If you're editing or creating an Option Set manually, once you've added your options, you'll need to assign a function to each one in order for it to affect your design.

Functions tell Customily what to do with the shopper’s input — like change a text, switch an image, or display a QR code. If you skip this step, the option will still appear on your product page, but it won’t do anything in the live preview.

When are Functions assigned?

• Automatically:
  When Option Sets are created automatically (like when creating a design or creating them from a template), Customily will assign the correct function to each option based on your template. In most cases, you won’t need to change anything.

• Manually:
  If you’re creating your Option Set from scratch — or editing an existing one — you’ll need to manually assign a function to each option. This gives you full control over how each input affects your design.

How to assign a Function

1. Open the Option Set you want to edit.

2. Find the option you want to work with and click to expand it.
   

3. Scroll down and find the Customily Functions section. Click to open it.
   

4. Click + Add Customily Function
   

5. Choose the appropriate function based on what you want the shopper’s input to change.
   

6. Select the template element it should affect. If you know the ID of the element you can type it, but it's easiest to use the magnifying glass to identify the element. 
   
   If the option set is linked to a template (for example if the set was created automatically and you're editing it) you'll see elements available on it to select one. If not, first select the template and then find the element you want to affect. 
   
   Only compatible elements will be shown to prevent mismatches. Choose your element and click select.
   

   Tip

   Most functions are linked to a design element — like a text box, image placeholder, or dynamic image — so they can control how that element behaves.

   However, some functions don’t connect to specific elements:

   Layout Visibility: You’ll assign a layout to each value inside the option. Only one layout is shown at a time, based on the shopper’s selection.

   Change Template: You’ll assign a template to each value inside the option. Only one template will load at a time, based on the shopper's selection.

   Add Shopify Product: For dropdowns or swatches, you’ll assign a product to each value. For text fields or checkboxes, you’ll define the product directly inside the function’s settings.

   These options won’t show any element connections, but they still require proper configuration to work as expected.

7. A single option can power multiple changes in your design — just assign more than one function! For example:

   One dropdown can change the font type of several text boxes at once.

   One color swatch can control the text color and the vector color of different elements.

   This gives you the flexibility to create powerful personalization with fewer shopper inputs — making the experience simpler and more intuitive. To add another function simply click again + Add Customily Function and configure it.