I want to create a hidden input field:
<input type="hidden" th:value="${map.version} name="version"/>
Problem:
version maybe a non existing attribute yet (I am not talking about null!).
Right now I am getting an Exception Property or field 'version' cannot be found on object
What I need:
If it does not exist, th:value statement maybe ignored or tag removed
CLARIFICATION:
map comes from Spring Controller in a handler-method:
#PostMapping("/new")
public String handleMapFormSubmit(
#ModelAttribute("map") #Valid AddMapCommand command, BindingResult result ) {
if ( result.hasErrors() ) {
return "map-form";
}
// do some stuff
return ".....";
}
Problem is that map (AddMapCommmand) in this handler-method does not contain the version attribute. In another handler-method (UpdateMapCommand) it does. The whole point is to reuse the map-form thymeleaf template in both scenarios which are almost similar.
You can try the instanceof operator to be used only for the object that contains the property:
<input type="hidden"
th:if="${map instanceof T(my.project.UpdateMapCommand)}"
th:value="${map.version} name="version">
For future reference, it is extremely confusing using a variable like map and not have the reader interpret it as a java.util.Map. You should change your map variable name to make it less confusing, or at least for the purpose of asking the question on StackOverflow.
Related
I try to pass an object to th:onclick.
When I pass a string(afficherDetails() function), everything is ok
When I pass an object(afficherDetails2() function), in the called function the object seems ok but it is empty.
function afficherDetails(employee) {
console.log("afficher Details");
document.getElementById("detailledFirstNameDataLabelId").textContent = employee.firstName;
document.getElementById("detailledLastNameDataLabelId").textContent = employee.lastName;
document.getElementById("detailledAddressDataLabelId").textContent = employee.address;
document.getElementById("detailledTitleDataLabelId").textContent = employee.title;
document.getElementById("detailledManagerDataLabelId").textContent = employee.manager;
}
function afficherDetails2(name) {
console.log("afficher Details");
document.getElementById("detailledFirstNameDataLabelId").textContent = name;
}
<td><button th:data-parameter1="${employee}" th:onclick=" afficherDetails(this.getAttribute('data-parameter1')) ">details</button></label></td>
<!--td><button th:data-parameter1="${employee.firstName}" th:onclick=" afficherDetails2(this.getAttribute('data-parameter1')) ">details</button></label></td-->
</tr>
Is it a correct behavior ? Can't we pass a complex object and we can only pass simple object?
thanks for your answer
Short answer:
You can pass a complex object to a HTML attribute - but it will be reduced to a string by the object's toString() method.
Therefore, in your case, an attempt to do the following in JavaScript...
var something = employee.firstName;
...will do nothing because the function is passed a string not an object - and therefore employee.firstName will be undefined in JavaScript.
Longer answer:
Bear in mind a couple of points:
A HTML attribute expects to contain a string:
<button th:data-parameter1="SOME VALUE IN HERE" ... >
So, the attribute data-parameter1 will be populated by Thymeleaf using a string.
All Thymeleaf processing happens on the server. Thymeleaf removes all its processing directives from the template and replaces them with valid HTML. Your JavaScript does not have access to the original Java object - just to whatever representation of that object was added to the HTML by Thymeleaf.
Let's assume you use something such as:
th:data-parameter1="${employee.firstName}"
Assuming employee.firstName evaluates to a string (John) then that is what Thymeleaf will use to produce this:
data-parameter1="John"
But if you try this:
th:data-parameter1="${employee}"
Assuming employee is your custom Java bean, then Thymeleaf will call its toString() method to use as the string.
If you have not defined a toString() method in your Employee class, then the underlying Object.toString() method will be used - and you will see something like the following - a string representation of the unique object, based on the object's name and hash code:
data-parameter1="org.yourpackage.Employee#bcb8097"
You can provide your own implementation of toString() in your Employee class to provide more useful information. But it has to be a string which can be placed in a HTML attribute.
For example, if you pass an ArrayList to the button:
List<String> names = Arrays.asList("John", "Mary");
and:
th:data-parameter1="${names}"
then your HTML button will contain this:
data-parameter1="[John, Mary]"
because [John, Mary] is the result of how ArrayList has implemented its toString() method.
