kendoGrid and multiselectbox column initialization using query string parameters - kendo-grid

Question

I am implementing a custom solution that will initialize kendoGrid (and its multiselect columns) by applying filters to the grid using query string parameters. I am using Kendo UI v2014.2.903 and multiselectbox user extension.
To achieve this, I have a custom JavaScript function that parses query string parameters into filter object and applies it to kendoGrid's dataSource property using its filter method. Code snippet below:
var preFilterQueryString = getPreFilterQuery(queryString);
if (preFilterQueryString != '') {
kendoGrid.dataSource.filter(parseFilterString(preFilterQueryString));
}
I am initializing multiselectbox as follows:
args.element.kendoMultiSelectBox({
dataSource: getAutoCompleteDataSource(column.field),
valuePrimitive: true,
selectionChanged: function (e) {
//ignored for brevity
}
});
My problem is if I set filters to multiselectbox using above approach, they are not applied correctly to the data set.
For example, if I pass single filter as "Vancouver", correct result set is displayed. Choices in the multiselectbox are "All" and "Vancouver". However, Vancouver choice is not checked in the multiselectbox. Is that by design? Please see image below.
single filter image
If I pass in two filters Vancouver and Warsaw, only the last filter Warsaw is applied to the grid and data set containing only Warsaw is displayed. Again, none of the choices are checked in the multiselectbox.
two filters image
Below is the filter object that is applied to dataSource.filter() method.
kendoGrid's filter object image
Troubleshooting
Below is condensed version (for brevity) of selectionchanged event handler of a multiselectbox column.
if (e.newValue && e.newValue.length) {
var newValue = e.newValue;
console.log('e.newValue: ' + e.newValue);
filter.filters = [];
for (var i = 0, l = newValue.length; i < l; i++) {
filter.filters.push({field: field,operator: 'contains',value: newValue[i]});
}
kendoGrid.dataSource.filter(allFilters);
}
I noticed that when two filters are passed, e.newValue is "Warsaw" instead of an array - "[Vancouver, Warsaw]"
I spent lot of time troubleshooting why only Warsaw is applied to the data set.
Here's what I found out:
_raiseSelectionChanged function is what raises selection changed event. In that function, I noticed that it sets newValue and oldValue event arguments. To set newValue it uses "Value" function. Value function uses the below code to retrieve all the selected list items and return them.
else {
var selecteditems = this._getSelectedListItems();
return $.map(selecteditems, function (item) {
var obj = $(item).children("span").first();
return obj.attr("data-value");
}).join();
}
_getSelectedListItems function uses jQuery filter to fetch all list items that have css class ".selected"
_getSelectedListItems: function () {
return this._getAllValueListItems().filter("." + SELECTED);
},
There's a _select event which seems to be adding ".selected" class to list items. When I put a breakpoint on line 286, it is hitting it only once and that is for Warsaw. I am unable to understand why it is not getting called for Vancouver. I am out of clues and was wondering if anyone has pointers.
debug capture of _select function
Below is kendoMultiSelectBox user extension for your reference:
//MultiSelect - A user extension of KendoUI DropDownList widget.
(function ($) {
// shorten references to variables
var kendo = window.kendo,
ui = kendo.ui,
DropDownList = ui.DropDownList,
keys = kendo.keys,
SELECT = "select",
SELECTIONCHANGED = "selectionChanged",
SELECTED = "k-state-selected",
HIGHLIGHTED = "k-state-active",
CHECKBOX = "custom-multiselect-check-item",
SELECTALLITEM = "custom-multiselect-selectAll-item",
MULTISELECTPOPUP = "custom-multiselect-popup",
EMPTYSELECTION = "custom-multiselect-summary-empty";
var lineTemplate = '<input type="checkbox" name="#= {1} #" value="#= {0} #" class="' + CHECKBOX + '" />' +
'<span data-value="#= {0} #">#= {1} #</span>';
var MultiSelectBox = DropDownList.extend({
init: function (element, options) {
options.template = kendo.template(kendo.format(lineTemplate, options.dataValueField || 'data', options.dataTextField || 'data'));
// base call to widget initialization
DropDownList.fn.init.call(this, element, options);
var button = $('<input type="button" value="OK" style="float: right; padding: 3px; margin: 5px; cursor: pointer;" />');
button.on('click', $.proxy(this.close, this));
var popup = $(this.popup.element);
popup.append(button);
},
options: {
