crawl space of programming

Some application cannot be run in multiple instance for several reasons. So you need to avoid a second instance will run, but how? You cannot directly block the execution of your application, so you need to take care of the problem in your code.

Sometimes you need to loop cells in Excel. In fact it is looping rows and columns, because cells have two dimensions. The rows are counted up, but the columns are named alphabetic. Looping them is not that easy and gets harder until you hit the Z , because the next 'letter' would be AA . So a number would be more easy.

If you are using an asp:hyperlink to another page in your provider hosted app you will see the SharePointContextProvider will not be able to handle the redirect. To fix the problem you need to add a click event and call a redirect in your code behind.

It is a while since Microsoft launched the Add In (or App) architecture for SharePoint, but there are still things they change or we are not familiar with. In August 2016 there was a change in giving tenant permissions to provider hosted Add Ins using app-only mode and Azure Access Control Service (ACS).

You maybe know the problem; you are updating or creating a set of items using the JSOM and the changes are made to only one item. The  reason is that the process in the back (Event Receiver etc.) can handle only one item at the same time and if it takes to long it misses the update event for the other items. So you need to make sure the update waits until the update before is done. The deal is that the JSOM context works asynchronous. Some of you are using promisses or methods like that. I made a solution that is working without any other library.

If you are building a TypeScript project in Visual Studio Code you will get intellisense and that is cool. But if you want to add jQuery into your ts file the intellisense shows you errors. So how to use it? All you need to do are some simple steps.

Some actions in SharePoint (e.g. executing querys) can take a while. You want the user to not do any action or even change the data while your process is running. So you need the wait dialog that SharePoint is displaying some time. Calling the dialog is pretty easy. All you need is a line of code.