Share point 2013 coding standards and best practices 1.0

SharePoint 2013 coding standards and best practices

Contents
1) Using SharePoint data and objects efficiently
2) Working with folders and lists
3) Deleting Multiple Versions of a List Item
4) Writing applications that scale to large numbers of users
5) Using SPQuery Objects
6) Using Web Controls
7) Creating Timer Jobs
8) File naming restrictions
9) Accessing web and site objects
10) Access external systems
11) Dispose objects
12) Exception handling in SharePoint
13) General Principals

Using SharePoint Data and Objects Efficiently
Caching is one good way to improve system performance. However, you must weigh the benefits
of caching against the need for thread safety. Additionally, you should not create certain
SharePoint objects within event receivers because this will cause performance problems related
to excessive database calls.
Caching Data and Objects
Many developers use the Microsoft .NET Framework caching objects (for example,
System.Web.Caching.Cache) to help take better advantage of memory and increase overall
system performance. But many objects are not "thread safe" and caching those objects can
cause applications to fail and unexpected or unrelated user errors.
Caching SharePoint Objects That Are Not Thread Safe
You might try to increase performance and memory usage by caching
SPListItemCollection objects that are returned from queries. In general, this is a good practice;
however, the SPListItemCollection object contains an embedded SPWeb object that is not thread
safe and should not be cached. For example, assume the SPListItemCollection object is cached
in a thread. As other threads try to read this object, the application can fail or behave strangely
because the embedded SPWeb object is not thread safe. For more information about the SPWeb
object and thread safety, see the Microsoft.SharePoint.SPWeb class. The guidance in the
following section describes how you can prevent multiple threads from attempting to read the
same cached object.
Understanding the Potential Pitfalls of Thread Synchronization
You might not be aware that your code is running in a multithreaded environment (by
default, Internet Information Services, or IIS, is multithreaded) or how to manage that
environment. The following example shows the code some developers use to cache
Microsoft.SharePoint.SPListItemCollection objects.
Bad Coding Practice
Caching an Object That Multiple Threads Might Read
public void CacheData()
{
SPListItemCollection oListItems;
oListItems = (SPListItemCollection)Cache["ListItemCacheName"];
if(oListItems == null)
{
oListItems = DoQueryToReturnItems();
Cache.Add("ListItemCacheName", oListItems, ..);
}
}
Although the use of the cache in this example is functionally correct, because the ASP.NET cache object
is thread safe, it introduces potential performance problems. (For more information about ASP.NET
caching, see the Cache class.) If the query in the preceding example takes 10 seconds to complete,
many users could try to access that page simultaneously during that amount of time. In this case, all of
the users would run the same query, which would attempt to update the same cache object. If that
same query runs 10, 50, or 100 times, with multiple threads trying to update the same object at the
same time—especially on multiprocess, hyperthreaded computers—performance problems would
become especially severe.

To prevent multiple queries from accessing the same objects simultaneously, you must change the
code as follows.
Applying a Lock
Checking for null
private static object _lock = new object();
{
lock(_lock)
{
{
}
}
}
You can increase performance slightly by placing the lock inside the if(oListItems == null)
code block.
When you do this, you do not need to suspend all threads while checking to see if the data is already
cached. Depending on the time it takes the query to return the data, it is still possible that more than o
ne user might be running the query at the same time.
This is especially true if you are running on multiprocessor computers. Remember that the more proces
sors that are running and the longer the query takes to run, the more likely putting the lock in the
if() code block will cause problems.
If you want to make absolutely sure that another thread has not createdoListItems before the curre
nt thread has a chance to work on it, you could use the following pattern.
Applying a Lock
Rechecking for null
C#
{
{
lock (_lock)
{
//Ensure that the data was not loaded by a concurrent thread while waiting for
lock.
oListItems = (SPListItemCollection)Cache[“ListItemCacheName”];
if (oListItems == null)
{

