I would like to explicitly set a button as enabled in the html file. The reason is that my code later on toggles the button to disabled and if the code crashes or so I might see the button disabled.
I can disable the button with
$("#btn").attr("disabled","true")
but then an html containing:
<button id="btn" disabled="false">I want to be enabled!</button>
still shows the button as disabled.
The inspector shows:
<button id="btn" disabled="">I want to be enabled!</button>
I know I can do
$("#btn").removeAttr("disabled")
or similar, but it is not convenient to do that for many elements in the html.
HTML doesn't use boolean values for boolean attributes, surprisingly.
In HTML, boolean attributes are specified by either merely adding the attribute name, or (especially in XHTML) by using the attribute name as its value.
<input type="checkbox" disabled> <!-- HTML -->
<input type="checkbox" disabled /> <!-- Also HTML -->
<input type="checkbox" disabled="disabled" /> <!-- XHTML and HTML -->
This is documented in the HTML specification: http://www.w3.org/TR/html5/infrastructure.html#boolean-attribute
A number of attributes are boolean attributes. The presence of a boolean attribute on an element represents the true value, and the absence of the attribute represents the false value.
The values "true" and "false" are not allowed on boolean attributes. To represent a false value, the attribute has to be omitted altogether.
To add to the confusion, in the DOM these boolean attributes are specified with boolean values, for example:
/** #type HTMLInputElement */
const inputElement = document.createElement('input');
inputElement.disabled = true; // <-- The DOM *does* use a proper boolean value here.
console.log( inputElement.disabled ); // Prints "true"
inputElement.disabled = false;
console.log( inputElement.disabled ); // Prints "false"
...to add even more confusion - due to JavaScript's falsyness - using string values with the property will not work as you'd expect:
inputElement.disabled = 'true';
console.log( inputElement.disabled ); // Prints "true"
inputElement.disabled = 'false';
console.log( inputElement.disabled ); // *Still* prints "true"
(This is because the JavaScript string 'false' is not type-coerced into the JavaScript boolean value false).
Also, some HTML attributes do have true and false as possible values, such as contentEditable (which also has inherit as a third option), also consider <form autocomplete=""> which can be on and off (and many other values), which might trip some people up too. I think some legacy (Internet Explorer 4.0-era) extensions like <object> and <applet> may have had boolean attributes, and definitely had booleans in their child <param value=""> attributes, that's just an historical curiosity at this point).
In future, can help someone.
selectLanguage.onchange = function() {
var value = selectLanguage.value;
if (value != '') {
submitLanguage.removeAttr('disabled');
} else {
submitLanguage.attr('disabled', 'disabled');
}
// submitLanguage.attr('enabled', 'enabled');
}
I know this is an old topic but as there is no marked answer, does this help? This does answer the explicitly marked as enabled question.
<button enabled>My Text</button>
<!-- Which also works as: -->
<button enabled="enabled">My Text</button>
I too am investigating this for use to enabled a button when validation occurs. I hope this helps someone.
If you are using AngularJS, try ng-disabled instead. In this case you can use stuff like:
ng-disabled="true"
ng-disabled="false"
ng-disabled={{expression}}
and it works as expected....
You have to use element.removeAttribute("disabled");
Thanks
In 2022 if you're using EJS or Vue, you should be setting it as:
EJS:
<div <%=true?'enabled':'disabled'%> ></div>
Vue:
<div :disabled="someFuncInMethods()"></div>
Related
Have been looking for this answer in SO, but perhaps I'm not frasing it correctly or there is actually no answer yet for this.
I am using an input component that uses a key to render it valid (green border) or invalid (red border) and I would like to add it dynamically:
<Input type="select" valid /> //This input has green border
<Input type="select" invalid /> //This input has red border
Since they key valid/invalid has no value like true or false, I'm not sure how to change it dynamically through a function since as far as I'm aware, I can change values dynamically with a JSX expression, but not add a key itself.
Can you please suggest a way to add 'valid' or 'invalid' tag dynamically without value?
"Without value" is actually not accurate. What you see there is syntactic sugar for valid={true} and invalid={true}.
So, the same can be accomplished by:
const valid = // whatever logic here to determine if it's valid.
<Input type="select" valid={valid} invalid={!valid} /> // Either return or assign to something.
Alternatively:
let inputProps = {type: 'select'};
if (/* whatever logic here to determine if it's valid*/) {
inputProps.valid = true;
}
else {
inputProps.invalid = true;
}
<Input {...inputProps} />; // Either return or assign to something.
But the latter is a lot more verbose.
Not sure if this will work but give it a try.
JSX reads properties without values/= as boolean/true.
Set null values:
<Input type="select" invalid={null} />
You can then conditionally show valid or invalid input elements
I have an Angular form. The fields are validated using the ng-pattern attribute. I also have a reset button. I'm using the Ui.Utils Event Binder to handle the reset event like so:
<form name="searchForm" id="searchForm" ui-event="{reset: 'reset(searchForm)'}" ng-submit="search()">
<div>
<label>
Area Code
<input type="tel" name="areaCode" ng-model="areaCode" ng-pattern="/^([0-9]{3})?$/">
</label>
<div ng-messages="searchForm.areaCode.$error">
<div class="error" ng-message="pattern">The area code must be three digits</div>
</div>
</div>
<div>
<label>
Phone Number
<input type="tel" name="phoneNumber" ng-model="phoneNumber" ng-pattern="/^([0-9]{7})?$/">
</label>
<div ng-messages="searchForm.phoneNumber.$error">
<div class="error" ng-message="pattern">The phone number must be seven digits</div>
</div>
</div>
<br>
<div>
<button type="reset">Reset</button>
<button type="submit" ng-disabled="searchForm.$invalid">Search</button>
</div>
</form>
As you can see, when the form is reset it calls the reset method on the $scope. Here's what the entire controller looks like:
angular.module('app').controller('mainController', function($scope) {
$scope.resetCount = 0;
$scope.reset = function(form) {
form.$setPristine();
form.$setUntouched();
$scope.resetCount++;
};
$scope.search = function() {
alert('Searching');
};
});
I'm calling form.$setPristine() and form.$setUntouched, following the advice from another question here on Stack Overflow. The only reason I added the counter was to prove that the code is being called (which it is).
The problem is that even after reseting the form, the validation messages don't go away. You can see the full code on Plunker. Here's a screenshot showing that the errors don't go away:
I started with the comment from #Brett and built upon it. I actually have multiple forms and each form has many fields (more than just the two shown). So I wanted a general solution.
I noticed that the Angular form object has a property for each control (input, select, textarea, etc) as well as some other Angular properties. Each of the Angular properties, though, begins with a dollar sign ($). So I ended up doing this (including the comment for the benefit of other programmers):
$scope.reset = function(form) {
// Each control (input, select, textarea, etc) gets added as a property of the form.
// The form has other built-in properties as well. However it's easy to filter those out,
// because the Angular team has chosen to prefix each one with a dollar sign.
// So, we just avoid those properties that begin with a dollar sign.
let controlNames = Object.keys(form).filter(key => key.indexOf('$') !== 0);
// Set each control back to undefined. This is the only way to clear validation messages.
// Calling `form.$setPristine()` won't do it (even though you wish it would).
for (let name of controlNames) {
let control = form[name];
control.$setViewValue(undefined);
}
form.$setPristine();
form.$setUntouched();
};
$scope.search = {areaCode: xxxx, phoneNumber: yyyy}
Structure all models in your form in one place like above, so you can clear it like this:
$scope.search = angular.copy({});
After that you can just call this for reset the validation:
$scope.search_form.$setPristine();
$scope.search_form.$setUntouched();
$scope.search_form.$rollbackViewValue();
There doesn't seem to be an easy way to reset the $errors in angular. The best way would probably be to reload the current page to start with a new form. Alternatively you have to remove all $error manually with this script:
form.$setPristine(true);
form.$setUntouched(true);
// iterate over all from properties
angular.forEach(form, function(ctrl, name) {
// ignore angular fields and functions
if (name.indexOf('$') != 0) {
// iterate over all $errors for each field
angular.forEach(ctrl.$error, function(value, name) {
// reset validity
ctrl.$setValidity(name, null);
});
}
});
$scope.resetCount++;
You can add a validation flag and show or hide errors according to its value with ng-if or ng-show in your HTML. The form has a $valid flag you can send to your controller.
ng-if will remove or recreate the element to the DOM, while ng-show will add it but won't show it (depending on the flag value).
EDIT: As pointed by Michael, if form is disabled, the way I pointed won't work because the form is never submitted. Updated the code accordingly.
HTML
<form name="searchForm" id="searchForm" ui-event="{reset: 'reset(searchForm)'}" ng-submit="search()">
<div>
<label>
Area Code
<input type="tel" name="areaCode" ng-model="areaCode" ng-pattern="/^([0-9]{3})?$/">
</label>
<div ng-messages="searchForm.areaCode.$error">
<div class="error" ng-message="pattern" ng-if="searchForm.areaCode.$dirty">The area code must be three digits</div>
</div>
</div>
<div>
<label>
Phone Number
<input type="tel" name="phoneNumber" ng-model="phoneNumber" ng-pattern="/^([0-9]{7})?$/">
</label>
<div ng-messages="searchForm.phoneNumber.$error">
<div class="error" ng-message="pattern" ng-if="searchForm.phoneNumber.$dirty">The phone number must be seven digits</div>
</div>
</div>
<br>
<div>
<button type="reset">Reset</button>
<button type="submit" ng-disabled="searchForm.$invalid">Search</button>
</div>
</form>
JS
$scope.search = function() {
alert('Searching');
};
$scope.reset = function(form) {
form.$setPristine();
form.$setUntouched();
$scope.resetCount++;
};
Codepen with working solution: http://codepen.io/anon/pen/zGPZoB
It looks like I got to do the right behavior at reset. Unfortunately, using the standard reset failed. I also do not include the library ui-event. So my code is a little different from yours, but it does what you need.
<form name="searchForm" id="searchForm" ng-submit="search()">
pristine = {{searchForm.$pristine}} valid ={{searchForm.$valid}}
<div>
<label>
Area Code
<input type="tel" required name="areaCode" ng-model="obj.areaCode" ng-pattern="/^([0-9]{3})?$/" ng-model-options="{ allowInvalid: true }">
</label>
<div ng-messages="searchForm.areaCode.$error">
<div class="error" ng-message="pattern">The area code must be three digits</div>
<div class="error" ng-message="required">The area code is required</div>
</div>
</div>
<div>
<label>
Phone Number
<input type="tel" required name="phoneNumber" ng-model="obj.phoneNumber" ng-pattern="/^([0-9]{7})?$/" ng-model-options="{ allowInvalid: true }">
</label>
<div ng-messages="searchForm.phoneNumber.$error">
<div class="error" ng-message="pattern">The phone number must be seven digits</div>
<div class="error" ng-message="required">The phone number is required</div>
</div>
</div>
<br>
<div>
<button ng-click="reset(searchForm)" type="reset">Reset</button>
<button type="submit" ng-disabled="searchForm.$invalid">Search</button>
</div>
</form>
And JS:
$scope.resetCount = 0;
$scope.obj = {};
$scope.reset = function(form_) {
$scope.resetCount++;
$scope.obj = {};
form_.$setPristine();
form_.$setUntouched();
console.log($scope.resetCount);
};
$scope.search = function() {
alert('Searching');
};
Live example on jsfiddle.
Note the directive ng-model-options="{allowinvalid: true}". Use it necessarily, or until the entry field will not be valid, the model value is not recorded. Therefore, the reset will not operate.
P.S. Put value (areaCode, phoneNumber) on the object simplifies purification.
Following worked for me
let form = this.$scope.myForm;
let controlNames = Object.keys(form).filter(key => key.indexOf('$') !== 0);
for (let name of controlNames) {
let control = form [name];
control.$error = {};
}
In Short: to get rid of ng-messages errors you need to clear out the $error object for each form item.
further to #battmanz 's answer, but without using any ES6 syntax to support older browsers.
$scope.resetForm = function (form) {
try {
var controlNames = Object.keys(form).filter(function (key) { return key.indexOf('$') !== 0 });
console.log(controlNames);
for (var x = 0; x < controlNames.length; x++) {
form[controlNames[x]].$setViewValue(undefined);
}
form.$setPristine();
form.$setUntouched();
} catch (e) {
console.log('Error in Reset');
console.log(e);
}
};
I had the same problem and tried to do battmanz solution (accepted answer).
I'm pretty sure his answer is really good, but however for me it wasn't working.
I am using ng-model to bind data, and angular material library for the inputs and ng-message directives for error message , so maybe what I will say will be useful only for people using the same configuration.
