Showing only last six months in a dropdown

Question

I have a month column (a choice column) in my document library. Its format is, for example, "Jan 2013".

I have the following requirements:

1. The month dropdown should always show only the previous 6 months relative to the current month.

   For example, if the current month is March 2013, then only the months starting from October 2012 to March 2013 should be populated in the dropdown

2. There is another column in my document library called "date", which is in a date format. It should not be shown in the default view. The date field should automatically be set as the 1st date of the month selected from the month column.

   For example: If the month selected is March 2013, the date should be 1/3/2013.

Answer 1

Sorry for late response.. You're right, there is no "NewForm.aspx" on document libraries. So what can you do is adding the following javascript to the "EditForm.aspx" file of the related document library. You've to edit "EditForm.aspx" file in advanced mode by using SharePoint Designer. Add these code after PlaceHolderPageTitleInTitleArea tag.

In your document library one single line of text field (called as Month in my code) and a Datetime field (called as Day in my code).

This javascript first hides the textfield for Month field and shows a dropdown list that includes last three months.

Probably you've to optimize the javascript code :) But I tried it in my environment, it works.

<script type="text/javascript">

_spBodyOnLoadFunctionNames.push("addItemsToCombo");

var month = new Array();
month[0] = "January";
month[1] = "February";
month[2] = "March";
month[3] = "April";
month[4] = "May";
month[5] = "June";
month[6] = "July";
month[7] = "August";
month[8] = "September";
month[9] = "October";
month[10] = "November";
month[11] = "December";

function addItemsToCombo()
{
    var today = new Date();

    var inputs = document.getElementsByTagName("input");
    for (i=0; i<inputs .length; i++)
    {
        if (inputs[i].getAttribute("Title")=="Month")
        {
            inputs[i].setAttribute("style","display:none;");
            var select = document.createElement("select");
            select.setAttribute("name","tempMonth");
            select.setAttribute("id","tempMonth");
            var currentMonth = today.getMonth();
            var currentYear = today.getFullYear();
            var option = document.createElement("option");
            option.innerHTML = "Select";
            option.setAttribute("value", "");
            select.appendChild(option);
            for(j=0; j<6; j++)
            {

                var option = document.createElement("option");
                if (currentMonth<0)
                {
                    option.innerHTML = month[currentMonth+12] + " " + (currentYear -1);
                    option.setAttribute("value", currentMonth +12 + " " + (currentYear -1));

                }
                else    
                {
                    option.innerHTML = month[currentMonth] + " " + currentYear;
                    option.setAttribute("value", currentMonth + " " + currentYear);
                }
                select.appendChild(option);
                currentMonth = currentMonth-1;
            }
            select.onchange = function() {monthChange();};
            inputs[i].parentElement.appendChild(select);
        }

    }

}

function monthChange()
{
    var combo = document.getElementById("tempMonth");
    var inputs = document.getElementsByTagName("input");
    for (i=0; i<inputs .length; i++)
    {
        if (inputs[i].getAttribute("Title")=="Month")
        {
            inputs[i].value = combo.options[combo.selectedIndex].text;
        }
        if (inputs[i].getAttribute("Title")=="Day")
        {
            var selectedMonthYear = combo.value.split(" ");
            var mm = parseInt(selectedMonthYear[0]) + 1;
            var yyyy = selectedMonthYear[1];
            if (mm<10)
            {
                mm = "0"+mm;
            }
            var firstOfMonth = "01/"+mm+"/"+yyyy;
            inputs[i].value = firstOfMonth;
            inputs[i].setAttribute("disabled","disabled");
        }
    }
}

</script> 

Answer 2

I think it's not possible by default SharePoint columns. Here are the possible solutions:

• In the Page_Load event of the NewForm.aspx you can write a code that changes or inserts the items in the combobox.
• You can write a javascript in NewForm.aspx that uses DOM to insert new items to the combobox.

You can use a javascript code like this: http://keremozen.com/wp-content/uploads/2013/03/addItemToCombo.js

Hope these help