1.
I'm using the HTML_Table Renderer. How can I use multiple grids on the
same page?
The setRequestPrefix()
method is the solution for this problem. Each DataGrid for the page needs
such a prefix that is internally used before the GET parameters for sorting
and paging. An example of the usage:
require_once 'Structures/DataGrid.php';
$datagrid1 = new Structures_DataGrid();
$datagrid2 = new Structures_DataGrid();
$datagrid1->bind('SELECT * FROM trade', array('dsn' => DSN));
$datagrid2->bind('SELECT * FROM stock', array('dsn' => DSN));
$datagrid1->setRequestPrefix('trade_');
$datagrid2->setRequestPrefix('stock_');
$datagrid1->render();
$datagrid2->render(); |
Note :
You need to call setRequestPrefix()
before calling
bind().
2.
Which DataSource drivers are recommended?
Currently there are four DataSource drivers that are recommended in the
sense of efficiency:
DB_DataObject
DB_Table
DBQuery
MDB2
These four drivers will only fetch the needed records from the database.
For example, if you have a row limit of 15 records per page, they will
only fetch (up to) 15 records.
All other DataSource drivers can, of course, also be used. But there is
no logic implemented (better said: implementable) to avoid fetching (or
keeping in memory) unneeded records.
3.
I'd like to add row numbers to my DataGrid. How can I do this?
You need a formatter
for the new column that should hold the row number. The first parameter
that is passed to such a formatter function contains a
currRow value with the row number per page. For
calculating the row number relative to the whole table, you need to take
also the getCurrentRecordNumberStart()
method into account.
The following code snippet shows you how to define the formatter function
and how to add the column (with # as the column label
and right aligned values):
function formatRowNumber($params, $recordNumberStart)
{
return $params['currRow'] + $recordNumberStart;
}
$datagrid->addColumn(
new Structures_DataGrid_Column(
'#',
null,
null,
array('style' => 'text-align: right;'),
null,
'formatRowNumber',
$datagrid->getCurrentRecordNumberStart()
)); |
4.
I'm using the Excel Renderer and would like to have the € sign in
the resulting Excel file, but I always get only a box or some funny
characters. How can I get the right € sign?
Instead of using an encoding like ISO-8859-15, you need to use
Windows-1252.
5.
Streaming is a nice feature. Why isn't streaming the default behaviour?
Streaming support in Structures_DataGrid is intended to be used with
large datasets. But it can also be used with very small datasets without
loss of performance.
As always, there is an exception to this rule: When you're using one of the
DataSource drivers that fetch data from a database and you have queries that
need a lot of time for computation of the results, you should not use
streaming, as running such a complex query multiple times will need even
more time, of course.
