| DHTMLX Documentation

# Storing additional data

There are three possible approaches to load additional data:
- hidden columns;
- user data;
- attributes.

## Hidden columns

It is possible to define a column as hidden - in such case it will not be visible for a user, but it will be accessible by API. So it will be possible to take the data from it.
In case of initialization from js code:
...
grid.init();
grid.setColumnHidden(index,true);
In case of initialization from XML:
<rows>
<head>
<column hidden="true">Dummy</column>
...
The data can be accessed as data of any other columns:
grid.cells(i,j).getValue();
grid.cells(i,j).setValue(some);
Data of a hidden column is included in the serialization by default, can't be controlled by setSerializableColumns command.
This data is available during dataprocessor calls.

## UserData

UserData is a special tag, which can be a child of rows or row tags. In the first case userdata is related to the whole grid, while in the second case it will be related to a specific row.
<?xml version='1.0' encoding='iso-8859-1'?>
<rows>
<userdata name="somName1">some data</userdata>
<row id="unique_rowid">
<userdata name="someName1"> some row data </userdata>
<userdata name="someName2"> some row data </userdata>
<cell>cell content</cell>
<cell><![CDATA[<font color="red">cell</font> content]]></cell>
</row>
</rows>
To access global userdata:
grid.getUserData("","someName1"); // some data
grid.setUserData("","someName1","new value");
To access row related userdata:
grid.getUserData("unique_rowid","someName1"); // some row data
grid.setUserData("unique_rowid","someName1","new value");
The userdata may be included in the serialization using setSerializationLevel command (is disabled by default).
This data is available during dataprocessor calls.

## Attributes ( dhtmlxgrid 1.6+ )

When loading from XML any attribute of row or cell tag can be accessed programmatically.
<?xml version='1.0' encoding='iso-8859-1'?>
<rows>
<row id="unique_rowid" some="data">
<cell some="data">cell content</cell>
</row>
</rows>
To access row attributes:
grid.getRowAttribute("unique_rowid","some");
grid.setRowAttribute("unique_rowid","some","new value");
To access cell attributes:
grid.cells(i,j).getAttribute("some");
grid.cells(i,j).setAttribute("some","new value");
If you want to include such custom attributes in the serialization, some special steps are required:
grid.xml.row_attrs.push("some"); // will include some attribute of a row in the serialization
grid.xml.cell_attrs.push("some"); // will include some attribute of a cell in the serialization
This data is not available during dataprocessor calls.
© DHTMLX, 2008