Let's say I have a data like this:
[
{ID: 1, SomeForeignKeyID: 4, IsFkEnabled: true},
{ID: 2, SomeForeignKeyID: 9, IsFkEnabled: false}
]
Kendo Grid is using this data:
columns.Bound(m => m.ID);
columns.ForeignKey(p => p.SomeForeignKeyID, ViewBag.ForeignKeys as IEnumerable<object>, "Value", "Name");
Here's the problem: how to make ForeignKey column editable, but only in rows, where IsFkEnabled == true? Edit mode is InCell.
Notes:
Approach #1
Use the grid's edit event and then do something like this:
$("#grid").kendoGrid({
dataSource: dataSource,
height: "300px",
columns: columns,
editable: true,
edit: function (e) {
var fieldName = e.container.find("input").attr("name");
// alternative (if you don't have the name attribute in your editable):
// var columnIndex = this.cellIndex(e.container);
// var fieldName = this.thead.find("th").eq(columnIndex).data("field");
if (!isEditable(fieldName, e.model)) {
this.closeCell(); // prevent editing
}
}
});
/**
* @returns {boolean} True if the column with the given field name is editable
*/
function isEditable(fieldName, model) {
if (fieldName === "SomeForeignKeyID") {
// condition for the field "SomeForeignKeyID"
// (default to true if defining property doesn't exist)
return model.hasOwnProperty("IsFkEnabled") && model.IsFkEnabled;
}
// additional checks, e.g. to only allow editing unsaved rows:
// if (!model.isNew()) { return false; }
return true; // default to editable
}
Demo here (updated for Q1 2014)
To use this via the MVC fluent syntax, simply give the anonymous edit
function above a name (e.g. onEdit
):
function onEdit(e) {
var fieldName = e.container.find("input").attr("name");
// alternative (if you don't have the name attribute in your editable):
// var columnIndex = this.cellIndex(e.container);
// var fieldName = this.thead.find("th").eq(columnIndex).data("field");
if (!isEditable(fieldName, e.model)) {
this.closeCell(); // prevent editing
}
}
and reference it like this:
@(Html.Kendo().Grid()
.Name("Grid")
.Events(events => events.Edit("onEdit"))
)
The disadvantage to this is that the editor gets created first before the edit event is triggered, which can sometimes have undesirable visual effects.
Approach #2
Extend the grid by overriding its editCell
method with a variation that triggers a beforeEdit
event; for that to work with grid options, you'll also need to override the init method:
var oEditCell = kendo.ui.Grid.fn.editCell;
var oInit = kendo.ui.Grid.fn.init;
kendo.ui.Grid = kendo.ui.Grid.extend({
init: function () {
oInit.apply(this, arguments);
if (typeof this.options.beforeEdit === "function") {
this.bind("beforeEdit", this.options.beforeEdit.bind(this));
}
},
editCell: function (cell) {
var that = this,
cell = $(cell),
column = that.columns[that.cellIndex(cell)],
model = that._modelForContainer(cell),
event = {
container: cell,
model: model,
field: column.field
};
if (model && this.trigger("beforeEdit", event)) {
// don't edit if prevented in beforeEdit
if (event.isDefaultPrevented()) return;
}
oEditCell.call(this, cell);
}
});
kendo.ui.plugin(kendo.ui.Grid);
then use it similar to #1:
$("#grid").kendoGrid({
dataSource: dataSource,
height: "300px",
columns: columns,
editable: true,
beforeEdit: function(e) {
var columnIndex = this.cellIndex(e.container);
var fieldName = this.thead.find("th").eq(columnIndex).data("field");
if (!isEditable(fieldName, e.model)) {
e.preventDefault();
}
}
});
The difference of this approach is that the editor won't get created (and focused) first. The beforeEdit
method is using the same isEditable
method from #1.
See a demo for this approach here.
If you want to use this approach with MVC wrappers but don't want / can't extend GridEventBuilder, you can still bind your event handler in JavaScript (place below the grid MVC initializer):
$(function() {
var grid = $("#grid").data("kendoGrid");
grid.bind("beforeEdit", onEdit.bind(grid));
});