I have a drop downdown box and trying to bind the selected account number to fromAccount inside the transfer bean.
I am seeing the value as null in the controller.
<select class="form-control" th:field="${customer.transferBean.fromAccount}">
<option
th:each="fromAccount: ${customer.accountBean}"
th:value="${fromAccount.accountNum}"
th:text="${fromAccount.accountNum}" ></option>
</select>
controller code:
#PostMapping("/accounttransfer")
public String accountTransfer(#Valid CustomerBean customerBean, BindingResult bindingResult, Model model)
Not sure what i am missing. I am using spring boot and thymeleaf for html.
Thanks.
You are using wrong syntax
"th:field="${customer.transferBean.fromAccount}"
for specifying bind field, you should use *{} not ${} and only combined with th:object on parent or ansestor level.
More details on bindingm you can find in Thymeleaf docs
Related
As per my understanding, model attributes are associated with every request and they can not survive multiple requests, until we add them as flashAttributes.
I have a simple controller method which shows a couple of options to user to select from. However, those options are being attached to thymeleaf template using model attributes.
<div class="input-group mb-3" th:each="ingredient : ${recipes.ingredients}">
<div class="input-group-prepend">
<div class="input-group-text">
<input aria-label="Checkbox for following text input" name="ingredient"
th:value="${ingredient.name}" type="checkbox">
</div>
<input aria-label="Text input with checkbox" class="form-control" disabled
th:value="${ingredient.name + ' ' + ingredient.price + 'Rs.'}"
type="text">
</div>
assume "recipes" as model attribute here, which was injected to modelMap inside the controller.
when bean validation fails, below line exectutes.
if (errors.hasErrors()) return "selectItem";
and selectItem template is re-rendered, but whatever model attributes I have set inside previous controller vanishes.
I have solved this using a #ModelAttribute method inside the same controller to set model attributes for every HTTP requests for the specific controller(until it is not in controllerAdvice for global effect).
I am being confused if I am on right way || is there any elegant way to achieve this.
Setting Model attribute for every request is kind of overhead, when I want them to be available for handful of request mappings.
When you say:
selectItem template is re-rendered, but whatever model attributes I
have set inside previous controller vanishes.
You mean that when the page reloads due to validation errors, your model attributes are no longer existing and Thymeleaf probably returns an error, because it cannot find them, correct?
If this is the case, then you have to manually prepare the same model attributes within the if statement (i.e. adding them to your MapModel):
if (errors.hasErrors()) {
map.addAttribute("recipes", recipes);
return "selectItem";
}
Alternatively, if you need this model attribute also on other pages in your controller, you can reduce code duplication by declaring a method with the ModelAttribute annotation, which will add this attribute to all models in your controller:
#ModelAttribute("recipes")
public Recipes loadRecipes() {
// get list of Recipes
return list;
}
sorry for a dumb question but i can't understand quite what happens, and if it is what i suspect.. well i am really at a loss.
i am using spring boot + thymeleaf + materialize css to show and validate a form.
now what i don't meet in many examples that i see is this case:
some form fields are pre-filled and should seem disabled to the client, showing their pre-filled values. this pre-filling takes place in the controller, while i handle some other request, and redirect to this view
i am binding a pojo to the form using th:object like this
<form id="register_form" action="#" th:action="#{/showform}" th:object="${userInfo}" method="post">
<div class="input-field">
<label th:text="#{label.surname}" for="surname"></label>
<input type="text" th:field="*{surname}" id="surname" th:attr="value=${userInfo.surname}" />
</div>
<div class="input-field">
<label th:text="#{label.name}" for="givenname"></label>
<input type="text" th:field="*{givenname}" id="givenname" th:attr="value=${userInfo.givenname}" disabled="disabled" />
</div></form>
and getting it in the POST handler of the controller like this:
#RequestMapping(value = {"/showform"}, method = RequestMethod.POST)
public ModelAndView submitFormPage(#ModelAttribute("userInfo") #Valid UserInfo userInfo,
BindingResult bindingResult, RedirectAttributes redir)
{
ModelAndView mview = new ModelAndView();
if (bindingResult.hasErrors())
{
// show form again with error messages
mview.addObject("userInfo", userInfo);
mview.setViewName("/showform");
}
else
{
// ...
}
return mview;
}
RedirectAttributes is there for some other reason. As you can see, there are two elements on a form, and first one is enabled, and the second disabled.
Their values are populated correctly with pre-filled values from the POJO i pass to the view via the ModelMap. i can also trace it in the GET handler.
but the ModelMap i get back from the view contains the aforementioned POJO with NULL values in place of the elements that are bound to the disabled controls. i would expect them to be populated by the contents of the value attribute, even though those controls are disabled. the enabled controls carry their values alright.
or is it just that disabled controls simply are not included in the postback? if this is the case, how would you suggest me to do it? some suggested adding an obscure CSS that would "fake" the behaviour of a disabled control. or have i missed something in the general wiring?
i think with horror of possible workarounds - but i must be doing something wrong.. th:attr was one of the workarounds i tried, but it doesn't seem to do the trick. i also tried using th:id and th:disabled but it didn't help either.
