A HeaderSet represents a collection of headers. The HeaderSet is an object returned by the success callback
of the fetchHeaders method on DataGridDataSource. This implementation of HeaderSet is used by the
CollectionDataGridDataSource.
Gets the depth of an index starting at a particular level. The depth is the number
of levels spanned by the header.
Parameters:
Name
Type
Argument
Description
index
number
the absolute index of the depth to get
level
number
<optional>
the level of the header, 0 is the outermost header
Returns:
the number of levels spanned by the header at the specified position
Type
number
getExtent(index, level) : {Object}
Gets the extent of an index on a particular level within the context of the headerSet. Extent is defined as the
number of indexes covered by the header. If the extent extends beyond the start and end of the requested
range the extent should be trimmed to the edge of the requested range and the object for {'more': {before, after}}
should have the value appropriate boolean set. For innermost headers the extent will always be 1.
Parameters:
Name
Type
Argument
Description
index
number
the absolute index along the innermost header of the extent to get, 0 is the first header in the data source
level
number
<optional>
the level of the header, 0 is the outermost header and increments by 1 moving inward
Returns:
an object containing two values
extent: the number of absolute indexes spanned by the header at this index
bounded by the edges of the result set for the specified axis.
more: object with keys 'before'/'after' and boolean values true/false representing whether
there are more indexes before/after what is in the headerSet
Type
Object
getLabel(level) : {*}
Gets the label for the level along the axis of that header. Specify null to have no header labels.
Parameters:
Name
Type
Description
level
number
the header level to retrieve the label data for
Returns:
the data for the header label
Type
*
getLevelCount : {number}
Gets the actual number of levels of the result set for the specified axis. The levels
are the counted from the outermost header indexed at 0, and moving inwards toward the
databody would increment the level by 1.
Returns:
the number of levels of the result set
Type
number
getMetadata(index, level) : {Object}
Gets the metadata of the specified index. An error is throw when 1) the range is not yet available and
2) the index specified is out of bounds.
The metadata that the data source can optionally return are:
1) sortDirection - the initial sort direction of the header. Valid values are "ascending" and "descending".
2) key - the key of the row/column header.
Parameters:
Name
Type
Argument
Description
index
number
the absolute index of the header in which we want to retrieve the metadata from.
level
number
<optional>
the level of the header, 0 is the outermost header and increments by 1 moving inward