I'm newbie in Angular2 and in web globally , I want to launch an action that changes an oject paramater value in the Database when checking a checkbox and or unchecking it using Material-Design, I tried with [(ngModel)] but nothing happened. the idea is that i have to add some propositions with checked | unchecked status to tell if it is a true or false proposition. Here is the proposition model
export class PropositionModel {
id:string;
wordingP:string; // the proposition
propStatus:Boolean; // the proposition status
}
here is the Html code for a proposition :
<div class="uk-width-xlarge-1-1 uk-width-medium-1-2">
<div (submit)="addProp1()" class="uk-input-group">
<span class="uk-input-group-addon"><input type="checkbox" data-md-icheck/></span>
<label>Proposition 1</label>
<input [(ngModel)]="proposition1.wordingP" type="text" class="md-input" required class="md-input"/>
</div>
</div>
here is the TypeScript code for adding the proposition:
addProp1() {
this.proposition1 = new PropositionModel();
this.proposition1.propStatus = false;
this.propositionService.addProposition(this.proposition1)
.subscribe(response=> {
console.log(response);
console.log(this.proposition1);
this.proposition1 = new PropositionModel();})
}
And as you can see i made it a false by default for the proposition status and I want to change it once i checked the proposition.
Here is an image how it looks for a better issue understanding.
Any help Please ?
StackBlitz
Template: You can either use the native change event or NgModel directive's ngModelChange.
<input type="checkbox" (change)="onNativeChange($event)"/>
or
<input type="checkbox" ngModel (ngModelChange)="onNgModelChange($event)"/>
TS:
onNativeChange(e) { // here e is a native event
if(e.target.checked){
// do something here
}
}
onNgModelChange(e) { // here e is a boolean, true if checked, otherwise false
if(e){
// do something here
}
}
If you add double paranthesis to the ngModel reference you get a two-way binding to your model property. That property can then be read and used in the event handler. In my view that is the most clean approach.
<input type="checkbox" [(ngModel)]="myModel.property" (ngModelChange)="processChange()" />
You can use ngModel like
<input type="checkbox" [ngModel]="checkboxValue" (ngModelChange)="addProp($event)" data-md-icheck/>
To update the checkbox state by updating the property checkboxValue in your code and when the checkbox is changed by the user addProp() is called.
Check Demo: https://stackblitz.com/edit/angular-6-checkbox?embed=1&file=src/app/app.component.html
CheckBox: use change event to call the function and pass the event.
<label class="container">
<input type="checkbox" [(ngModel)]="theCheckbox" data-md-icheck
(change)="toggleVisibility($event)"/>
Checkbox is <span *ngIf="marked">checked</span><span
*ngIf="!marked">unchecked</span>
<span class="checkmark"></span>
</label>
<div>And <b>ngModel</b> also works, it's value is <b>{{theCheckbox}}</b></div>
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);
});
I've got a load of checkboxes that are checked by default. My users will probably uncheck a few (if any) of the checkboxes and leave the rest checked.
Is there any way to make the form POST the checkboxes that are not checked, rather than the ones that are checked?
The solution I liked the most so far is to put a hidden input with the same name as the checkbox that might not be checked. I think it works so that if the checkbox isn't checked, the hidden input is still successful and sent to the server but if the checkbox is checked it will override the hidden input before it. This way you don't have to keep track of which values in the posted data were expected to come from checkboxes.
<form>
<input type='hidden' value='0' name='selfdestruct'>
<input type='checkbox' value='1' name='selfdestruct'>
</form>
Add a hidden input for the checkbox with a different ID:
<input id='testName' type='checkbox' value='Yes' name='testName'>
<input id='testNameHidden' type='hidden' value='No' name='testName'>
Before submitting the form, disable the hidden input based on the checked condition:
form.addEventListener('submit', () => {
if(document.getElementById("testName").checked) {
document.getElementById('testNameHidden').disabled = true;
}
}
I solved it by using vanilla JavaScript:
<input type="hidden" name="checkboxName" value="0"><input type="checkbox" onclick="this.previousSibling.value=1-this.previousSibling.value">
Be careful not to have any spaces or linebreaks between this two input elements!
You can use this.previousSibling.previousSibling to get "upper" elements.
With PHP you can check the named hidden field for 0 (not set) or 1 (set).
