Constructor

HTML::Dashboard->new()

Constructs a new dashboard object. By default, this generates an HTML table with "border='1'" and sets the background color of all even rows to light grey (#eeeeee). These defaults can be overridden (cf. below).

Setting Data

$dash->set_data_without_captions( $data )

$dash->set_data_with_captions( $data )

Takes a reference to an array of array references of rows (i.e. a two-dimensional array). All rows must contain the same number of columns.

Use "set_data_without_captions" if the array contains only data, without captions. Use "set_data_with_captions" if the array contains captions in the first row (as is common, e.g., for data returned from database queries). Captions can be specified or overridden using "set_captions" (cf. below).

The data set is only accessed by reference, i.e. it is not copied. This should be advantageous for large data sets, but will lead to strange results if the data set changes after having been set, but before any one of the output routines is called.

Output

$dash->as_text()

$dash->as_text( $page )

Returns the data as tab-delimited text string, after content formatters (or collaters), sorting, views, and pagination have been applied. No other formatting directives (e.g. odd/even rows, or hi/med/low triggers) are applied. The string will include captions (if they have been set).

In the resulting text string, columns are separated by tabs (\t), rows are separated by single newlines (\n). Tabs, newlines, and backslashes in the data are escaped through a preceding backslash (\).

$dash->as_HTML()

$dash->as_HTML( $page )

Returns the data as a single HTML string. The string contains an HTML table, from the opening "<table>" to the closing "</table>" tag.

No HTML-escaping of data (i.e. of cell content) is performed. If required, specify an appropriate formatter for the data to perform any conversions.

Both functions can be called with an optional integer argument. If no argument is supplied, all rows are returned. If an integer argument in the range

  0 <= $page < $dash->pagecount()

is supplied, only the rows in the specified page (plus captions, if any) are returned. If a page outside the legal range is specified, a warning is emitted and all rows are returned. (Do not forget to call "$dash->set_pagesize(...)" before using this feature. By default, the pagesize is set to infinity, i.e. all rows are returned.)

Captions, Pagination, Views, Sorting

$dash->set_captions( @captions )

$array_ref = $dash->get_captions()

Sets captions for the columns. The captions will be rendered on every page (if pagination is used), using "<th>" tags. The number of captions provided must match the number of columns in the data. If captions have been set explicitly using this function, these captions will be used, even if the data itself contains captions in the first row (i.e. if the data has been set using "set_data_with_captions()").

$dash->set_pagesize( $rows_per_page )

$rows_per_page = $dash->get_pagesize()

$pages = $dash->get_pagecount()

Restricts the number of data rows per page (i.e. not counting captions). Setting the pagesize to anything but a positive integer turns pagination off, so that all rows will be returned.

$dash->set_view( @column_indices )

$array_ref = $dash->get_view()

The set of columns shown can be restricted using "set_view()". This function takes an array of column indices (0..$num_of_cols) to be shown. Defaults to all columns.

$dash->set_sort( sub { ... } )

Sets a comparator routine which will be used to sort the rows before rendering them. The comparator routine will be given two rows (as array references) and must return "an integer less than, equal to, or greater than 0", depending on how the rows are to be ordered (cf. Camel, entry on "sort"). Entire rows are passed to the comparator, before views (if any) are applied.

Note that the comparator will be called as a regular routine! This implies in particular that the comparator must parse @_ itself - arguments will not be passed through the "global" variables $a and $b as for the "sort" built-in.

Example:

  $dash->set_sort( sub { my ( $x, $y ) = @_; $x->[0] <=> $y->[0] } )
    

This sorts the rows numerically on the contents of the first column.

Formatting Options

There are three groups of formatting options:

• Options applied to plain HTML tags (i.e. the "<table>", "<tr>", "<th>", and "<td>" tags).
• Options to generate "striped reports" (i.e. tables, where the formatting is dependent on the row- or column-index).
• Options which are only applied when a data-dependent condition is fulfilled.

The last group is more complicated, because not only do the actual formatting options have to be set, but also the "trigger" and the range of table cells to which it is supposed to be applied.

Formatting options can be set using three different ways:

1.

Single argument: e.g. "$dash->set_table( "border='1'" )" or "$dash->set_first_row( 'red' )".

2.

As explicit CSS style directive: e.g. "$dash->set_th( style => 'font-size: x-large' )" or "$dash->set_even_row( style => 'background-color: yellow' )".

3.

By naming a CSS class: e.g. "$dash->set_td( class => 'highlighted' )" or "$dash->set_even_col( class => 'evencol' )". (Obviously, the class set in this way should be defined in a stylesheet referenced by the HTML page containing the dashboard.)

When using the "style" and "class" methods, a "style" or "class" argument is included into the appropriate HTML tags, and set to the supplied value. Note that repeated calls to these functions are additive, not exclusive. In other words, the following two code samples are equivalent:

  $dash->set_even_row( style => 'background-color: yellow' );
  $dash->set_even_row( style => 'font-size: x-large' );

is equivalent to:

  $dash->set_even_row( style => 'background-color: yellow; font-size: x-large' );

(The module will supply semicolons between different style directives when merging the results from repeated calls.)

To erase previous style directives, assign "undef" explicitly: "$dash->set_even_row( style => undef )".