}
}
}
}
If the cache is already populated, this last example performs as well as the initial implementation.
If the cache is not populated and the system is under a light load, acquiring the lock will cause a slight
performance penalty.
This approach should significantly improve performance when the system is under a heavy load,
because the query will be executed only once instead of multiple times, and queries are usually
expensive in comparison with the cost of synchronization.
The code in these examples suspends all other threads in a critical section running in IIS, and prevents
other threads from accessing the cached object until it is completely built.
This addresses the thread synchronization issue; however, the code is still not correct because it is
caching an object that is not thread safe.
To address thread safety, you can cache a DataTable object that is created from the
SPListItemCollection object.
You would modify the previous example as follows so that your code gets the data from
the DataTable object.
Good Coding Practice
Caching a DataTable Object
C#
{
DataTable oDataTable;
lock(_lock)
{
oDataTable = (DataTable)Cache["ListItemCacheName"];
if(oDataTable == null)
{
oDataTable = oListItems.GetDataTable();
Cache.Add("ListItemCacheName", oDataTable, ..);
}
}
}
For more information and examples of using the DataTable object, and other good ideas for
developing SharePoint applications, see the reference topic for the DataTable class.
Using Objects in Event Receivers
Do not instantiate SPWeb, SPSite, SPList, or SPListItem objects within an event receiver. Event receivers
that instantiate SPSite, SPWeb, SPList, or SPListItem objects instead of using the instances passed via the
event properties can cause the following problems:
 They incur significant additional roundtrips to the database. (One write operation can result in up to five
additional roundtrips in each event receiver.)

 Calling the Update method on these instances can cause subsequent Update calls in other registered
event receivers to fail.
Bad Coding Practice
Instantiating a SPSite Object inside an Event Receiver
C#
public override void ItemDeleting(SPItemEventProperties properties)
{
using (SPSite site = new SPSite(properties.WebUrl))
using (SPWeb web = site.OpenWeb())
{
SPList list = web.Lists[properties.ListId];
SPListItem item = list.GetItemByUniqueId(properties.ListItemId);
// Operate on item.
}
}
}
Using SPItemEventProperties
C#
// Retrieve SPWeb and SPListItem from SPItemEventProperties instead of
// from a new instance of SPSite.
SPWeb web = properties.OpenWeb();
// Operate on SPWeb object.
SPListItem item = properties.ListItem;
// Operate on item.
If you do not apply this fix in your code, when you call Update on the new instance, you must
invalidate it with the Invalidate method in the appropriate child class of SPEventPropertiesBase (for
example,
SPItemEventProperties.InvalidateListItem or SPItemEventProperties.InvalidateWeb).
Working with Folders and Lists
When folders and lists grow in size, custom code that works with them needs to be designed in
ways that optimize performance. Otherwise, your applications will run slowly and even cause timeouts to
occur. The following recommendations for addressing performance concerns while working with large
folders and lists
Do not use SPList.Items
SPList.Items selects all items from all subfolders, including all fields in the list. Use the
following alternatives for each use case.
Retrieving all items in a list
Use SPList.GetItems(SPQuery query) instead. Apply filters, if appropriate, and specify
only the fields you need to make the query more efficient. If the list contains more than 2,000
items, you will need to paginate the list in increments of no more than 2,000 items. The following
code example shows how to paginate a large list.

Retrieving Items with SPList.GetItems
C#
SPQuery query = new SPQuery();
SPListItemCollection spListItems ;
string lastItemIdOnPage = null; // Page position.
int itemCount = 2000
while (itemCount == 2000)
{
// Include only the fields you will use.
query.ViewFields = "<FieldRef Name="ID"/><FieldRef Name="ContentTypeId"
/>";
query.RowLimit = 2000; // Only select the top 2000.
// Include items in subfolder (if necessary).
query.ViewAttributes = "Scope="Recursive"";
StringBuilder sb = new StringBuilder();
// To make it order by ID and stop scanning the table, specify the OrderBy
override attribute.
sb.Append("<OrderBy Override="TRUE"><FieldRef Name="ID"/></OrderBy>");
//.. Append more text as necessary ..
query.Query = sb.ToString();
// Get 2,000 more items.
SPListItemCollectionPosition pos = new SPListItemCollectionPosition(lastIt
emIdOnPage);
query.ListItemCollectionPosition = pos; //page info
spListItems = spList.GetItems(query);
lastItemIdOnPage = spListItems.ListItemCollectionPosition.PagingInfo;
// Code to enumerate the spListItems.
// If itemCount <2000, we finish the enumeration.
itemCount = spListItems.Count;
}
The following example shows how to enumerate and paginate a large list.
C#
SPWeb oWebsite = SPContext.Current.Web;
SPList oList = oWebsite.Lists["Announcements"];
SPQuery oQuery = new SPQuery();
oQuery.RowLimit = 10;
int intIndex = 1;
do
{
Response.Write("<BR>Page: " + intIndex + "<BR>");
SPListItemCollection collListItems = oList.GetItems(oQuery);
foreach (SPListItem oListItem in collListItems)

