December 15, 2011

Get current user and handle a success callback

In my previous post I needed the accound id of the current user for posting new list items. To retrieve the id, we can push this to the client from the code behind, or get the current user using Client Object Model. To provide a more generic way we can write a js function which get the current user. But we must even provide some callback functionality, otherwise we don’t know if the operation was successful or not. Let’s be inspired by success and error properties in $.ajax:

December 15, 2011

jQuery tmplItem and no ids

tmplItem() works even without ids. To get the current data:

$(this).tmplItem().data;
```If you want to remove, just invoke the ajax and remove with [$.parents](http://api.jquery.com/parents/):

$(this).parents(“li”).remove();


##### Updating data inside tmplItems

If you want to achieve some fancy dependency tracking, consider [knockout.js](http://knockoutjs.com/). But if you just want to update the data object inside a tmplItem, just change the object and call update:

var t = $(this).tmplItem(); var obj = t.data; obj.Address = “hello avenue”; t.update();

December 15, 2011

Update list items with listdata.svc

In one of my previous posts I showed how to retrieve data from listdata.svc with jQuery $.getJSON method. Getting data is very simple, listdata.svc provides a powerful restful interface with filtering, expanding and other features. Read the best and short introduction to listdata.svc by Suneet Sharma or a more detailed and technical article about filters, functions and operators by Mike Flasko at Microsoft with short examples here. Now back to listdata.svc in the SharePoint environment. Corey Roth provides a good images and sample results. For REST the “http verbs” are very important: GET, POST, PUT, DELETE.. SharePoint RESTful interface defines these verbs like that:

December 14, 2011

Add content to a provisioned publishing page

We can use PublishingPageContent Property to write content to a page:

<?xml version="1.0" encoding="utf-8"?>
<Elements xmlns="http://schemas.microsoft.com/sharepoint/">
 <Module Name="Pages" Url="$Resources:cmscore,List\_Pages\_UrlName;" >
 <File Path="Pages\\Help.aspx" Url="Help.aspx" Type="GhostableInLibrary">
 <Property Name="Title" Value="Contoso Help Page" />
 <Property Name="PublishingPageLayout" Value="~SiteCollection/\_catalogs/masterpage/ContosoPageLayout.aspx, Text page" />
 <Property Name="ContentType" Value="$Resources:cmscore,contenttype\_welcomepage\_name;" />
 <Property Name="PublishingPageContent" Value="hello world"/>
 </File>
 </Module>
</Elements>

December 14, 2011

The cleanest auto resize for a textarea

The cleanest way to auto-resize a textarea while typing (like wall post on Facebook) is George Papadakis solution. It uses only standard javascript and provides eventlisteners for IE (attachEvent) and other browsers (addEventListener): [sourcecode language=“javascript”] window.onload = function() { var t = document.getElementsByTagName(’textarea’)[0]; var offset= !window.opera ? (t.offsetHeight - t.clientHeight) : (t.offsetHeight + parseInt(window.getComputedStyle(t, null).getPropertyValue(‘border-top-width’))) ; var resize = function(t) { t.style.height = ‘auto’; t.style.height = (t.scrollHeight + offset ) + ‘px’; } t.addEventListener && t.addEventListener(‘input’, function(event) { resize(t); }); t[‘attachEvent’] && t.attachEvent(‘onkeyup’, function() { resize(t); }); } [/sourcecode] Other solutions are <a href=“https://github.com/padolsey/jQuery.fn.autoResize/blob/master/jquery.autoresize.js, jQuery.autogrow, elastic

December 14, 2011

javascript load callback for UpdatePanel

Using asp:UpdatePanel isn’t so easy with jQuery(document).ready() or jQuery(window).load(). The jQuery selectors can’t find elements which are not shown in the beginning. All other elements which are loaded dynamically are difficult to catch. I found a solution in forums.asp.net. A user called germanz creates an jQuery event listener AjaxReady, he uses the ASP.NET built-in PageRequestManager. If there only few usages of it it can be invoked directly from a PageRequestManager instance:

December 13, 2011

jQuery UI Datepicker

As an alternative to asp:Calendar we can use the fancy jQuery UI Datepicker:

$(document).ready(function () {
	$.datepicker.setDefaults($.datepicker.regional\["sv"\]);
	$("#").datepicker({
		changeMonth: true,
		changeYear: true,
		yearRange: "-120:+0" 
	});
});
```I found this a much simple and best solution for an [birthdate input](http://stackoverflow.com/questions/339956/whats-the-best-ui-for-entering-date-of-birth). We can set [international options](http://stackoverflow.com/questions/1865091/jquery-datepicker-language-problem), [year range](http://stackoverflow.com/questions/269545/jquery-datepicker-years-shown), [year](http://stackoverflow.com/questions/3164898/jquery-ui-datepicker-next-and-previous-year) and [month navigation](http://jqueryui.com/demos/datepicker/dropdown-month-year.html). Other options I have tried are asp:Calendar, ajaxtoolkit:CalendarExtender and DateJs. jQuery UI is the most simple much more than datepicker and works smoothily with SharePoint.

December 13, 2011

ASP.NET Ajax Toolkit

To integrate ASP.NET Ajax Toolkit is not the most straight forward task in SharePoint. If you want to take the risk, “Inspired by Technology” provides the best guide so far.

December 12, 2011

Sort a lib when column headers are hidden

Just add this to the url in the browser address bar:

?SortField=Modified&SortDir=Asc

December 8, 2011

Push a copy of an object to client

To reduce postbacks and database calls, a copy of the current object(s) can be pushed down to the client in JSON format. Say a webpart renders information about a person, another webpart shows related information which is retrieved dynamically (like web services). Instead of getting the current person from the database in the second webpart again, we can reuse the same person object from the first webpart. To do so we must provide a DataContract for the Person class: