Dynamic Calculations based on underlying data - php

Question

The story.
I'm trying to calculate product cost's based on multiple varying factors. My system currently works perfectly using PHP functions however I would like to add some Ajax in order to produce a more user friendly experience.
How I currently do it.
Entities
//entity/ProductRecipe.php
public function productcost2amountcost() {
$this->productcost = null;
$am = $this->amount;
$cu = $this->product->getCostunit();
$productcost = $am * $cu;
$this->productcost = $productcost;
$this->recipe->fixRecipecost();
$this->recipe->fixCostperyield();
}
//entity/Recipe.php
public function fixRecipecost() {
$this->recipecost = 0;
foreach ($this->product AS $pc) {
$this->recipecost += $pc->getProductcost();
$this->setRecipecost($this->recipecost);
}
}
public function fixCostperyield(){
$this->costperyield = null;
$cy = $this->recipeyield;
$rc = $this->recipecost;
$this->costperyield = $rc / $cy;
}
Forms
//Form/RecipeType.php
$builder
->add('recipename', 'text', array(
'label' => 'Recipe Name'))
->add('recipeyield', 'number', array(
'label' => 'Recipe Yield'))
->add('product', 'collection', array(
'label' => 'Ingredients',
'type' => new ProductRecipeType(),
'allow_add' => true,
'by_reference' => false,
'allow_delete' => true,
));
//Form/ProductRecipeType.php
$builder
->add('product', 'entity', array(
'class' => 'BCInventoryBundle:Product',
'property' => 'prodlist',
))
->add('amount', 'number', array(
'label'=>'Quantity',
))
->add('measure', 'entity', array(
'class' => 'BCInventoryBundle:Measures',
'property' => 'unit',
))
->add('productcost' ,'money', array(
'currency' => false,
'read_only' => 'true',
))
;
As I stated before this all works fine, albeit a bit boring and static.
Issue
As you can see from the picture. The ProductRecipe is used as a collection of form's from within the Recipe form. What I want is once the User has selected a product from the Database (Butter) and stated a quantity (1) and measure (kg) I need Ajax to first get the UnitCost (all Units get converted to Grams and update a filed called Unitcost)
1kg convert to g = 1000, 1000 * unitcost (0.0079600000) = £7.96 <- This needs to be put into the ProductCost field of the form.
Any help would greatly be appreciated even a point in the right direction would be amazing. I've spent hours Google-ing but the stuff that comes up never quite seems to be what I need especially when it comes to Symfony2 related.
How do I run the productcost2amountcost() function using Ajax in order to fill the ProductCost field without a page refresh.
Thank-you in advance. Doug.
The Answer
Thank's to Santiag00 after much trial and error for us both we got it working. He's updated his part but I'd like to elaborate a bit.
Javascript
//Calc.js
$(document).on('change', '.products, .amounts, .unit', function(event) {
var amount = $(this).parent().parent().parent().find('.amounts').val();
var productId = $(this).parent().parent().parent().find('.products').val();
var unit = $(this).parent().parent().parent().find('.unit').val();
var productCostField = $(this).parent().parent().parent().find('.product-costs');
//The above assign a Var to each of the field's needed for the JS
console.log(productCostField);
console.log("Amount: " + amount + " - ProductID: " + productId + " - unit: " + unit);
if (amount == "" || productId == "" || unit == "") {
// Don't make the Ajax call if you are missing one of the two values
return false;
}
// This will be triggered every time a product or amount input field is changed
$.post(
Routing.generate('calculate_cost'),
//This line is what connects to the Function in the controller and defined in routing.yml. Made easier by
//https://github.com/FriendsOfSymfony/FOSJsRoutingBundle/blob/master/Resources/doc/index.md
{
// Use the corresponding amount and product ID
product: productId, amount: amount, unit: unit,
},
function(data) {
data = JSON.parse(data);
if (!data.success) {
// An error was thrown in the controller
alert(data.message);
}
else {
// Update the corresponding productCost field using the data from the controller
console.log("Product cost: " + data.productCost);
productCostField.val(data.productCost);
}
}
);
}
);
The Route Called from the above JS.
//routing.yml
calculate_cost:
pattern: /productcost
defaults: { _controller: "BCInventoryBundle:ProductRecipe:getProductCost" }
options:
expose: true
Last of all, the function called from the above JS.
//ProductRecipeController.php
public function getProductCostAction(Request $request) {
$amount = $request->request->get('amount', null);
$productId = $request->request->get('product', null);
$unit = $request->request->get('unit', null);
if (empty($amount) || empty($productId)) {
return new \Symfony\Component\HttpFoundation\Response(json_encode(array('success' => false, 'message' => 'Bad input')));
}
$em = $this->getDoctrine()->getManager();
$product = $em->getRepository('MyBundle:Product')->find($productId);
$u = $em->getRepository('MyBundle:Measures')->find($unit);
$mass = new Mass($amount, $u->getUnit());
$fam = $mass->toUnit('g');
if (empty($product)) {
return new \Symfony\Component\HttpFoundation\Response(json_encode(array('success' => false, 'message' => 'Invalid product')));
}
$productCost = $product->getCostunit() * $fam;
return new \Symfony\Component\HttpFoundation\Response(json_encode(array('success' => true, 'productCost' => $productCost)));
}
I really hope this can be helpful to other people out there. If you find it useful please up-vote Santiag00 we spent ages trying to figure this out. The main part to notice is how we had to select the field's because of how nested they were when using embedded forms in Symfony.