{
Response.Write(SPEncode.HtmlEncode(oListItem["Title"].ToString()) +"<BR>
");
}
oQuery.ListItemCollectionPosition = collListItems.ListItemCollectionPositi
on;
intIndex++;
} while (oQuery.ListItemCollectionPosition != null);
Getting items by identifier
Instead of using SPList.Items.GetItemById, use SPList.GetItemById(int id, string field1,
params string[] fields). Specify the item identifier and the field that you want.
Do not enumerate entire SPList.Items collections or SPFolder.Files collections.
Accessing the methods and properties that are listed in the left column of the following
table will enumerate the entire SPList.Items collection, and cause poor performance and
throttling for large lists. Instead, use the alternatives listed in the right column
Poor performing Methods and Properties Better performing alternatives
SPList.Items.Count SPList.ItemCount
SPList.Items.XmlDataSchema Create a SPQuery object to retrieve only
the items you want.
SPList.Items.NumberOfFields Create a SPQuery object (specifying the
ViewFields) to retrieve only the items you
want.
SPList.Items[System.GUID] SPList.GetItemByUniqueId(System.GU
ID)
SPList.Items[System.Int32] SPList.GetItemById(System.Int32)
SPList.Items.GetItemById(System.Int32) SPList.GetItemById(System.Int32)
SPList.Items.ReorderItems(System.Boolea
n[], System.Int32[], System.Int32)
Perform as paged query by using
SPQuery and reorder the items within
each page.
Note:
The SPList.ItemCount property is the recommended way to retrieve the number of items in
a list. As a side effect of tuning this property for performance, however, the property can
occasionally return unexpected results. If the precise number is required, you should use the
poorer performing GetItems(SPQuery query), as shown in the preceding example.
Whenever possible, acquire a reference to a list by using the list's GUID or URL as a key.
You can retrieve an SPList object from the SPWeb.Lists property by using the list's GUID
or display name as an indexer. Using SPWeb.Lists[GUID] andSPWeb.GetList(strURL) is always
preferable to using SPWeb.Lists[strDisplayName]. Using the GUID is preferable because it is
unique, permanent, and requires only a single database lookup. The display name indexer
retrieves the names of all the lists in the site and then does a string comparison with them. If you

have a list URL instead of a GUID, you can use the GetList method to look up the list's GUID in
the content database before retrieving the list.
Deleting Multiple Versions of a List Item
When you delete multiple versions of a list item, use the DeleteByID method; do not use the
Delete method. You will experience performance problems if you delete each SPListItemVersion
object from a SPListItemVersionCollection object. The recommended practice is to create and
array that contains the ID properties of each version and then delete each version by using the
SPFileVersionCollection.DeleteByID method. The following examples demonstrate both the
approach that is not recommended approach to deleting all versions of the first item of a custom
list.
Bad coding practice
Deleting each SPListItemVersion object
C#
SPSite site = new SPSite("site url");
SPWeb web = site.OpenWeb();
SPList list = web.Lists["custom list name"];
SPListItem item = list.GetItemById(1);
SPListItemVersionCollection vCollection = item.Versions;
ArrayList idList = new ArrayList();
foreach(SPListItemVersion ver in vCollection)
{
idList.Add(ver.VersionId);
}
foreach(int verID in idList)
{
SPListItemVersion version = vCollection.GetVersionFromID(verID);
try
{
version.Delete();
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
Good coding practice
Deleting each version of a list item by using the SPFileVersionCollection.DeleteByID method
C#
SPFile file = web.GetFile(item.Url);
SPFileVersionCollection collection = file.Versions;
foreach (SPFileVersion ver in collection)
{

idList.Add(ver.ID);
}
foreach (int verID in idList)
{
try
{
collection.DeleteByID(verID);
}
{
}
}
Writing applications that scale to large numbers of users
You might be aware that you need to write your code to be scalable so that it can handle multiple
users simultaneously. A good example is creating custom navigation information for all sites and
subsites on each page or as part of a master page. If you have a SharePoint site on a corporate
intranet and each department has its own site with many subsites, your code might resemble the
following:
C#
public void GetNavigationInfoForAllSitesAndWebs()
{
foreach(SPSite oSPSite in SPContext.Current.Site.WebApplication.Sites)
{
try
{
SPWeb oSPWeb = oSPSite.RootWeb;
AddAllWebs(oSPWeb);
}
finally
{
oSPSite.Dispose();
}
}
}
public void AddAllWebs(SPWeb oSPWeb)
{
foreach(SPWeb oSubWeb in oSPWeb.Webs)
{
try
{
//.. Code to add items ..
AddAllWebs(oSubWeb);
}
finally
{
if (oSubWeb != null)
oSubWeb.Dispose();
}
}
}

