When you start an ASP.NET MVC project in Visual Studio 2008, you get a fully loaded site template, including login forms and the like. In the default form to login, you will find this in the markup...
<%= Html.CheckBox("rememberMe") %>
When you view the source in the browser, you will see that this renders to...
<input id="rememberMe" name="rememberMe" type="checkbox" value="true" />
<input name="rememberMe" type="hidden" value="false" />
What is the purpose of this hidden field, and the default values? Is there a reason for this? Makes no sense to me.
This is the comment from the ASP.NET MVC source:
// Render an additional <input type="hidden".../> for checkboxes. This
// addresses scenarios where unchecked checkboxes are not sent in the request.
// Sending a hidden input makes it possible to know that the checkbox was present
// on the page when the request was submitted.
In short: unchecked checkboxes (values) are not sent in the request. If the checkbox is unchecked then the value from the hidden input will be send in the request.
Related
If you've ever looked at what ASP.NET MVC actually renders when you use #Html.CheckBoxFor, then you've seen that each checkbox you request to be rendered actually results in the emission of not one but two input tags. One is the "true" value checkbox, and the other is for "false." The latter input is of type "hidden".
Generally this doesn't cause problems if you're using ASP.NET MVC correctly. You wouldn't notice the input doubling unless you tried to, for example, do something directly with Request.Form(e.g. Why does ASP.NET MVC Html.CheckBox output two INPUTs with the same name?)
My question, though, is how screen readers deal with this. For example, can they be relied upon to correctly report only the visible checkbox to the site user?
Screen readers will ignore hidden inputs.
Given the example you cite in your comment, it returns this code:
<div class="col pure-u-xl-1-3 pure-u-lg-1-3 pure-u-md-1 pure-u-sm-1 pure-u-xs-1">
<label>Home Club Newsletter</label>
<input checked="checked" … id="newsletter" name="JoinHomeClub" type="checkbox" value="true">
<input name="JoinHomeClub" type="hidden" value="false">
<span class="checkbox-label">Yes, please sign me Up!</span>
</div>
Right off the bat there is a problem here because the <label> is not associated with the control, and the visible text that is next to the checkbox is not associated with the field.
When I access the field in NVDA, all it says is "checkbox checked". There is no accessible name at all.
But to your question…
Your question was related to the <input type="hidden">. As #SLaks said, screen readers ignore <input type="hidden">. The fact that they have the same name value is no problem. If they had the same id value, then you would have a problem (how it would manifest in a screen reader depends on things and stuff).
I am using Sitecore 7.1. I created one search page and created a textbox by using the Web Form For marketer in it. On button click I want catch the text box value in a new page name search-result. How can I catch the WFFFM text box value in New page? I Don't want use JavaScript click event and query string.
<form class="search-form" action="/searchresults" method='get' >
<label><input type="text" name="searchText" id="searchText" placeholder="#placeholderText"></label>
<input type="submit" name="submit" value="" class="#cssClass">
</form>
But i am getting below type of URL
http://www.xyz/searchresults?searchText=searchTextHere&submit=
Can you capture the "onsubmit" event and update the URL to whatever you need using Javascript? You only said not to use onclick event. I'm assuming that you may want to have /searchresults/ as a result. Of course, I assume that your routes are set for this and searchresults can process this correctly.
i am new in MVC and try to learning through googling & online tutorial.
i search Form binding with Model sample in MVC and got many sample code but i am not getting a sample code for a complete form where all kind of html controls are used like
checkbox
radiobutton
listbox control
drodownlist
textarea
hiddenfields
checkboxlist
radiobuttonlist etc
and all controls should be bind through model with server side and client side both kind of validation. form should have two textbox one dropdown, 3 checkboxes and 2 radio button, one listbox control and if possible provide guide line to work with checkboxlist & radiolist.
