Welcome!

Artificial Intelligence Authors: Ashish Nanjiani, Rajeev Kozhikkattuthodi, Liz McMillan, Elizabeth White, Yeshim Deniz

Related Topics: PowerBuilder, Microsoft Cloud, Artificial Intelligence

PowerBuilder: Article

DataWindow Magic: Menu Security

Designing and implementing your own

Security is a must for most corporate applications. This article will give you a starting point to designing and implementing your own. We will do it with a table that is added to the example database and implement it in ancestor code. The idea is that you should only have to add rows to a table to implement your security.

The Table
The security table will provide a means to turn on and off controls and menu items as our inherited objects are constructed.

Security

Login_name varchar(20) PK

Application varchar(20) PK

Item_type varchar(10) PK

Item_name varchar(20) PK

Priviledge varchar(2)

 

Security

Column Name

Data Type

Description

Login_name

Varchar(20) PK

The login name of the user

Application

Varchar(20) PK

The name of the application

Item_type

Varchar(10) PK

Might be window or menu or a type of control in a window like a command button. We will only cover menu types in this article.

Item_name

Varchar(60) PK

Menu item name like "File" or "New"

Priviledge

Char(2)

NULL = no priviledges

R = read only

I = Invisible

W = read/write

The Item Datastore
Although I had several choices I decided to create a datastore that would return all of the specified item types for an application. If I was in a menu I could look for menus. If I was in a window I could look for windows.

Ds_security_list data source

SELECT "security"."application",  
"security"."item_name",  
"security"."priviledge",  
"security"."login_name" 
FROM "security" 
WHERE ( "security"."item_type" = :as_itemType ) AND 
( "security"."application" = :as_appName ) AND 
"security"."login_name" = :as_loginName

This will give you all the items and privileges for the supplied application name and itemtype.

Now that we have this we can start our menu.

The Root Menu
Menus don't have constructors. We are going to implement our security with a function. I created a new menu and added a function called mf_loadSecurity.

Here is the code for mf_loadSecurity

M_root.mf_loadSecurity(as_loginName, as_appName)

// First get a list of all menu security items
datastore lds
lds = create datastore
lds.dataobject = "ds_security_list"
lds.settransobject( sqlca)

// Now retrieve
long ll_row, ll_max
ll_max = lds.retrieve(as_loginName, as_appName, "menu")

Let's discuss this code a little before we continue. As you'll see, handling a menu programmatically, for any reason, is necessarily complex.

The menu object has an array of items in it. Each of those items is another menu item that also has its array of items.

If the array of items in any particular menu item has no elements, then that is a bottom level menu item. If there are elements in the array then those elements compose the sub-menu for that menu item.

You might want to read the last couple of paragraphs a few times. Here, let me give you an example.

For my article I created a menu object inherited from m_root and named m_main that looks something like the following:

I didn't want to confuse the issue too much so I put in only the File menu option along the top. Under File I put New and Exit. Under New I put Test 1, Test 2, and Test 3.

Here is how the menu looks in the menu painter.

Note that I have an item called Invisible in the menu. This comes from m_root. I put it there to implement system-wide shortcuts. The visible property for this is FALSE.

For our test we are only concerned with the Test 1, Test 2, and Test 3 menu items. I am going to make Test 1 read-only and Test 2 invisible.

Since we have this metaphor of arrays of menu items within menu items we are forced to use recursion. Don't worry, though, we'll walk through it.

Recursion
Recursion has been known to throw even the bravest programmer into fits of apprehension. Essentially we need two functions. One just fires off the recursive function for every element in its item array. The recursive function will check to see if the arguments to itself are a match. If so, it returns itself. If they are not then it loops through its own item array, calling itself for each element.

The function mf_loadSecurity calls the recursive function. The first part loads the datastore that holds the security list. We have already defined that. The mf_loadSecurity takes two arguments. Those are the arguments that are used to retrieve that array.

