Attribute option - add a placeholder for the drop-down select option

[nattywebdev]

When I add an attribute and options to a product, the add to cart form shows the first item in the Select box. I would like to insert a placeholder there instead to make it clear that an option must be selected, for example:

Where would I look to provide this placeholder? I could do it with jQuery but I'd rather have it displayed correctly by the code.

(I'm using Select2 already but don't see a place to add this there.)

Any pointers much appreciate.

[bugfolder]

You could use hook_form_uc_product_add_to_cart_form_alter() to add array('' => t('Pick one')) to the select options on the form and add a validate function to disallow someone not selecting one of the desired options. See uc_clearance_form_uc_product_add_to_cart_form_alter() in UC Clearance for similar modification of the attribute picker.

[nattywebdev]

@bugfolder I don't seem to be able to find the relevant item to add a placeholder to. I've used dpm($form) to display all the form elements but can't see anything relevant. Could you advise please?
Here's the values displayed:

... (Array, 22 elements)
#attributes (Array, 1 element)
class (Array, 2 elements)
0 (String, 32 characters ) uc-product-add-to-cart-form-5655
1 (String, 27 characters ) uc-product-add-to-cart-form
nid (Array, 2 elements)
#type (String, 5 characters ) value
#value (String, 4 characters ) 5655
qty (Array, 3 elements)
#type (String, 11 characters ) uc_quantity
#title (String, 8 characters ) Quantity
#default_value (String, 1 characters ) 1
actions (Array, 2 elements)
#type (String, 7 characters ) actions
submit (Array, 4 elements)
node (Array, 2 elements)
#type (String, 5 characters ) value
#value (Object) Node
attributes (Array, 5 elements)
#theme (String, 24 characters ) uc_attribute_add_to_cart
#id (String, 43 characters ) uc_product_add_to_cart_form-5655-attributes
13 (Array, 7 elements)
#type (String, 6 characters ) select
#default_value (String, 3 characters ) 217
#options (Array, 2 elements)
#ajax (Array, 2 elements)
#title (String, 29 characters ) EPP block or plate variations
#description (String, 0 characters )
#required (String, 1 characters ) 0
#tree (Boolean) TRUE
#weight (Integer) -1
#form_id (String, 32 characters ) uc_product_add_to_cart_form_5655
#type (String, 4 characters ) form
#build_id (String, 48 characters ) form-EQ8CikVReyV3mK3uowjB8qG1CesYXHu3pGps9XmGhlk
form_build_id (Array, 5 elements)
#type (String, 6 characters ) hidden
#value (String, 48 characters ) form-EQ8CikVReyV3mK3uowjB8qG1CesYXHu3pGps9XmGhlk
#id (String, 48 characters ) form-EQ8CikVReyV3mK3uowjB8qG1CesYXHu3pGps9XmGhlk
#name (String, 13 characters ) form_build_id
#parents (Array, 1 element)
#token (String, 32 characters ) uc_product_add_to_cart_form_5655
form_token (Array, 4 elements)
#id (String, 48 characters ) edit-uc-product-add-to-cart-form-5655-form-token
#type (String, 5 characters ) token
#default_value (String, 43 characters ) O4lViJswKwzbCvNJHGnAhOdcHuoSrRMNaCNAiD7kkx8
#parents (Array, 1 element)
0 (String, 10 characters ) form_token
form_id (Array, 4 elements)
#type (String, 6 characters ) hidden
#value (String, 32 characters ) uc_product_add_to_cart_form_5655
#id (String, 37 characters ) edit-uc-product-add-to-cart-form-5655
#parents (Array, 1 element)
#id (String, 32 characters ) uc-product-add-to-cart-form-5655
#method (String, 4 characters ) post
#action (String, 48 characters ) /epp/10-double-wedding-ring-acrylic-template-set
#theme_wrappers (Array, 1 element)
0 (String, 4 characters ) form
#tree (Boolean) FALSE
#parents (Array, 0 elements)
#validate (Array, 2 elements)
0 (String, 36 characters ) uc_product_add_to_cart_form_validate | (Callback) uc_product_add_to_cart_form_validate();
1 (String, 39 characters ) uc_out_of_stock_validate_form_addtocart | (Callback) uc_out_of_stock_validate_form_addtocart();
