Develop Reference

How to retrieve a payment method on the client side?

We are running an App with a Angular/Typescript frontend and a .NET backend, using Stripe Elements and Stripe.NET respectively.
We are currently using the "Sources" API.
The frontend can create sources, the backend saves them to our specific users. When you open the frontend again, the backend sends a list of source ids. The frontend then collects the data it needs to display those sources directly from Stripe so the user can pick one of his saved sources to pay and does not have to enter all the data again.
Enter the Payment Method / Payment Intend API.
Due to EU regulations Stripe has a new API that requires us to create cards no longer as "source" but as a "PaymentMethod". So I implemented that in the backend, opened the frontend in my IDE, updated the #types/stripe-v3 package and found the new payment intent API.
The only thing missing: I cannot figure out how the frontend is to access the payment method data, once created. I can create it. Send it to the backend. The backend can retrieve it. Send back the ID to the frontend... and now what? How to display the payment methods available?
I had expected a stripe.retrievePaymentMethod() as there is a stripe.retrieveSource(). But no such luck.
The only option I currently see to present the user with a list of existing payment methods is getting this info on the backend and piping it all, class by class, property by property to the client. Basically copying every single data class stripe has into our own backend REST definition. That cannot be right.
What am I missing? Why is there no stripe.retrievePaymentMethod() on the frontend? Did I not understand some fundamental facts about what those APIs should do?

After contacting Stripe directly, it was confirmed that that's just the way it is:
I think it's just an oversight that we didn't add one.
There are similar functions in the mobile SDK so I don't see why we shouldn't have it
There are no immediate plans to add the functionality back in in the very near future,
so as a workaround, I will tunnel all the data through our backend(s).

If I understand as well, I think your problem is following and the sequence of that. I hope this helps you.

I have implemented a payment gateway like ccAvenue with DotNet and angular, in my case, I send the data to the server, and from the server, I tried to redirect to the payment gateway, but APIs return some result, and the result can not be redirected.
So I created a web-form with implementation, I redirected my app to web-forms page and from there I called the ccAvenue page, and in the response URL, I send the response page of webforms only and after saving the response I redirected to my angular app.

Here is workaround if you want to process 3Dsecure cards and still support other methods like SEPA.
You could attach both, confirmed PaymentIntent (payment method) or Source to the Customer object.
On your frontend you could implement both (StripeElements with client secret for 3Dsecure cards) and IBAN element for SEPA.
I could provide my code example how I save payment intent to the customer. It's in PHP, but for other languages logic should be the same.
Assuming that our client already confirmed PaymentIntent and we have it's id:
$intent = \Stripe\PaymentIntent::retrieve($stripe_intent_id);
$payment_method = \Stripe\PaymentMethod::retrieve($intent->payment_method);
$stripe_customer = Stripe\Customer::create([
'payment_method' => $intent->payment_method,
]);
In case you've already created Customer object before you could use attach method:
$payment_method->attach(['customer' => 'cus_FTkGe4lv5LfyI0']);
Then you'll be able to charge using Customer object PaymentMethod or Source;
I didn't try to attach both methods to the same customer object (we only allow customer to have one payment option at the same time), but it should work. Let me know if it works for you.

How to get specific property of gmail emails when requesting a list?

I work with Gmail API, I found how to get a list of message ids and, in a loop, how to get specific properties of those emails separately.
Problem is to make request for each email is very slow, mainly when my client have hundreds of mails ordered in hundreds labels...
I've tried to find a method to get one specific property at the first request, when I use UsersResource.MessagesResource.ListRequest, but unsuccessfully...
For information, the property I want to get is "Message-ID" (not the id given by Google).
I did it once with Exchange Web Service, that why I'm looking to do it with Gmail API, if possible.
Thanks for answers in advance.
PS: Excuse my English, which is not my native language.

When you make your request to the API you can send an optional parameter called fields it will allow you to return a partial response and just the fields that you are intrested in
Documentation
https://www.googleapis.com/demo/v1?key=YOUR-API-KEY&fields=kind,items(title,characteristics/length)

payment_status in Paypal

I am using Website Payments Standard integration and in PDT I am confused about showing message to customer on return page if transaction fails due to something, but I cant get messages directly as a response from Paypal, rather I get codes. I was thinking to create a function that will take code as a Parameter and return Error Message. I went here and read about payment_status variable. I got confused when I saw same variable can can set to 1 value off 11 at one place and off 3 at another. What exactly it will return in my scenario? 1 off 3 or 1 off 11?
Edit
See that variable under Mass Pay Variables and Payment Information Variables in this link.