There is a misunderstanding here I think about the use of disabled.
A readonly element is just not editable, but gets sent when the
according form submits. a disabled element isn't editable and isn't
sent on submit. Another difference is that readonly elements can be
focused (and getting focused when "tabbing" through a form) while
disabled elements can't.
More detailed comparison
So to answer your question: you should opt for readonly if you want to bind your attributes to your pojo and still the user can't edit them.
I have a form and post data into controller via Thymeleaf:
<form action="lia.html" th:action="#{/lia}" th:object="${myRequest}" method="post">
At another place of my html page, if a user click a particular button, I want to modify that object and send it to same controller.
I have already that object which has been initialised. Button is not a part of any form. How can I send that object into a controller with Thymeleaf.
PS: I know that I can send it via Javascript or put such buttons into a form but I want to learn the Thymeleaf way.
I think the only similar approach to what you're looking for is using bind with Spring EL expressions.
Thanks to the advanced form-field binding capabilities in Spring MVC,
we can use complex Spring EL expressions to bind dynamic form fields
to our form-backing bean. This will allow us to create new Row objects
in our SeedStarter bean, and to add those rows’ fields to our form at
user request.
Take a look the next link, where is good example:
http://www.thymeleaf.org/doc/tutorials/2.1/thymeleafspring.html#dynamic-fields
The button
<button type="submit" name="removeRow"
th:value="${rowStat.index}" th:text="#{seedstarter.row.remove}">Remove row</button>
Request Mapping
#RequestMapping(value="/seedstartermng", params={"removeRow"})
public String removeRow(
final SeedStarter seedStarter, final BindingResult bindingResult,
final HttpServletRequest req) {
final Integer rowId = Integer.valueOf(req.getParameter("removeRow"));
seedStarter.getRows().remove(rowId.intValue());
return "seedstartermng";
}
I have checkboxes tag in my web application with spring mvc. Checkboxes are created from a map in controller like this:
Map demOrgs = createMap();
model.addAttribute("demOrgs", demOrgs); // example : (1, my-description)
1 --> will be value of checkbox
my-description --> will be label of checkbox
In my jsp :
<form:form commandName="myBean" method="POST" >
<form:checkboxes items="${demOrgs}" path="demOrg" element='div class="checkboxes"' />
</form:form>
My bean has only one field :
String demOrg;
When I send the form demOrg attribute has the value of checkboxes clicked, for example: (1,5,8)
I store myBean in session, when I go to the next step in my application. But when I return, I want the checkboxes were checked, still checked and isn't that way.
When the bind value of checkbox is a boolean value, allways work but I'm binding a custom value :
<input id="demOrg1" type="checkbox" value="2" name="demOrg">
<label for="demOrg1">My label description</label>
<input id="demOrg2" type="checkbox" value="3" name="demOrg">
<label for="demOrg2">My label description 2</label>
.....
Does anyone know how to do this?
thanks to all!!
What does the signature of your controller method look like? Are you including myBean as a method signature argument, annotated with #ModelAttribute ?
Something like:
#RequestMapping(......)
public String myController (#ModelAttribute MyBeanType myBean, Model model) {
Map demOrgs = createMap();
model.addAttribute("demOrgs", demOrgs);
model.addAttribute(myBean);
}
Optionally you can annotate the method parameter with #Valid as well if you are using JSR-303 bean validation .
I think the trick is to make sure your demOrg property is actually a collection. Check out the
checkbox reference here. In particular, the text that says:
Typically the bound property is a collection so it can hold multiple values selected by the user.
Though "myBean" is stored in the session, isn't it reloaded again from the database when the controller is ran?
I'm new to Spring and little confused of how to use beans for populating and retrieving values to/from the view.
Here is what I'm doing now.
In the controller I'm initializing two beans xxxMain.java and xxxView.java. I'm using xxxMain.java to retrieve values FROM the view and xxxView.java for pre-populating the view.
Here is my controller
#RequestMapping(value = "accounting", method = RequestMethod.GET)
public String showPage( Model model) {
XXXMain xxxMain = new XXXMain();
XXXView xxxView = new XXXView();
service.loadXXXForm(xxxMain, xxxView);
model.addAttribute("xxxMain", xxxMain);
model.addAttribute("xxxView", xxxView);
return "admin/xxx";
}
So as I'm using the xxxMain.java for retrieving I'm coding the jsp like this.
<form:form modelAttribute="XXXMain" method="post" action="/app/home/save">
</form:form>
also I'm using Spring tags, like
<form:input path="name" size="15"/>
Now, when the fields in the view are empty, all is fine, but when I have to pre-populate the fields, I'm not sure what approach to take as
<form:input path="name" size="15"/>
does not has a value attribute to populate the field. So what I have done is populate the XXXMain.java class along with the XXXView.java class with the default values, as you can see in the controller code snippet. That way values are pre-populated when view is first loaded. But I'm not sure if I'm doing the right thing by populating the xxxMain.java file which in fact should only contain the user entered values.
How can I improve this design?
Thanks a lot.
Ravi
Here is an example I wrote which might help steer you right.