ], [Ball],
    [`C`  ], [Car],
  ),
  kind: table,
  caption: "English alphabet"
)

[PgBiel]

Hello,

map-cells provides you a cellx as a parameter and expects you to return a cellx. When you return the cell's content, you are discarding all other properties from the cellx.

This means you need to do the following:

map-cells: cell => {
      if cell.y == 0 {
        cell.align = right  // no effect
        cell.fill = blue    // no effect
        cell.content = {
          set text(size: 14pt, fill: red)
          strong(cell.content)
        }
      }
      else {
        cell.content = {
          set text(size: 12pt)
          cell.content
        }
      }
      cell   // return the cell with the modified properties
    },

Note that there is no other way to provide data to tablex other than by returning the cell here - the cell variable is just a copy of the real cellx, so modifying the copy doesn't do anything unless you return it. Hope that clears it up!

[yoonghm]

Thanks!