if anyone knows that kind of url then plzz inform me or if possible please give me a sample code of a complete form where all the above controls will be there with model binding and validation. thanks
in the Views there is a helper called Html you can use it in the view like #Html
there are all things that you wanted, for example
#Html.HiddenFor
#Html.RadioButtonFor
#Html.TextAreaFor
and so on
search for asp.net mvc Html helpers
another smaple
#Html.CheckBox("sameName")
#Html.CheckBox("sameName")
#Html.CheckBox("sameName")
#Html.CheckBox("sameName")
it will produce this html
<input type="checkbox" name="sameName" />
<input type="checkbox" name="sameName" />
<input type="checkbox" name="sameName" />
<input type="checkbox" name="sameName" />
take a look at this website
Have a look here:
It Explains,
Rendering a Form in ASP.NET MVC Using HTML Helpers
http://msdn.microsoft.com/en-us/library/dd410596%28v=vs.100%29.aspx
http://stephenwalther.com/archive/2009/03/03/chapter-6-understanding-html-helpers
I am working with a struts2 based application
Inside my JSP page for form submission is it mandatory to use s:form (Predefined struts component )
Because when i tried this way it worked (calling the Action class under struts.xml )
<s:form action="HelloWorld" >
<s:submit />
</s:form>
But When I tried to use normal form submission as shown
<form action="HelloWorld">
<input type="Submit"/>
</form>
It isn't working , it gave me 404 error .
please tell me is it mandatory to use and for data submission ??
A struts form action and an HTML tag form action are different. You can use a standard HTML form tag with struts if you create a struts specific URL for example (off the top of my head):
if using in multiple places, generate the url in and call like this -
<s:url id="myActionUrl" action="HelloWorld" />
<form action="<s:property value="%{myActionUrl}" />">
<input type="Submit"/>
</form>
or using in a single instance -
<form action="<s:url id="myActionUrl" action="HelloWorld" />">
<input type="Submit"/>
</form>
You can often look at the page source in your browser to see what Struts generates and recreate it manually like this. You will often end up using additional struts tags such as property to retrieve values from your value stack, but it is useful at times, for instance when generating JavaScript code dynamically.
No, it's not mandatory to use any of the S2 tags, but as Russell says, you need to duplicate the correct action URL.
You also need to be a little careful when mixing-and-matching S2 form tags with non-S2 HTML form tags, because the default S2 theme adds additional HTML markup to the page; they don't just create form tags--the default theme uses table tags to lay out the form.
You can use s:form for form and
<input type="Submit"/>
can be replaced by
<button type="submit"/>
It's not about which to use,it is what you want from it.Struts2 tags provides additional capabilities to the form.
Please go through below two links to get the diffrence
1] http://struts.apache.org/release/2.1.x/docs/form-tags.html
2] http://www.w3schools.com/tags/tag_form.asp
some facilities such as namespace,tooltip,tooltipIconPath and many are provided by struts2 tags.
I am using an id value that I pass in a hidden field. When the user submits the form I need the hidden field for my update. After the update, a new value is placed in the hidden field in the model and sent back to the view. What seems so strange is the helper always uses the first value, never updates. For example, look at the following from the View:
<%: Html.Hidden("MyId",Model.MyId) %>
<%: Model.MyId %>
First time in a look at the source in the browser yields:
<input type="hidden" id="MyId" name="MyId" value="1" />
1
** submit back to controller and model updates the MyId property to 2.
Back at the browser I now find:
<input type="hidden" id="MyId" name="MyId" value="1" />
2
The very same model property has different values! The helper method is somehow grabbing it from a prior model instance or something?
Any help greatly appreciated on what I am not understanding. BTW..get the same behavior with Html.TextBox and Html.TextBoxFor.
Thanks.
That's how HTML helpers work and it's by design. When binding they will first look at the value in the GET/POST request to see if the value is present and after that in the model. If a value is found in the request they will simply ignore the value you set in the model.
Normally you are not supposed to modify the data sent in the request inside your controller action. But if anyhow you decide to do it you will need to either roll your own helper or simply:
<input type="hidden" name="MyId" value="<%= Model.MyId %>" />