Set focus on on ASP.NET MVC model errors - asp.net-mvc

I've got a model that does some validation checking and adds the errors to ModelState:
ViewData.ModelState.AddModelError("mycontrol", "message")
They display fine on the view side, but is there a way to set the focus to the control that corresponds to the validation message? Right now, the page refreshes and stays at the top of the page, so if the error is towards the end of the page, it's not obvious to the user what happened.
Note: Another solution would be for ValidationSummary to show the list of errors at the top of the page, but I've never been able to get it to display anything. All my errors are displayed via ValidationMessage.
Edit: I found my problem with ValidationSummary. The markup I had was:
<% Html.ValidationSummary()%>
which should have been:
<%=Html.ValidationSummary()%>
I'd still like to know how to snap to the field with the error however.

Some jquery goodness to scroll to the first input with an error. The tricky bit is that you have to get the underlying DOM element BEFORE you invoke focus() as the focus() method on a jQuery object fires the focus event instead of giving focus to the element.
<script type='text/javascript'>
$(document).ready( function()
{
var input = $('.input-validation-error:first');
if(input)
{
input.focus();
}
});
</script>

You could use JavaScript to find the input elements on the page that have the MVC validation HTML class (input-validation-error) added, and move the carat to the first one. That /should/ move the screen to that element although I haven't tested it.
A JS library such as jQuery will make this straightforward to do.

Related

ASP.Net MVC Getting hidden field value in javasccript

I have asked this same basic question before several times without a response, but let me try one more time, breaking it down as simple as possible.
I have a strongly-typed view with a hidden field on it.
When the view renders server-side, I am setting the value of the hidden field to a property of the model.
When the view renders client-side, I want to get the value of the hidden field (that was set during the server-side render) and display it in a java script alert box.
This should be a simple thing to do and yet I am unable to make it work. I have set a break-point in the view and I can see that the hidden field is being set to the correct value. But the javascript will not display that value.
The page/view being rendering has been gone to before. At the time I want to display this alert, I am going back to that page and now I want to see the alert.
It is as if the page is being cached, so instead of using the new value for the hidden field it is using the old value (from the first time the page was visited). If the DOM is being cached, how I can prevent that so that each time I visit the page I get the updated values of the page and not the cached ones? What am I doing wrong??
#<input type="hidden" id="hdnShowMsg" value="#Model.ShowMsg" />
<script>
alert($('#hdnShowMsg').val());
</script>
Your script may be firing before your document is fully rendered. Use the jQuery document ready function.
http://api.jquery.com/ready/
<script>
$(function() {
alert($('#hdnShowMsg').val());
});
</script>
Also note that document ready is not supported within a jQuery Mobile document and you may run into problems depending on what part of the DOM you are trying to manipulate.
Use $(document).bind("pageinit", function() {}) instead.
http://jquerymobile.com/demos/1.2.1/docs/api/events.html

making unobtrusive validation work when using Select2 ASP.NET MVC

Select boxes converted to Select2, do not automatically integrate with unobtrusive validation mechanism in ASP.NET MVC framework.
For example, on a form which contains a regular select box (marked as required in model definition), submitting the form while no options have been selected in the select box, will cause the border and background of the select box to take a reddish color, and by using #Html.ValidationMessageFor, error messages, if any, can be displayed beside the box. However if the select box is converted to a Select2 component, then none of the mentioned features work any more. Even the validation error message will not show up.
It seems that the reason for even the validation error message not showing, is because Select2 changes the display CSS property of the original select box to none (display:none), and I guess the unobtrusive validation script does not bother generating error messages for invisible fields.
Any ideas / solutions?
This issue isn't really specific to Select2, but rather to the jQuery unobtrusive validator.
You can turn on validation for hidden fields as highlighted in this answer.
$.validator.setDefaults({
ignore: ''
});
As the comments noted, it didn't work inside an anonymous callback function within $(document).ready(). I had to put it at the top level.
I've run into similar issues with the select2 plugin. I don't know exactly which features you're using specifically, but in my experience, when you set an element as a select2 in the document.ready event, the plugin will change some of the element's attributes on the fly (inspect one of the elements after your page has finished loading - oftentimes you'll see the id and class properties are different than what you're seeing when you view source).
It's difficult to offer more without actually seeing the code, but here's a few ideas to get you started:
First off, obviously make sure you have the a link to your select2.css stylesheet in the header.
Then, since you're talking about form submissions, I'd recommend you examine whether or not you're getting a full postback or submitting via AJAX (if you're using jQueryMobile, you're using AJAX unless you override it in the jquerymobile.js file or set a data-ajax="false" in your form attributes). You can just look at the value returned by Request.IsAjaxRequest() for this. Obviously if you're submitting via ajax, you won't hit the document.ready event and the select2 won't initialize properly and you'd need to figure out a way around that. Try refreshing the page after the submit and see if it renders the select2 component.
Then I'd suggest examining the elements and see if they're not behaving like you'd expect because you're actually trying to work with classes that the plugin has reassigned at runtime. You can either just adjust your logic, or you can dig into the select2 code itself and change the behavior - it's actually fairly well-documented what the code is doing, and if you hop on the Google group for select2, Igor is usually pretty quick to follow up with questions.
like this
$('select').on('select2:select', function (evt){
$(this).blur();
});
$('body').on('change', 'select.m-select2', function () {
$(this).blur();
})

How to make getJSON to update correctly an element after page loaded in jQuery Mobile?

