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Posts from the ‘Technology’ Category

4
Jun

Impersonating Any User On SharePoint

Generally when a SharePoint web part, or similar custom code, is running on SharePoint the active SPContext will either be impersonating the current user’s account, or the guest account (if enabled). This means that all of SharePoint’s security is maintained when accessing lists, items, etc. However; there may be some instances when you want the custom code to be able to access items (or lists, etc) which the current user does not have access to without actually giving the user direct access to these particular items. Fortunately this is a pretty easy task to achieve and can be achieved in a number of ways.

Method 1) Using elevated security.

This method takes advantaged of the Microsoft.SharePoint.SPSecurity static helper methods, in particular the RunWithElevatedPrivileges method. The objective of this method is to execute code with full control regardless of the users delegated roles. Example:

SPSecurity.RunWithElevatedPrivileges(() =>
                                         {
                                             // Code running with full control
                                         });

Or for a single method call you can omit the curly braces:

SPSecurity.RunWithElevatedPrivileges(() => /* Call method with full control */);

The most important thing to note here is that any SharePoint context objects that have already been instantiated outside of the elevated security blocks does not have full control, even if referenced from within the elevated security blocks. This means that you can not simply call SPSecurity.RunWithElevatedPrivileges(() => SPContext.Current.ListItem.Delete()); and expect it to work if the current user does not have permission to the delete the current list item, instead you must instantiate a new SPSite object within the elevated security blocks and then delete the list item. For example:

SPSecurity.RunWithElevatedPrivileges(() =>
    {
        using (SPSite site = new SPSite(SPContext.Current.Site.ID))
        {
            using (SPWeb web = site.OpenWeb(SPContext.Current.Web.ID))
            {
                SPList list = web.Lists[SPContext.Current.List.ID];
                SPListItem item = list.Items[SPContext.Current.ListItem.UniqueId];
 
                item.Delete();
            }
        }
    });

Now when the above code runs is should not have any problems deleting the current list item, even if the current user does not have permission to delete the item.

Method 2) Impersonating another user.

This is another simple method which involves instantiating a new SPSite object running under a different context to that of the invoking users’ context. To achieve this when we are instantiating the new SPSite object we simply pass in the SPUserToken of the user we wish to impersonate. For example, we could run under the system account:

using (SPSite site = new SPSite(SPContext.Current.Site.ID, SPContext.Current.Site.SystemAccount.UserToken))
{
    // code here
}

The thing to note with this method is that the user being impersonated needs to have permission to perform the actions specified.

The UserToken is available from SPUser objects. So prior to creating the new SPSite object you would need to find the user object for the user you wish to impersonated, or otherwise have some way of reference the user’s token.

6
May

Google Chrome: Faster Than Lightning

14
Apr

Adobe, Stop Killing My Internets!

I am not sure if it just me, but lately it seems that Adobe Flash Player is becoming more and more unreliable, and causing my web browser (be it Chrome, FireFox and/or I.E. — I prefer Chrome, although I wish it supported ICC profiles like FireFox) to constantly crash.

Has Adobe Flash Player Caused Your Browser To Crash?

View Results

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As Adobe Flash is widely used it, unfortunately, is not practical to completely remove it from your machine; however there are a few simple tools which let you automatically block Flash from loading unless you white-list the site or click on the flash to play it. This technique is also great for preventing those annoying Flash ads that popup in your face (Although some of them do look pretty cool)!

Continue Reading To Find Out How To Stop Adobe Killing Your Internets!

4
Apr

Unable To Instantiate TRIM Database: 80040154

I recently came across this error while attempting to connect to TRIM 6 R2 via the TRIMSDK: Retrieving the COM class factory for component with CLSID {8A354548-6BCB-11D3-B273-00A0C9FC3DC0} failed due to the following error: 80040154.

This was a little alarming because it was using the same data adapter as a few other TRIM projects, which were working fine; the only difference between the project was that this particular project was a WPF application, and all of the other applications were ASP.NET applications. This particular application had also previously worked fine, the only change was that I had been upgraded to a 64-bit environment.

After a bit of playing around and research I discovered the TRIM SDK will not connect under a 64-bit process.

Workaround:

  1. In Visual Studio, right-click your project and go to Properties (last item).
  2. Select the Build tab.
  3. Change the Configuration option to All Configurations.
  4. Change the Platform Target to x86.

This will ensure that your application will only run under an x86 architecture, and will be able to connect to TRIM even on a 64-bit host.

