How to change the price ? (add_to_cart)

Question

Here is my code

function addToCart($product_id, $quantite){
    global $user;
    $product = commerce_product_load($product_id);
  $line_item = commerce_product_line_item_new($product, $quantite);
  $line_item->data['context']['product_ids'] = array($product_id);
  $line_item->commerce_unit_price->amount  = '900';
  commerce_cart_product_add($user->uid, $line_item);
}

The above code add the product to the cart with the correct quantity but the price isn't changed ... Any idea ?

Update (resolved thanks to scott's answer)

//Panier
function addToCartCallback()
{
    addToCart($_POST['product_id'], $_POST['quantite']);
}

function addToCart($product_id, $quantite){
  global $user;
  $product = commerce_product_load($product_id);
  $line_item = commerce_product_line_item_new($product, $quantite);
  $line_item->data['context']['product_ids'] = array($product_id);
  commerce_cart_product_add($user->uid, $line_item);
  $order = commerce_cart_order_load($user->uid);
  commerce_cart_order_refresh($order);
}


function groupes_views_commerce_cart_line_item_refresh($line_item, $order_wrapper) {
  global $user;
  $idProduit = $line_item->commerce_product['und'][0]['product_id'];
  $prix = getPrixClient(getIdClient($user->uid), $idProduit) * 100;
  $line_item->commerce_unit_price[LANGUAGE_NONE]['0']['amount'] = $prix;
  $line_item->commerce_unit_price[LANGUAGE_NONE]['0']['data']['components']['0']['price']['amount'] = $prix;
}

Answer 1

I thought of another way to do it.

Start with code that just adds the product to the cart without modifying.

function addToCart($product_id, $quantite) {
    commerce_cart_product_add_by_id($product_id, $quantite);
}

Then you can use a hook to modify the line item amount

//alter the price in cart & order
function my_module_commerce_cart_line_item_refresh($line_item, $order_wrapper) {

    $price = 100; //1 dollar
    $line_item->commerce_unit_price[LANGUAGE_NONE]['0']['amount']=$price;
    //alter the base_price component
    $line_item->commerce_unit_price[LANGUAGE_NONE]['0']['data']['components']['0']['price']['amount']=$price;

}

If this doesn't work try forcing the cart refresh e.g.

function addToCart($product_id, $quantite) {
    global $user;
    commerce_cart_product_add_by_id($product_id, $quantite);
    $order = commerce_cart_order_load($user->uid);
    commerce_cart_order_refresh($order);
}

Answer 2

Programmatically adding or modifying the price of a line item is quite tricky.

Here is an example of updating a line item amount

// Create a line item with quantity 1 and this product.
$line_item = commerce_product_line_item_new($product, 1, $order->order_id);

// set up price data
$line_item_price = commerce_price_field_data_auto_creation();
$line_item_price['amount'] = 900.0 * 100; // DC stores in cents
$line_item_wrapper = entity_metadata_wrapper('commerce_line_item', $line_item);
$line_item_wrapper->commerce_unit_price = $line_item_price;

// fix price data components
commerce_line_item_rebase_unit_price($line_item_wrapper->value());

// Save the line item to get its ID.
commerce_line_item_save($line_item);

Take a look at this article for a full example of adding a line item programmatically.

http://divingintodrupal8.com/#drupal-commerce-adding-line-items-programmatically

Edit:

Here is your code with a couple of changes. Note when we create the order now we set the status to 'cart'.

function addToCartTest($product_id , $quantite){
  global $user;

  // first create a new order
  $order = commerce_order_new ($user-uid, 'cart');
  // Save the order so its ID is assigned.
  commerce_order_save($order);
  $order_wrapper = entity_metadata_wrapper('commerce_order', $order);
  //Now we can add a line item - assuming $price is the amount without sales tax
  // get product by sku
  $product = commerce_product_load($product_id);
  // Create a line item with quantity 1 and this product.
  $line_item = commerce_product_line_item_new($product, $quantite, $order->order_id);
  // set up price data
  $line_item_price = commerce_price_field_data_auto_creation();
  $line_item_price['amount'] = 100 * 100; // DC stores in cents
  $line_item_wrapper = entity_metadata_wrapper('commerce_line_item', $line_item);
  $line_item_wrapper->commerce_unit_price = $line_item_price;
  // fix price data components
  commerce_line_item_rebase_unit_price($line_item_wrapper->value());
  // apply sales tax
  //commerce_tax_rate_apply(my_module_tax_rate(), $line_item);
  // Save the line item to get its ID.
  commerce_line_item_save($line_item);
  // Add the line item to the order using the wrapper.
  $order_wrapper->commerce_line_items[] = $line_item;      
  commerce_order_save($order);
}

Also note the code above sets the amount to $100.