My personal favorite is to add a hidden field with the same name that will be used if the check-box is unchecked. But the solution is not as easy as it may seems.
If you add this code:
<form>
<input type='hidden' value='0' name='selfdestruct'>
<input type='checkbox' value='1' name='selfdestruct'>
</form>
The browser will not really care about what you do here. The browser will send both parameters to the server, and the server has to decide what to do with them.
PHP for example takes the last value as the one to use (see: Authoritative position of duplicate HTTP GET query keys)
But other systems I worked with (based on Java) do it the way around - they offer you only the first value.
.NET instead will give you an array with both elements instead
I'll try to test this with node.js, Python and Perl at sometime.
you don't need to create a hidden field for all checkboxes just copy my code.
it will change the value of checkbox if not checked the value will assign 0 and if checkbox checked then assign value into 1
$("form").submit(function () {
var this_master = $(this);
this_master.find('input[type="checkbox"]').each( function () {
var checkbox_this = $(this);
if( checkbox_this.is(":checked") == true ) {
checkbox_this.attr('value','1');
} else {
checkbox_this.prop('checked',true);
//DONT' ITS JUST CHECK THE CHECKBOX TO SUBMIT FORM DATA
checkbox_this.attr('value','0');
}
})
})
A common technique around this is to carry a hidden variable along with each checkbox.
<input type="checkbox" name="mycheckbox" />
<input type="hidden" name="mycheckbox.hidden"/>
On the server side, we first detect list of hidden variables and for each of the hidden variable, we try to see if the corresponding checkbox entry is submitted in the form data or not.
The server side algorithm would probably look like:
for input in form data such that input.name endswith .hidden
checkboxName = input.name.rstrip('.hidden')
if chceckbName is not in form, user has unchecked this checkbox
The above doesn't exactly answer the question, but provides an alternate means of achieving similar functionality.
I know this question is 3 years old but I found a solution that I think works pretty well.
You can do a check if the $_POST variable is assigned and save it in a variable.
$value = isset($_POST['checkboxname'] ? 'YES' : 'NO';
the isset() function checks if the $_POST variable is assigned. By logic if it is not assigned then the checkbox is not checked.
$('input[type=checkbox]').on("change",function(){
var target = $(this).parent().find('input[type=hidden]').val();
if(target == 0)
{
target = 1;
}
else
{
target = 0;
}
$(this).parent().find('input[type=hidden]').val(target);
});
<p>
<input type="checkbox" />
<input type="hidden" name="test_checkbox[]" value="0" />
</p>
<p>
<input type="checkbox" />
<input type="hidden" name="test_checkbox[]" value="0" />
</p>
<p>
<input type="checkbox" />
<input type="hidden" name="test_checkbox[]" value="0" />
</p>
If you leave out the name of the checkbox it doesn't get passed.
Only the test_checkbox array.
You can do some Javascript in the form's submit event. That's all you can do though, there's no way to get browsers to do this by themselves. It also means your form will break for users without Javascript.
Better is to know on the server which checkboxes there are, so you can deduce that those absent from the posted form values ($_POST in PHP) are unchecked.
I also like the solution that you just post an extra input field, using JavaScript seems a little hacky to me.
Depending on what you use for you backend will depend on which input goes first.
For a server backend where the first occurrence is used (JSP) you should do the following.
<input type="checkbox" value="1" name="checkbox_1"/>
<input type="hidden" value="0" name="checkbox_1"/>
For a server backend where the last occurrence is used (PHP,Rails) you should do the following.
<input type="hidden" value="0" name="checkbox_1"/>
<input type="checkbox" value="1" name="checkbox_1"/>
For a server backend where all occurrences are stored in a list data type ([],array). (Python / Zope)
You can post in which ever order you like, you just need to try to get the value from the input with the checkbox type attribute. So the first index of the list if the checkbox was before the hidden element and the last index if the checkbox was after the hidden element.
For a server backend where all occurrences are concatenated with a comma (ASP.NET / IIS)
You will need to (split/explode) the string by using a comma as a delimiter to create a list data type. ([])
Now you can attempt to grab the first index of the list if the checkbox was before the hidden element and grab the last index if the checkbox was after the hidden element.
image source
I would actually do the following.
