Controlling select options with a numeric field - Silverstripe - silverstripe

Question

'Quantity' is a simple numeric field in the backend.
In a form on the front-end website I'm displaying a dropdown select menu 'Quantity' that shows a max of ten items (and defaults to 10 items if no quantity is provided)
So, for example, if 5 is entered then the select menu should only show options 1 - 5.
This works, but what is a better way to write this:
<% if Quantity %>
<% if Quantity == 1 %>
<option value="1">1</option>
<% end_if %>
<% if Quantity == 2 %>
<option value="1">1</option>
<option value="2">2</option>
<% end_if %>
<% if Quantity == 3 %>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<% end_if %>
<% if Quantity == 4 %>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<% end_if %>
<% if Quantity == 5 %>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
<% end_if %>
<% if Quantity == 6 %>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
<option value="6">6</option>
<% end_if %>
<% if Quantity == 7 %>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
<option value="6">6</option>
<option value="7">7</option>
<% end_if %>
<% if Quantity == 8 %>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
<option value="6">6</option>
<option value="7">7</option>
<option value="8">8</option>
<% end_if %>
<% if Quantity == 9 %>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
<option value="6">6</option>
<option value="7">7</option>
<option value="8">8</option>
<option value="9">9</option>
<% end_if %>
<% if Quantity > 9 %>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
<option value="6">6</option>
<option value="7">7</option>
<option value="8">8</option>
<option value="9">9</option>
<option value="10">10</option>
<% end_if %>
<% else %>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
<option value="6">6</option>
<option value="7">7</option>
<option value="8">8</option>
<option value="9">9</option>
<option value="10">10</option>
<% end_if %>

Answer 1

Method 1 (Best)
Let's say you've created a Form object for this. You could create a method in your form object to populate the dropdownfield.
MyForm.php
public function setQuantity($quantity)
{
$range = ArrayLib::valuekey(range(1, $quantity));
$this->Fields()->dataFieldByName('QuantityDropdownField') // your dropdownfield
->setSource($range);
return $this;
}
Method 2 (Okay)
If you don't want to create a Silverstripe form for this. You could do this.
Page.php
public function getQuantityArrayList()
{
$array = [];
for ($i = 1; $i <= $this->Quantity; $i++) {
$array[] = ArrayData::create([
'Value' => $i
]);
}
return ArrayList::create($array);
}
Page.ss
<% loop $QuantityArrayList %>
<option value="$Value">$Value</option>
<% end_loop %>
Method 3 (Bad)
If, for whatever reason you don't like that either you could do this.
Page.ss
<option value="1">1</option>
<% if not $Quantity || $Quantity == 2 %>
<option value="2">2</option>
<% end_if %>
<% if not $Quantity || $Quantity == 3 %>
<option value="3">3</option>
<% end_if %>
<% if not $Quantity || $Quantity == 4 %>
<option value="4">4</option>
<% end_if %>
<% if not $Quantity || $Quantity == 5 %>
<option value="5">5</option>
<% end_if %>
<% if not $Quantity || $Quantity == 6 %>
<option value="6">6</option>
<% end_if %>
<% if not $Quantity || $Quantity == 7 %>
<option value="7">7</option>
<% end_if %>
<% if not $Quantity || $Quantity == 8 %>
<option value="8">8</option>
<% end_if %>
<% if not $Quantity || $Quantity == 9 %>
<option value="9">9</option>
<% end_if %>
<% if not $Quantity || $Quantity > 9 %>
<option value="10">10</option>
<% end_if %>
All these are better than what you have got right now.
I haven't tested any of this, but you probably get the idea.