I took a lot of look at the formController object in javascript, in fact there is a lot of $ angular function as battmanz noted, and there is in addition, your fields names, which are object with some functions in its fields.
So what is clearing your form ?
Usually I see a form as a json object, and all the fields are binded to a key of this json object.
//lets call here this json vm.form
vm.form = {};
//you should have something as ng-model = "vm.form.name" in your view
So at first to clear the form I just did callback of submiting form :
vm.form = {};
And as explained in this question, ng-messages won't disappear with that, that's really bad.
When I used battmanz solution as he wrote it, the messages didn't appear anymore, but the fields were not empty anymore after submiting, even if I wrote
vm.form = {};
And I found out it was normal, because using his solution actually remove the model binding from the form, because it sets all the fields to undefined.
So the text was still in the view because somehow there wan't any binding anymore and it decided to stay in the HTML.
So what did I do ?
Actually I just clear the field (setting the binding to {}), and used just
form.$setPristine();
form.$setUntouched();
Actually it seems logical, since the binding is still here, the values in the form are now empty, and angular ng-messages directive is triggering only if the form is not untouched, so I think it's normal after all.
Final (very simple) code is that :
function reset(form) {
form.$setPristine();
form.$setUntouched();
};
A big problem I encountered with that :
Only once, the callback seems to have fucked up somewhere, and somehow the fields weren't empty (it was like I didn't click on the submit button).
When I clicked again, the date sent was empty. That even more weird because my submit button is supposed to be disabled when a required field is not filled with the good pattern, and empty is certainly not a good one.
I don't know if my way of doing is the best or even correct, if you have any critic/suggestion or any though about the problem I encountered, please let me know, I always love to step up in angularJS.
Hope this will help someone and sorry for the bad english.
You can pass your loginForm object into the function ng-click="userCtrl.login(loginForm)
and in the function call
this.login = function (loginForm){
loginForm.$setPristine();
loginForm.$setUntouched();
}
So none of the answers were completely working for me. Esp, clearing the view value, so I combined all the answers clearing view value, clearing errors and clearing the selection with j query(provided the fields are input and name same as model name)
var modelNames = Object.keys($scope.form).filter(key => key.indexOf('$') !== 0);
modelNames.forEach(function(name){
var model = $scope.form[name];
model.$setViewValue(undefined);
jq('input[name='+name+']').val('');
angular.forEach(model.$error, function(value, name) {
// reset validity
model.$setValidity(name, null);
});
});
$scope.form.$setPristine();
$scope.form.$setUntouched();
What's the suggested "best practice" way to use Knockout's "attr" data binding with standalone attributes like "readonly" and "disabled"?
These attributes are special in that they are generally enabled by setting the attribute value to the attribute name (although many browsers work fine if you simply include the attribute names without any values in the HTML):
<input type="text" readonly="readonly" disabled="disabled" value="foo" />
However, if you don't want these attributes to be applied, the general practice is to simply omit them altogether from the HTML (as opposed to doing something like readonly="false"):
<input type="text" value="foo" />
Knockout's "attr" data binding doesn't support this scenario. As soon as I provide an attribute name, I need to provide a value as well:
<input type="text" data-bind="attr: { 'disabled': getDisabledState() }" />
Is there a cross-browser way turn off 'disabled' or 'readonly'? Or is there a trick with a custom binding that I can use to not render anything if I don't want the item disabled or made read-only?
Knockout's "attr" data binding does support this scenario just return null or undefined from your getDisabledState() function then it won't emit the attribute.
Demo Fiddle.
You can also create a binding for readonly like this:
ko.bindingHandlers['readonly'] = {
'update': function (element, valueAccessor) {
var value = ko.utils.unwrapObservable(valueAccessor());
if (!value && element.readOnly)
element.readOnly = false;
else if (value && !element.readOnly)
element.readOnly = true;
}
};
Source: https://github.com/knockout/knockout/issues/1100
Knockout has an enable binding as well as a disable binding.
I'm not sure if these were available when the question was asked, but anyone referring back to this issue should be aware.
I am trying to use the form method checkValidity().
http://html5test.com/ tells me that my browser (Chrome) support the form-level checkValidity method.