The payment_status would be various things depending on the txn_type. That's why they are separated in categories like that. If you get a txn_type of masspay, then the payment_status would only be 1 of those 3. The majority of the txn_type's will have a payment_status that falls in the list of 11 you mentioned. If you're using a standard button you'll typically follow the information under the Payment Information Variables section.
On another note, make sure you're not using PDT to handle any post-payment processing like updating your database, sending email notifications, etc. Even with Auto-Return enabled there is no guarantee the user will make it back to your return URL, and if they don't, that code will never run.
Instead, you should use IPN to handle such processing, which is very similar to PDT except that it happens separate from the checkout flow altogether. As soon as any transaction takes place on your account PayPal's server will POST data about that transaction to your IPN listener URL. The data will be the same as what you're looking at with PDT, but IPN will always be triggered regardless of whether or not the user makes it back to your site.
IPN will also allow you to correctly handle things like pending payments from e-checks, fraud filters, etc. that would need to clear before you deliver the product. You'll get an IPN when the pending payment takes place, and another IPN when that payment is updated to completed, failed, or whatever.
IPN also allows you to automate tasks based on refunds, disputes, etc. It's a very powerful tool, and again, it's definitely recommended over PDT.

Cellular/Network SMS integration for Quiz application

I tried with google but no success, what i want to do is to make sms poll/quiz type of thing where user can send sms to "7766" and get response like "Welcome to ABC. reply with 1 to get you new question, 2 with help, and 3 to view your result " . this will be a a two way communication and on sending any sms will cost $10 .
Here are my question:
How can i do that?
Do i need to ask sim [provider for tht Number (7766)
This should work from some specific country only.
I need to charge amount on entering the QUIZ.
Well as new to this, i dont see any starting point from wher i can start. I need reference or some one already did that or like this thn kindly share that.

Perhaps you can have an ecommerce solution on your website (Paypal for example) and then once your user has paid, they have access to a portion of your site that uses an HTTP SMS API. An example of a provider of such a service would be http://www.bulksms.co.uk/w/eapi-sms-gateway.htm
These APIs allow you to send messages, receive delivery reports and receive replies (amongst other things).
It's quite a wide-ranging question though.

Embedded screen - security

We have a web application : C# + SQL 2k5
Different companies send us information, we parse, them, do different things, and come up with a simple list for each of our customers. The list will look the same, but will have different information based on the customer.
They should not have access to each other's data.
We would like to create a page which would be embedded on their own site. I was thinking about using something like an iFrame.
Basically customer ABC would embed on his own abc.com an iframe with a URL (we will give them the parameters needed) and his clients will see our data on his site.
The other customer, lets call him xyz, has an other website xyz.com, will do the same thing, but in the url I should make a difference between them.
I would like to know how is the best, safest way to proceed.
How should I start to build up this page that is going to be embedded.
How should I make a difference between the 2 customers? The only way to get info from them is the parameters they send me, and eventually, I could get the 'parent' of my embedded iFrame, so that might help me restrict xyz to embed using url parameter info to get data from abc. See my dilemma?
Probably a unique identifier for each customer (like a GUID?) will be needed, and they woul dnot know each other's ID ... Or is there a more secure way to do things like this?
Any help would be appreciated.
Thanks

Embed a publically visible unique id in the URL and process this to extract the client id. e.g.
<IFRAME src="http://example.com/1122334455667788aabbcc">
You could check the Request.UrlReferrer to ensure that the request see this answer
However the only safe way of doing this is to provide an authenticated API that the site uses server side to process via a services API (e.g. WCF), or at the very least an authenticated HttpWebRequest; any other way leaves your data only as secure as a publically visible unique id.

Take a look at how one of the credit card processing portals do this (eg WorldPay or Paypal). There are several ways.
At the very least you need provide each customer with a unique ID that they send you.