I'm using a template with custom CSS (.less) for checkboxes (making them appear as "Yes|No", "On|Off", etc.)
Using #Html.CheckboxFor(model => model.BooleanProperty, new { #class="custom-switch" }) results in a checkbox not appearing, at all.
So I got to digging around, found many questions on here with similar issues, but none of the solutions worked for me so far. The solution I'm currently working on is to use a custom EditorFor template. This is rendering the checkbox correctly, however, what I'm experiencing is that if the slider is switched to "NO", it's passing across to the controller as null instead of false, and if it's switched to "YES" it's passing across to the controller as "on".
I know that Html.CheckboxFor renders a checkbox element followed by a hidden input element. What purpose does this serve? Following are rendered HTML from the two methods as well any questions pertaining to that specific :
Straight HTML for Checkbox
::before ::after
When this is passed to the controller, why is the value of BoolProperty "true,false"?
#Html.CheckboxFor(model => model.BoolProperty, new { #class="custom-switch" })
<input checked="checked" data-val="true" data-val-required="The BoolProperty is required." id="BoolProperty" name="BoolProperty" type="checkbox" value="true" class="custom-switch">
<input name="BoolProperty" type="hidden" value="false">
What purpose does the hidden input field play? If I remember right, only the first "BoolProperty" named value would actually be passed to the controller anyways. I can't find anything that would suggest that one updates the other when the value changes, and through testing, I've noticed that the value does not change.
#Html.EditorFor(model => model.BoolProperty, new { #class = "custom-switch" })
<input type="checkbox" checked name="BoolProperty" class="custom-switch">
<label>::before ::after</label>
Why would this pass across the values of "on" or null to the controller? Why not true and false?
The Boolean Editor Template
#model Boolean?
var isChecked = ViewData["checked"] != null && ViewData["checked"].ToString() == "true";
<input type="checkbox" checked="#(isChecked ? "checked" : string.Empty)" name="#name" class="#ViewData["class"].ToString()" />
<label class="lbl"></label>
The hidden field is there to force the field to be included in the form POST even when nothing is checked. Without it, the field is omitted altogether, per the standard. You wouldn't know the difference between a "false" value or a non-existent field.
http://www.w3.org/TR/html401/interact/forms.html
As far as why it uses "on" vs "true", that is something you can control yourself. If you want true/false instead of on/off, use that. "on" is just a default, but not required.
<input type="checkbox" class="checkbox" name="BoolProperty" value="true" />
<input type="hidden" class="checkbox" name="BoolProperty" value="false" />
About the hidden field
I can't find anything that would suggest that one updates the other
when the value changes, and through testing, I've noticed that the
value does not change.
No, it doesn't change. The browsers, then a checkbox is not checked, don't submit anything using that name. So, the hidden propose is to submit the value "false" (with the same name) when the checkbox isn't checked.
When the checkbox is checked (as you said) the posted value is "true,false" (first the value of the checkbox and then the value of the hidden). The MVC binder deals with this string to convert it to true value setting it to the BooleanProperty.
About the on value
It is the default value for the checkbox. See here.
Related
I'm following this article
https://www.w3schools.com/howto/howto_css_custom_checkbox.asp
for a checkbox, but how do I set and get the check value?
As I need to a do a post back with the value.
<label class="container">Accept Offers?
<input type="checkbox" id="Offers" name="Offers"/>
span class="checkmark"></span>
</label>
change your code to this
<input type="checkbox" id="Offers" value="checkedValue" name="Offers"/>
If you see the Request.Form object or query-string (in case of HTTP GET submission) you will see the value, If this is not checked null will be seen or Request.Form will have not that key that belong to Checkbox.
I have a boolean variable and if it is true I want to set some checkboxes to disabled
I was able to make my input text boxes readonly by using this inside my HTML for the text box:
readonly ="<%# myIsReadOnly %>"
But checkboxes don't have that. So wanted to make them disabled if that variable is true.
How do I do that? I am also on VB language.
The example of CheckBox I have is something like this:
<input type = checkbox" name="blah" id="blah"/>
You can manually stick in server-side code to render both attribute and value.
<input type="checkbox" <%= myIsReadOnly ? "disabled='disabled'" : "" %> />
I've been trying to get the default checkbox template written for my Boolean editors and I've run into an issue due to how MVC Razor renders multiple input elements for a single boolean model property.
I have this template defined:
#model Boolean?
<div class="check-box">
#Html.CheckBox("", Model.HasValue && Model.Value)
#Html.LabelForWithoutText(m => m, new object())
</div>
If I manually write out the HTML like:
<div class="check-box">
<input type="checkbox" title="Create?" value="true" name="check" id="chkCreate">
<label title="Create?" for="chkCreate"></label>
</div>
Everything works fine.
But when Razor renders my template on a Boolean property of a model the html is rather different. Due to how MVC renders other hidden inputs for posting booleans back to action methods.
