Set product sale price programmatically in WooCommerce 3 - php

Question

I have a Woocommerce store set up with various product categories.
I want to apply a 20% discount to all products, which belong to the product category Cuckoo
For now all I'm trying to achieve is set a sale price in my functions.php
It tried as follows:
/*
* For a specific date, 20% off all products with product category as cuckoo clock.
*/
function cuckoo_minus_twenty($sale_price, $product) {
$sale_price = $product->get_price() * 0.8;
return $sale_price;
};
// add the action
add_filter( 'woocommerce_get_sale_price', 'cuckoo_minus_twenty', 10, 2 );
If I var_dump the result of $sale_price after the calculation I get the correct answer, however the price display on the front-end strikes out the regular price and displays the sale price as the regular price.
Is there a hook/filter I can use to achieve this?
I've also tried setting the sale price by doing:
$product->set_sale_price($sale_price);
to no avail.

Answer 1

The hook woocommerce_get_sale_price is deprecated since WooCommerce 3 and replaced by woocommerce_product_get_sale_price.
Also Product displayed prices are cached. When sale price is active, regular price is also active.
Try this instead:
// Generating dynamically the product "regular price"
add_filter( 'woocommerce_product_get_regular_price', 'custom_dynamic_regular_price', 10, 2 );
add_filter( 'woocommerce_product_variation_get_regular_price', 'custom_dynamic_regular_price', 10, 2 );
function custom_dynamic_regular_price( $regular_price, $product ) {
if( empty($regular_price) || $regular_price == 0 )
return $product->get_price();
else
return $regular_price;
}
// Generating dynamically the product "sale price"
add_filter( 'woocommerce_product_get_sale_price', 'custom_dynamic_sale_price', 10, 2 );
add_filter( 'woocommerce_product_variation_get_sale_price', 'custom_dynamic_sale_price', 10, 2 );
function custom_dynamic_sale_price( $sale_price, $product ) {
$rate = 0.8;
if( empty($sale_price) || $sale_price == 0 )
return $product->get_regular_price() * $rate;
else
return $sale_price;
};
// Displayed formatted regular price + sale price
add_filter( 'woocommerce_get_price_html', 'custom_dynamic_sale_price_html', 20, 2 );
function custom_dynamic_sale_price_html( $price_html, $product ) {
if( $product->is_type('variable') ) return $price_html;
$price_html = wc_format_sale_price( wc_get_price_to_display( $product, array( 'price' => $product->get_regular_price() ) ), wc_get_price_to_display( $product, array( 'price' => $product->get_sale_price() ) ) ) . $product->get_price_suffix();
return $price_html;
}
Code goes in function.php file of your active child theme (active theme).
Tested and works on single product, shop, product category and tag archive pages.
The continuation in:
Wrong Woocommerce cart item price after setting programmatically product sale price

Answer 2

I realiced, you more or less need all of the following filters to make the HTML work out of the box.
add_filter( 'woocommerce_product_get_price', 'custom_dynamic_sale_price', 10, 2 );
add_filter( 'woocommerce_product_variation_get_price', 'custom_dynamic_sale_price', 10, 2 );
add_filter( 'woocommerce_product_get_sale_price', 'custom_dynamic_sale_price', 10, 2 );
add_filter( 'woocommerce_product_variation_get_sale_price', 'custom_dynamic_sale_price', 10, 2 );
add_filter( 'woocommerce_variation_prices_price', 'custom_dynamic_sale_price', 10, 2 );
add_filter( 'woocommerce_variation_prices_sale_price', 'custom_dynamic_sale_price', 10, 2 );
And you need to make sure you've changed the woocommerce_get_variation_prices_hash becasue of the stored transients if you want to display it correctly for variable products.
You may find the gist i've created for a client useful
https://gist.github.com/xandl/743fb6af60827eb95ad42b20b478b020

Answer 3

use woocomerce_get_sale_price filter.
add_filter('woocommerce_get_sale_price', 'my_custom_price', 99, 2);
add_filter('woocommerce_get_price', 'my_custom_price', 99, 2);
function my_custom_price( $price, $product )
{
//your logic for calculating the new price here
$price = $product->get_regular_price() * 0.8;
//Return the new price (this is the price that will be used everywhere in the store)
return $price;
}