Looking at the QuickSpecs for TRIM 7 it is being based on a 64-bit architecture and therefore this issue should be eliminated come TRIM 7 (in addition to some SDK enhancements and UI integration tools).

17
Feb

Oracle 06413: Connection Not Open (x64)

Having changed to a 64-bit development machine at work recently I ran in to an Oracle error while trying to generate files using CodeSmith. This error was ORA-06413: Connection Not Open. Assuming it was a connection string error, as I had not ran this particular generation in some time and it was likely that the server or username/password had changed, I proceeded to test the connection from SQL Developer. Success!

After ruling out that the connection was indeed valid I did a quick Google search for the error message. After a few clicks I discovered a very well known (has been around for a few years) Oracle issue; When executing an Oracle command from an application with parentheses or equals — ‘(‘ or ’)’ or ‘=’ — in the path then the specified error message is thrown.

In this particular case CodeSmith had been installed under C:\Program Files (x86)\CodeSmith\ which was causing Oracle to fail. The quickest work around was to simply move CodeSmith from the Program Files (x86) path e.g. in to C:\CodeSmith\. However; there is a patch (5383042) for Oracle 10g, which I believe is also applied to Oracle 11G.

16
Feb

Australian Internet Filter: What Can I Do?

What is it?

The Australian Federal Government is introducing a mandatory ISP-level filtering of all Refused Classification (RC) rated content. This means all websites (or part-thereof) which have been refused classification under Australia’s classification laws will be blacklisted.

See the Electronic Frontiers Open Internet website for more information.

What can I do?

The simplest thing you can do is sign the EFA’s online petition.

Additionally you can contact your local member of parliament or contact Senator Conroy, the Minister for Broadband, Communications and the Digital Economy.

Take Action!

4
Feb

iiNet Vs AFACT: The Verdict

As a lot of people are probably already aware iiNet was taken to court by the Australian Federation Against Copyright Theft (AFACT) for allegedly allowing its customers to illegally download copyrighted material (e.g. movies, music, etc).

This morning Justice Cowdroy has ruled in favour of iiNet stating that “I find that iiNet simply can’t be seen as approving infringement”. His verdict was that the “copyright (infringement) occured as result of use of BitTorrent, not the Internet” and that “iiNet has no control over (the) Bittorrent system and (is) not responsible for (the) Bittorrent system.”

Common sense and Australia’s Internet Freedom prevails, for now (see mandatory Australia Internet Censoring).

26
Nov

Win 7 Live Messenger Task Bar Fix

Windows 7 Task barFor those of you ‘lucky’ enough to have already updated to the new Windows 7 then you have probably already noticed the major changes to the task bar. Good or bad, you decide. Personally, I like some of the new functionality that it provides but I also enjoy a slim task bar — similar to that of Vista. Fortunately Microsoft provided a “Use small icons” option in the task bar properties (right-click the task bar and select properties) which makes the task bar a similar size to that of Vista.

Changing the task bar to use small icons, however, does not fix the fact that Windows Live Messenger likes to constantly take up a space in the task bar even when the window is not open. Since there does not currently appear to be an option in Windows Live Messenger to display the program in the system tray, instead of on the task bar, we need to use a simple work around.

WLMCompatibility

First, close any current Windows Live Messenger instances. Then open your start menu and locate the Windows Live Messenger shortcut. Right-click the shortcut and select properties. Switch to the Compatibility tab and check “Run this program in compatibility mode for:” and select Window Vista (Service Pack 2)”. Now start Windows Live Messenger and problem solved. You should now see the Windows Live Messenger icon in the system tray. As you would on Vista, XP, etc.

3
Sep

Telstra HTC Touch HD — Enable Weather Module

HTC Touch HD Weather ModuleONE of the best features built-into the HTC Touch HD would have to be the weather module. This module allows you to view the current weather conditions, as well as a four day forecast and all in a pretty cool looking interface. However; for some unknown reason Telstra decided to disable the weather module by default, instead opting to include a bunch of somewhat completely useless modules of its own.

There is good news… through a bit of editing you are able to re-enable the weather module and, if you desire, remove the unnecessary Telstra modules. First thing is first; we need to find the file which contains the HTC Touch Flow configuration. The file we are after is 26948339_manila.xml which is located in the Windows directory. Back this original file up. Copy this file on to your storage card, or somewhere you can access it from your computer (alternative you could use an application such as Total Commander to edit the file from your mobile device).