However, using jsfiddle http://jsfiddle.net/LcgnQ/2/ I have tried the following html and javascript snippets:
<form id="profileform" name="profileform">
<input type="text" id="firstname" required>
<input type="button" id="testbutton" value="Test">
</form>
$('#testbutton').bind('click',function(){
try{
alert($('#profileform').checkValidity());
}
catch(err){alert('err='+err)};
});
I'm getting an error: object has no method checkValidity()
What am I doing wrong?
Try:
$('#profileform')[0].checkValidity()
When you select $('#profileform') you get a jQuery object array. To access actual DOM properties you must select the first item in the array, which is the raw DOM element.
#robertc 's Answer is perfect. Anyway I'd just add another way to do it using jQuery's .get([index]) function. It also retrieves the DOM element for the given index, or all of the matched DOM elements if there's no index declared.
In the end it is exactly the same, only written in a bit more verbose way:
$('#profileform').get(0).checkValidity()
Leaving you the docs right here: https://api.jquery.com/get/
Just another way:
// Fetch all the forms we want to apply custom Bootstrap validation styles to
var forms = document.getElementsByName('profileform');
// Loop over them and prevent submission
var validation = Array.prototype.filter.call(forms, function (form) {
form.addEventListener('submit', function (event) {
if (form.checkValidity() === false) {
event.preventDefault();
event.stopPropagation();
}
}, false);
});
There is no way to have a tri-state check button (yes, no, null) in HTML, right?
Are there any simple tricks or work-arounds without having to render the whole thing by oneself?
Edit — Thanks to Janus Troelsen's comment, I found a better solution:
HTML5 defines a property for checkboxes called indeterminate
See w3c reference guide. To make checkbox appear visually indeterminate set it to true:
element.indeterminate = true;
Here is Janus Troelsen's fiddle. Note, however, that:
The indeterminate state cannot be set in the HTML markup, it can only be done via Javascript (see this JSfiddle test and this detailed article in CSS tricks)
This state doesn't change the value of the checkbox, it is only a visual cue that masks the input's real state.
Browser test: Worked for me in Chrome 22, Firefox 15, Opera 12 and back to IE7. Regarding mobile browsers, Android 2.0 browser and Safari mobile on iOS 3.1 don't have support for it.
Previous answer
Another alternative would be to play with the checkbox transparency
for the "some selected" state (as Gmail does used to
do in previous versions). It will require some javascript and a CSS
class. Here I put a particular example that handles a list with
checkable items and a checkbox that allows to select all/none of them.
This checkbox shows a "some selected" state when some of the list
items are selected.
Given a checkbox with an ID #select_all and several checkboxes with
a class .select_one,
The CSS class that fades the "select all" checkbox would be the
following:
.some_selected {
opacity: 0.5;
filter: alpha(opacity=50);
}
And the JS code that handles the tri-state of the select all checkbox
is the following:
$('#select_all').change (function ()
{
//Check/uncheck all the list's checkboxes
$('.select_one').attr('checked', $(this).is(':checked'));
//Remove the faded state
$(this).removeClass('some_selected');
});
$('.select_one').change (function ()
{
if ($('.select_one:checked').length == 0)
$('#select_all').removeClass('some_selected').attr('checked', false);
else if ($('.select_one:not(:checked)').length == 0)
$('#select_all').removeClass('some_selected').attr('checked', true);
else
$('#select_all').addClass('some_selected').attr('checked', true);
});
You can try it here: http://jsfiddle.net/98BMK/
You could use HTML's indeterminate IDL attribute on input elements.