#submit (Array, 1 element)
0 (String, 34 characters ) uc_product_add_to_cart_form_submit | (Callback) uc_product_add_to_cart_form_submit();
#theme (Array, 2 elements)
0 (String, 32 characters ) uc_product_add_to_cart_form_5655
1 (String, 27 characters ) uc_product_add_to_cart_form | (Callback) uc_product_add_to_cart_form();
Krumo version 0.2.1a | [http://krumo.sourceforge.net(link is external)](http://krumo.sourceforge.net/)Click to expand. Double-click to show path. Called from /app/web/themes/bs_saq/template.php, line 68  
... (Array, 22 elements)
#attributes (Array, 1 element)
class (Array, 2 elements)
0 (String, 32 characters ) uc-product-add-to-cart-form-5293
1 (String, 27 characters ) uc-product-add-to-cart-form
nid (Array, 2 elements)
#type (String, 5 characters ) value
#value (String, 4 characters ) 5293
qty (Array, 3 elements)
#type (String, 11 characters ) uc_quantity
#title (String, 8 characters ) Quantity
#default_value (String, 1 characters ) 1
actions (Array, 2 elements)
#type (String, 7 characters ) actions
submit (Array, 4 elements)
node (Array, 2 elements)
#type (String, 5 characters ) value
#value (Object) Node
attributes (Array, 5 elements)
#theme (String, 24 characters ) uc_attribute_add_to_cart
#id (String, 43 characters ) uc_product_add_to_cart_form-5293-attributes
3 (Array, 7 elements)
#type (String, 6 characters ) select
#default_value (String, 1 characters ) 9
#options (Array, 3 elements)
#ajax (Array, 2 elements)
#title (String, 4 characters ) Seam
#description (String, 0 characters )
#required (String, 1 characters ) 0
#tree (Boolean) TRUE
#weight (Integer) -1
#form_id (String, 32 characters ) uc_product_add_to_cart_form_5293
#type (String, 4 characters ) form
#build_id (String, 48 characters ) form-u_DlIKA1JV1xmhlWcGvTlvl1vxVBUYRijYiRFoZu1Q4
form_build_id (Array, 5 elements)
#type (String, 6 characters ) hidden
#value (String, 48 characters ) form-u_DlIKA1JV1xmhlWcGvTlvl1vxVBUYRijYiRFoZu1Q4
#id (String, 48 characters ) form-u_DlIKA1JV1xmhlWcGvTlvl1vxVBUYRijYiRFoZu1Q4
#name (String, 13 characters ) form_build_id
#parents (Array, 1 element)
0 (String, 13 characters ) form_build_id
#token (String, 32 characters ) uc_product_add_to_cart_form_5293
form_token (Array, 4 elements)
#id (String, 48 characters ) edit-uc-product-add-to-cart-form-5293-form-token
#type (String, 5 characters ) token
#default_value (String, 43 characters ) X0GsQs3rGenvNBvNHPrzacBFzAzoWvzk-1iEm1mA8G8
#parents (Array, 1 element)
0 (String, 10 characters ) form_token
form_id (Array, 4 elements)
#type (String, 6 characters ) hidden
#value (String, 32 characters ) uc_product_add_to_cart_form_5293
#id (String, 37 characters ) edit-uc-product-add-to-cart-form-5293
#parents (Array, 1 element)
0 (String, 7 characters ) form_id
#id (String, 32 characters ) uc-product-add-to-cart-form-5293
#method (String, 4 characters ) post
#action (String, 48 characters ) /epp/10-double-wedding-ring-acrylic-template-set
#theme_wrappers (Array, 1 element)
0 (String, 4 characters ) form
#tree (Boolean) FALSE
#parents (Array, 0 elements)
#validate (Array, 2 elements)
0 (String, 36 characters ) uc_product_add_to_cart_form_validate | (Callback) uc_product_add_to_cart_form_validate();
1 (String, 39 characters ) uc_out_of_stock_validate_form_addtocart | (Callback) uc_out_of_stock_validate_form_addtocart();
#submit (Array, 1 element)
0 (String, 34 characters ) uc_product_add_to_cart_form_submit | (Callback) uc_product_add_to_cart_form_submit();
#theme (Array, 2 elements)
0 (String, 32 characters ) uc_product_add_to_cart_form_5293
1 (String, 27 characters ) uc_product_add_to_cart_form | (Callback) uc_product_add_to_cart_form();
Krumo version 0.2.1a | [http://krumo.sourceforge.net(link is external)](http://krumo.sourceforge.net/)Click to expand. Double-click to show path. Called from /app/web/themes/bs_saq/template.php, line 68

[bugfolder]

The select elements for attributes are found in $form['attributes']. The example dpm(...) you sent doesn't seem to match the example in your first comment, though. The key will be a number (the attribute code). For example, in my site where I've done this, the first attribute select's options are at $form['attributes'][24]['#options']. Your will probably have a different numeric key.

[nattywebdev]

Thanks for that advice @bugfolder - I can see the attribute elements now. My attribute id is 9.

I've added
'''
$form['attributes'][9]['#options'] = array('' => t('Search for product...'));
'''
but nothing changes - does that look right to you?

(I need to explain that I'm very inexperienced in this so appreciate the hand-holding!)

[bugfolder]

That's not quite right, because you've now replaced all of the existing options with your placeholder; what you want to do is add your placeholder to the beginning of the list. So something like:

$form['attributes'][9]['#options'] = array('' => t('Search for product...')) + $form['attributes'][9]['#options'];

But you should have seen a change with what you did. So let's debug a little deeper.

First, would you post a screenshot of the attribute drop-down that we're working on?

Next, in your hook_alter implemention, add this line:

dpm($form['attributes'][9]['#options'], 'options');

And report what's displayed.

[nattywebdev]

Here's the select list for the attribute:

[nattywebdev]

I added dpm($form['attributes'][9]['#options'], 'options'); and this was reported:

[nattywebdev]

I also added your suggested line

$form['attributes'][9]['#options'] = array('' => t('Search for product...')) + $form['attributes'][9]['#options'];

but that resulted in this:

(in case that helps!)

[argiepiano]

Are you sure you are receiving the variable $form by reference? If not, none of the changes to that variable in your function will apply.

[argiepiano]

https://www.php.net/manual/en/language.references.pass.php

[nattywebdev]

This is the code I have in my template.php:

function bs_saq_form_uc_product_add_to_cart_form_alter(&$form, &$form_state) {

  dpm($form['attributes'][9]['#options'], 'options');

  $form['attributes'][9]['#options'] = array('' => t('Search for product...')) + $form['attributes'][9]['#options'];

//  $form['attributes'][9]['#options'] = array('' => t('Search for product...'));

}

Does that answer your question, @argiepiano ?

[bugfolder]

Would you try giving the placeholder element a key of 0 or -1?

Robert

[nattywebdev]

You mean like this?

$form['attributes'][9]['#options'] = array('0' => t('Search for product...')) + $form['attributes'][9]['#options'];

As that still gives the same error (line 72 is that line above):
Error: Unsupported operand types in bs_saq_form_uc_product_add_to_cart_form_alter() (line 72 of /app/web/themes/bs_saq/template.php).

[bugfolder]

Weird. I can't see why that wouldn't work. (Perhaps our local guru, @argiepiano, will see it instantly.) Meanwhile, let's try breaking up steps to narrow down the issue.

$options =  $form['attributes'][9]['#options'];
$new_options = array(0 => t('Search for product...'));
$new_options += $options;
$form['attributes'][9]['#options'] = $new_options;

I expect there will still be an error, but at least we'll see where it's coming from.

[nattywebdev]

I've added that:

and now see:
Error: Unsupported operand types in bs_saq_form_uc_product_add_to_cart_form_alter() (line 76 of /app/web/themes/bs_saq/template.php).

so it's here:
$new_options += $options;

I'm running php 7.4 - would that matter?