I would like to connect to Bloomberg - data stream of stock quotations to our trading system written in Delphi.
The API libraries provided for download on the Bloomberg website (http://www.bloomberglabs.com/api/libraries/) do not include a version specific for Delphi.
Is there a way to access the Bloomberg API from Delphi if only C/C++, Java, .Net, Perl and Python libraries are available?
You can use without any problem the C/C++ SDK and map function calls into Delphi with the external keyword . Take a look at this example for more information .
However as someone stated in the comments since the API you are talking about just embed calls to a web service, you could just call the web service from Delphi or define your own API on Delphi based on the web service spec. You can just have a look at the source of the C/C++ and try yo convert it to Delphi.
If calling directly the web service or converting the the API to Delphi is not an option for you, you can just use the C/C++ API as external functions call.
Usually if I encounter the need to consume a web service where Delphi integration is not easy, I recommend to write a thin 'proxy' with one of the available SDKs.
Communication between the proxy and the Delphi side then can be implemented using simple file transfer, or a network protocol (such as HTTP).
In this case it could be:
(Bloomberg) <== Java SDK ==> (Java proxy) <== HTTP ==> (Delphi application)
The key advantage is that a first protoype can be implemented very quick, because all required parts are already present:
download SDK and create a Java web service (server) project
create small Delphi prototype which sends a HTTP request using Indy
in the Java web service, map the request parameters to a BB API call
map BB API call response to a Java web service response
read response in Delphi application
Related
I have a Java web service (with some server side business logic) created with jsp and servlets. Is there any useful way to let Dart and Java communicate / talk to each other? Does it make sense?
This is one solution: https://www.dartlang.org/articles/json-web-service/
Http can be sent or received by most languages.
A Dart client-side web application can indeed interact with server-side web services.
The language or platform that the server-side web services are written in and deployed on are unimportant as long as both sides support the protocols and data formats used to exchange messages.
Presumably your web service uses HTTP as the transport protocol and either XML or JSON as the data format. The article mentioned by #kpie should be a good starting point.
I'm planning to develop an adapter to access Siebel CRM data for my iOS app. I'm a new bee into this Siebel technology. I 've the Siebel CRM up an running in my workstation with sample db data. Could any one help me in getting this done? please excuse me if i've hosted this ques in a wrong stack.
There seems to be only 2 valid ways to do that:
SOAP webservices
REST api (but for this you need to have jboss or weblogic server: Sebel Bookshelf)
all other ways (Java Siebel Data Bean, COM interfaces, direct db access) got lots of issues: like issues with java on iOS ( I think it is not possible to run on iPhone), issues with legacy COM interfaces on iOS and numerous issues with direct db connection (complexity, stability, reusability...)
SOAP is out of the box on Siebel but requires more coding on iOS side, REST is easier on iOS or any webpage but requires some middlware:
JBoss/WebLogic + and RESTfull Siebel client form Siebel (available somewhere on their page)
java data bean app that produces REST
soap client that produces REST
I have worked on 2 projects involving iOS and Siebel: first one using JBoss and second project that used SOAP client which translated requests to/from REST. SOAP client approach was more stable (in comparison to RESTfull client from vendor - as the RESTfull client connects to Siebel internally using Java Data Bean) on Siebel 7.8.
In both cases we picked REST to talk to iOS as it allows easier deveopment on iOS side and also possiblity to easly utilize it in projects creating webpages to simplify/tune siebel GUI for different purpose..
If you're current system is sample db, then you have installed developer instance of Siebel. It uses a Sybase database. The server installation will use Oracle/MSSQL server. If you are ok with database connection, you can check that.
For Webservices, by default , Siebel does not support JSON/REST api. Only the older SOAP structure is supported. You will have to go through oracle bookshelves to setup an inbound webservice in Siebel.
But just to add, the latest version of Siebel's UI uses javascript/CSS, and runs on any browser, including IOs .
I've got a custom HTTP Server created using Delphi 7 and Ararat Synapse which receives HTTP GET from another application with a simple set of variables.
For example: http://myserver.com/get?Variable1=adsds&Variable2=asdasdasdsa&Variable3=aasdsadasdsad
The application source is similar to this - http://searchco.de/codesearch/view/13374072
Now, my customer needs me provide a SOAP interface. Completely new to SOAP, I did some research and found it to be very complicated. I would like to know what's the easier way to incorporate this interface to my HTTP server. Or should I find ready made SOAP To HTTP Conversion app if there is such a software. Thank you.
Note: I'm not the original developer of the HTTP Server.
There is a Web Service Toolkit for Free Pascal and Delphi which can be used to write SOAP servers.
I have not yet used it myself but it is in active development and might be compatible with Synapse.
Update: the current version seems to include support for Internet Direct (Indy) and Synapse (HTTP server and TCP server).
You need to write a SOAP server, which not only generates SOAP responses from SOAP requests, but which also provides a WSDL document telling the users what requests they can make.
Since your completely new to SOAP here are some 'starter' links:
General:
SOAP, WDSL, HTTP, XSD? What the?
List of publicly available web services (I would start writring a small testapp that consumes SOAP)
With Delphi:
Developing Web Services with Delphi
Web Services Made Easy With Delphi
Web services with Delphi
The fact that you are using Delphi 7 makes things more difficult, since later versions have better support:
Debugging/Testing Win32 SOAP Web Services (D2007). Bob has more SOAP articles
For testing both serving and consuming SOAP you should use SoapUI, a great free tool (What is SOAPUI?).
