How to Write a jQuery Plugin

It is actually pretty simple, you just have to follow a basic template. Here I am showing you how to build one to change elements to a round shape. Please note that because I use border radius here in the example you need IE9+ to view the result.

(function ($) {

    //This is where you define your plugin name, in this case - makeMeRound

    $.fn.makeMeRound = function (options) {

        //Extend default settings with options passed through paramete

        var settings = $.extend({

            //Below are default settings, can be overridden by parameter

            'border_color': 'red',

            'border_width': '2px'

        }, options);

        //Wrapped in a each loop in case jQuery selector returns a collection of elements

        //We return this here to maintain chainability during method calls

        return this.each(function () {

            //Below is the core of the plugin

            var max = $(this).width() > $(this).height() ? $(this).width() : $(this).height();

            $(this).css('width', max).css('height', max).css('border-color', settings.border_color).css('border-width', settings.border_width).css('border-radius', '50% 50% 50% 50%');

        });

    };

})(jQuery); //To make sure that your plugin doesn't collide with other libraries that might use the dollar sign

 

//Calling plugin

$(document).ready(function () {

    $('input').makeMeRound(); //use default setting

    $('img').makeMeRound({ 'border_width': '2px' }); //specify custom setting

});

The above script operating on the html below

<input type="button" value="Click Me" style="border-width:1px;width:100px;height:25px;"/>
<img border="1px" src="http://www.tutordoctor.com/sites/default/files/Halloween.jpg" />

will produce the following result

 

 

Using Anonymous Type as Method Parameter

Came across a petty good article with code ready for copy and paste:
http://blog.functionalfun.net/2010/08/practical-linq-6-anonymous-types-as.html

This one shows how to convert an object to Dynamic:
http://blog.jorgef.net/2011/06/converting-any-object-to-dynamic.html

How To Calculate Display Form Absolute URL

string serverUrl = item.ParentList.ParentWeb.Site.Url;

if(item.ParentList.ParentWeb.Site.ServerRelativeUrl != "/")           

    serverUrl= item.ParentList.ParentWeb.Site.Url.Substring(0, item.ParentList.ParentWeb.Site.Url.IndexOf(item.ParentList.ParentWeb.Site.ServerRelativeUrl));

string absoluteUrl = String.Format("{0}{1}?id={2}", serverUrl, item.ParentList.DefaultDisplayFormUrl, item.ID.ToString());

How To Check Whether Current User Belongs To A Certain Group Using JavaScript

Using JavaScript Client Object Model:

 

function isCurrentUserInGroup(groupName, functionUserInGroup, functionUserNotInGroup, functionGroupNotFound, functionOnError) {

    var ctx = new SP.ClientContext.get_current();

    //Get info of current user

    var currentUser = ctx.get_web().get_currentUser();

    ctx.load(currentUser, 'Id', 'LoginName');

    //Retrieve all site groups

    var groups = ctx.get_web().get_siteGroups();

    ctx.load(groups);

 

    ctx.executeQueryAsync(function (sender, args) {

        //See whether the group exists

        var groupFound = false;

        var groupEnumerator = groups.getEnumerator();

        while (groupEnumerator.moveNext() && !groupFound) {

            var group = groupEnumerator.get_current();

            if (group.get_title() == groupName) {

                //Found the group, now try to load users of this group

                groupFound = true;

                var users = group.get_users();

                ctx.load(users);

                ctx.executeQueryAsync(function (sender, args) {

                    //See whether the user exists

                    var userFound = false;

                    var userEnumerator = users.getEnumerator();

                    while (userEnumerator.moveNext() && !userFound) {

                        var user = userEnumerator.get_current();

                        if (user.get_id() == currentUser.get_id()) {

                            //User exists in the group

                            userFound = true;

 

                            if (functionUserInGroup != null)

                                functionUserInGroup();

                        }

                    }

 

                    //User doesn't exist in the group

                    if (!userFound && (functionUserNotInGroup != null))

                        functionUserNotInGroup();

 

                }, function (sender, args) {

                    if (functionOnError != null)

                        functionOnError(sender, args);

 

                });

            }

        }

 

        //Group doesn't exist

        if (!groupFound && (functionGroupNotFound != null))

            functionGroupNotFound();

 

    }, function (sender, args) {

        if (functionOnError != null)

            functionOnError(sender, args);

 

    })

 

}

 

// Sample usage 

ExecuteOrDelayUntilScriptLoaded(function () {

    isCurrentUserInGroup('Approvers',

                         function () {

                            alert('User is in the group.');

                         },

                         function () {

                            alert('User is NOT in the group.');

                         },

                         function () {

                             alert('Group does NOT exist.');

                         },

                         function (sender, args) {

                             alert('Request failed.' + args.get_message() + '\n' + args.get_stackTrace());

                         });

}, "sp.js");

 

How To Override Created/Created By/Modified/Modified By Fields

A lot of people ran into issues when trying to achieve the goal. The trick is really simple, you just need to call SPListItem.UpdateOverwriteVersion() instead of SPListItem.Update() or SPListItem.SystemUpdate().
                             

         item["Author"] = web.SiteUsers["sp2010\\user1"];

         item["Editor"] = web.SiteUsers["sp2010\\user2"];

         item["Created"] = DateTime.Now.AddYears(-50);

         item["Modified"] = DateTime.Now.AddYears(50);

         item.UpdateOverwriteVersion();