Once we retrieve that datastore we have a row for every row in the security table that matches the login name of the user and the application name has an item_type of ‘menu'. At this point we are not worried about the window security. The mf_loadSecurity will loop through all of those to work its magic.

Note that I could have gone the opposite route and looped through each and every menu item recursively then done a singleton select in each one. I chose the former because I think it will be rare that we will have a row for all of the menu items and thus this will be a faster response time. Here we do one call to the server for the result set rather than one call for every menu item.

I loop through every row. I extract the privilege and the item name for each row. I call the recursive function for each row, looking for the item. I pass myself and the item name.

The recursive function mf_findMenuItem will return the found menu item or a null. If it is a null then the menu item was not found.

If the item was indeed found then I set the appropriate property for that menu item (depending on the privilege that I just read).

If you look closely at the code for mf_loadSecurity while reading the explanation you should be able to understand rather easily.

mf_findMenuItem
mf_findMenuItem is the recursive function. It calls itself from within itself. Recursion is not terribly complicatee but you have to remember to give yourself some way to unwind from the function otherwise you waste a lot of processing.

M_root.mf_findMenuItem(menu amenu, string as_name)

//Are we there yet?
if amenu.text = as_name then
return amenu // Yes, we are... let's go home
end if
// This wasn't a match, we have to look in the item array

long ll_row, ll_max
menu lmenu_return // the return value
setNull(lmenu_return) // default to null

// Loop through the item array

ll_max = upperBound(amenu.item)
for ll_row = 1 to ll_max
// Call myself for every element in the array

lmenu_return = mf_findMenuItem(amenu.item[ll_row], as_name)
if isNull(lmenu_return) then
// It was not a match, look in the next element
else
return lmenu_return // We got a match, time to unwind
end if
next

// No match in the entire item array, sorry about that.
return lmenu_return

The comments should make this fairly obvious but I'll walk you through it anyway.

We have two arguments. One is the menu that we would like to search. Remember, it has its own item array. First we check to see if this menu item is a match. If it is then we're done. If it's not then we have to search every element in the item array for a match.

That's basically all there is to it.

Insert Security Rows in the Database
Next we need to insert the two rows in the database that will let us have the effect we want. One row has to set the ‘Test 1' menu item to read-only and the other sets ‘Test 2' to invisible.

Rows for our security table

INSERT INTO "security" 
( "login_name",  
"application",  
"item_type",  
"item_name",  
"priviledge" ) 
VALUES ( 'dba',  
'security_test',  
'menu',  
'Test 1',  
'R' )  ;

INSERT INTO "security" 
( "login_name",  
"application",  
"item_type",  
"item_name",  
"priviledge" ) 
VALUES ( 'dba',  
'security_test',  
'menu',  
'Test 2',  
'I' )  ;

Implementing the Menu Security
Now we inherit a window from w_root and we give it the m_main menu. Then we go to the open event of w_root and put in the following code:

W_main.open

m_root lmenu
lmenu = this.menuid
lmenu.mf_loadsecurity("dba" , "security_test" )

This should be pretty self-explanatory. You might not be aware of what the second line means. The menuid property of any window is the menu object that is assigned to that window.

You might wonder why I would add this code to the open event and not the ue_postOpen. The answer lies in the functionality of the open even and ue_postOpen.

The open event happens before the drawing of the window. The ue_postOpen is posted in the ancestor window (w_root) and therefore happens after the window is drawn. In our case we don't want the window to be displayed until after the security happens so this is one of the very rare instances where we want code in the open as opposed to the postOpen events.

The Final Touch
Lastly we have to add the code for the Application open event to fire everything off.

Application open event

// Profile EAS Demo DB V115
SQLCA.DBMS = "ODBC"
SQLCA.AutoCommit = False
SQLCA.DBParm = "ConnectString='DSN=EAS Demo DB V115;UID=dba;PWD=sql'"
connect using sqlca;

open(w_main)

Of Course There Is Always More
If you think about the menu security you will soon realize that we don't allow for duplicate menu texts. Only the first match to a text will be found. We could change this by comparing the menu name rather than text. That would be something like m_root.m_file.m_new.Test1. That won't be a hard change if you want to do it yourself.