name: "MultiSelectBox",
index: -1,
showSelectAll: true,
preSummaryCount: 1, // number of items to show before summarising
emptySelectionLabel: '', // what to show when no items are selected
selectionChanged: null // provide callback to invoke when selection has changed
},
events: [
SELECTIONCHANGED
],
refresh: function () {
// base call
DropDownList.fn.refresh.call(this);
this._updateSummary();
$(this.popup.element).addClass(MULTISELECTPOPUP);
},
current: function (candidate) {
return this._current;
},
open: function () {
var self = this;
this._removeSelectAllItem();
this._addSelectAllItem();
if ($(this.ul).find('li').length > 6) {
$(this.popup.element).css({ 'padding-bottom': '30px' });
}
else {
$(this.popup.element).css({ 'padding-bottom': '0' });
}
DropDownList.fn.open.call(this);
//hook on to popup event because dropdown close does not
//fire consistently when user clicks on some other elements
//like a dataviz chart graphic
this.popup.one('close', $.proxy(this._onPopupClosed, this));
},
_onPopupClosed: function () {
this._removeSelectAllItem();
this._current = null;
this._raiseSelectionChanged();
},
_raiseSelectionChanged: function () {
var currentValue = this.value();
var currentValues = $.map((currentValue.length > 0 ? currentValue.split(",") : []).sort(), function (item) { return item.toString(); });
var oldValues = $.map((this._oldValue || []).sort(), function (item) { return item ? item.toString() : ''; });
// store for next pass
this._oldValue = $.map(currentValues, function (item) { return item.toString(); });
var changedArgs = { newValue: currentValues, oldValue: oldValues };
if (oldValues) {
var hasChanged = ($(oldValues).not(currentValues).length == 0 && $(currentValues).not(oldValues).length == 0) !== true;
if (hasChanged) {
//if (this.options.selectionChanged)
// this.options.selectionChanged(changedArgs);
this.trigger(SELECTIONCHANGED, changedArgs);
}
}
else if (currentValue.length > 0) {
//if (this.options.selectionChanged)
// this.options.selectionChanged(changedArgs);
this.trigger(SELECTIONCHANGED, changedArgs);
}
},
_addSelectAllItem: function () {
if (!this.options.showSelectAll) return;
var firstListItem = this.ul.children('li:first');
if (firstListItem.length > 0) {
this.selectAllListItem = $('<li tabindex="-1" role="option" unselectable="on" class="k-item ' + SELECTALLITEM + '"></li>').insertBefore(firstListItem);
// fake a data object to use for the template binding below
var selectAllData = {};
selectAllData[this.options.dataValueField || 'data'] = '*';
selectAllData[this.options.dataTextField || 'data'] = 'All';
this.selectAllListItem.html(this.options.template(selectAllData));
this._updateSelectAllItem();
this._makeUnselectable(); // required for IE8
}
},
_removeSelectAllItem: function () {
if (this.selectAllListItem) {
this.selectAllListItem.remove();
}
this.selectAllListItem = null;
},
_focus: function (li) {
if (this.popup.visible() && li && this.trigger(SELECT, { item: li })) {
this.close();
return;
}
this.select(li);
},
_keydown: function (e) {
// currently ignore Home and End keys
// can be added later
if (e.keyCode == kendo.keys.HOME ||
e.keyCode == kendo.keys.END) {
e.preventDefault();
return;
}
DropDownList.fn._keydown.call(this, e);
},
_keypress: function (e) {
// disable existing function
},
_move: function (e) {
var that = this,
key = e.keyCode,
ul = that.ul[0],
down = key === keys.DOWN,
pressed;
if (key === keys.UP || down) {
if (down) {
if (!that.popup.visible()) {
that.toggle(down);
}
if (!that._current) {
that._current = ul.firstChild;
} else {
that._current = ($(that._current)[0].nextSibling || that._current);
}
} else {
//up
// only if anything is highlighted
if (that._current) {
that._current = ($(that._current)[0].previousSibling || ul.firstChild);
}
}
if (that._current) {
that._scroll(that._current);
}
that._highlightCurrent();
e.preventDefault();
pressed = true;
} else {
pressed = DropDownList.fn._move.call(this, e);
}
return pressed;
},
selectAll: function () {
var unselectedItems = this._getUnselectedListItems();
this._selectItems(unselectedItems);
// todo: raise custom event
},
unselectAll: function () {
var selectedItems = this._getSelectedListItems();
this._selectItems(selectedItems); // will invert the selection
// todo: raise custom event
},
_selectItems: function (listItems) {
var that = this;
$.each(listItems, function (i, item) {
var idx = ui.List.inArray(item, that.ul[0]);
that.select(idx); // select OR unselect
});
},
_selectItem: function () {
// method override to prevent default selection of first item, done by normal dropdown