You can send a certain Java objects directly to JavaScript - see JavaScript serialization. But that is probably off-topic for this question.
One extra note: In the following:
th:onclick="afficherDetails(this.getAttribute('data-parameter1'));"
You are using th:onclick - but there are no Thymeleaf expressions in the attribute, so there is nothing for Thymeleaf to process. You can just use:
onclick="afficherDetails(this.getAttribute('data-parameter1'));"
Sorry if this is an obvious question, but I didn't had much luck so far.
I am having an input of a submit type in my View:
<input type="submit"
value="Remove Question"
class="btn btn-outline-danger"
formaction=#Url.Action("Survey_RemoveQuestion",
new Survey_Question_Wrapper() {
Survey = Model,
Question = Model.Questions[i] })/>
In my controller I have a handler, which looks like this:
public ActionResult Survey_RemoveQuestion(Survey_Question_Wrapper s)
{
s.Survey.Questions.Remove(s.Question);
return View("SurveyEdit", s.Survey);
}
The Survey_Question_Wrapper has 2 constructors: a default empty one and the one, who accepts 2 parameters and assigns them to fields.
The problem which I am struggle with, is that the Survey_RemoveQuestion method
is invoked with an object, build with the default constructor, so his fields are null's.
I believe there is something obvious I am missing. Many thanks in advance.
No, the problem is not relevant with Survey_Question_Wrapper constructors. You are trying to pass the complex types to controller via GET. You can't send the complex types directly like that.
You should serialize it and send it as string. (I used Json.Net, you can use another library)
<input type = "submit"
value="Remove Question"
class="btn btn-outline-danger"
formaction=#Url.Action("Survey_RemoveQuestion",
new
{
s = JsonConvert.SerializeObject(new Survey_Question_Wrapper
{
Survey = Model,
Question = Model.Questions[i]
}
)
})/>
And controller part looks like;
public ActionResult Survey_RemoveQuestion(string s)
{
//Deserialize it
var obj = JsonConvert.DeserializeObject<Survey_Question_Wrapper>(s);
obj.Survey.Questions.Remove(obj.Question);
return View("SurveyEdit", obj.Survey);
}
Also, if you want to send complex types to server, its proper way to perform it using POST instead of GET.
I've got an issue with my fieldset in Zend Framework 2.
The user is able to save his personal data over a form. If he already save this, they should be prefilled with the data from database. This worked fine as it was only a form, but I need the address data in a fieldset, so that I can use it at other parts of my program. Now the input fields stays empty.
At the beginning, I fill the personal data in a session. My data looks like this:
object(Application\Model\Product\PersonalData)#247 (3) {
["tel":protected]=> string(0) ""
["birthday":protected]=> string(10) "2013-01-01"
["address":protected]=> object(Application\Model\Account\Addresses)#248 (15) {
["firstname":protected]=> string(5) "Ernie"
["surname":protected]=> string(6) "Muppet"
...
}
}
As you can see, the data is already bind to the given objects, PersonalData as main, and Addresses for the fieldset. This seems to work then.
Then I put it in my form:
$oForm->setData($oForm->getHydrator()->extract($_SESSION->getPersonalData()));
return new ViewModel(array('form'=>$oForm));
The addressFieldset has a hydrator and a binding, which does work, because all objects are perfectly filled. The only problem is, that when I open the page, the input-fields are empty, only birthday and telephone are filled, which are directly on the form
My form implements the address-fieldset like this:
$addressFieldset = new AddressFieldset($lang);
$addressFieldset->setUseAsBaseFieldset(true);
$addressFieldset->setName('address');
$this->add($addressFieldset);
I think that it might be just a problem with the correct addressing of my fieldset, but I can't explain why it would be filled correctly after posting the data then. All I want is that he fill the setData in my Fieldset.
I hope you understand my question and could help me.
Thanks a lot,
Svenja
EDIT:
I analysed it a bit more now, it's very strange and I don't know what went wrong.