My proposal would be using
three appropriate unicode characters for the three states e.g. ❓,✅,❌
a plain text input field (size=1)
no border
read only
display no cursor
onclick handler to toggle thru the three states
See examples at:
http://jsfiddle.net/wf_bitplan_com/941std72/8/
/**
* loops thru the given 3 values for the given control
*/
function tristate(control, value1, value2, value3) {
switch (control.value.charAt(0)) {
case value1:
control.value = value2;
break;
case value2:
control.value = value3;
break;
case value3:
control.value = value1;
break;
default:
// display the current value if it's unexpected
alert(control.value);
}
}
function tristate_Marks(control) {
tristate(control,'\u2753', '\u2705', '\u274C');
}
function tristate_Circles(control) {
tristate(control,'\u25EF', '\u25CE', '\u25C9');
}
function tristate_Ballot(control) {
tristate(control,'\u2610', '\u2611', '\u2612');
}
function tristate_Check(control) {
tristate(control,'\u25A1', '\u2754', '\u2714');
}
<input type='text'
style='border: none;'
onfocus='this.blur()'
readonly='true'
size='1'
value='❓' onclick='tristate_Marks(this)' />
<input style="border: none;"
id="tristate"
type="text"
readonly="true"
size="1"
value="❓"
onclick="switch(this.form.tristate.value.charAt(0)) {
case '❓': this.form.tristate.value='✅'; break;
case '✅': this.form.tristate.value='❌'; break;
case '❌': this.form.tristate.value='❓'; break;
};" />
You can use radio groups to achieve that functionality:
<input type="radio" name="choice" value="yes" />Yes
<input type="radio" name="choice" value="No" />No
<input type="radio" name="choice" value="null" />null
Here is a runnable example using the mentioned indeterminate attribute:
const indeterminates = document.getElementsByClassName('indeterminate');
indeterminates['0'].indeterminate = true;
<form>
<div>
<input type="checkbox" checked="checked" />True
</div>
<div>
<input type="checkbox" />False
</div>
<div>
<input type="checkbox" class="indeterminate" />Indeterminate
</div>
</form>
Just run the code snippet to see how it looks like.
You can use an indeterminate state: http://css-tricks.com/indeterminate-checkboxes/. It's supported by the browsers out of the box and don't require any external js libraries.
I think that the most semantic way is using readonly attribute that checkbox inputs can have. No css, no images, etc; a built-in HTML property!
See Fiddle:
http://jsfiddle.net/chriscoyier/mGg85/2/
As described here in last trick:
http://css-tricks.com/indeterminate-checkboxes/
Like #Franz answer you can also do it with a select. For example:
<select>
<option></option>
<option value="Yes">Yes</option>
<option value="No">No</option>
</select>
With this you can also give a concrete value that will be send with the form, I think that with javascript indeterminate version of checkbox, it will send the underline value of the checkbox.
At least, you can use it as a callback when javascript is disabled. For example, give it an id and in the load event change it to the javascript version of the checkbox with indeterminate status.
Besides all cited above, there are jQuery plugins that may help too:
for individual checkboxes:
jQuery-Tristate-Checkbox-plugin: http://vanderlee.github.io/tristate/
for tree-like behavior checkboxes:
jQuery Tristate: http://jlbruno.github.io/jQuery-Tristate-Checkbox-plugin/
EDIT
Both libraries uses the 'indeterminate' checkbox attribute, since this attribute in Html5 is just for styling (https://www.w3.org/TR/2011/WD-html5-20110113/number-state.html#checkbox-state), the null value is never sent to the server (checkboxes can only have two values).
To be able to submit this value to the server, I've create hidden counterpart fields which are populated on form submission using some javascript. On the server side, you'd need to check those counterpart fields instead of original checkboxes, of course.
I've used the first library (standalone checkboxes) where it's important to:
Initialize the checked, unchecked, indeterminate values
use .val() function to get the actual value
Cannot make work .state (probably my mistake)
Hope that helps.
Refering to #BoltClock answer, here is my solution for a more complex recursive method:
http://jsfiddle.net/gx7so2tq/2/
It might not be the most pretty solution but it works fine for me and is quite flexible.
I use two data objects defining the container:
data-select-all="chapter1"
and the elements itself:
data-select-some="chapter1"
Both having the same value. The combination of both data-objects within one checkbox allows sublevels, which are scanned recursively. Therefore two "helper" functions are needed to prevent the change-trigger.