var that = this,
options = that.options,
useOptionIndex,
value;
useOptionIndex = that._isSelect && !that._initial && !options.value && options.index && !that._bound;
if (!useOptionIndex) {
value = that._selectedValue || options.value || that._accessor();
}
if (value) {
that.value(value);
} else if (that._bound === undefined) {
that.select(options.index);
}
},
_select: function (li) {
var that = this,
value,
text,
idx;
li = that._get(li);
if (li && li[0]) {
idx = ui.List.inArray(li[0], that.ul[0]);
if (idx > -1) {
if (li.hasClass(SELECTED)) {
li.removeClass(SELECTED);
that._uncheckItem(li);
if (this.selectAllListItem && li[0] === this.selectAllListItem[0]) {
this.unselectAll();
}
} else {
li.addClass(SELECTED);
that._checkItem(li);
if (this.selectAllListItem && li[0] === this.selectAllListItem[0]) {
this.selectAll();
}
}
if (this._open) {
that._current(li);
that._highlightCurrent();
}
var selecteditems = this._getSelectedListItems();
value = [];
text = [];
$.each(selecteditems, function (indx, item) {
var obj = $(item).children("span").first();
value.push(obj.attr("data-value"));
text.push(obj.text());
});
that._updateSummary(text);
that._updateSelectAllItem();
that._accessor(value, idx);
// todo: raise change event (add support for selectedIndex) if required
that._raiseSelectionChanged();
}
}
},
_getAllValueListItems: function () {
if (this.selectAllListItem) {
return this.ul.children("li").not(this.selectAllListItem[0]);
} else {
return this.ul.children("li");
}
},
_getSelectedListItems: function () {
return this._getAllValueListItems().filter("." + SELECTED);
},
_getUnselectedListItems: function () {
return this._getAllValueListItems().filter(":not(." + SELECTED + ")");
},
_getSelectedItemsText: function () {
var text = [];
var selecteditems = this._getSelectedListItems();
$.each(selecteditems, function (indx, item) {
var obj = $(item).children("span").first();
text.push(obj.text());
});
return text;
},
_updateSelectAllItem: function () {
if (!this.selectAllListItem) return;
// are all items selected?
if (this._getAllValueListItems().length == this._getSelectedListItems().length) {
this._checkItem(this.selectAllListItem);
this.selectAllListItem.addClass(SELECTED);
}
else {
this._uncheckItem(this.selectAllListItem);
this.selectAllListItem.removeClass(SELECTED);
}
},
_updateSummary: function (itemsText) {
if (!itemsText) {
itemsText = this._getSelectedItemsText();
}
if (itemsText.length == 0) {
this._inputWrapper.addClass(EMPTYSELECTION);
this.text(this.options.emptySelectionLabel);
return;
} else {
this._inputWrapper.removeClass(EMPTYSELECTION);
}
if (itemsText.length <= this.options.preSummaryCount) {
this._textAccessor(itemsText.join(", "));
}
else {
this._textAccessor(itemsText.length + ' selected');
}
},
_checkItem: function (itemContainer) {
if (!itemContainer) return;
itemContainer.children("input").prop("checked", true);
},
_uncheckItem: function (itemContainer) {
if (!itemContainer) return;
itemContainer.children("input").removeAttr("checked");
},
_isItemChecked: function (itemContainer) {
return itemContainer.children("input:checked").length > 0;
},
value: function (value) {
if(value != undefined)
console.log("value", value);
var that = this,
idx,
valuesList = [];
if (value !== undefined) {
if (!$.isArray(value)) {
valuesList.push(value);
this._oldValue = valuesList; // to allow for selectionChanged event
}
else {
valuesList = value;
this._oldValue = value; // to allow for selectionChanged event
}
// clear all selections first
$(that.ul[0]).children("li").removeClass(SELECTED);
$("input", that.ul[0]).removeAttr("checked");
$.each(valuesList, function (indx, item) {
var hasValue;
if (item !== null) {
item = item.toString();
}
that._selectedValue = item;
hasValue = value || (that.options.optionLabel && !that.element[0].disabled && value === "");
if (hasValue && that._fetchItems(value)) {
return;
}
idx = that._index(item);
if (idx > -1) {
that.select(
that.options.showSelectAll ? idx + 1 : idx
);
}
});
that._updateSummary();
}
else {
var selecteditems = this._getSelectedListItems();
return $.map(selecteditems, function (item) {
var obj = $(item).children("span").first();
return obj.attr("data-value");
}).join();
}
},
});
ui.plugin(MultiSelectBox);
})(jQuery);
UPDATE
I came across documentation for multiselectbox's select event that clearly states that the select event is not fired when an item is selected programmatically. Is it relevant to what I am trying to do? But why is it firing for one of the filters even though I am setting them programmatically?
enter link description here