Once you are up to the WDSL you should know what types of WSDL exist and the whole namespaces mess...
Simple. I created a LINQ-TO-SQL Entity model, created a website, added a Data Service (*.svc) to this site and made sure it works by writing a simple .NET console application. The service works fine and cannot be modified.
Now I'm going to write a Delphi application (2007) for WIN32 which will have to call this data service. And while Delphi has no major problems importing a SOAP service, it can't import this service since it provides no WSDL...
So, two options. I could figure out how to generate a WSDL based on this data service or I'll have to find another way to consume this service. (Or just give up, but I hate to quit this challenge.) So, any advise?
ADO.NET Data Services are REST services. They are not SOAP WebServices and I don't think REST uses WSDL. You can call REST services from Delphi using HTTP GET/PUT/POST/DELETE. You could use Indy's TIdHTTPClient. See http://msdn.microsoft.com/en-us/library/cc668786.aspx for url examples. The results are in the Atom format, which is a XML format. You could parse it with TXMLDocument. They can also return JSON.
Maybe you can use the project Jedi "url grabber" components to consume the service. I have managed to get live share data using these in the past. I do not know exactly how your setup works, but maybe these can be helpful.
http://www.delphi-jedi.org/
You should also look at synapse, a small easy to use library which works well with REST. The latest version, which can be downloaded via SVN, works well in Delphi 2009.
I have some delphi code which, given a list of items, calculates the total price taking into account any special deals that might apply.
This code is non-trivial to rewrite in another language.
How should I set it up to communicate with a website running on the same server? The website will need to ask it for a price every time the user updates their shopping cart. It's possible that there will be multiple concurrent requests.
The delphi code needs to maintain an in-memory list of special deals, periodically refreshed from a database. So it cannot simply be executed every time or anything as simple as that.
I don't know what the website is written in, or even which http server it runs under, so I'm just looking for ideas or standard methods.
It sounds like the win32 app is already running as a Windows Service on the box. So, if you can't modify that service, you are going to have to deal with whatever way it wants to accept and respond to requests. This could be through sockets or some higher level communication protocol like web services.
You could do a couple of things. Write an assembly that knows how to communicate with the service and have your web site use that assembly. Or you could build a shim service that knows how to communicate with the legacy service, but exposes communication over higher level protocols such as web services. Either way will have the benefit of hiding the concurrency, threading and communications issue behind an easy to call interface, but the latter will make communicating with the service easier for everyone going forward.
If you can modify the delphi app to take an XML request and respond with an XML answer over a TCP socket (ideally using the HTTP protocol), you will be able to make it interoperate with most web server frameworks relatively easily. But the exact details of how to make that integration happen will depend on the language/framework it was written in.
If the web server is on windows you can compile your delphi app as a DLL that can return XML or HTML, taking parameters as part of the URL or a POST operation. Some details on making a Delphi DLL for web servers are here.
It doesn't matter what web server or OS the existing system is running under. What matters is what you want YOUR code to run under. If it is windows then the easiest solution would be to use WebBroker and write a custom ISAPI application, or use SOAP to expose web services. The first method could be used if you wanted to write a rest like API for instance, the second if your web application has the ability to consume web services.
Another option, if you are running both on the same box under IIS, is to create a COM/Automation object which you then invoke via server side scripting (ASP). If the application is an ASP.NET application, then I would use PRISM to port your code into an assembly.
I have done this with a quite complicated workers compensation calculator. I created a windows service using RemObjects Sdk. The calculations are exposed as a soap method so it can be accessed by nearly anything.
It's not necessary to use RemObjects in the service but it makes it much easier to do as it handles a lot of the underlying plumbing. The clients don't need RemObjects, they just need to be able to call soap methods. Nearly any programming langugae can do that.
You could also create an isapi dll for IIS that exposes a soap interface. This would be useful if other websites on different servers needed access to the methods. However I have handled this in my case by opening a port in the firewall to access my windows service.
There is a lot of examples on the web. A couple of places to start reading are About.Com and Dr Bob.
Torn this app into Windows Service. Write Web Service that will communicate with your windows service. You should spend some time designing your Web Service, because this Web Service is going to be your consistent interface, shielding old Delphi app. So in the future whenever you will want to write web app, mobile app, or whatever you will imagine, you will have one consistent interface – XML Web Service.
A popular way to integrate a web application with background services is a message broker.
The message flow would be:
the web application sends a "calculation request" message to a message destination on the message broker, which contains all needed parameters and also a correlation id to match the calculation request with the response from the Delphi service
one (or, in a high availability / load balanced environment more) Delphi services handle the messages: pull the next incoming message, process it by feeding the parameters to the calculation engine, and send a "calculation result message" back to the web server
the web server can either synchronously wait for the response (and discard responses which have no matching correlation ide) and build the result HTML document, or continue with other tasks and asynchronously receive the calculation result in a separate thread, for example in a Ajax based web application
See for an introduction this slideshow about the Dopplr image service:
http://de.slideshare.net/carsonified/dopplr-its-made-of-messages-matt-biddulph-presentation
If you can make it a service (but not a library), you have to do inter-process communication somehow - there are a few ways to do this on Windows:
Sockets directly which is hardest since you have to do marshalling/auth yourself
Shared Memory (yuck!)
RPC which works great but isn't trivial
DCOM which is easier but a pain to configure
WCF - but can you call it from your Windows Service written in Delphi?