Have my hidden input field with the same name with the checkbox input
<input type="hidden" name="checkbox_name[]" value="0" />
<input type="checkbox" name="checkbox_name[]" value="1" />
and then when i post I first of all remove the duplicate values picked up in the $_POST array, atfer that display each of the unique values.
$posted = array_unique($_POST['checkbox_name']);
foreach($posted as $value){
print $value;
}
I got this from a post remove duplicate values from array
"I've gone with the server approach. Seems to work fine - thanks. – reach4thelasers Dec 1 '09 at 15:19" I would like to recommend it from the owner. As quoted: javascript solution depends on how the server handler (I didn't check it)
such as
if(!isset($_POST["checkbox"]) or empty($_POST["checkbox"])) $_POST["checkbox"]="something";
Most of the answers here require the use of JavaScript or duplicate input controls. Sometimes this needs to be handled entirely on the server-side.
I believe the (intended) key to solving this common problem is the form's submission input control.
To interpret and handle unchecked values for checkboxes successfully you need to have knowledge of the following:
The names of the checkboxes
The name of the form's submission input element
By checking whether the form was submitted (a value is assigned to the submission input element), any unchecked checkbox values can be assumed.
For example:
<form name="form" method="post">
<input name="value1" type="checkbox" value="1">Checkbox One<br/>
<input name="value2" type="checkbox" value="1" checked="checked">Checkbox Two<br/>
<input name="value3" type="checkbox" value="1">Checkbox Three<br/>
<input name="submit" type="submit" value="Submit">
</form>
When using PHP, it's fairly trivial to detect which checkboxes were ticked.
<?php
$checkboxNames = array('value1', 'value2', 'value3');
// Persisted (previous) checkbox state may be loaded
// from storage, such as the user's session or a database.
$checkboxesThatAreChecked = array();
// Only process if the form was actually submitted.
// This provides an opportunity to update the user's
// session data, or to persist the new state of the data.
if (!empty($_POST['submit'])) {
foreach ($checkboxNames as $checkboxName) {
if (!empty($_POST[$checkboxName])) {
$checkboxesThatAreChecked[] = $checkboxName;
}
}
// The new state of the checkboxes can be persisted
// in session or database by inspecting the values
// in $checkboxesThatAreChecked.
print_r($checkboxesThatAreChecked);
}
?>
Initial data could be loaded on each page load, but should be only modified if the form was submitted. Since the names of the checkboxes are known beforehand, they can be traversed and inspected individually, so that the the absence of their individual values indicates that they are not checked.
I've tried Sam's version first.
Good idea, but it causes there to be multiple elements in the form with the same name. If you use any javascript that finds elements based on name, it will now return an array of elements.
I've worked out Shailesh's idea in PHP, it works for me.
Here's my code:
/* Delete '.hidden' fields if the original is present, use '.hidden' value if not. */
foreach ($_POST['frmmain'] as $field_name => $value)
{
// Only look at elements ending with '.hidden'
if ( !substr($field_name, -strlen('.hidden')) ) {
break;
}
// get the name without '.hidden'
$real_name = substr($key, strlen($field_name) - strlen('.hidden'));
// Create a 'fake' original field with the value in '.hidden' if an original does not exist
if ( !array_key_exists( $real_name, $POST_copy ) ) {
$_POST[$real_name] = $value;
}
// Delete the '.hidden' element
unset($_POST[$field_name]);
}
You can also intercept the form.submit event and reverse check before submit
$('form').submit(function(event){
$('input[type=checkbox]').prop('checked', function(index, value){
return !value;
});
});
I use this block of jQuery, which will add a hidden input at submit-time to every unchecked checkbox. It will guarantee you always get a value submitted for every checkbox, every time, without cluttering up your markup and risking forgetting to do it on a checkbox you add later. It's also agnostic to whatever backend stack (PHP, Ruby, etc.) you're using.
// Add an event listener on #form's submit action...
$("#form").submit(
function() {
// For each unchecked checkbox on the form...
