Welcome!

Artificial Intelligence Authors: Yeshim Deniz, Peter Silva, Liz McMillan, Kevin Benedict, Rene Buest

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
Keeping pace with advancements in software delivery processes and tooling is taxing even for the most proficient organizations. Point tools, platforms, open source and the increasing adoption of private and public cloud services requires strong engineering rigor - all in the face of developer demands to use the tools of choice. As Agile has settled in as a mainstream practice, now DevOps has emerged as the next wave to improve software delivery speed and output. To make DevOps work, organization...
DevOps is often described as a combination of technology and culture. Without both, DevOps isn't complete. However, applying the culture to outdated technology is a recipe for disaster; as response times grow and connections between teams are delayed by technology, the culture will die. A Nutanix Enterprise Cloud has many benefits that provide the needed base for a true DevOps paradigm.
What sort of WebRTC based applications can we expect to see over the next year and beyond? One way to predict development trends is to see what sorts of applications startups are building. In his session at @ThingsExpo, Arin Sime, founder of WebRTC.ventures, will discuss the current and likely future trends in WebRTC application development based on real requests for custom applications from real customers, as well as other public sources of information,
SYS-CON Events announced today that Interoute, owner-operator of one of Europe's largest networks and a global cloud services platform, has been named “Bronze Sponsor” of SYS-CON's 20th Cloud Expo, which will take place on June 6-8, 2017 at the Javits Center in New York, New York. Interoute is the owner-operator of one of Europe's largest networks and a global cloud services platform which encompasses 12 data centers, 14 virtual data centers and 31 colocation centers, with connections to 195 add...
TechTarget storage websites are the best online information resource for news, tips and expert advice for the storage, backup and disaster recovery markets. By creating abundant, high-quality editorial content across more than 140 highly targeted technology-specific websites, TechTarget attracts and nurtures communities of technology buyers researching their companies' information technology needs. By understanding these buyers' content consumption behaviors, TechTarget creates the purchase inte...
With the introduction of IoT and Smart Living in every aspect of our lives, one question has become relevant: What are the security implications? To answer this, first we have to look and explore the security models of the technologies that IoT is founded upon. In his session at @ThingsExpo, Nevi Kaja, a Research Engineer at Ford Motor Company, will discuss some of the security challenges of the IoT infrastructure and relate how these aspects impact Smart Living. The material will be delivered i...
In his session at @ThingsExpo, Eric Lachapelle, CEO of the Professional Evaluation and Certification Board (PECB), will provide an overview of various initiatives to certifiy the security of connected devices and future trends in ensuring public trust of IoT. Eric Lachapelle is the Chief Executive Officer of the Professional Evaluation and Certification Board (PECB), an international certification body. His role is to help companies and individuals to achieve professional, accredited and worldw...
Your homes and cars can be automated and self-serviced. Why can't your storage? From simply asking questions to analyze and troubleshoot your infrastructure, to provisioning storage with snapshots, recovery and replication, your wildest sci-fi dream has come true. In his session at @DevOpsSummit at 20th Cloud Expo, Dan Florea, Director of Product Management at Tintri, will provide a ChatOps demo where you can talk to your storage and manage it from anywhere, through Slack and similar services ...
My team embarked on building a data lake for our sales and marketing data to better understand customer journeys. This required building a hybrid data pipeline to connect our cloud CRM with the new Hadoop Data Lake. One challenge is that IT was not in a position to provide support until we proved value and marketing did not have the experience, so we embarked on the journey ourselves within the product marketing team for our line of business within Progress. In his session at @BigDataExpo, Sum...
SYS-CON Events announced today that SoftLayer, an IBM Company, has been named “Gold Sponsor” of SYS-CON's 18th Cloud Expo, which will take place on June 7-9, 2016, at the Javits Center in New York, New York. SoftLayer, an IBM Company, provides cloud infrastructure as a service from a growing number of data centers and network points of presence around the world. SoftLayer’s customers range from Web startups to global enterprises.
SYS-CON Events announced today that Ocean9will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Ocean9 provides cloud services for Backup, Disaster Recovery (DRaaS) and instant Innovation, and redefines enterprise infrastructure with its cloud native subscription offerings for mission critical SAP workloads.
SYS-CON Events announced today that Linux Academy, the foremost online Linux and cloud training platform and community, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Linux Academy was founded on the belief that providing high-quality, in-depth training should be available at an affordable price. Industry leaders in quality training, provided services, and student certification passes, its goal is to c...
SYS-CON Events announced today that Telecom Reseller has been named “Media Sponsor” of SYS-CON's 20th International Cloud Expo, which will take place on June 6–8, 2017, at the Javits Center in New York City, NY. 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.
SYS-CON Events announced today that Loom Systems will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Founded in 2015, Loom Systems delivers an advanced AI solution to predict and prevent problems in the digital business. Loom stands alone in the industry as an AI analysis platform requiring no prior math knowledge from operators, leveraging the existing staff to succeed in the digital era. With offices in S...
SYS-CON Events announced today that T-Mobile will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. As America's Un-carrier, T-Mobile US, Inc., is redefining the way consumers and businesses buy wireless services through leading product and service innovation. The Company's advanced nationwide 4G LTE network delivers outstanding wireless experiences to 67.4 million customers who are unwilling to compromise on ...
SYS-CON Events announced today that Cloudistics, an on-premises cloud computing company, has been named “Bronze Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Cloudistics delivers a complete public cloud experience with composable on-premises infrastructures to medium and large enterprises. Its software-defined technology natively converges network, storage, compute, virtualization, and management into a ...
SYS-CON Events announced today that CA Technologies has been named “Platinum Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY, and the 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 ...
SYS-CON Events announced today that Infranics will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Since 2000, Infranics has developed SysMaster Suite, which is required for the stable and efficient management of ICT infrastructure. The ICT management solution developed and provided by Infranics continues to add intelligence to the ICT infrastructure through the IMC (Infra Management Cycle) based on mathemat...
Now that the world has connected “things,” we need to build these devices as truly intelligent in order to create instantaneous and precise results. This means you have to do as much of the processing at the point of entry as you can: at the edge. The killer use cases for IoT are becoming manifest through AI engines on edge devices. An autonomous car has this dual edge/cloud analytics model, producing precise, real-time results. In his session at @ThingsExpo, John Crupi, Vice President and Eng...
In the enterprise today, connected IoT devices are everywhere – both inside and outside corporate environments. The need to identify, manage, control and secure a quickly growing web of connections and outside devices is making the already challenging task of security even more important, and onerous. In his session at @ThingsExpo, Rich Boyer, CISO and Chief Architect for Security at NTT i3, will discuss new ways of thinking and the approaches needed to address the emerging challenges of securit...