The single-argument version is intended as a short-cut and has a slightly different meaning, depending on the group of formatting option it is applied to. When applied to a direct HTML option (i.e. when used with "set_table()", "set_tr()", "set_th()", or "set_td()"), the argument is pasted unmodified into the corresponding HTML tag. When used with any other option, the argument is interpreted as the desired background color for the cell, row, or column. The specified background color will be applied as an explicit "style" argument, not as a "bgcolor" argument. In other words, the following calls are (almost) equivalent:

  $dash->set_first_row( 'cyan' );
  $dash->set_first_row( style => 'background-color: cyan' );

It is legal to set conflicting formatting options and will not prevent generation of HTML output. However, no guarantees are made about the appearance of the dashboard in the browser in this case.

In the following, "[format]" always stand for formatting options in any one of the three legal syntax variants as discussed above!

General HTML Options

$dash->set_table( "[format]" )

$dash->set_tr( "[format]" )

$dash->set_th( "[format]" )

$dash->set_td( "[format]" )

$hash_ref = $dash->get_table()

$hash_ref = $dash->get_tr()

$hash_ref = $dash->get_th()

$hash_ref = $dash->get_td()

If set, these options are always included into all tags. This is mostly useful to style the entire table, or cells in the header row.

Striped Reports

$dash->set_first_row( "[format]" )

$dash->set_odd_row( "[format]" )

$dash->set_even_row( "[format]" )

$dash->set_last_row( "[format]" )

$hash_ref = $dash->get_first_row()

$hash_ref = $dash->get_odd_row()

$hash_ref = $dash->get_even_row()

$hash_ref = $dash->get_last_row()

$dash->set_first_col( "[format]" )

$dash->set_odd_col( "[format]" )

$dash->set_even_col( "[format]" )

$dash->set_last_col( "[format]" )

$hash_ref = $dash->get_first_col()

$hash_ref = $dash->get_odd_col()

$hash_ref = $dash->get_even_col()

$hash_ref = $dash->get_last_col()

Options set with these functions are applied to rows or columns as appropriate. Note that first, last, even, and odd is understood with reference to the page or the view, not the total data set.

Options for first and last prevail over options for even and odd. Options for columns prevail over options for rows.

Conditional Formatting (Triggers)

Formatting options in this group are only applied if a "trigger" evaluates to true. Therefore, the functions below all take a function reference as argument, besides the actual formatting options.

All triggers have a "priority" from highest (hi), over intermediate (med) to lowest (low). If multiple triggers evaluate to true for a certain part of the dashboard (say, a cell), then only the formatting option with the highest priority is applied.

The intended application is to show whether a set of data is "in the green" or "in the red". Given the prioritization logic of the triggers, this can be easily achieved, without the need for exclusive bounds or conditions across the set of triggers, using code like this:

  $dash->set_row_low( sub{ ...; $x < 3  }, 'green' );
  $dash->set_row_med( sub{ ...; $x < 7  }, 'yellow' );
  $dash->set_row_hi(  sub{ ...; $x > 10 }, 'red' );

$dash->set_row_hi( sub{ my ( $row_ref ) = @_; ... }, "[format]" )

$dash->set_row_med( sub{ my ( $row_ref ) = @_; ... }, "[format]" )

$dash->set_row_low( sub{ my ( $row_ref ) = @_; ... }, "[format]" )

If the triggers evaluates to true, the formatting option is applied to the entire row. The argument to the trigger is an array-ref to the current row. (Additional arguments: index of row in page, and index of row in data set.)

$dash->set_col_hi( $col, sub{ my ( $cell ) = @_; ... }, "[format]" )

$dash->set_col_med( $col, sub{ my ( $cell ) = @_; ... }, "[format]" )

$dash->set_col_low( $col, sub{ my ( $cell ) = @_; ... }, "[format]" )

The first argument to this function is the index of the column in the data set (not in the view!) to which the formatting should be applied. If the triggers evaluates to true, the formatting option is applied to all cells in the column. The argument to the trigger is the contents of the current cell in the specified column.(Additional arguments: the index in the view and in the data set.)

$dash->set_cell_hi( $col, sub{ my ( $cell ) = @_; ... }, "[format]" )

$dash->set_cell_med( $col, sub{ my ( $cell ) = @_; ... }, "[format]" )

$dash->set_cell_low( $col, sub{ my ( $cell ) = @_; ... }, "[format]" )

The first argument to this function is the index of the column in the data set (not in the view!) to which the formatting should be applied. If the triggers evaluates to true, the formatting option is applied to the current cell only. The argument to the trigger is the contents of the current cell in the specified column.(Additional arguments: the index in the view and in the data set.)

Options set with triggers are merged (do not clobber) with options set for first/last and even/odd. (This allows one to have a striped report, and use triggers to change the text color only.)

Options with high (hi) priority prevail over (clobber) options with intermediate (med) priority, which prevail over options with low priority. Options for cells prevail over options for columns, which prevail over options for rows.

Content Formatters

$dash->set_format( $column, sub { ... } )

$dash->set_collate( $column, sub { ... } )

If set, the registered function is called for each row. Its output is used as contents for the current row's cell in the column with index $column.

A formatter set with the first function is given the contents of the data in the current cell, while a collater set with the second function is given the entire row (as array).

Examples:

  $dash->set_format( 1, sub { my ( $x ) = @_; sprintf( "%.2f", $x ) } )
  $dash->set_collate( 1, sub { my ( $r ) = @_; $r[1] . ':' . $r[2] } )