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Lightswitch - HTMLclient




It has been to long since my last post. As everyone else I have had trouble with finding time to blog. 

Recently I have been playing with the new Visual Studio Lightswitch (you can get update 2 here: http://www.microsoft.com/en-us/download/details.aspx?id=38188). Why is it so cool, because it is pure HTML5 and will run in any modern browser being Mac, PC, tablet, IPAD, Iphone, Androd etc. 

There are some nice posts out there to get you started, however I was looking for a way to on-the-fly created dropdown lists boxes (what we call ChoiceList in Lightswitch). I found this blogpost about someone else wondering about the same thing:

http://www.datazx.cn/Fv7p5a/6x-DE/y10q2an129q/2q7xs6/6mdggtxi-id9i-f4ij-s8ms-i94bt9tfcjg423rsdfd.html


That guy Huy is pretty awesome (he as an answer to almost every question), and I felt all hope was lost when he stated that it was not possible. Reading further down, I noticed this guy pointing me in the right direction. Apparently the choice "field" has a variable for holding the choiceItems. 

Off we go then. Lets create a local data item on an edit screen and create a dummy item in the choice list:





















Then add the data item to the edit list:





















Run the application to see that our choice list is rendered:

























Yes, it is working fine. Now let's write a little javascript to create the content in the dropdown:

First open the code editor:






















/// 
var myDropdown;
var myValues = new Array();
myapp.AddEdittblProduct.created = function (screen) {
    // Write code here.
    choice = screen.findContentItem("CodeChoice");
    myValues[0] = { "value": 1, "stringValue": "Dropitem1" };
    myValues[1] = { "value": 2, "stringValue": "Dropitem2" };
    myValues[2] = { "value": "Dropitem3", "stringValue": "Dropitem3" };
    myValues[3] = { "value": "Dropitem3", "stringValue": "Dropitem4" };
    choice.choiceList = myValues;
};

Lets run it again and see what we have:
























There you go. You can now add items to a dropdown in code.

I have no idea if this is a supported solution, the Lightswitch team will have to comment on that. In the mean time, please use it at your own risk. 

NOTE! If you skip adding an dummy item to the choicelist, this metod will not work!!

Cya


Comments

  1. Very nice, but how do you bind your Choice list back to your data?

    ReplyDelete
  2. Does anyone know how do we bind dropdown list from a view ?
    And once user select data from dropdown, how to we assign back to Database.

    ReplyDelete
  3. Is there an example like this that will work with VS 2015?

    ReplyDelete
  4. Is there an example for dynamically populating choice lists in the LightSwitch HTML client using VS 2015?

    ReplyDelete
    Replies
    1. Hi, not that I know of. Lightswitch is currently in the dark. Last blogpost is from 2014 and I cannot find any news about it since. Someone mentioned something about a patent lawsuit against Microsoft. Hopefully we will hear something about in at Ignite 2016, however chances are slim to say the least!

      Cheers

      Tore

      Delete

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