public function walkPath($path, $missingRowColumns = false, $maxSubtableRows = 0)
    {
        $pathLength = count($path);

        $table = $this;
        $next = false;
        for ($i = 0; $i < $pathLength; ++$i) {
            $segment = $path[$i];

            $next = $table->getRowFromLabel($segment);
            if ($next === false) {
                // if there is no table to advance to, and we're not adding missing rows, return false
                if ($missingRowColumns === false) {
                    return array(false, $i);
                } else {
                    // if we're adding missing rows, add a new row

                    $row = new DataTableSummaryRow();
                    $row->setColumns(array('label' => $segment) + $missingRowColumns);

                    $next = $table->addRow($row);

                    if ($next !== $row) {
                        // if the row wasn't added, the table is full

                        // Summary row, has no metadata
                        $next->deleteMetadata();
                        return array($next, $i);
                    }
                }
            }

            $table = $next->getSubtable();
            if ($table === false) {
                // if the row has no table (and thus no child rows), and we're not adding
                // missing rows, return false
                if ($missingRowColumns === false) {
                    return array(false, $i);
                } elseif ($i != $pathLength - 1) {
                    // create subtable if missing, but only if not on the last segment

                    $table = new DataTable();
                    $table->setMaximumAllowedRows($maxSubtableRows);
                    $table->metadata[self::COLUMN_AGGREGATION_OPS_METADATA_NAME]
                        = $this->getMetadata(self::COLUMN_AGGREGATION_OPS_METADATA_NAME);
                    $next->setSubtable($table);
                    // Summary row, has no metadata
                    $next->deleteMetadata();
                }
            }
        }

        return array($next, $i);
    }
public function walkPath($path, $missingRowColumns = false, $maxSubtableRows = 0)
    {
        $pathLength = count($path);

        $table = $this;
        $next = false;
        for ($i = 0; $i < $pathLength; ++$i) {
            $segment = $path[$i];

            $next = $table->getRowFromLabel($segment);
            if ($next === false) {
                // if there is no table to advance to, and we're not adding missing rows, return false
                if ($missingRowColumns === false) {
                    return array(false, $i);
                } else {
                    // if we're adding missing rows, add a new row

                    $row = new DataTableSummaryRow();
                    $row->setColumns(array('label' => $segment) + $missingRowColumns);

                    $next = $table->addRow($row);

                    if ($next !== $row) {
                        // if the row wasn't added, the table is full

                        // Summary row, has no metadata
                        $next->deleteMetadata();
                        return array($next, $i);
                    }
                }
            }

            $table = $next->getSubtable();
            if ($table === false) {
                // if the row has no table (and thus no child rows), and we're not adding
                // missing rows, return false
                if ($missingRowColumns === false) {
                    return array(false, $i);
                } elseif ($i != $pathLength - 1) {
                    // create subtable if missing, but only if not on the last segment

                    $table = new DataTable();
                    $table->setMaximumAllowedRows($maxSubtableRows);
                    $table->metadata[self::COLUMN_AGGREGATION_OPS_METADATA_NAME]
                        = $this->getMetadata(self::COLUMN_AGGREGATION_OPS_METADATA_NAME);
                    $next->setSubtable($table);
                    // Summary row, has no metadata
                    $next->deleteMetadata();
                }
            }
        }

        return array($next, $i);
    }
public function walkPath ( $ path , $ missingRowColumns = false , $ maxSubtableRows = 0 ) { $ pathLength = count ( $ path ) ; $ table = $ this ; $ next = false ; for ( $ i = 0 ; $ i < $ pathLength ; ++ $ i ) { $ segment = $ path [ $ i ] ; $ next = $ table -> getRowFromLabel ( $ segment ) ; if ( $ next === false ) { // if there is no table to advance to, and we're not adding missing rows, return false if ( $ missingRowColumns === false ) { return array ( false , $ i ) ; } else { // if we're adding missing rows, add a new row $ row = new DataTableSummaryRow ( ) ; $ row -> setColumns ( array ( 'label' => $ segment ) + $ missingRowColumns ) ; $ next = $ table -> addRow ( $ row ) ; if ( $ next !== $ row ) { // if the row wasn't added, the table is full // Summary row, has no metadata $ next -> deleteMetadata ( ) ; return array ( $ next , $ i ) ; } } } $ table = $ next -> getSubtable ( ) ; if ( $ table === false ) { // if the row has no table (and thus no child rows), and we're not adding // missing rows, return false if ( $ missingRowColumns === false ) { return array ( false , $ i ) ; } elseif ( $ i != $ pathLength - 1 ) { // create subtable if missing, but only if not on the last segment $ table = new DataTable ( ) ; $ table -> setMaximumAllowedRows ( $ maxSubtableRows ) ; $ table -> metadata [ self :: COLUMN_AGGREGATION_OPS_METADATA_NAME ] = $ this -> getMetadata ( self :: COLUMN_AGGREGATION_OPS_METADATA_NAME ) ; $ next -> setSubtable ( $ table ) ; // Summary row, has no metadata $ next -> deleteMetadata ( ) ; } } } return array ( $ next , $ i ) ; }
Traverses a DataTable tree using an array of labels and returns the row
it finds or `false` if it cannot find one. The number of path segments that
were successfully walked is also returned.

If `$missingRowColumns` is supplied, the specified path is created. When
a subtable is encountered w/o the required label, a new row is created
with the label, and a new subtable is added to the row.

Read [http://en.wikipedia.org/wiki/Tree_(data_structure)#Traversal_methods](http://en.wikipedia.org/wiki/Tree_(data_structure)#Traversal_methods)
for more information about tree walking.

@param array $path The path to walk. An array of label values. The first element
refers to a row in this DataTable, the second in a subtable of
the first row, the third a subtable of the second row, etc.
@param array|bool $missingRowColumns The default columns to use when creating new rows.
If this parameter is supplied, new rows will be
created for path labels that cannot be found.
@param int $maxSubtableRows The maximum number of allowed rows in new subtables. New
subtables are only created if `$missingRowColumns` is provided.
@return array First element is the found row or `false`. Second element is
the number of path segments walked. If a row is found, this
will be == to `count($path)`. Otherwise, it will be the index
of the path segment that we could not find.
Traverses a DataTable tree using an array of labels and returns the row it finds or false if it cannot find one . The number of path segments that were successfully walked is also returned .