handle one to many relationship in thymeleaf using spring mvc - spring

Question

I'm having One entity as Vendor and Another as Address and the relationship between both of them is One To Many form Vendor to Address.
Note : I am using JPA
My Vendor Entity
public class Vendor {
private Integer id;
private String name;
private List<Address> address;
// getter and setters
}
Address class:
public class Address {
private Integer id;
private String addressline1;
private String addressline2;
//getter and setters
}
Now I am using Thymeleaf , I have a scenario where I need to add the address dynamically to a form for the particular vendor.
How do I do Object binding for the Address object in Vendor using Thymeleaf in spring mvc?

Answer 1

Comment if i didn't understand your question correct, it's a bit unclear to me...
In order to access the address(s) of a vendor, you provide a vendor within your controller (something like model.addAttribute("vendor", currentVendor);) and call vendor.address in your html file. Please note that this will give you a list so you need to iterate to show all address:
<tr th:each="address : ${vendor.address}">
<td th:text="${address.id}">1</td>
<td th:text="${address.addressline1}"></td>
<td th:text="${address.addressline2}"></td>
</tr>

Answer 2

Uhhh, that's tricky because binding to form doesn't work in a dynamic way. That means you can't do something like #Viergelenker suggests AND bind each address-object to his own form.
You can add a single address object to the model, e.g.
model.addAttribute("address", addressObject); // Snippet for Model-object
modelAndView.addObject("address", addressObject); // Snippet for ModelAndView object
and then define a form in yout template like:
<form .... method=".." th:object="${address}">
<input type="hidden" th:field="*{id}" >
<input type="text" th:field="*{addressline1}" >
<input type="text" th:field="*{addressline2}" >
</form>
Unfortunately it is not possible to add a array or list to the model and bind each object in that collection to his own form:
/* The following code doesn't work */
<th:block th:each="address : ${addresses}">
<form .... method=".." th:object="${address}">
<input type="text" th:field="*{addressline1}" >
...
</form>
</th:block>
or
/* The following code doesn't work */
<th:block th:each="address, stat : ${addresses}">
<form .... method=".." th:object="${addresses[__stat.index__]}">
<input type="text" th:field="*{addressline1}" >
...
</form>
</th:block>
What you can do is not to use form binding and just send some name-value pairs from forms without the binding (just use the name and the th:value attributes and not the th:field attribute in your forms) to the controller, get them there from the HttpServletRequest object and create/update/delete address-objects ... or bind the whole Vendor object to a form (note the use of stat.index):
<form th:object="${vendor}">
<input type="hidden" th:field="*{id}">
<input type="hidden" th:field="*{name}"> // feel free to make that field editable
<th:block th:each="addr, stat : *{address}">
<input type="hidden" th:field="*{address[__${stat.index}__].id}">
<input type="text" th:field="*{address[__${stat.index}__].addressline1}">
<input type="text" th:field="*{address[__${stat.index}__].addressline2}">
</th:block>
</form>