While the previous code disposes of objects properly, it still causes problems because the code
iterates through the same lists over and over.
For example, if you have 10 site collections and an average of 20 sites or subsites per site
collection, you would iterate through the same code 200 times.
For a small number of users this might not cause bad performance.
But, as you add more users to the system, the problem gets worse, as shown in below table.
Users Iterations
10 2000
50 10000
100 200000
250 500000
Although the code executes for each user that hits the system, the data remains the same for eac
h user.
The impact of this can vary depending on what the code is doing. In some cases, repeating code
might not cause performance problem; however, in the previous example the system must create
a COM object (SPSite or SPWeb objects are created when retrieved from their collections),
retrieve data from the object, and then dispose of the object for each item in the collection. This
can have a significant impact on performance.
How to make this code more scalable or fine-tune it for a multiple user environment can be a hard
question to answer. It depends on what the application is designed to do.
You should take the following into consideration when asking how to make code more scalable:
a) Is the data static, somewhat static, or dynamic?
b) Is the data same for all users, or does it change? For example, does it change depending on
the user who is logged on, the part of the site being accessed, or the time of year?
c) Is the data easily accessible or does it require a long time to return the data? For example, is
it returning from a long-running database query or from remote databases that can have
some network latency in the data transfers?
d) Is the data public or does it require a high level of security?
e) What is the size of the data?
f) Is the SharePoint site on a single server or on a server farm?
How you answer the previous questions will determine in which of several ways you can
make your code more scalable and handle multiple users. The intent of this article is not to
provide answers for all of the questions or scenarios but to provide a few ideas that you can
apply to your specific needs. The following sections offer areas for your consideration.
Caching Raw Data
You can cache your data by using the System.Web.Caching.Cache object.
This object requires that you query the data one time and store it in the cache for access by other
users.
If your data is static, you can set up the cache to load the data only one time and not expire until
the application is restarted, or to load the data once per day to ensure data freshness.

You can create the cache item when the application starts, when the first user session starts, or
when the first user tries to access that data.
If your data is somewhat static, you can set up the cached items to expire within a certain number
of seconds, minutes, or hours after the data is created.
This enables you to refresh your data within a timeframe that is acceptable to your users.
Even if the data is cached for only 30 seconds, under heavy loads you will still see improved
performance because you are running the code only one time every 30 seconds instead of
multiple times per second for each user who hits the system.
Security trimming is another issue to consider whenever you cache data.
For example, if you cache items as you iterate through a list, you may get only a subset of the
data (the data that the current user can see), or if you use a DataTable object to cache all of the
items in a list, you have no easy way of applying security trimming to users who belong to groups
that can see only a subset of the data. For more information about storing security trimmed data
in caches, see the CrossListQueryCache class.
In addition, ensure you consider the issues described earlier in Caching Data and Objects.
Building Data before Displaying It
Think about how your cached data will be used. If this data is used to make run-time
decisions, putting it into a Dataset or DataTable object might be the best way to store it.
You can then query those objects for the data to make run-time decisions.
If the data is being used to display a list, table, or formatted page to the user, consider building a
display object and storing that object in the cache.
At run time, you need only retrieve the object from the cache and call its render function to display
its contents.
You could also store the rendered output; however, this can lead to security issues and the
cached item could be quite large, causing increased page swapping or memory fragmentation.
Caching For a Single Server or Server Farm
Depending on how you set up your SharePoint site, you might have to address certain caching
issues differently.
If your data must be the same on all servers at all times, then you must ensure that the same
data is cached on each server.
One way to ensure this is to create the cached data and store it on a common server or in a
Microsoft SQL Server database.
Again, you must consider how much time it takes to access the data and what security issues can
arise from storing the data on a common server.
You can also create business-layer objects that cache data on a common sever, and then access
that data by using various interprocess communications that are available in networking objects
or APIs.
Whenever possible, acquire a reference to a list by using the list's GUID or URL as a key.
You can retrieve a SPList object from the SPWeb.Lists property by using the list's GUID
or display name as an indexer.
Using SPWeb.Lists[GUID] and SPWeb.GetList(strURL) is always preferable to using
SPWeb.Lists[strDisplayName].
Using the GUID is preferable because it is unique, permanent, and requires only a single
database lookup.
The display name indexer retrieves the names of all the lists in the site and then does a string
comparison with them.
If you have a list URL instead of a GUID, you can use the GetList method to look up the list's
GUID in the content database before retrieving the list.