You could also use this metaphor to implement window level security. Using the same table then looping through the control array for the window in the open event looking for window controls that are in the security table for the user name and application. That should be simple enough for you now that you know how to do it.

NOTE: The code in this article uses my proprietary tools.pbl. You can reproduce it or you can write me asking for both the source of this article and the tools pbl as well. My e-mail address is at the bottom of the article.

Also, all the data for the application comes from the sample database that comes with PowerBuilder. That is the database that almost all of my readers have. I have had to expand the table though to support the needs of this article.

More Stories By Richard (Rik) Brooks

Rik Brooks has been programming in PowerBuilder since the final beta release before version 1. He has authored or co-authored five books on PowerBuilder including “The Definitive DataWindow”. Currently he lives in Mississippi and works in Memphis, Tennessee.

Comments (0)

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


@ThingsExpo Stories
SYS-CON Events announced today that Datanami has been named “Media Sponsor” of SYS-CON's 21st International Cloud Expo, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Datanami is a communication channel dedicated to providing insight, analysis and up-to-the-minute information about emerging trends and solutions in Big Data. The publication sheds light on all cutting-edge technologies including networking, storage and applications, and the...
SYS-CON Events announced today that EnterpriseTech has been named “Media Sponsor” of SYS-CON's 21st International Cloud Expo, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. EnterpriseTech is a professional resource for news and intelligence covering the migration of high-end technologies into the enterprise and business-IT industry, with a special focus on high-tech solutions in new product development, workload management, increased effi...
SYS-CON Events announced today that MobiDev, a client-oriented software development company, will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place October 31-November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. MobiDev is a software company that develops and delivers turn-key mobile apps, websites, web services, and complex software systems for startups and enterprises. Since 2009 it has grown from a small group of passionate engineers and business...
SYS-CON Events announced today that GrapeUp, the leading provider of rapid product development at the speed of business, will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place October 31-November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Grape Up is a software company, specialized in cloud native application development and professional services related to Cloud Foundry PaaS. With five expert teams that operate in various sectors of the market acr...
SYS-CON Events announced today that Ayehu will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on October 31 - November 2, 2017 at the Santa Clara Convention Center in Santa Clara California. Ayehu provides IT Process Automation & Orchestration solutions for IT and Security professionals to identify and resolve critical incidents and enable rapid containment, eradication, and recovery from cyber security breaches. Ayehu provides customers greater control over IT infras...
Artificial intelligence, machine learning, neural networks. We’re in the midst of a wave of excitement around AI such as hasn’t been seen for a few decades. But those previous periods of inflated expectations led to troughs of disappointment. Will this time be different? Most likely. Applications of AI such as predictive analytics are already decreasing costs and improving reliability of industrial machinery. Furthermore, the funding and research going into AI now comes from a wide range of com...
In this presentation, Striim CTO and founder Steve Wilkes will discuss practical strategies for counteracting fraud and cyberattacks by leveraging real-time streaming analytics. In his session at @ThingsExpo, Steve Wilkes, Founder and Chief Technology Officer at Striim, will provide a detailed look into leveraging streaming data management to correlate events in real time, and identify potential breaches across IoT and non-IoT systems throughout the enterprise. Strategies for processing massive ...
SYS-CON Events announced today that Conference Guru has been named “Media Sponsor” of SYS-CON's 21st International Cloud Expo, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. A valuable conference experience generates new contacts, sales leads, potential strategic partners and potential investors; helps gather competitive intelligence and even provides inspiration for new products and services. Conference Guru works with conference organi...
