axe-core/lib/commons/table/traverse.js

Accessibility engine for automated Web UI testing

function traverseTable(dir, position, tableGrid, callback) {
  let result;
  const cell = tableGrid[position.y]
    ? tableGrid[position.y][position.x]
    : undefined;
  if (!cell) {
    return [];
  }
  if (typeof callback === 'function') {
    result = callback(cell, position, tableGrid);
    if (result === true) {
      // abort
      return [cell];
    }
  }

  result = traverseTable(
    dir,
    {
      x: position.x + dir.x,
      y: position.y + dir.y
    },
    tableGrid,
    callback
  );
  result.unshift(cell);
  return result;
}

/**
 * Traverses a table in a given direction, passing the cell to the callback
 * @method traverse
 * @memberof axe.commons.table
 * @instance
 * @param  {Object|String} dir Direction that will be added recursively {x: 1, y: 0}, 'left';
 * @param  {Object}   startPos    x/y coordinate: {x: 0, y: 0};
 * @param  {Array}    [tablegrid]  A matrix of the table obtained using axe.commons.table.toArray (OPTIONAL)
 * @param  {Function} callback Function to which each cell will be passed
 * @return {NodeElement}       If the callback returns true, the traversal will end and the cell will be returned
 */
function traverse(dir, startPos, tableGrid, callback) {
  if (Array.isArray(startPos)) {
    callback = tableGrid;
    tableGrid = startPos;
    startPos = { x: 0, y: 0 };
  }

  if (typeof dir === 'string') {
    switch (dir) {
      case 'left':
        dir = { x: -1, y: 0 };
        break;
      case 'up':
        dir = { x: 0, y: -1 };
        break;
      case 'right':
        dir = { x: 1, y: 0 };
        break;
      case 'down':
        dir = { x: 0, y: 1 };
        break;
    }
  }

  return traverseTable(
    dir,
    {
      x: startPos.x + dir.x,
      y: startPos.y + dir.y
    },
    tableGrid,
    callback
  );
}

export default traverse;