I'm trying to get a getJSON result to update an HTML element on page load, within a jquery mobile loaded website.
Now, I've read I should not rely on ready(), but bind to pageInit. So I tried, but it just won't work. I've tried many other events that could be logical to try within the API event documentation, without any success.
The closest I come to success is after the page is loaded, via ajax, if I refresh the page manually (with the browser's refresh button), getJSON does update the corresponding HTML element. And you guess, it's not what I want to achieve. Here is what the code looks like now, and where it is placed...
<div data-role="page">
<script>
$( '#pageContainer' ).live( 'pageinit',function(event){
//an alert() here does fire right before the page is shown in the browser
//here is the getJSON code.
});
</script>
Now, I need help to try to figure how to make it work. I only want an element X in the page to update with the text returned from a jSON when the page appears in the browser! Like a normal ready() function would have done !
(Maybe it is relevant to specify I'm running RC2 ?)
If you can't use JSONP here, have you tried setting a setTimeout()? You have to trigger a callback after the json object is loaded so timing is essential.

How to set focus of ICEFaces component after initial rendering?

I have a complex ICEFaces XHTML page that renders certain components conditionally, based on flags set as the user enters data on the page. What I'd like to do is direct focus to a certain field as soon as it appears, which may not be during the initial render of the page.
The ICEFaces documentation suggests that I can do this using the focus attribute of the outputBody component. Specifically:
If you setting the initial focus, the focused component must be rendered on first render call, if not then set the focus attribute only when the component gets rendered.
This seems to suggest that I can manipulate the value of the focus attribute at the time that my conditional component gets rendered. However, I don't see any attributes of the inputText component that allow me to change a value at the time the component is rendered.
Am I misreading the documentation? When and where can I alter the value of the focus attribute of outputBody so that my conditionally-rendered field gets the input focus when it appears? Or am I using the wrong tool to solve this problem?
Maybe you can use this
JavascriptContext.applicationFocus(FacesContext.getCurrentInstance(), "form:fieldM");
You can use some Javascript to set focus on an element.
Here's the Java snippet required to do this:
JavascriptContext.addJavascriptCall(FacesContext.getCurrentInstance(),
"document.getElementById('myForm:myTxtBox').focus();");
myTxtBox is the ID of your form element, and myForm is the ID of your form.
You can use this wherever you are changing certain variables' values to render/hide fields.
Due to the fact that I'm using both Seam and ICEFaces, I was not able to invoke Javascript reliably from my server-side Java code. I was, however, able to add the necessary Javascript in-line in my XHTML, within the ui:component that was being conditionally rendered, close to the input field I needed the focus to go to. The relevant section of my XHTML looks like this:
<ice:panelGroup id="textPanelInput" >
<ice:form id="textInputForm" partialSubmit="true" style="vertical-align:middle;">
<ice:inputText id="textInput" valueChangeListener="#{appField.valueChangeListener}"
size="#{appField.fieldDefLengthAsInt}"
value="#{appField.value}"
styleClass="fieldStyle" rendered="#{appField!=null}"
>
</ice:inputText>
<ice:message id="jo" for="textInput" />
</ice:form>
</ice:panelGroup>
<script type="text/javascript">document.getElementById('panelsFields:0:textInputForm:textInput').focus();</script>
The Javascript line at the bottom is the line I added to solve my problem. All of the code above is in a ui:component block that may or may not be rendered, based on other conditions. When this ui:component block is rendered, my Javascript goes with it, and sets the input focus to my desired input field.
ICEfaces supports javascript api which has setting focus function. Thus you may use it like in the next excerpt:
<script type="text/javascript">
jQuery(document).ready(function () {
ice.applyFocus(elementId);
});
</script>
elementId is jsf component clientId.
ICEFaces javascript Api

Changing the hash but not moving the page using jquery ui tabs

I added the following code to change the hash to the tab name:
$("#tabs > ul").tabs({
select: function(event, ui){
window.location.hash = ui.tab.hash;
}
} );
This works fine in FF3 but in IE7 it moves down the page (depending on the tab selected anywhere from somewhere near the top of the page all the way down to the very end of the page).
I tried changing it to:
$("#tabs > ul").tabs();
$("#tabs > ul").bind("tabsshow", function(event, ui) {
window.location = ui.tab.hash;
})
This leads to identical behavior in both IE7 and FF3, which moves the page down to the top of the selected tab.
I would like the tab to be changed, the hash to be updated, but the page not moved at all, which is how it works in FF3 in my first example, but not in IE7.
Thanks.
Notes: JQuery 1.3.1 / JQuery-UI 1.6rc6
If there's an element on the page that has the same id as what you're setting the hash to, for instance you're trying to set the browser hash to #cars and there's already a div#cars on the page, the browser will scroll you down to where that div is.
To my knowledge, there are 3 possible workarounds
1) Change the browser hash to something else such as #thecars.
2) Change your existing markup in some similar manner.
3) On some event, changing the id of your similarly named markup, then changing the browser hash, then rechanging the name of markup back to it's original value should also theoretically work. This is obviously a bad and slow workaround, just thought I'd mention it.
You could try having a "return false;" after you set the window location but I can't be sure.
Unfortunately, your problems won't end there. There are other issues with navigating back and forth across multiple browsers--nothing may change, page may reload, page state might be mangled, javascript may get reinitialized etc.
You may want to have a look at Tabs v2 which uses the History/Remote plugin though it has not been updated for jQuery 1.3+.
This demo is easier to understand. If you look at the javascript source, you'll notice the use of iframes to handle states.
There is also the History Event plugin and the jHistory plugin to achieve what you want.
Would like to hear back how things turns out and what solution you went with.
What Chris suggested worked for me, had no clue even a div could link via the #. So my solution is quite simple, in the show: event handler, I do the following, it's not perfect in that back button won't be in history, but that's another job for BBQ history plugin. All my divs simply have id="tab-cars", id="tab-trucks"... strip out the 'tab-' part and put it into the url hash.
var name = ui.panel.id.substr(4);
location.hash = '#'+name;

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