$(this).find($("input:checkbox:not(:checked)")).each(
// Create a hidden field with the same name as the checkbox and a value of 0
// You could just as easily use "off", "false", or whatever you want to get
// when the checkbox is empty.
function(index) {
var input = $('<input />');
input.attr('type', 'hidden');
input.attr('name', $(this).attr("name")); // Same name as the checkbox
input.attr('value', "0"); // or 'off', 'false', 'no', whatever
// append it to the form the checkbox is in just as it's being submitted
var form = $(this)[0].form;
$(form).append(input);
} // end function inside each()
); // end each() argument list
return true; // Don't abort the form submit
} // end function inside submit()
); // end submit() argument list
$('form').submit(function () {
$(this).find('input[type="checkbox"]').each( function () {
var checkbox = $(this);
if( checkbox.is(':checked')) {
checkbox.attr('value','1');
} else {
checkbox.after().append(checkbox.clone().attr({type:'hidden', value:0}));
checkbox.prop('disabled', true);
}
})
});
I see this question is old and has so many answers, but I'll give my penny anyway.
My vote is for the javascript solution on the form's 'submit' event, as some has pointed out. No doubling the inputs (especially if you have long names and attributes with php code mixed with html), no server side bother (that would require to know all field names and to check them down one by one), just fetch all the unchecked items, assign them a 0 value (or whatever you need to indicate a 'not checked' status) and then change their attribute 'checked' to true
$('form').submit(function(e){
var b = $("input:checkbox:not(:checked)");
$(b).each(function () {
$(this).val(0); //Set whatever value you need for 'not checked'
$(this).attr("checked", true);
});
return true;
});
this way you will have a $_POST array like this:
Array
(
[field1] => 1
[field2] => 0
)
What I did was a bit different. First I changed the values of all the unchecked checkboxes. To "0", then selected them all, so the value would be submitted.
function checkboxvalues(){
$("#checkbox-container input:checkbox").each(function({
if($(this).prop("checked")!=true){
$(this).val("0");
$(this).prop("checked", true);
}
});
}
I would prefer collate the $_POST
if (!$_POST['checkboxname']) !$_POST['checkboxname'] = 0;
it minds, if the POST doesn't have have the 'checkboxname'value, it was unckecked so, asign a value.
you can create an array of your ckeckbox values and create a function that check if values exist, if doesn`t, it minds that are unchecked and you can asign a value
Might look silly, but it works for me. The main drawback is that visually is a radio button, not a checkbox, but it work without any javascript.
HTML
Initialy checked
<span><!-- set the check attribute for the one that represents the initial value-->
<input type="radio" name="a" value="1" checked>
<input type="radio" name="a" value="0">
</span>
<br/>
Initialy unchecked
<span><!-- set the check attribute for the one that represents the initial value-->
<input type="radio" name="b" value="1">
<input type="radio" name="b" value="0" checked>
</span>
and CSS
span input
{position: absolute; opacity: 0.99}
span input:checked
{z-index: -10;}
span input[value="0"]
{opacity: 0;}
fiddle here
I'd like to hear any problems you find with this code, cause I use it in production
The easiest solution is a "dummy" checkbox plus hidden input if you are using jquery:
<input id="id" type="hidden" name="name" value="1/0">
<input onchange="$('#id').val(this.checked?1:0)" type="checkbox" id="dummy-id"
name="dummy-name" value="1/0" checked="checked/blank">
Set the value to the current 1/0 value to start with for BOTH inputs, and checked=checked if 1. The input field (active) will now always be posted as 1 or 0. Also the checkbox can be clicked more than once before submission and still work correctly.
Example on Ajax actions is(':checked') used jQuery instead of .val();
var params = {
books: $('input#users').is(':checked'),
news : $('input#news').is(':checked'),
magazine : $('input#magazine').is(':checked')
};
params will get value in TRUE OR FALSE..
Checkboxes usually represent binary data that are stored in database as Yes/No, Y/N or 1/0 values. HTML checkboxes do have bad nature to send value to server only if checkbox is checked! That means that server script on other site must know in advance what are all possible checkboxes on web page in order to be able to store positive (checked) or negative (unchecked) values. Actually only negative values are problem (when user unchecks previously (pre)checked value - how can server know this when nothing is sent if it does not know in advance that this name should be sent). If you have a server side script which dynamically creates UPDATE script there's a problem because you don't know what all checkboxes should be received in order to set Y value for checked and N value for unchecked (not received) ones.
Since I store values 'Y' and 'N' in my database and represent them via checked and unchecked checkboxes on page, I added hidden field for each value (checkbox) with 'Y' and 'N' values then use checkboxes just for visual representation, and use simple JavaScript function check() to set value of if according to selection.