When I debug I can see that $fieldset->getValue() returns all data I need. So I thought that the binding might be wrong and I did this to debug it step by step:
$values = $this->form->get('address')->getValue();
$addressFieldset = $this->form->get('address');
$aValues = $addressFieldset->getHydrator()->extract($values);
$addressFieldset->bindValues($aValues);
I went to the Fieldset.php and bindValues does perfectly what it should (it is only a recapitulation anyway(?)), call the hydrator and fill my object. But if I show in the elements, all values are NULL.
I already checked my elements twice. The only different between the model and the elements is a different order of declaration. I call the method setUseAsBaseField(true) in the fieldset and the form, too. I can't understand why the data is in values but not in elements.
It's very strange, because I have something and it good work. Are you confident that the expression $_SESSION->getPersonalData() to return the desired result? You are using a very strange session.
http://framework.zend.com/manual/2.1/en/modules/zend.session.container.html
To EDIT (I'm sorry my english):
You can use different types of hydrator, for example
ArraySerializable (by default, your entity must have getArrayCopy()
and exchangeArray() methods, in your case) ArraySerializable is the hydrator by default.
First you have to bind a form with entity $form->bind(new Entity()); The entity will bind to the base fieldset. If the base fieldset not specified, the entity will bind with the form, because the form inherits fieldset. If the entity is an aggregate, ie, its properties contain another objects, for each of these objects should be your fildset.
In constructor this children fieldsets you should use
$this->setObject(new MyChildrenEntity());
As a result, the entity properties will be extracted to the form
elements.
After that, you should only work with the form, but not with its
elements or fieldsets.
You can pass any data in the form, so form elements will get this
values. $form->setData($this->getRequest()->getPost()); This method use internal populateValues() method. If the form has elements with an appropriate name, they will be assigned to these values. If the form has fieldsets, they will also be transferred to these values.
As long as the form fails to validate, the entity of these values
will not be assigned. These values are assigned to entities only
in case of successful verification. IsValid () method uses the
internal method bindValues () if the validation was successful.
After successful validation, you can get the entity using getData()
method $entity = $form->getData();
P.S.: If you are doing a complex "haсk", do not be offended by this simple explanation.
I finally found the solution!
At first, this link helped me:
Populating fieldsets
I didn't integrate the fieldset Input-Filter in the Form Input Filter.
But that wasn't all I have to do. My Form-Datamodel looks like this:
interface IPersonalData
{
public function getTel();
public function getBirthday();
public function getAddress();
public function setTel($tel);
public function setAddress(IAddresses $address);
public function setBirthday($birthday);
}
This is only the interface, but Address is an object. And that is the problem. When the form tries to fill the fieldset, he only accept arrays. So I have to extract my object in the getter-method to an array.
I don't think that this is very useful, because I normaly want to get my object with this method. So I write a method "getAddressAsArray()" which looks like this:
public function getAddressAsArray()
{
$oAddressHydrator = new AddressHydrator();
if(isset($this->address))
{
return $oAddressHydrator->extract($this->address);
}
return array();
}
The extract-method of my hydrator changed like this:
public function extract($object)
{
if(!$object instanceof IPersonalData)
{
throw new \InvalidArgumentException('$object must be an instance of Application\Model\Product\IPersonalData');
}
return array(
'telephone' => $object->getTel(),
'address' => $object->getAddressAsArray(),
'birthday' => $object->getBirthday(),
);
}
I'm still new to SpringMVC (and jstl for that matter). I'm trying to populate options in a select from a list of objects. I've found a way to do it using c:forEach, but I keep thinking there HAS to be a way to make the form:options method work.
I've browsed around, and about the closest thing I can find to official documentation on the items attribute is here >> http://static.springsource.org/spring/docs/2.0.x/reference/spring-form.tld.html#spring-form.tld.options
It says the items attribute is for
"The Collection, Map or array of objects used to generate the inner 'option' tags"
My confusion is what kind of Collection, Map, or array of objects it's looking for. What format do they need to be in? Is it looking for a Collection or array of type String specifically? Can I use
List<MyObject>
and if so, what would MyObject have to have in it in order for this to be valid (i.e. methods, variables)?