Answer 1

One solution would be to install "FOSJsRoutingBundle" (https://github.com/FriendsOfSymfony/FOSJsRoutingBundle) to expose routes in Javascript. That way you would be able to create a new action in a Controller that would calculate a product cost and return it as a JSON to the HTML.
The action in the controller could look something like this:
/**
* #Route("/productcost", name="calculate_cost", options={"expose"=true})
* #Method("POST")
*/
public function getProductCostAction(Request $request) {
$amount = $request->request->get('amount', null);
$productId = $request->request->get('product', null);
if (empty($amount) || empty($productId)) {
return new \Symfony\Component\HttpFoundation\Response(json_encode(array('success' => false, 'message' => 'Bad input')));
}
$product = $this->getDoctrine()->getManager()->getRepository('ProductBundle:ProductRecipe')->findOneBy(array('id' => $productId));
if (empty($product)) {
return new \Symfony\Component\HttpFoundation\Response(json_encode(array('success' => false, 'message' => 'Invalid product')));
}
$productCost = $product->getCostunit() * $amount;
return new \Symfony\Component\HttpFoundation\Response(json_encode(array('success' => true, 'productCost' => $productCost)));
}
And then the AJAX call could look like this:
<script>
$(document).on('change', '.products, .amounts', function(event) {
var amount = $(this).parent().children('.amounts').val();
var productId = $(this).parent().children('.products').val();
if (amount == "" || productId == "") {
// Don't make the Ajax call if you are missing one of the two values
return false;
}
// This will be triggered every time a product or amount input field is changed
$.post(
Routing.generate('calculate_cost'),
{
// Use the corresponding amount and product ID
amount: amount,
product: productId
},
function(data) {
data = JSON.parse(data);
if (!data.success) {
// An error was thrown in the controller
alert(data.message);
}
else {
// Update the corresponding productCost field using the data from the controller
$(this).parent().children('.product-costs').val(data.productCost);
}
}
);
});
</script>

Answer 2

productcost2amountcost seems too complex and it has strong relation to state of the model.
If you want to update DB (or some store) each time client sends ajax request, you can use productcost2amountcost. But it is expensive and risky. (You must control the order of requests) [Solution1]
If you want to treat requests more simply, I think you should convert productcost2amountcost to stateless (as a procedure) and some small logic. (State managed by client) [Solution2]
New procedures receive some parameter (e.g. product, quantity, measure) through ajax, and send response (e.g. productcost).
(If you use temporary models (non-stored), you can use productcost2amountcost. But you should remove reference to Recipe from productcost2amountcost)
But in this case, I think you don't have to use ajax.
You can calculate all costs by javascript with the form data (include hidden unit cost and measure scale) for usability, and re-calculate in server side for update at last. [Solution3]
Logic duplication and calculation of different architecture are damn, but it is maybe simple solution.