Windows Forms

20-Jul-08 16:00

Hi,

I'm looking for a point in the right direction with regards to access control. What I mean by AC is the ability to set a View/Add/Edit/Delete restriction on a field in a windows form.

For example, lets say I have a contact screen with a Display name edit box. I only want this field editable for particular users.

Does anyone have any tips on how to achieve this? My initial thought was to store an identifier of all the controls in the db and have a base form loop through through all the controls on a form. It would then apply the access rights. ie. if you only have the right to view a field, set the control to readonly. If you don't have the right to view it, set the control to invisible. This seems like a really cumbersome approach.

Thanks in advance to anyone willing to provide tips and suggestions Smile | :)

Ryan

Mycroft Holmes20-Jul-08 20:22

Mycroft Holmes

20-Jul-08 20:22

I'll be interested in the results of this enquiry, heres my solution.
2 apps required 1 is user manager, 2nd is the client app.

User manager do store and manages the users and groups for each app (we have about 9 apps managed by this system)
Each app has a set of roles (public being the default), servers (we allow the user to select a target server) and objects (forms, buttons, panels/areas etc). Objects are requested by the user and defined by the developer.
Each object has and AEDX flag (add/edit/delete/execute) so a role can see the object (default) but the actions are managed.
User manager generates and enum to used in the development code
Each client app has a security function (using the object name) and death and mayhem to any junior dev who changes a controlled object.
Security function is applied to each object, yes hard coded, the user wants to control.
The business can then control the access to the object they have defined.

While I have built and used this method for over 10 years on ## apps, not once have I had to implement a tightly controlled environment. At most they want to restrict access to a number of forms or possible limit the group who can edit some data.

Shoulda done an article Laugh | :laugh:

Never underestimate the power of human stupidity
RAH

RyanEK21-Jul-08 12:44

21-Jul-08 12:44

Thanks for your reply Mycroft. It looks like brute force seems to be the way to go. I haven't seen any other real solutions to this problem so I think you really should write that article! Smile | :)

Mycroft Holmes21-Jul-08 14:16

Mycroft Holmes

21-Jul-08 14:16

I do prefer the enum solution, while it means you (your users) need to identify the objects to be managed you do not have to iterate all the objects on a form.

The other benifit is that the users must identify the objects which also emphasises the number of object they need to manage, always a good thing to rub the users nose in the support nightmare!

Never underestimate the power of human stupidity
RAH

RyanEK21-Jul-08 16:14

21-Jul-08 16:14

I've had a thought... what if somehow, a user can put a form into design mode? The user can then for example, set the property of a control to read only. It would then save the settings as a 'template' which could then be linked to a group of users. This template can then be loaded as a form is displayed. Do you think that's feasible?

Mycroft Holmes21-Jul-08 17:32

Mycroft Holmes

21-Jul-08 17:32

I can see a number of drawback (read nightmares)
Manage what a user can change on the "design mode" form seems to be the showstopper

RyanEK wrote:
what if somehow

I don't think this is feasible withiout VS installed

RyanEK wrote:
save the settings as a 'template'

I have no experience with templates in VS so cannot comment other than Huh!

RyanEK wrote:
Do you think that's feasible?

Nope - absolutely not - I would not even entertain the idea, seems to me you would be making a rod for your own back and a support nightmare.

Never underestimate the power of human stupidity
RAH

RyanEK21-Jul-08 17:59

21-Jul-08 17:59

Let me clarify what I mean, a (high level) user will have the option to launch the windows app in 'design mode' which means they have the ability to move controls, set properties etc. eg. http://www.codeproject.com/KB/miscctrl/MovableControls.aspx[^]

Once designed, the layout of the form can be saved as an XML and loaded as needed. This XML will determine which controls users has access to.

Again... thanks for all the help! Smile | :)

darkelv21-Jul-08 23:26

darkelv

21-Jul-08 23:26

It is feasible, though not in the way of putting the control into designer mode. Doing this will put the control to the user on what can or can not be access by a user group.

We did one of the web application using javascript (only activated for admin logon) to bring up a dialog box to set the read/write/etc access.

On desktop application, you can probably sub class the controls, use mouse right click to bring up a context menu or a dialog box to set the access.

darkelv20-Jul-08 23:37

darkelv

20-Jul-08 23:37

So far have not found any "standard practice" from MS, so, was using the brute force way to loop through the controls & menu items (they are not part of form :\) and visible/enable each of them manually.

RyanEK21-Jul-08 12:46

Crystal report preview is working but when running form its not working

21-Jul-08 12:46

This was what I was afraid of... I've been using this method since back in my Delphi days. Thanks anyways Smile | :)

amistry_petlad19-Jul-08 19:27

amistry_petlad

19-Jul-08 19:27

Hi all
I have added table fields from the table in the crystal report viewer but when I execute that form it doesn't show me that records.
But in preview it shows me all values.

Excel Workbook Creation

Bagyaraj Palani17-Jul-08 21:30

Bagyaraj Palani

17-Jul-08 21:30

Hi,
Am trying to create a new excel workbook by combining many worksheets(Different excel files) through programatically(c#.net). i did the same successfully. But, i have a issue as, The target Excel file changes the color format of the source files, that change the background color like dirty green, red... am not able to get the exact output.

The procedure i wrote the code is:
open source file->select the worksheet-> copy the content->create and open new excel file-> paste -> save and close.

Note: If i do the above procedure by manually, the same error arrives

Thanks in advance
Bagyaraj P

very large data app

bfis10813717-Jul-08 9:33

bfis108137

17-Jul-08 9:33

I have basically about 25 pages of questions ranging from multiple choice (radio buttons) to check all that apply (check boxes). I started to incorporate it into a tabbed form but after 4 pages, I already have 8 tabs, and it seems to load slow as well. IS it ok to do this. IS there a better way? Maybe can you possibly keep the controls from being loaded on each tab until that tab is opened????

Paul Conrad17-Jul-08 16:49

Paul Conrad

17-Jul-08 16:49

bfis108137 wrote:
basically about 25 pages of questions ranging from multiple choice (radio buttons) to check all that apply (check boxes). I started to incorporate it into a tabbed form but after 4 pages

Yikes. You might want to look at a more efficient design if possible.

bfis108137 wrote:
IS there a better way?

Not sure, without being there to actually see what's going on. You could probably have all those pages get trimmed down and use forms for each page only when they are needed.

"The clue train passed his station without stopping." - John Simmons / outlaw programmer

"Real programmers just throw a bunch of 1s and 0s at the computer to see what sticks" - Pete O'Hanlon

bfis10813717-Jul-08 19:14

bfis108137

17-Jul-08 19:14

What do you mean by trimmed down?

Paul Conrad18-Jul-08 2:57

Paul Conrad

18-Jul-08 2:57

Simplify the problem, if possible. Hmmm | :|

"The clue train passed his station without stopping." - John Simmons / outlaw programmer

"Real programmers just throw a bunch of 1s and 0s at the computer to see what sticks" - Pete O'Hanlon

darkelv17-Jul-08 17:28

darkelv

17-Jul-08 17:28

Yikes, what happen if the user ask you to add 1 question between question 4 and 5? Reorganize the whole thing again?

You can consider having the question defined in database, with section-page-question kind of hierarchy. On the application, dynamically creates the controls base on the type of question (radio or checkboxes). When user goes to next page (detecting tab change or some event), recreate the next page, so on and so forth.