path: root/themes/hugo-pt2021/layouts/shortcodes/table.html

{{/*
Custom Hugo table shortcode which renders tables by:

1. Reads table definition and data from a structured (JSON, TOML, or
   YAML) data file in the site data directory.
2. Renders the table using CSS classes rather than inline styles.

Why does this shortcode exist?

1. The default Markdown table markup in Hugo is horrible for anything
   more than rudimentary tables.
2. The default Markdown table renderer in Hugo does not give you a way
   to set cell alignment without using inline styles, which means
   enabling `unsafe-inline` in your `Content-Security-Policy` header.
3. I prever specifying table contents in an external structured file
   rather than inline.

Features:

* Sets reasonable default `title` and `aria-label` attributes on
  table, column headers, and cells.
* Annotates column headers and cells with coordinate and column ID data
  attributes for easy styling.
* Add an optional table caption.
* Add optional table, header, row, and cell IDs.
* Specify cell alignment on a per-column or per-cell basis,
* Specify custom table, row, and cell CSS classes.
* Use a custom `data-` attribute prefix to prevent collisions.
* Render cell values as markup or raw HTML.

By default this shortcode renders using Bulma classes, but that can be
changed by setting individual CSS classes in the `params.table_shortcode`
section of the site's `config.toml`.

... TODO: move documentation to README.md, document all options ...
Notes:
* IDs keys that begin with "_" should not be used, because we use
  them to set some option.
* document `params.table_shortcode` TOML options
* document cell values as literal or as dict (latter allows custom
  alignment, id, colspan, and rowspan, class)
* row tooltip with _row and id with _id

Example:

  {{< table "favorite-fruits" "fruits" >}}

And the corresponding `data/favorite-fruits/fruits.yaml`:

  ---
  # table name (required)
  name: "Favorite Fruits"

  # column list (required)
  cols:
    - id: "name"
      name: "Name"
    - id: "color"
      name: "Color"
    - id: "description"
      name: "Description"

  # table rows (required)
  rows:
    - name: "Apple"
      color: "Red or Green"
      description: "Sweet if red, or sour if green."
    - name: "Banana"
      color: "Yellow"
      description: "Skin is slipping hazard on floor."
    - name: "Orange"
      color: "Orange"
      description: "Citrus bonanza."
    - name: "Peach"
      color: "Orange"
      description: "Don't eat the core!"

This shortcode will render the following table:

    <table class='table' title='Favorite Fruits' aria-label='Favorite Fruits'>
      <caption>My favorite fruits.</caption>

      <thead>
        <tr>
          <th title='Name' aria-label='Name' data-th_x='0' data-col_id='name'>
            Name
          </th>

          <th title='Color' aria-label='Color' data-th_x='1' data-col_id='color'>
            Color
          </th>

          <th title='Description' aria-label='Description' data-th_x='2' data-col_id='description'>
            Description
          </th>
        </tr>
      </thead>

      <tbody>
        <tr data-tr_y='0'>
          <td title='Name' aria-label='Name' data-td_x='0' data-col_id='name'>
            Apple
          </td>

          <td title='Color' aria-label='Color' data-td_x='1' data-col_id='color'>
            Red or Green
          </td>

          <td title='Description' aria-label='Description' data-td_x='2' data-col_id='description'>
            Sweet if red, or sour if green.
          </td>
        </tr>

        ... (other rows omitted for brevity) ...
      </tbody>
    </table>

You can also configure alignment on a per-column or per-cell basis, and
you can override the `class` attribute for individual cells.
*/}}

{{/* get config from site params (default to bulma) */}}
{{- $config := default (dict "data_prefix" "" "table_base_css" "table" "cell_align_left" "has-text-left" "cell_align_center" "has-text-centered" "cell_align_justify" "has-text-justified" "cell_align_right" "has-text-right") $.Site.Params.table_shortcode -}}

{{/* get data prefix */}}
{{- $dp := $config.data_prefix | safeHTMLAttr -}}

{{/* get table data */}}
{{- $table := (dict) -}}
{{- if .Get 1 -}}
  {{/* get table data from site data */}}
  {{- $table = (index .Site.Data.tables (.Get 0) (.Get 1)) -}}
{{- else -}}
  {{/* get table data from page params */}}
  {{- $table = (index $.Page.Params "tables" (.Get 0)) -}}
{{- end -}}

<table
  {{/* emit table ID */}}
  {{- if $table.id -}}id='{{- $table.id -}}'{{- end -}}

  {{/* base (e.g. "table" in bulma) and custom CSS class for table */}}
  class='{{- $config.table_base_css }} {{ default "" $table.css -}}'

  {{/* table tooltip and ARIA label */}}
  title='{{- default $table.name $table.tip -}}'
  arial-label='{{- default $table.name $table.tip -}}'
>
  {{- if $table.caption -}}
    {{/* render caption */}}
    <caption>{{- $table.caption -}}</caption>
  {{- end -}}

  {{/* render table headers */}}
  <thead>
    <tr>
      {{- range $x, $col := $table.cols -}}
        {{- $is_map := reflect.IsMap $col -}}

        {{- if $is_map -}}
          {{/* col is a map, reference keys */}}

          {{/* set default css */}}
          {{- $css := "" -}}

          {{/* get alignment */}}
          {{- $align := default "" $col.align -}}
          {{- if eq $align "left" -}}
            {{- $css = $config.cell_align_left -}}
          {{- else if eq $align "center" -}}
            {{- $css = $config.cell_align_center -}}
          {{- else if eq $align "justified" -}}
            {{- $css = $config.cell_align_justify -}}
          {{- else if eq $align "right" -}}
            {{- $css = $config.cell_align_right -}}
          {{- end -}}

