This is similar to, but different from other questions around this topic.
I have a table with a list of records, each having a select checkbox.
In the table header I have a "Select All" checkbox.
When the user checks/unchecks "Select All" the records are selected/unselected. This works fine.
However, I need to deselect my "Select All" checkbox when one or more of the records are deselected.
My markup:
<table>
<thead>
<tr>
<th>Name</th>
<th><input type="checkbox" data-bind="checked: SelectAll" /></th>
</tr>
</thead>
<tbody data-bind="foreach: $data.People">
<tr>
<td data-bind="text: Name"></td>
<td class="center"><input type="checkbox" data-bind="checked: Selected" /></td>
</tr>
</tbody>
</table>
My script (edited):
function MasterViewModel() {
var self = this;
self.People = ko.observableArray();
self.SelectAll = ko.observable(false);
self.SelectAll.subscribe(function (newValue) {
ko.utils.arrayForEach(self.People(), function (person) {
person.Selected(newValue);
});
});
}
my.Person = function (name, selected) {
var self = this;
self.Name = name;
self.Selected = ko.observable(false);
}
This is similar to, but different from other questions around this topic.
I have a table with a list of records, each having a select checkbox.
In the table header I have a "Select All" checkbox.
When the user checks/unchecks "Select All" the records are selected/unselected. This works fine.
However, I need to deselect my "Select All" checkbox when one or more of the records are deselected.
My markup:
<table>
<thead>
<tr>
<th>Name</th>
<th><input type="checkbox" data-bind="checked: SelectAll" /></th>
</tr>
</thead>
<tbody data-bind="foreach: $data.People">
<tr>
<td data-bind="text: Name"></td>
<td class="center"><input type="checkbox" data-bind="checked: Selected" /></td>
</tr>
</tbody>
</table>
My script (edited):
function MasterViewModel() {
var self = this;
self.People = ko.observableArray();
self.SelectAll = ko.observable(false);
self.SelectAll.subscribe(function (newValue) {
ko.utils.arrayForEach(self.People(), function (person) {
person.Selected(newValue);
});
});
}
my.Person = function (name, selected) {
var self = this;
self.Name = name;
self.Selected = ko.observable(false);
}
2 Answers
Reset to default 6This works
http://jsfiddle/AneL9/
self.SelectAll = ko.puted({
read: function() {
var item = ko.utils.arrayFirst(self.People(), function(item) {
return !item.Selected();
});
return item == null;
},
write: function(value) {
ko.utils.arrayForEach(self.People(), function (person) {
person.Selected(value);
});
}
});
but will give you a ordo n ^ 2 problem when selecting deselecting all, you can use a pasuable puted to get around that
http://www.knockmeout/2011/04/pausing-notifications-in-knockoutjs.html
edit: You can also extend the puted with a throttle, this way you avoid the ordo n^2 problem
.extend({ throttle: 1 })
http://jsfiddle/AneL9/44/
You should make SelectAll puted observable like this:
self.SelectAll = ko.puted({
read: function() {
var persons = self.People();
for (var i = 0, l = persons.length; i < l; i++)
if (!persons[i].Selected()) return false;
return true;
},
write: function(value) {
ko.utils.arrayForEach(self.People(), function(person){
person.Selected(value);
});
}
});
and strip SelectAll.subscribe out.
http://jsfiddle/Yqj59/