In a Page. How to add a flag that inform last time a list was modified

Question

I have a custom page like this :

These are my links (refresh once a day. Last refresh time : **XXXXX** )

link1
link2
link3

And I have a custom list.

I want to add "last modified time" or "modified X mins ago" instead of "XXXXX" of the custom list in my page. Is that possible ? Might be easy for advanced dev, but I can't find what to googled.

I found this and this. So I tried to add JS via embedded code in my page :

<script language='javascript' type='text/javascript'>
var siteUrl = "http://mysite/mysubsite";
var context = new SP.ClientContext(siteUrl);
var web = context.get_web();
var list = web.get_lists().getByTitle('MyListName');
var value = SP.List.get_lastItemModifiedDate();
write(value);
</script>

But this doesn't return anything. As I'm not a developer, I really don't understand what's going on, Any ideas?

I have to say that I also tried this (I've customized variable as needed) without success :

function ReadListItem() {
    siteUrl = "my site Url";
    var listTitle = "NewsList";
    //Get the current client context
    var context = new SP.ClientContext(siteUrl);
    var newsList = context.get_web().get_lists().getByTitle(listTitle);
    var camlQuery = new SP.CamlQuery();         
    camlQuery.set_viewXml('<View><Query><OrderBy><FieldRef Name=\'Modified\' Ascending="FALSE"/></OrderBy><RowLimit>1</RowLimit></Query></View>";')
    this.listItems = newsList.getItems(camlQuery);
    context.load(listItems);
    context.executeQueryAsync(ReadListItemSucceeded, ReadListItemFailed);
}

function ReadListItemSucceeded(sender, args) {
    var itemsString = '';
    var enumerator = listItems.getEnumerator();
    while (enumerator.moveNext()) {
        var listItem = enumerator.get_current();
        itemsString += 'Modified On: ' + listItem.get_item('Modified');
    }
    $("#P1").append(itemsString);
}

Answer 1

Change your Javascript to

<script language='javascript' type='text/javascript'>
SP.SOD.executeOrDelayUntilScriptLoaded(function(){
var siteUrl = "http://mysite/mysubsite";
    var context = new SP.ClientContext(siteUrl);
    var ctx = SP.ClientContext.get_current();
var web = ctx.get_web();
var lists = web.get_lists();
var list = lists.getByTitle("MyListTitle");
ctx.load(list, "LastItemModifiedDate");
ctx.executeQueryAsync(
    function() {
        alert(list.get_lastItemModifiedDate());
    },
    function() {}
);
}, 'sp.js');

</script>

You need to load what you want in the context object and then execute the query

Answer 2

You can do this with JavaScript and the JavaScript Object Model, called JSOM in SharePoint 2013.

Go read this: http://msdn.microsoft.com/en-us/jj163201(v=office.15)

Try this: http://code.msdn.microsoft.com/SharePoint-2013-Execute-a41c49ff

function retrieveListItems(siteUrl) { 
    var clientContext = new SP.ClientContext(siteUrl); 
    var oList = clientContext.get_web().get_lists().getByTitle('Announcements'); 

    var camlQuery = new SP.CamlQuery(); 
    camlQuery.set_viewXml( 
        '<View><Query><Where><Geq><FieldRef Name=\'ID\'/>' +  
        '<Value Type=\'Number\'>1</Value></Geq></Where></Query>' +  
        '<RowLimit>10</RowLimit></View>' 
    ); 
    this.collListItem = oList.getItems(camlQuery); 

    clientContext.load(collListItem); 
    clientContext.executeQueryAsync( 
        Function.createDelegate(this, this.onQuerySucceeded),  
        Function.createDelegate(this, this.onQueryFailed) 
    );  
} 

function onQuerySucceeded(sender, args) { 
    var listItemInfo = ''; 
    var listItemEnumerator = collListItem.getEnumerator(); 

    while (listItemEnumerator.moveNext()) { 
        var oListItem = listItemEnumerator.get_current(); 
        listItemInfo += '\nID: ' + oListItem.get_id() +  
            '\nTitle: ' + oListItem.get_item('Title') +  
            '\nBody: ' + oListItem.get_item('Body'); 
    } 

    alert(listItemInfo.toString()); 
} 

function onQueryFailed(sender, args) { 
    alert('Request failed. ' + args.get_message() +  
        '\n' + args.get_stackTrace()); 
}

Answer 3

Well you can use CAML Query and following query should bring you last modified item:

SPQuery query = new SPQuery();
query.Query = string.Concat(
      @"<OrderBy> 
           <FieldRef Name='Modified' Ascending='False' /> 
        </OrderBy>");
query.RowLimit = 1;

var myList = web.Lists.TryGetList("ListTitle");

if (myList != null)
{
   var itemCollection = myList.GetItems(query);

   var result = string.Empty;

   if (itemCollection.Count > 0)
   {
       SPListItem item = itemCollection[0];
       var lastModifiedDate = DateTime.Parse(item["Modified"].ToString());
       TimeSpan span = DateTime.Now - lastModifiedDate;
       result = "modified " + span.TotalMinutes + " mins ago";
   }

   // use result
}

This should help