          <th
            {{if $css}} class='{{- $css -}}'{{- end}}
            title='{{- default $col.name $col.tip -}}'
            aria-label='{{- default $col.name $col.tip -}}'
            data-{{- $dp -}}th_x='{{- $x -}}'
            data-{{- $dp -}}id='{{- $col.id -}}'
          >
            {{- $col.name -}}
          </th>
        {{- else -}}
          {{/* col is a string */}}
          <th
            title='{{- $col -}}'
            aria-label='{{- $col -}}'
            data-{{- $dp -}}th_x='{{- $x -}}'
            data-{{- $dp -}}id='{{- $x -}}'
          >
            {{- $col -}}
          </th>
        {{- end -}}
      {{- end -}}
    </tr>
  </thead>

  {{- if $table.rows -}}
    <tbody>
      {{/* is the first column a map? */}}
      {{- $first_col_is_map := reflect.IsMap (index $table.cols 0) -}}

      {{/* render rows */}}
      {{- range $y, $row := $table.rows -}}
        {{- if $first_col_is_map -}}
          <tr
            {{/* emit row ID */}}
            {{- if $row._id -}}
              id='{{- $row._id -}}'
            {{- end -}}

            {{- if $row._tip -}}
              {{/* emit row tooltip */}}
              title='{{- $row._tip -}}'
              aria-label='{{- $row._tip -}}'
            {{- end -}}

            {{- if $row._css -}}
              {{/* emit row css */}}
              class='{{- $row._css -}}'
            {{- end -}}

            {{/* row position */}}
            data-{{- $dp -}}tr_y='{{- $y -}}'
          >
            {{- range $x, $col := $table.cols -}}
              {{/* get cell */}}
              {{- $cell := index $row $col.id -}}
              {{- $is_map := reflect.IsMap $cell -}}

              {{/* get cell value */}}
              {{- $val := "" -}}
              {{- if $is_map -}}
                {{- $val = index $cell "val" -}}
              {{- else -}}
                {{- $val = $cell -}}
              {{- end -}}

              {{/* get cell ID */}}
              {{- $cell_id := "" -}}
              {{- if $is_map -}}
                {{- if index $cell "id" -}}
                  {{- $cell_id = $cell.id -}}
                {{- end -}}
              {{- end -}}

              {{/* get cell tip */}}
              {{- $tip := (default $col.name $col.tip) -}}
              {{- if $is_map -}}
                {{- if index $cell "tip" -}}
                  {{- $tip = index $cell "tip" -}}
                {{- end -}}
              {{- end -}}

              {{/* get cell alignment */}}
              {{- $align := $col.align -}}
              {{- if and $is_map -}}
                {{- if (index $cell "align") -}}
                  {{- $align = index $cell "align" -}}
                {{- end -}}
              {{- end -}}

              {{/* get default cell css */}}
              {{- $css := "" -}}
              {{- if eq $align "left" -}}
                {{- $css = $config.cell_align_left -}}
              {{- else if eq $align "center" -}}
                {{- $css = $config.cell_align_center -}}
              {{- else if eq $align "justified" -}}
                {{- $css = $config.cell_align_justify -}}
              {{- else if eq $align "right" -}}
                {{- $css = $config.cell_align_right -}}
              {{- end -}}

              {{/* get cell css override */}}
              {{- if $is_map -}}
                {{- if index $cell "css" -}}
                  {{- $css = $cell.css -}}
                {{- end -}}
              {{- end -}}

              {{/* get colspan */}}
              {{- $colspan := 1 -}}
              {{- if $is_map -}}
                {{- if index $cell "colspan" -}}
                  {{- $colspan = $cell.colspan -}}
                {{- end -}}
              {{- end -}}

              {{/* get rowspan */}}
              {{- $rowspan := 1 -}}
              {{- if $is_map -}}
                {{- if index $cell "rowspan" -}}
                  {{- $rowspan = $cell.rowspan -}}
                {{- end -}}
              {{- end -}}

              {{/* emit cell */}}
              <td
                {{/* emit cell ID */}}
                {{- if $cell_id -}}
                  id='{{- $cell_id -}}'
                {{- end -}}

                title='{{- $tip -}}'
                aria-label='{{- $tip -}}'
                class='{{- $css -}}'

                data-{{- $dp -}}td_x='{{- $x -}}'
                data-{{- $dp -}}col_id='{{- $col.id -}}'

                {{- if gt $colspan 1 -}}
                  colspan='{{- $colspan -}}'
                {{- end -}}

                {{- if gt $rowspan 1 -}}
                  rowspan='{{- $rowspan -}}'
                {{- end -}}
              >
                {{- if $is_map -}}
                  {{- if $cell.html -}}
                    {{/* render as raw HTML */}}
                    {{- $val | safeHTML -}}
                  {{- else -}}
                    {{/* render as markup */}}
                    {{- $val | $.Page.RenderString -}}
                  {{- end -}}
                {{- else -}}
                  {{/* render as markup */}}
                  {{- $val | $.Page.RenderString -}}
                {{- end -}}
              </td>
            {{- end -}}
          </tr>
        {{- else -}}
          {{/* first column is string, rows are arrays of values */}}
          <tr
            {{/* row position */}}
            data-{{- $dp -}}tr_y='{{- $y -}}'
          >
            {{- range $x, $col := $table.cols -}}
              <td
                title='{{- $col -}}'
                aria-label='{{- $col -}}'
              >
                {{- index $row $x -}}
              </td>
            {{- end -}}
          </tr>
        {{- end -}}
      {{- end -}}
    </tbody>
  {{- end -}}
</table>