Sharepoint - Set current user to a form field as a default value

This is my solution to set the current user as a default value of a Sharepoint 2013 form field.

1- Define a folder to place javascript files. I used the following path:
"~sitecollection/_catalogs/masterpage/Display Templates/"

2- Upload the following files to the location you defined on step 1. Use the import files button on your sharepoint designer.

File 1: the jquery library.
File 2: the jquery SP Service library.
File 3: the custom javascript for the field you want to update.


Edit the file 3 in sharepoint designer after import (or in another editor before import) and replace 'Req' by the name of your field name in the list:
var fieldName = 'Req';

3 - Use the designer to edit the default list form for New Item (in this case nx.aspx)

4 - Add the following references to forms design. 

<SharePoint:ScriptLink ID="jquery" runat="server" LoadAfterUI="True" Name="~sitecollection/_catalogs/masterpage/Display Templates/jquery-1.12.3.js"/>

<SharePoint:ScriptLink ID="spservices" runat="server" LoadAfterUI="True" Name="~sitecollection/_catalogs/masterpage/Display Templates/jquery.SPServices-2014.02.js"/>
 
<SharePoint:ScriptLink ID="trsp" runat="server" LoadAfterUI="True" Name="~sitecollection/_catalogs/masterpage/Display Templates/trsp.js"/>

Note that you shloud update the path if you uploaded the scripts into a different path.

 A good place for you to drop this lines of code is before the form table. Search for <Sharepoint:FormField and FieldName=the first field of your form. Paste the lines before the first <tr> as shown above.


5 - Disable minimum download strategy

If you try to run your form you will experience that the code works just sometimes and not every time. You should disable minimum download strategy feature. To do this go to site settings, manage site features and disable it.

And we are done!
Here is my sample on field "Req"