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Dmitry Maslennikov · Jan 27, 2019

Well, such an interesting topic, and also quite wide.

Ok, TWAIN, is an API for image sources, it can be scanner or photo camera. You just asking about working with TWAIN, without any explanation of how you are going to use it and what sort of devices you going to utilize.

So, I'll just share some of my experience. How I've used only scanners, different types and with different workflows.

  • Server way. One or more stream document scanner (sorry don't know right term in English). Just any scanner which can work in network and configured to place all scans to some network folder or send my emails. Before sending some documents to this scanner, the operator should stick some barcode, on the title page, or on added empty first page. On the server side, we have used ABBYY Recognition Server, which just watches some folder, and can decode barcode and recognize text in the document, pack it in XML and place it in another folder. This folder was watched by Ensemble, where we searched for barcode in our system and placed this as an attachment to this document. With recognized text, we also are able to search documents in our system by the content of this document.
  • Client way. The operator working with a personal scanner connected right to his machine. While our application web-based and the server is far from this scanner, we used only client resources to scan images. We used java-applet which worked directly with TWAIN sources, so operator just called some functionality right from our application after finishing the scan, it has appeared as an attachment in the document. But this case now has some issues due to limitations for JAVA plugins in modern browsers. But it is now possible to find some modern solutions which may help to get access to twain on modern browsers, you can just google it.
Dmitry Maslennikov · Jan 25, 2019

CACHE.DAT or IRIS.DAT, can only grow during normal work. But you can shrink it manually. But it is not as easy as it maybe sounds. And depends on version which you use, only past few versions were added with the compact tool. On very old versions you have to copy data from old database to thew new one.

You can read my articles, about internal structure of CACHE.DAT, just to know what is this inside. And about database with visualization, where you can see how to compact database, and how it actually works.

Dmitry Maslennikov · Jan 24, 2019

Sounds quite strange, why do you need to parse the connection? DbVisualizer works through JDBC, but there you limited only with SQL. If you would write own application which will work over JDBC, you will get more options. But JDBC is just only one option for remote access. You can find more options in the documentation, in different languages.

Dmitry Maslennikov · Jan 23, 2019

SSO, can be achieved in some different ways. It can work over OAuth2, NTLM, Kerberos, SAML and so on. In different projects, I have used Kerberos/NTLM and OAuth2. But real SSO was only with Kerberos. And when you already have LDAP Auth in your application, it will be quite easy to add SSO. But also depends on which OS and which WEB server you have. On Windows much easier to start with IIS while so difficult to find a working module for Apache. On Linux there is also could be a problem to find the latest version of the module which will work with the latest version of apache. But when you will manage to get it worked on web-server side, on Caché side, almost nothing to do left. When you get first unauthorized request, you should return back with status 401, and say which method of authentication you need through header WWW-Authenticate: NTLM. Then if web server managed to get username, it will send it by header REMOTE_USER. Of course, you will not get password, you just use this username and authorize session. 

Dmitry Maslennikov · Jan 23, 2019

If your server on windows, you have two connection options. 

  • Terminal. Available only locally, and can use windows security. Enabled by default.
  • Telnet. Used to connect from outside. Disabled by default (you can activate this service in SMP.). After enabling, you can connect using terminal or any other tool by default port 22.

If your server on Linux. You have only one option is csession or irissession tool which works only locally to the server. For remote access you should use ssh or telnet. But you can't configure telnet from Cache. You should do it by yourself.

Dmitry Maslennikov · Jan 22, 2019

How Caché works with licenses, actually very interesting and sometimes quite difficult to understand, but it is possible to find a balance for everybody. Fortunately, at the same time, it has actually some tricks on how to turn it on your side.

The first important thing is every time when user login, you should log in the user not only in security but license as well. In this case, if the user uses the same IP address will be used the license unit.

In your case, I'm not even sure about forcing log out, do you really need it? You mentioned that your application still web, and does not matter is at wrapped as an application or opened right from the browser. You should have the same behaviour. So, you can reduce timeout for the session, add some timer which will ping the server from time to time when app is active to extend session time. Sessions on the server side also have a grace period after a timeout which is 5 minutes long, in most cases enough to return back from the call.

Dmitry Maslennikov · Jan 21, 2019

Well,

this add-in url is

/isc/studio/templates/%25ZEN.Template.AddInWizard.SOAPWizard.cls?Namespace=USER

But when you redirect with Redirect directive, your query part dissapear. And it opens with default namespace %SYS.

To solve it you should use mod_rewrite instead with RewriteCond and RewriteRule directives. I don't give you any examples, just don't have a good place to check it. But I think I can find it.

Dmitry Maslennikov · Jan 20, 2019

Usually, the problem which you can face with SSL, is, how to trust self-signed certificate. In your case looks like, you have one server for development, and everybody connects to this one server. And in this case, there are two ways to make this SSL trusted,

  • if you have a domain name which publicly available, from the internet. Internal servers should not be available from outside, just only one server, where you can generate certificate with Let'sEncrypt. And you can make wildcard certificate as well. 
  • you don't have such domain name, and don't have access from outside. So, you should have own certificate server, and make by yourself. I think this way is a bit harder.

For local instances, when you need SSL only on your machine for yourself, you can use the mkcert tool and any subdomain from localtest.me (which goes to localhost) for example.

Dmitry Maslennikov · Jan 7, 2019

CACHE.DAT or even IRIS.DAT does not have any relation with operation system. So, you can easily move database files between instances on different OS and versions. But you should remember about data itself, like differences between 8-bit and Unicode. And code, which should be compiled for particular version but also not depends on OS.

You can find some details about database format from my articles.