Currently, when I try to use MyObject, I get an exception that says -
ConverterNotFoundException: No converter found capable of converting from type com.example.MyObject to type java.lang.String
Do I need to make a converter? Where would that go? How would that work? I've googled that error message and haven't really turned up anything specific to what I'm trying to do... (Most are results about Roo)
the MyObject class looks like this:
public class MyObject{
private String company;
private Customer customer;
private Address customerAddress;
public String getCompany() {
return company;
}
public void setCompany(String company) {
this.company = company;
}
public Customer getCustomer() {
return customer;
}
public void setCustomer(Customer customer) {
this.customer = customer;
}
public Address getCustomerAddress() {
return customerAddress;
}
public void setCustomerAddress(Address customerAddress) {
this.customerAddress = customerAddress;
}
}
and I'm trying to use it as such:
<form:select path="myObjectList">
<form:option value="0"/>
<form:options items="myObjectList" />
</form:select>
Does anyone know specifically what is incorrect about this method? Or, should I be using a
List<String>
to accomplish what I'm doing?
EDIT here's the stack trace >> http://pastebin.com/2c5XBCmG
The Spring Documentation says this about the items attribute of the form:options tag:
The items attribute is typically populated with a collection or array
of item objects. itemValue and itemLabel simply refer to bean
properties of those item objects, if specified; otherwise, the item
objects themselves will be stringified. Alternatively, you may specify
a Map of items, in which case the map keys are interpreted as option
values and the map values correspond to option labels. If itemValue
and/or itemLabel happen to be specified as well, the item value
property will apply to the map key and the item label property will
apply to the map value.
In a nutshell, if you need to use a List of your Custom Beans as the items attribute you need to use also the itemValue and itemLabel attributes. Personally, I'll prefer using Maps -LinkedHashMap instances speciffically- for populating my select tags, but that's a matter of taste.
Adapting an example from the Spring Documentation, your code should look like this:
<form:select path="commandAttribute">
<form:option value="-" label="--Please Select"/>
<form:options items="${countryList}" itemValue="company" itemLabel="company"/>
</form:select>
I'm using the company attribute as both itemValue and itemLabel, but you're free to choose the attributes that fit your requirements.
Usualy I am doing it with spring tag like this :
<springform:select path="myObjectList" id="selected_company">
<springform:option value="0" label="--- Select One ---"></springform:option>
<springform:options items="${myObjectList}" itemValue="company" itemLabel="company"></springform:options>
</springform:select>
don't forget including the namespace declaration :
xmlns:springform="http://www.springframework.org/tags/form"
I have been trying to use one View for updating an object and all its child collections (based on one-to-many relationships in an SQL Server database with an Entity Framework model).
It was suggested I should use AutoMapper, and I tried that and got it to work. (see Trying to use AutoMapper for model with child collections, getting null error in Asp.Net MVC 3 ).
But the solution is really hard to maintain. And when I try the simple one I had to begin with, using an entity object directly as the model (a "Consultant" object, the parent of all the child collections), I am able to get all the correct changed data back in the POST, and I can use UpdateModel to get them, including child collections. Simple. Granted, UpdateModel only worked after creating a custom model binder from a tip here at SO:
From my custom model binder:
public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
{
bindingContext.ModelMetadata.ConvertEmptyStringToNull = false;
return base.BindModel(controllerContext, bindingContext);
}
protected override void SetProperty(ControllerContext controllerContext, ModelBindingContext bindingContext, PropertyDescriptor propertyDescriptor, object value)
{
ModelMetadata propertyMetadata = bindingContext.PropertyMetadata[propertyDescriptor.Name];
propertyMetadata.Model = value;
string modelStateKey = CreateSubPropertyName(bindingContext.ModelName, propertyMetadata.PropertyName);
// Try to set a value into the property unless we know it will fail (read-only