<input type="hidden" id="N1" name="N1" value="Y" />
<input type="checkbox"<?php if($N1==='Y') echo ' checked="checked"'; ?> onclick="check(this);" />
<label for="N1">Checkbox #1</label>
use one JavaScript onclick listener and call function check() for each checkboxe on my web page:
function check(me)
{
if(me.checked)
{
me.previousSibling.previousSibling.value='Y';
}
else
{
me.previousSibling.previousSibling.value='N';
}
}
This way 'Y' or 'N' values are always sent to server side script, it knows what are fields that should be updated and there's no need for conversion of checbox "on" value into 'Y' or not received checkbox into 'N'.
NOTE: white space or new line is also a sibling so here I need .previousSibling.previousSibling.value. If there's no space between then only .previousSibling.value
You don't need to explicitly add onclick listener like before, you can use jQuery library to dynamically add click listener with function to change value to all checkboxes in your page:
$('input[type=checkbox]').click(function()
{
if(this.checked)
{
$(this).prev().val('Y');
}
else
{
$(this).prev().val('N');
}
});
#cpburnz got it right but to much code, here is the same idea using less code:
JS:
// jQuery OnLoad
$(function(){
// Listen to input type checkbox on change event
$("input[type=checkbox]").change(function(){
$(this).parent().find('input[type=hidden]').val((this.checked)?1:0);
});
});
HTML (note the field name using an array name):
<div>
<input type="checkbox" checked="checked">
<input type="hidden" name="field_name[34]" value="1"/>
</div>
<div>
<input type="checkbox">
<input type="hidden" name="field_name[35]" value="0"/>
</div>
<div>
And for PHP:
<div>
<input type="checkbox"<?=($boolean)?' checked="checked"':''?>>
<input type="hidden" name="field_name[<?=$item_id?>]" value="<?=($boolean)?1:0?>"/>
</div>
All answers are great, but if you have multiple checkboxes in a form with the same name and you want to post the status of each checkbox. Then i have solved this problem by placing a hidden field with the checkbox (name related to what i want).
<input type="hidden" class="checkbox_handler" name="is_admin[]" value="0" />
<input type="checkbox" name="is_admin_ck[]" value="1" />
then control the change status of checkbox by below jquery code:
$(documen).on("change", "input[type='checkbox']", function() {
var checkbox_val = ( this.checked ) ? 1 : 0;
$(this).siblings('input.checkbox_handler').val(checkbox_val);
});
now on change of any checkbox, it will change the value of related hidden field. And on server you can look only to hidden fields instead of checkboxes.
Hope this will help someone have this type of problem. cheer :)
You can add hidden elements before submitting form.
$('form').submit(function() {
$(this).find('input[type=checkbox]').each(function (i, el) {
if(!el.checked) {
var hidden_el = $(el).clone();
hidden_el[0].checked = true;
hidden_el[0].value = '0';
hidden_el[0].type = 'hidden'
hidden_el.insertAfter($(el));
}
})
});
The problem with checkboxes is that if they are not checked then they are not posted with your form. If you check a checkbox and post a form you will get the value of the checkbox in the $_POST variable which you can use to process a form, if it's unchecked no value will be added to the $_POST variable.
In PHP you would normally get around this problem by doing an isset() check on your checkbox element. If the element you are expecting isn't set in the $_POST variable then we know that the checkbox is not checked and the value can be false.
if(!isset($_POST['checkbox1']))
{
$checkboxValue = false;
} else {
$checkboxValue = $_POST['checkbox1'];
}
But if you have created a dynamic form then you won't always know the name attribute of your checkboxes, if you don't know the name of the checkbox then you can't use the isset function to check if this has been sent with the $_POST variable.
function SubmitCheckBox(obj) {
obj.value = obj.checked ? "on" : "off";
obj.checked = true;
return obj.form.submit();
}
<input type=checkbox name="foo" onChange="return SubmitCheckBox(this);">
If you want to submit an array of checkbox values (including un-checked items) then you could try something like this:
<form>
<input type="hidden" value="0" name="your_checkbox_array[]"><input type="checkbox">Dog
<input type="hidden" value="0" name="your_checkbox_array[]"><input type="checkbox">Cat
</form>
$('form').submit(function(){
$('input[type="checkbox"]:checked').prev().val(1);
});