Remote Function Calls to Outside Internet site

[programsplus]

I am signing a new client that wants to be able to interface with an outside software/company (carrier411) that monitors �trucking� drivers/carriers for safety and insurance information, and then updates them when there is a change or update, etc� this would allow for notifications when a drivers safety rating drops, or insurance is expired, or renewed, etc without the need to manually monitor or update- that would automatically update a desktop application.

1) Can an application written in Alpha V9 Platinum (Desktop) create functions and scripts that call remote functions across the internet.

2) If this is yes, the documentation provided from the link below details what is needed to be done to create the interface. I am looking for someone that could write the interface (January 1, 2009 deadline).

http://www.carrier411.com/webservices.cfm

If you have information that would help me, or are interested in working on this project, please feel free to email me directly.

Thank you
Lynda Huddleston

[Lenny Forziati]

Re: Remote Function Calls to Outside Internet site

1) Can an application written in Alpha V9 Platinum (Desktop) create functions and scripts that call remote functions across the internet.

Sure, Alpha Five has a number of HTTP functions that you can use to send requests to remote servers. http_post() is a good starting point, though you may need to drop down to http_fetch() which gives a bit more flexibility.

2) If this is yes, the documentation provided from the link below details what is needed to be done to create the interface. I am looking for someone that could write the interface (January 1, 2009 deadline).

http://www.carrier411.com/webservices.cfm

A search on the message board for posts about HTTP and SOAP will give some good direction. Among those results, here is a thread where I helped someone properly send a SOAP request and get a response.

[Tim Kiebert]

Re: Remote Function Calls to Outside Internet site

Thanks Lenny,

I have had a look at that thread and it has helped with understanding a bit. I think at this stage the question of is it possible has been answered and exactly how will be on ongoing trial and error. I think that their (link in previous post) examples using php are confusing the issue for me and I wil concentrate on working with the alpha functions. I think it is boiling down to

-- the correct syntax in constructing the body of the 'Post' request (and maybe the header)
---- to call the remote function within the webservice
---- and supply the arguments to that function

Once that gets working we will see what the response looks like and go from their.

If you could point us to some resources on this it would be much appreciated. I have been checking out w3scools.com, w3.org and wikipedia. These are great for general info but I haven't managed to digest it enough so that the links between all the bits come together. It feels like I am close and just missing that last piece. If you have any other snippets of code lying around that you could share.

Once I get a few more details from the webservice re their required syntax I will be back. And if a miracle happens it might even be to report success. :)

And

[Lenny Forziati]

Re: Remote Function Calls to Outside Internet site

I'm not sure what you need pointers to. Here is the basic process. Let me know what else you might need pointers on.

1. Build a request body.
2. Send the request to the remote server.
3. Read the response and possibly take some action based on it.

Build the Request
The request body format depends on the API created by the service provider, in this case Carrier411. Unless you are well versed in PHP, it is probably better to look at the format they have defined and see what you must build instead of looking at a programming language you do not know and trying to reverse engineer it.

Ultimately, the request is just a character sting that follows a format they have defined, so you have a lot of flexibility in how you use Xbasic to build that string. Because it will be in XML format though, you may find it worthwhile to use MSXML via ActiveX to build the request body.

Send the Request
Because the request is an HTTP POST, you have a few options available. Listed by ease of use, they are http_post_page2(), http_post() and http_fetch().

I usually use http_post() as I personally find the balance of flexibility and ease of use to be about right.

http_post_page2() is NOT server safe and should never be used in an A5W page or any background thread. This is because it is built upon Microsoft's non-server-safe IXMLHTTPRequest object. http_post() and http_fetch() are server-safe and can be used in an A5W page or other background thread.

http_post_page2() will automatically follow a redirect if the server issues one, whereas http_post() and http_fetch() require you to look at the returned status code and programmatically follow a redirect if needed. A redirect is quite uncommon from most servers offering web services though.

http_fetch() allows you to set more options, such as specific headers, but also requires that you manually set more options. You may or may not need this, depending on the API created by your service provider.

Read the Request
http_post_page2() will return a string that is the body of the server's response. http_post() and http_fetch return a pointer that represents the entire response, including the HTTP headers and a body property which is the same string that would have been returned if http_post_page2() was used to send an identical request.

Much like assembling the request, Xbasic gives you a wide range of options to parse the response.

[Tim Kiebert]

Re: Remote Function Calls to Outside Internet site

Thanks for that very clear outline.

Besides those resources I mentioned I thought you may know of a 'How To Construct a SOAP message for Dummies' book or the like. :) Don't worry though, this is still early days and I am sure my friend 'google' will find something for me. I have learned heaps in the last two days.

The point I am at now is getting the message body correct and as you say I need to get into contact with Carrier411 techs and get an example message.
I did investigate the php (which I know nothing about) they are using and it is a library someone has written for handling SOAP messages that seems to read the wsdl file and then construct the message accordingly. I will leave that alone. As you say Alpha has all the tools needed.

Thanks again and will