NOTE: Due to the use of "Eval" and HTML4 specific tags, this class is now deprecated and the name has been changed from QDataGrid to QDataGridLegacy.

DataGrid control is used to display tabular information (e.g. lists)

The control itself will display things based off of an array of objects that gets set as the "Data Source". It is particularly useful when combined with the Class::LoadArrayByXXX() functions or the Class::LoadAll() that is generated by the CodeGen framework, or when combined with custom Class ArrayLoaders that you define youself, but who's structure is based off of the CodeGen framework.

The DataGrid essentially is a

<

table>. For each item in a datasource's Array, a row () will be generated. You can define any number of DataGridColumns which will result in a for each row. Within the DataGridColumn, you can specify the DataGridColumn::Html that should be displayed.

The HTML looks for the special back-tick character "", and will do PHP Eval's on antyhing within a pair of `. Moreover, the special variable $_ROW can be used to access the actual contents of that particular row's data in the main data source array.

So, for example, supposed the following: $strSimpleArray = {"Blah", "Foo", "Baz", "Fun"}; $dtgDataGrid = new DataGrid("dtgDataGrid"); $dtgDataGrid->AddColumn("Column Heading", "Contents: $_ROW"); $dtgDataGrid->DataSource = $strSimpleArray; This will generate a simple 4-row, 1-column table that contains the following: Column Heading -------------- Contents: Blah Contents: Foo Contents: Baz Contents: Fun In this case, $_ROW is a string, itself, which is each item in the DataSource's array.

Utilizing the back-tick and $_ROW feature, you can do infinitely more complicatd display functionality: $dtgDataGrid = new DataGrid("dtgDataGrid"); $dtgDataGrid->AddColumn("Title", "$_ROW->Title"); $dtgDataGrid->AddColumn("Calculated Result", "DisplayResults($_ROW->Calculate())"); $dtgDataGrid->DataSource = Foo::LoadAll(); This could then generate a table with much more data-rich information: Title Calculated Result ----------------- -------------------- Some Title Here $28,298.24 Foo Baz Bar $18,000.00 Blah (None) In this case, $_ROW is actually a Foo object.

IMPORTANT: Please note that while all properties can/should be set up only once within the form's !IsPostBack() clause, the DataSource MUST be set EVERY TIME. The contents of DataSource do NOT persist from postback to postback.

The appearance of the datagrid control appears to be complicated, but keep in mind that it simply utlizes the cascading nature of how browsers render tables based on styles assigned to the

<

table>, , and . In short: - Appearance properties defined to the DataGrid, itself, show up as HTML Attributes and CSS Styles within the

<

table> tag. - Appearance properties defined to a specific row's DataGridRowStyle will show up as HTML attributes within that specific row's tag. - Appearance properties defined to a DataGridColumn will show up as HTML attributes within that specific row's tag.

So, attributes will only show up if it is defined at that particular level. So if you define a background color for a DataGridRowStyle for a particular row, but not for a DataGridColumn or for the DataGrid in general, that background style will only show up in that row.

And due to the cascaiding nature of how browsers render tables, any undefined appearance property will simply inherit from the parent (where a 's parent is the , and the 's parent is the

<

table>, and any defined appearance property will simply override whatever was defined by the parent.

Sorting

Whether or not a column can be sorted depends on whether or not you define a SortByCommand (and subsequently a ReverseSortByComamnd) on the DataGridColumn itself. This SortByCommand is meant to be the SQL syntax used in an "ORDER BY" clause of a SQL query. This fits in really well with the CodeGen Framework's Class::LoadArrayByXXX() and Class::LoadAll() which takes "$strSortInfo" as an optional parameter. If a DataGrid is being sorted by a specific column, DataGrid::SortInfo will return to you the contents of DataGridColumn::SortByCommand (or ReverseSortByCommand if it's a reverse sort) for the specific column being sorted by. Therefore, you can set up your data source like: $dtgDataGrid->DataSource = Foo::LoadAll($dtgDataGrid->SortInfo);

Pagination

Pagination can be toggled on and off with the DataGrid::Paginate flag. When enabling pagination, you must specify how many items, TOTAL, are in the full list (DataGrid::TotalItemCount). The DataGrid will then automatically calculate the SQL Limit information (as used in a "LIMIT" clause of a SQL query) to be used when querying a specific subset of the total list. As with sorting, this fits really well with the CodeGen Framework's LoadArray methods which takes $strLimitInfo" as an optional parameter. Moreover, the codegen also auto-generates CountBy methods for every LoadAll/LoadArray method it generates to assist with the DataGrid::TotalItemCount property: $dtgDataGrid->TotalItemCount = Foo::CountAll(); $dtgDataGrid->DataSource = Foo::LoadAll($dtgDataGrid->SortInfo, $dtgDataGrid->LimitInfo);

Due to a bug with PHP, you cannot set a property of a property. DataGrid's AlternateRowStyle, HeaderRowStyle and RowStyle are obviously instances of DataGridRowStyle objects which have properties in and of themselves. So unfortuantely, the following code will NOT work: $dtgDataGrid->RowStyle->BackColor = "blue"; Instead, you will need to do the following: $objRowStyle = $dtgDataGrid->RowStyle; $objRowStyle->BackColor = "blue";