table.html

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Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
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    http://www.apache.org/licenses/LICENSE-2.0

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-->

<!--
    Uses the HTML <table> content model, but automatically adds a number to
    the <caption>.  Use this as <table is="cxx-table">, unlike the other custom
    elements.

    With class="list", the table represents a list, which will be organized
    into the number of columns set by the [columns] attribute.
-->
<polymer-element name="cxx-table" extends="table" constructor="CxxTableElement" attributes="columns">
  <template>
    <style>
      :host { margin-left: auto; margin-right: auto;
              border-collapse: collapse;
              border: thin solid black; }
      caption { white-space: nowrap; }
      polyfill-next-selector { content: 'caption caption' }
      ::content caption { display: inline; }

      polyfill-next-selector { content: 'th, td' }
      ::content th, ::content td {
        border-style: solid none; border-color: black;
        border-width: thin;
        padding: 0 0.25em; }

      polyfill-next-selector { content: ':host(.column-rules) th, :host(.column-rules) td' }
      :host(.column-rules) ::content th,
      :host(.column-rules) ::content td {
          border-left-style: solid;  border-right-style: solid;}

      polyfill-next-selector { content: 'th' }
      ::content th { border-bottom: double medium; }
      polyfill-next-selector { content: ':host(.single-border) th' }
      :host(.single-border) ::content th { border-bottom: solid thin; }

      polyfill-next-selector { content: ':host(.center) td' }
      :host(.center) ::content td { text-align: center; }

      polyfill-next-selector { content: ':host(.list) td' }
      :host(.list) ::content td { border: none; vertical-align: top; }

      polyfill-next-selector { content: ':host(.list) ul' }
      :host(.list) ::content ul { padding-left: 0; margin: 0;}
      polyfill-next-selector { content: ':host(.list) ul li::before' }
      :host(.list) ::content ul li::before { content: '';}
    </style>

    <caption>Table {{table_num}} — <wbr><content select="caption"></content></caption>
    <content></content>
  </template>
  <script>
    (function() {
      function renumberTables() {
        document.querySelectorAll('[is=cxx-table]').array().forEach(function(table, index) {
          table.table_num = index + 1;
        });
      }
      Polymer('cxx-table', {
        arrangeColumns: function() {
          // Balance list-tables so we don't have to do it manually.  I tried
          // using CSS columns, but the appearance isn't as nice.
          if (this.classList.contains('list')) {
            // Set ARIA role so screenreaders go straight to the list.
            this.setAttribute('role', 'presentation');

            // Avoid messing with tables that are manually formatted.
            if (this.rows.length == 1 &&
                this.rows[0].cells.length == 1 &&
                this.rows[0].cells[0].firstElementChild instanceof HTMLUListElement) {
              var tr = this.rows[0];
              var elems = tr.querySelectorAll('li').array();
              tr.cells[0].remove();
              var rows = Math.ceil(elems.length / this.columns);
              for (var column = 0; column < this.columns; column++) {
                var td = document.createElement('td');
                tr.appendChild(td);
                var ul = document.createElement('ul');
                td.appendChild(ul);
                for (var row = 0; row < rows; row++) {
                  var index = column*rows + row;
                  if (index < elems.length)
                    ul.appendChild(elems[index]);
                }
              }
            }
          }
        },
        domReady: function() {
          renumberTables.apply(this);
          this.arrangeColumns();
        },
        detached: renumberTables,
      });
    })();
  </script>
</polymer-element>