SYS-CON Events announced today that Cloud Academy named "Bronze Sponsor" of 21st International Cloud Expo which will take place October 31 - November 2, 2017 at the Santa Clara Convention Center in Santa Clara, CA. Cloud Academy is the industry’s most innovative, vendor-neutral cloud technology training platform. Cloud Academy provides continuous learning solutions for individuals and enterprise teams for Amazon Web Services, Microsoft Azure, Google Cloud Platform, and the most popular cloud com...
SYS-CON Events announced today that CA Technologies has been named "Platinum Sponsor" of SYS-CON's 21st International Cloud Expo®, which will take place October 31-November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. CA Technologies helps customers succeed in a future where every business - from apparel to energy - is being rewritten by software. From planning to development to management to security, CA creates software that fuels transformation for companies in the applic...
SYS-CON Events announced today that TMC has been named “Media Sponsor” of SYS-CON's 21st International Cloud Expo and Big Data at Cloud Expo, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Global buyers rely on TMC’s content-driven marketplaces to make purchase decisions and navigate markets. Learn how we can help you reach your marketing goals.
Internet of @ThingsExpo, taking place October 31 - November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 21st Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The Internet of Things (IoT) is the most profound change in personal and enterprise IT since the creation of the Worldwide Web more than 20 years ago. All major researchers estimate there will be tens of billions devic...
"MobiDev is a Ukraine-based software development company. We do mobile development, and we're specialists in that. But we do full stack software development for entrepreneurs, for emerging companies, and for enterprise ventures," explained Alan Winters, U.S. Head of Business Development at MobiDev, in this SYS-CON.tv interview at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
SYS-CON Events announced today that IBM has been named “Diamond Sponsor” of SYS-CON's 21st Cloud Expo, which will take place on October 31 through November 2nd 2017 at the Santa Clara Convention Center in Santa Clara, California.
SYS-CON Events announced today that Telecom Reseller has been named “Media Sponsor” of SYS-CON's 21st International Cloud Expo, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Telecom Reseller reports on Unified Communications, UCaaS, BPaaS for enterprise and SMBs. They report extensively on both customer premises based solutions such as IP-PBX as well as cloud based and hosted platforms.
We build IoT infrastructure products - when you have to integrate different devices, different systems and cloud you have to build an application to do that but we eliminate the need to build an application. Our products can integrate any device, any system, any cloud regardless of protocol," explained Peter Jung, Chief Product Officer at Pulzze Systems, in this SYS-CON.tv interview at @ThingsExpo, held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA
Multiple data types are pouring into IoT deployments. Data is coming in small packages as well as enormous files and data streams of many sizes. Widespread use of mobile devices adds to the total. In this power panel at @ThingsExpo, moderated by Conference Chair Roger Strukhoff, panelists looked at the tools and environments that are being put to use in IoT deployments, as well as the team skills a modern enterprise IT shop needs to keep things running, get a handle on all this data, and deliver...
The current age of digital transformation means that IT organizations must adapt their toolset to cover all digital experiences, beyond just the end users’. Today’s businesses can no longer focus solely on the digital interactions they manage with employees or customers; they must now contend with non-traditional factors. Whether it's the power of brand to make or break a company, the need to monitor across all locations 24/7, or the ability to proactively resolve issues, companies must adapt to...
SYS-CON Events announced today that Enzu will exhibit at SYS-CON's 21st Int\ernational Cloud Expo®, which will take place October 31-November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Enzu’s mission is to be the leading provider of enterprise cloud solutions worldwide. Enzu enables online businesses to use its IT infrastructure to their competitive advantage. By offering a suite of proven hosting and management services, Enzu wants companies to focus on the core of their ...
With major technology companies and startups seriously embracing Cloud strategies, now is the perfect time to attend 21st Cloud Expo October 31 - November 2, 2017, at the Santa Clara Convention Center, CA, and June 12-14, 2018, at the Javits Center in New York City, NY, and learn what is going on, contribute to the discussions, and ensure that your enterprise is on the right path to Digital Transformation.