The Razor version looks like this:
<div class="check-box">
<input type="checkbox" value="true" name="GloballyShare" id="GloballyShare" data-val-required="The GloballyShare field is required." data-val="true">
<input type="hidden" value="false" name="GloballyShare">
<label title="GloballyShare" for="GloballyShare"></label>
</div>
The problem is the extra hidden input. I don't want to change this behaviour as that will globally effect how MVC form work by default and I can't think of a way to deal with this in CSS.
So I'm wondering how this could be achieved. You can see a working example of the problem here:
Default CSS3 Checkbox Template in MVC
If you try it then remove the hidden input element and try it again the top most checkbox starts working the same as the bottom checkbox
I've just managed to fix the jsFiddle.
I changed the label selector from a + to a ~ and both checkboxes are now working:
.check-box input[type=checkbox]:checked + label {
Changed to:
.check-box input[type=checkbox]:checked ~ label {
Fixed jsFiddle
It seems this ought to be dead simple, but I'm stuck. I've written some asp.net code that outputs a pair of radio buttons:
<p>
<label for='chkYapper'>Yapper</label>
<input type='radio' name='yapper' id='chkYapper' value='yapper' checked='<%=gblYapperChecked %>' />
<br />
<label for='chkNonYapper'>non-Yapper</label>
<input type='radio' name='Yapper' id='chkNonYapper' value='nonYapper' checked='<%=gblNonYapperChecked %>' />
if (registrationUser.isYapper == 1)
{
gblYapperChecked = "checked";
gblNonYapperChecked = "";
}
else
{
gblYapperChecked = "";
gblNonYapperChecked = "checked";
}
As expected, I get two radio buttons, "Yapper" and "Non-Yapper". However, even when I step thru my code and see that gblYapperChecked is "checked" and gblNonYapperChecked is "", Non-Yapper is always selected by default in the web browser.
What am I doing wrong?
UpdateHere is the HTML code as it actually appears in the browser. "Yapper" should be selected, but "Non-Yapper" appears selected instead.
<p>
<label for='chkYapper'>Yapper</label>
<input type='radio' name='yapper' id='chkYapper' value='yapper' checked='checked' />
<br />
<label for='chkNonYapper'>non-Yapper</label>
<input type='radio' name='yapper' id='chkNonYapper' value='nonYapper' checked='' />
Note that the HTML "checked" attribute is generally determined by being present or not present. See http://www.w3.org/TR/html401/interact/forms.html#adef-checked for the spec.
In particular what this means is that if you want it to be checked you cna have checked, checked=true, checked=checked and so on. So what you want is to not have the checked attribute at all if you don't want the checkbox selected.
I would advise structure such as:
<input type='radio' name='Yapper' id='chkNonYapper' value='nonYapper' <%=registrationUser.isYapper?"":"checked='checked'" %> />
This should eliminate your checked attribute entirely dependant on your isYapper boolean.
The "checked" attribute is weird, it has no value. If a radio button is checked, include the "checked" attribute by itself in the tag. If unchecked, don't do anything. See here:
http://www.htmlcodetutorial.com/forms/_INPUT_TYPE_RADIO.html
Are you setting dblYapperChecked before or after the control is created? Personally, I'd run the radio buttons on the server side and set the checked value on the control directly, but your method should work if the values are set soon enough (try initializing them to the expected values and see if that makes a difference...)
So I've got three RadioButtons, They're not in a RadioButtonList because I need to add some textboxes next to each of them.
I've added a GroupName, and on the front end they behave as expected. ONLY ONE appears checked at a time.
However in the code, if I do:
RadioButton1.Checked = true;
RadioButton2.Checked = true;
RadioButton3.Checked = true;
I would expect only the last one, RadioButton3, to be checked, because they all belong to the same group. This is not the case. All three evaluate to true.... how can that be?
I have to set them explicitly to false... am I missing something?
I think this is the correct behavior although it is not what you might expect.
Consider that a RadioButton is just a CheckBox with some extended functionality to automatically to give that exclusive checking functionality. In the background it is still a checkbox though. See the hierarchy from MSDN:
System.Object
System.Web.UI.Control
System.Web.UI.WebControls.WebControl
System.Web.UI.WebControls.CheckBox
System.Web.UI.WebControls.RadioButton
The output has all items with the attribute checked="checked" output for the input of type="radio". Eg:
<input id="rad1" type="radio" name="Test" value="rad1" checked="checked" /><label for="rad1">1</label><br />
<input id="rad2" type="radio" name="Test" value="rad2" checked="checked" /><label for="rad2">2</label><br />
<input id="rad3" type="radio" name="Test" value="rad3" checked="checked" /><label for="rad3">3</label>
From the Checked property documenation:
Checked (inherited from CheckBox):
Gets or sets a value indicating
whether the CheckBox control is
checked.
So the Checked property acts just like the CheckBox version with no functionality included to look for other controls in the same group and remove them which makes sense since it is a singular control.