All the currently selected rows are stored on the grid options. Firstly in an array selectedRows that stores the data. Secondly is selectedNodesById that is a map of node id's (node id's are created by the grid) to selected nodes.
Use selectedRows to get list of the data items you provided, with the node information. This was implemented to give a familiar feel to people using ui-grid.
Use selectedNodesById if you want to work with the ag-grid nodes. This is preferred over selectedRows, as it provide you with more information and maps better to the internal representation of ag-grid.
The example below shows single row selection.
The example below shows multi-row selection.
Checkbox selection can be used in two places: a) row selection and b) group selection.
To include checkbox selection for a column, set the attribute 'checkboxSelection' to true on the column definition. You can set this attribute on as many columns as you like, however it doesn't make sense to have it in more one column in a table.
To enable checkbox selection for groups, set the attribute 'checkbox' to true for the group renderer. See the grouping section for details on the group renderer.
Selecting groups can have the effect of selecting the group row, or selecting all the children in the group. This is done by setting the attribute 'groupSelectsChildren' to true or false. When set to false, then selecting the group will select the group node. When set to true, then selecting the group will either select or deselect all of the children.
The example below shows checkbox selection with groups. Selecting the group has the effect of selecting the children. Likewise selecting all the children automatically selects the group. The group itself will never appear in the selectedRows list.
The example also shows a checkbox for selection on the age column. In practice, it is not normal to have more than two columns for selection, the below is just for demonstration. Having a checkbox within a non-group row is best for grids that are not using grouping.
If you select 'group' for the 'groupCheckboxSelection', then the group will be selectable as it's own entity.
Normal behaviour with the grid disallows deselection of nodes (ie once a node is selected, it remains selected until another row is selected in it's place). To allow deselection, set rowDeselection=true in the grid options.
There is an api function forEachNode. This is useful for doing group selections on a business key. The example below shows selecting all rows with country = 'United States'. This method is also useful when you load data and need to know the node equivalent of the data for selection purposes.
There are two callbacks with regards selection:
onRowSelected(row): Gets called when a row is selected and passes the selected row.
onSelectionChanged(): Gets called when a row is selected or deselected.