Here other Example with simple jQuery and property data-checked:
$("#checkbox")
.click(function(e) {
var el = $(this);
switch (el.data('checked')) {
// unchecked, going indeterminate
case 0:
el.data('checked', 1);
el.prop('indeterminate', true);
break;
// indeterminate, going checked
case 1:
el.data('checked', 2);
el.prop('indeterminate', false);
el.prop('checked', true);
break;
// checked, going unchecked
default:
el.data('checked', 0);
el.prop('indeterminate', false);
el.prop('checked', false);
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<label><input type="checkbox" name="checkbox" value="" checked id="checkbox"> Tri-State Checkbox </label>
As I needed something like this -without any plug-in- for script-generated checkboxes in a table... I ended up with this solution:
<!DOCTYPE html>
<html>
<body>
Toto <input type="checkbox" id="myCheck1" onclick="updateChkBx(this)" /><br />
Tutu <input type="checkbox" id="myCheck2" onclick="updateChkBx(this)" /><br />
Tata <input type="checkbox" id="myCheck3" onclick="updateChkBx(this)" /><br />
Tete <input type="checkbox" id="myCheck4" onclick="updateChkBx(this)" /><br />
<script>
var chkBoxState = [];
function updateChkBx(src) {
var idx = Number(src.id.substring(7)); // 7 to bypass the "myCheck" part in each checkbox id
if(typeof chkBoxState[idx] == "undefined") chkBoxState[idx] = false; // make sure we can use stored state at first call
// the problem comes from a click on a checkbox both toggles checked attribute and turns inderminate attribute to false
if(chkBoxState[idx]) {
src.indeterminate = false;
src.checked = false;
chkBoxState[idx] = false;
}
else if (!src.checked) { // passing from checked to unchecked
src.indeterminate = true;
src.checked = true; // force considering we are in a checked state
chkBoxState[idx] = true;
}
}
// to know box state, just test indeterminate, and if not indeterminate, test checked
</script>
</body>
</html>
A short snippet using an auxiliary variable and indeterminate:
cb1.state = 1
function toggle_tristate(cb) {
cb.state = ++cb.state % 3 // cycle through 0,1,2
if (cb.state == 0) {
cb.indeterminate = true;
cb.checked = true; // after 'indeterminate' the state 'false' follows
}
}
<input id="cb1" type="checkbox" onclick="toggle_tristate(this)">
Only state==0 is captured. The rest is handle automatically.
http://jsfiddle.net/6vyek2c5
You'll need to use javascript/css to fake it.
Try here for an example: http://www.dynamicdrive.com/forums/archive/index.php/t-26322.html
It's possible to have HTML form elements disabled -- wouldn't that do? Your users would see it in one of three states, i.e. checked, unchecked, and disabled, which would be greyed out and not clickable. To me, that seems similar to "null" or "not applicable" or whatever you're looking for in that third state.
There's a simple JavaScript tri-state input field implementation at
https://github.com/supernifty/tristate-checkbox
The jQuery plugin "jstree" with the checkbox plugin can do this.
http://www.jstree.com/documentation/checkbox
-Matt
Building on the answers above using the indeterminate state, I've come up with a little bit that handles individual checkboxes and makes them tri-state.
MVC razor uses 2 inputs per checkbox anyway (the checkbox and a hidden with the same name to always force a value in the submit). MVC uses things like "true" as the checkbox value and "false" as the hidden of the same name; makes it amenable to boolean use in API calls. This snippet uses a third hidden state to persist the last request values across submits.
Checkboxes initialized with the below will start indeterminate. Checking once turns on the checkbox. Checking twice turns off the checkbox (returning the hidden value of the same name). Checking a third time returns it to indeterminate (and clears out the hidden so a submit will produce a blank).
The page also populates another hidden (e.g., triBox2Orig) with whatever value was on the query string to start, so the 3 states can be initialized and persisted between submits.
$(document).ready(function () {
var initCheckbox = function (chkBox)
{
var hidden = $('[name="' + $(chkBox).prop("name") + '"][type="hidden"]');
var hiddenOrig = $('[name="' + $(chkBox).prop("name") + 'Orig"][type="hidden"]').prop("value");
hidden.prop("origValue", hidden.prop("value"));
if (!chkBox.prop("checked") && !hiddenOrig) chkBox.prop("indeterminate", true);
if (chkBox.prop("indeterminate")) hidden.prop("value", null);
chkBox.change(checkBoxToggleFun);
}
var checkBoxToggleFun = function ()
{
var isChecked = $(this).prop('checked');
var hidden = $('[name="' + $(this).prop("name") + '"][type="hidden"]');
var thirdState = isChecked && hidden.prop("value") === hidden.prop("origValue");
if (thirdState) { // on 3rd click of a checkbox, set it back to indeterminate
$(this).prop("indeterminate", true);
$(this).prop('checked', false);
}
hidden.prop("value", thirdState ? null : hidden.prop("origValue"));
};
var chkBox = $('#triBox1');
initCheckbox(chkBox);
chkBox = $('#triBox2');
initCheckbox(chkBox);
});