The section we are interested in are the items under the Navigation node and directly under the “root” PageGroup. This section contains a collection of Page elements, which define the items located along the bottom bar of the Touch Flow interface. The one we are interested in is weather.page — this should be commented out and appear similar to the following:

<!--
<Page Order="3" Name="weather.page" PackageName="HTC" Title="[[IDS_WEATHER]]" >
  <ComponentReference Name="page" Mode9Path="HTC\weather.mode9" Component="GizmoRoot" SmartComponent="true"  />
  <ComponentReference Name="icon_normal"   Mode9Path="HTC\icons.mode9" Component="Weather_Off" />
  <ComponentReference Name="icon_selected" Mode9Path="HTC\icons.mode9" Component="Weather_On" />
  <ComponentReference Name="icon_preview"  Mode9Path="HTC\icons.mode9" Component="Weather_Preview" />
</Page>
-->

To enable the weather module simply remove the comment blocks (<!– && –>) to end up with something similar to:

<Page Order="3" Name="weather.page" PackageName="HTC" Title="[[IDS_WEATHER]]" >
  <ComponentReference Name="page" Mode9Path="HTC\weather.mode9" Component="GizmoRoot" SmartComponent="true"  />
  <ComponentReference Name="icon_normal"   Mode9Path="HTC\icons.mode9" Component="Weather_Off" />
  <ComponentReference Name="icon_selected" Mode9Path="HTC\icons.mode9" Component="Weather_On" />
  <ComponentReference Name="icon_preview"  Mode9Path="HTC\icons.mode9" Component="Weather_Preview" />
</Page>

You could now also go and comment out the modules you do not wish to appear on the Touch Flow interface.

Once finished editing the file save it and replace the original file under the Windows directory (if you aren’t editing it directly) with this edited file. Restart the mobile device. You should now be able to see the weather module button on your Touch Flow interface. Enjoy.

Do not be alarmed if you incorrectly edit the xml file as the Touch Flow interface will simply not load, but you will still be able to use your mobile device. Simply go back and replace the file with the original back-up, or attempt to fix the issue.

19
Jun

See Code, See CodeRun

Merbla wrote a short post today about a site he came accross, CodeRun. The site is an online code respository, with the added advantage of an online IDE include on the site which allows you to see the code and run / debug it as it is. After signing up with a free account you can create your own projects (AJAX, ASP.NET, PHP and WPF — AJAX and ASP.NET also have support for facebook applications) which you can develop, store and run all from their website.

The concept is brilliant — everything from start to go can be done online via your standard web browse (currently only supports Internet Explorer and FireFox) and publishing of your source code is as simple as a right-click and a left-click. Once source has been published other people can freely go and search for source code in the repository and open it directly in the browser, make modifications and run them all from within the browser.

CodeRun Online IDE

However; The actuall implementation of it so fair (while still very impressive) is significantly lacking from a development perspective. Although it is possible to do the majority of thing you can do in Visual Studio, it is a little cumbersome and slow at times and does have a few limitions. For example, there is no toolbar — and therefore no drag and dropping of controls (which Microsoft presentations always seem to contain a lot of ;-).

Although the site seems to be focused on web applications some features are also unavaliable in the online IDE. You do not have the ability to create folders with underscores in them, and there does not seem to be anyway of creating the special ASP.NET folders such as App_Data or App_Themes… not such a big deal. Designer files are not automatically created and if you try to create one an exception is thrown saying the file already exists.

The biggest problem however is the speed. Perhaps it is just my machine or my internet connection, but the online IDE is very slow to use and navigate. Menues and and prompts tend to hang the browser for a couple of seconds before they load and the intellisense (ctrl+space) does not allows function correctly. Code highlighting, although not important or required, is lacking from the Visual Studio equivalent and take a signifant amont of time to process and display.

Copying and pasting from Visual Studio in to the online IDE also seems to be out of question, as it seems to past the text multiple times; Copy and paste from within the online IDE works fine.

All that being said the online IDE is quite feature rich and imitates Visual Studio very well. You are able to apply breakpoints and step through code, attach to processes (only online applications — not system processes), watch variables, etc. There is also an option to open a project from a zip file — which works great, providing you zip the project from the root of the project folder (it must not be under a sub folder).

In the end (as Merbla suggested in his post) something like this teamed up with StackOverflow, for the purpose of displaying simple solutions to problems with working example would be brilliant! However as far as online development goes I think there is a long way to go.

See running example: Hello World!

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