Thymeleaf select option resets to default

Question

There is a search form in html:

The default value in options is "First Name". When I choose, lets say, search by mobile phone, press "Search" and get the resulting page, the form options get reset to default value. But I need it to keep the variant I selected, in this case it was "Mobile Phone". What has to be changed in html?

Form filled in:

After receiving search results, 'options' should have remained "Mobile Phone":

html code:

<label class="labelWidthExtra">
    <select name="typeOfSearch">
        <option th:each="s : ${selection}" th:text="${s}">
        </option>
    </select>
</label>

In case of JSP + Spring tags the same is resolved very easily:

<label>
    <sf:select path="typeOfSearch" items="${selection}"/>
</label>

But Thymeleaf is confusing...

Answer 1

The solution was eventually found.

html side:

<option th:each="s : ${selection}"
        th:text="${s}"
        th:selected="${s.equals(selector)}">
</option>

Controller side (in Kotlin):

@PostMapping(value = "/contactsSearch")
    fun searchForContacts(@RequestParam(value = "typeOfSearch") typeOfSearch: String,
                          @RequestParam(value = "searchParam") searchParam: String, model: Model): String {
        val contacts = contactService.retrieveContactsBySearch(typeOfSearch, searchParam)
        model.addAttribute(CONTACT_LIST, contacts)
        model.addAttribute(SELECTOR, typeOfSearch)
        model.addAttribute(SEARCH_PARAM, searchParam)
        model.addAttribute(SELECTION, SELECTION_PARAMS)

        return CONTACTS_SEARCH
    }