Auto Clear Divi Cache

1. **Create a custom plugin or add the code to your theme's `functions.php` file**.

2. **Use the `save_post` action hook to listen for updates to Divi Builder pages**.

3. **Clear Divi’s cache programmatically**. Divi has a built-in function to clear its cache, which can be triggered manually.

Here's an example of how you can do this:

### Step 1: Hook into the page update process

add_action('save_post', 'clear_divi_cache_on_update', 10, 3);

function clear_divi_cache_on_update($post_id, $post, $update) {
    // Check if the post is a Divi Builder page (post type)
    if ($post->post_type === 'page' && class_exists('ET_Builder_Framework')) {
        // Make sure it’s a Divi Builder page
        if (get_post_meta($post_id, '_et_pb_layout', true)) {
            // Clear Divi cache
            et_pb_clear_all_transients();
        }
    }
}

### Explanation:
– The `save_post` action hook is fired whenever a post (or page) is saved.
– It checks if the post being saved is a page and if it’s a Divi Builder page by looking for the `_et_pb_layout` post meta key, which is only set for Divi pages.
– If it is a Divi Builder page, it clears the Divi cache using the `et_pb_clear_all_transients()` function.

### Step 2: Enable cache clearing on update

This code ensures that when a Divi Builder page is updated, Divi's cache is cleared automatically, ensuring that the latest changes are reflected immediately on the front-end.

Let me know if you need further adjustments or have any questions!

### Step 1: Update the Controller

In the controller, you need to handle the form submission. When you get the `products[]` field data (which will be an array of selected values), you can use `implode` to convert it into a single string and save it in your database column.

public function saveForm()
{
    if ($this->request->is('post')) {
        // Get the selected products as an array
        $selectedProducts = $this->request->getData('products');
        
        // Implode the array into a string, separating by commas (or any other separator)
        $productsString = implode(',', $selectedProducts);
        
        // Assuming you're saving this in a column 'products' in your database
        $entity = $this->YourModel->newEmptyEntity();
        $entity->products = $productsString;

        if ($this->YourModel->save($entity)) {
            $this->Flash->success(__('The products were saved.'));
        } else {
            $this->Flash->error(__('The products could not be saved.'));
        }
    }
}

### Step 2: Update the Form (No Change Needed)

Your existing form code for selecting products doesn't need changes:

echo $this->Form->control('products[]', [
    'type' => 'select',
    'multiple' => 'multiple', // Ensure that multiple items can be selected
    'options' => $bookOptions,
    'class' => 'form-control validate[required]',
    'label' => false
]);

### Step 3: Update the Database Schema

Ensure your database column (`products`) is a string type, like `TEXT` or `VARCHAR`, depending on the size of the data.

### Step 4: Saving and Retrieving the Data

– When the form is submitted, the `products[]` values will be collected as an array. The `implode(',', $selectedProducts)` will turn it into a comma-separated string, which you can store in your database.

– To retrieve the data, you'll use `explode(',', $productsString)` to get the array of values back if you need to use it as an array later.

Example retrieval and conversion back to an array:

$productsArray = explode(',', $entity->products);

This approach allows you to save multiple selected values from the `products[]` field in a single column of your database and retrieve them when needed.

### Step 1: Pass the Selected Values to the Form

If you're editing an existing record, you can pass the saved `products` string (which is a comma-separated list) as an array of selected values. Here's how to do it:

#### In the Controller:

If you are editing an existing record and want to pass the selected products back to the form, convert the saved string into an array and pass it to the view:

public function edit($id)
{
    $entity = $this->YourModel->get($id);
    
    // Convert the products string to an array (explode the comma-separated values)
    $selectedProducts = explode(',', $entity->products);
    
    // Pass the selected products to the view
    $this->set(compact('entity', 'selectedProducts'));
}

#### In the View:

In the form, use the `selected` option to preselect the products. If `selectedProducts` is passed as an array, CakePHP will automatically mark the selected options:

echo $this->Form->create($entity);

echo $this->Form->control('products[]', [
    'type' => 'select',
    'multiple' => 'multiple', // Enable multiple selection
    'options' => $bookOptions,
    'class' => 'form-control validate[required]',
    'label' => false,
    'value' => $selectedProducts // This preselects the values
]);

echo $this->Form->end();

### Step 2: Handle Form Submission and Save the Data

When the form is submitted, CakePHP will automatically handle the `products[]` field and return the selected values as an array. The controller should handle the form data as shown earlier and use `implode` to store it as a string in the database.

### Explanation:
– **Preselecting Options**: By passing the `$selectedProducts` array to the `value` attribute of the form control, CakePHP will mark those options as selected in the dropdown list when the form is rendered.
– **Multiple Selection**: The `multiple` attribute in the select field allows the user to select multiple options. The selected options are submitted as an array (`products[]`).
– **Database Storage**: The selected products are saved as a comma-separated string in the database using `implode`.

This way, when the form is displayed again, the previously selected products will appear as selected in the dropdown.

### Step 1: Handle Selection Using `in_array`

If you want to control the selection manually with `in_array`, you can use it to check whether a specific value is in the array of selected options. Here's an example:

#### In the View:

echo $this->Form->control('products[]', [
    'type' => 'select',
    'multiple' => 'multiple', // Enable multiple selection
    'options' => $bookOptions,
    'class' => 'form-control validate[required]',
    'label' => false,
    'value' => $selectedProducts, // You can pass the selected products as an array
]);

// If you need to manually set selected values using in_array:
foreach ($bookOptions as $key => $value) {
    $selected = in_array($key, $selectedProducts) ? 'selected' : ''; // Check if the option is selected
    echo "<option value="$key" $selected>$value</option>";
}

### Step 2: Using `in_array` with `FormHelper`

While CakePHP's `FormHelper` handles the selection automatically if you pass the array of selected values, you can manually apply the `in_array` check in custom cases. Here's an example:

echo $this->Form->control('products[]', [
    'type' => 'select',
    'multiple' => 'multiple', // Enable multiple selection
    'options' => $bookOptions,
    'class' => 'form-control validate[required]',
    'label' => false,
    'value' => $selectedProducts, // Automatically preselect the values passed
]);

// Custom in_array check to show selected options
echo '<select name="products[]" class="form-control" multiple="multiple">';
foreach ($bookOptions as $key => $value) {
    $selected = in_array($key, $selectedProducts) ? 'selected' : '';
    echo "<option value="$key" $selected>$value</option>";
}
echo '</select>';

### Step 3: Explanation

1. **`$selectedProducts`**: This array contains the values that should be selected. You usually fetch this from the database or form input (e.g., an array of selected product IDs).

2. **`in_array($key, $selectedProducts)`**: For each option, `in_array` checks whether the option value exists in the `$selectedProducts` array. If it does, the `selected` attribute is applied, making the option preselected in the dropdown.

3. **Using the `FormHelper`**: Normally, the `FormHelper` can handle the `value` attribute automatically, and you don't need `in_array` directly. Passing an array like `$selectedProducts` to the `value` will preselect the matching options.

This approach ensures that your dropdown shows the pre-selected options based on whether the selected values are contained in the `$selectedProducts` array.