// properties and null values with non-nullable types)
if (!propertyDescriptor.IsReadOnly)
{
try
{
if (value == null)
{
propertyDescriptor.SetValue(bindingContext.Model, value);
}
else
{
Type valueType = value.GetType();
if (valueType.IsGenericType && valueType.GetGenericTypeDefinition() == typeof(EntityCollection<>))
{
IListSource ls = (IListSource)propertyDescriptor.GetValue(bindingContext.Model);
IList list = ls.GetList();
foreach (var item in (IEnumerable)value)
{
list.Add(item);
}
}
else
{
propertyDescriptor.SetValue(bindingContext.Model, value);
}
}
}
catch (Exception ex)
{
// Only add if we're not already invalid
if (bindingContext.ModelState.IsValidField(modelStateKey))
{
bindingContext.ModelState.AddModelError(modelStateKey, ex);
}
}
}
}
Here's my simple Edit POST method:
[HttpPost]
[ValidateInput(false)] //To allow HTML in description box
public ActionResult Edit(int id, FormCollection collection)
{
Consultant consultant = _repository.GetConsultant(id);
UpdateModel(consultant);
_repository.Save();
return RedirectToAction("Index");
}
But after that UpdateModel worked. The problem is, at the next stage, when trying to call SaveChanges on the context, that fails. I'm getting this error:
The operation failed: The relationship
could not be changed because one or
more of the foreign-key properties is
non-nullable. When a change is made to
a relationship, the related
foreign-key property is set to a null
value. If the foreign-key does not
support null values, a new
relationship must be defined, the
foreign-key property must be assigned
another non-null value, or the
unrelated object must be deleted.
I don't understand what is wrong. I'm seeing all the correct values in the Consultant object posted, I just can't save it to database. The route of AutoMapper in this case (although an interesting tool) is not working well, it's complicating my code immensely and making the application, which should be rather simple, a nightmare to maintain.
Can anyone offer any insight into why I'm getting this error and how to overcome it?
UPDATE:
Reading some posts here, I found one that seemed slightly related: How to update model in the database, from asp.net MVC2, using Entity Framework? . I don't know if it relates to this, but when I inspected the Consultant object after POST it seems this object itself has entitykey, but the individual items in a collection do not (EntityKeySet = null). Each item however does have the correct id. I don't pretend to understand any of this with the EntityKey, so please explain if it has any bearings on my issue, and if so, how to resolve it...
UPDATE 2:
I thought of something that might have something to do with my problems: The View is using a technique described by Steven Sanderson (see http://blog.stevensanderson.com/2010/01/28/editing-a-variable-length-list-aspnet-mvc-2-style/ ), and when debugging it seems to me as if UpdateModel has trouble matching the items in a collection in the View with the ones in the actual Consultant object. I'm wondering if this has to do with the indexing in this technique. Here's the helper from that code (I can't follow it very well myself, but it uses a Guid to create indexes, which might be the problem):
public static class HtmlPrefixScopeExtensions
{
private const string idsToReuseKey = "__htmlPrefixScopeExtensions_IdsToReuse_";
public static IDisposable BeginCollectionItem(this HtmlHelper html, string collectionName)
{
var idsToReuse = GetIdsToReuse(html.ViewContext.HttpContext, collectionName);
string itemIndex = idsToReuse.Count > 0 ? idsToReuse.Dequeue() : Guid.NewGuid().ToString();
// autocomplete="off" is needed to work around a very annoying Chrome behaviour whereby it reuses old values after the user clicks "Back", which causes the xyz.index and xyz[...] values to get out of sync.
html.ViewContext.Writer.WriteLine(string.Format("<input type=\"hidden\" name=\"{0}.index\" autocomplete=\"off\" value=\"{1}\" />", collectionName, html.Encode(itemIndex)));
return BeginHtmlFieldPrefixScope(html, string.Format("{0}[{1}]", collectionName, itemIndex));
}
public static IDisposable BeginHtmlFieldPrefixScope(this HtmlHelper html, string htmlFieldPrefix)
{
return new HtmlFieldPrefixScope(html.ViewData.TemplateInfo, htmlFieldPrefix);
}
private static Queue<string> GetIdsToReuse(HttpContextBase httpContext, string collectionName)
{
// We need to use the same sequence of IDs following a server-side validation failure,
// otherwise the framework won't render the validation error messages next to each item.
string key = idsToReuseKey + collectionName;
var queue = (Queue<string>)httpContext.Items[key];
if (queue == null)
{
httpContext.Items[key] = queue = new Queue<string>();
var previouslyUsedIds = httpContext.Request[collectionName + ".index"];
if (!string.IsNullOrEmpty(previouslyUsedIds))
foreach (string previouslyUsedId in previouslyUsedIds.Split(','))
queue.Enqueue(previouslyUsedId);
}
return queue;
}
private class HtmlFieldPrefixScope : IDisposable
{
private readonly TemplateInfo templateInfo;
private readonly string previousHtmlFieldPrefix;
public HtmlFieldPrefixScope(TemplateInfo templateInfo, string htmlFieldPrefix)
{
this.templateInfo = templateInfo;
previousHtmlFieldPrefix = templateInfo.HtmlFieldPrefix;
templateInfo.HtmlFieldPrefix = htmlFieldPrefix;
}
public void Dispose()
{
templateInfo.HtmlFieldPrefix = previousHtmlFieldPrefix;
}
}
}
But then again, I wouldn't have thought this should be the problem since the hidden input contains the id in the value attribute, and I thought UpdateModel just looked at the name of the field to get Programs (the collection) and Name (the property), and then the value to the the id...? And then again there's seems to be some mismatch during update. Anyway, here's the generated html from FireBug also:
<td>
<input type="hidden" value="1" name="Programs[cabac7d3-855f-45d8-81b8-c31fcaa8bd3d].Id" id="Programs_cabac7d3-855f-45d8-81b8-c31fcaa8bd3d__Id" data-val-required="The Id field is required." data-val-number="The field Id must be a number." data-val="true">
<input type="text" value="Visual Studio" name="Programs[cabac7d3-855f-45d8-81b8-c31fcaa8bd3d].Name" id="Programs_cabac7d3-855f-45d8-81b8-c31fcaa8bd3d__Name">
<span data-valmsg-replace="true" data-valmsg-for="Programs[cabac7d3-855f-45d8-81b8-c31fcaa8bd3d].Name" class="field-validation-valid"></span>
</td>
Anyone know if this is the problem? And if so, how can I work around it to be able to easily update the collections with UpdateModel? (While still being able to add or remove items in the View before POST, which was the purpose of this technique to begin with).
It looks like there is a Parent entity that has a one to many relationship with your Consultant entity. When you change an attribute of the Consultant entity that is used as the ForeignKey for that relationship, Entity Framework sets the relevant field in the Parent entity to null to decouple the relationship. When that field is not nullable you'll get this error. Actually that error definition is surprisingly good, I've seen this problem with far more cryptic errors.
So, I recommend that you check the parent entity in the database, and proceed to a remedy from there (if you can change it to nullable all is well, if it is part of a different constraint -pk or suchlike- you'll have to fiddle with your object models). I'd ask you to post your entity models, but the chunk of text is intimidating as it is.
I think the error you are getting is related to: EF 4: Removing child object from collection does not delete it - why? You have created an orphan somewhere.
Yes it is related to HtmlPrefixScopeExtensions, but only because you are using Mvc Futures model binders.
In global.asax.cs comment out the line
Microsoft.Web.Mvc.ModelBinding.ModelBinderConfig.Initialize();
and retry: it will work ok !
The problem happens because the MVC futures model binder does not handle correctly this case. It converts ok the form data into your model when you submit the form, but it has a problem when filling the ModelState object when you use HtmlPrefixScopeExtensions to generate non incremental ids.
The model itself is correctly created from the form data. The problem lies inside ModelState which contains only the last value of the collection instead of all elements of the collection.
The strongly typed helper method - which renders the list - only select items which are in your Model property list AND in the matching ModelState entry which is converted into a list. So because there is only one item in the matching ModelState entry other list items get deselected.
This method called by the strongly typed helper code:
htmlHelper.GetModelStateValue(fullName, typeof(string[]))
returns only the last element of the list, because ModelState["Programs[cabac7d3-855f-45d8-81b8-c31fcaa8bd3d].List"].Value contains only the last element of the list.
This is a bug (or non supported scenario) in MVC3 Futures extensible model binders.