Avoid creating and destroying objects unnecessarily in code
Avoid creating and destroying objects unnecessarily in code, as this may require that
extra queries be made against the database and may even involve code that is incorrect.
In the following example, separate objects for the Tasks list must be instantiated each time the
indexer is used to set properties and the method for updating is called. This is not a
recommended practice.
Bad Practice
SPWeb myWeb = SPContext.Current.Web;
myWeb.Lists["Tasks"].Title = "List_Title";
myWeb.Lists["Tasks"].Description = "List_Description";
myWeb.Lists["Tasks"].Update();
Good Practice
SPWeb myWeb = SPContext.Current.Web;
SPList myList = myWeb.Lists["Tasks"];
myList.Title="List_Title";
myList.Description="List_Description";
myList.Update();
Note:
a) The object models in the Microsoft.SharePoint assembly optimize performance and minimize
the number of SQL queries that are made. However, to monitor code performance, it is
recommended that you use the SQL Profiler.
b) To return a single item from a collection, always use a Get* method when one is provided
through a parent object, instead of iterating through the entire collection and using an indexer.
5) Handling large folders and lists
When the size of folders and lists increases, you must design custom code that works
with them to optimize performance. Otherwise, your applications will run slowly and can cause
service or page load timeouts. The two primary areas for concern when handling large folders
and lists are the following:
Query throttling, which can cause the behavior of your code to change in unexpected and
unpredictable ways over time as your site evolves and your queries begin to return items that
exceed the query threshold.
Efficient retrieval of items from large folders and lists.
6) Throttling for Large List Queries
Microsoft SharePoint Foundation 2013 and Microsoft SharePoint Server 2013 apply a
default query threshold of 5,000 items.
Any custom code that relies on query result sets that can exceed this maximum will not perform
as expected.
Queries on lists consisting of more than 5,000 items that include fields that are not indexed in
their query conditions will also fail, because those queries must scan all rows in a list. Follow the
steps listed below to view and increase this limit or to enable the object model to override the
limit:
To view and increase this threshold or to enable the object model to override the threshold

On the Central Administration site, under Application Management, click Manage Web
Applications.
Click General Settings, and then click Resource Throttling.
View and update the threshold or allow the object model to override the limit.
7) Deleting Multiple Versions of a List Item
When you delete multiple versions of a list item, use the DeleteByID method; do not use
the Delete method. You will experience performance problems if you delete
eachSPListItemVersion object from a SPListItemVersionCollection object.
The recommended practice is to create an array that contains the ID properties of each version
and then delete each version by using the SPFileVersionCollection.DeleteByID method.
The following code examples demonstrate both the approach that is not recommended and the
recommended approach to deleting all versions of the first item of a custom list.
Bad Coding Practice
Deleting each SPListItemVersion object
SPListItemVersionCollection vCollection = item.Versions;
foreach(SPListItemVersion ver in vCollection)
{
idList.Add(ver.VersionId);
}
foreach(int verID in idList)
{
SPListItemVersion version = vCollection.GetVersionFromID(verID);
try
{
version.Delete();
}
{
}
}
Deleting each version of a list item by using the SPFileVersionCollection.DeleteByID method
SPFile file = web.GetFile(item.Url);
SPFileVersionCollection collection = file.Versions;
foreach (SPFileVersion ver in collection)

{
idList.Add(ver.ID);
}
foreach (int verID in idList)
{
try
{
collection.DeleteByID(verID);
}
{
}
}
Using SPQuery Objects
SPQuery objects can cause performance problems whenever they return large result sets.
The following suggestions will help you optimize your code so that performance will not suffer greatly
whenever your searches return large numbers of items.
Do not use an unbounded SPQuery object.
An SPQuery object without a value for RowLimit will perform poorly and fail on large lists.
Specify a RowLimit between 1 and 2000 and, if necessary, page through the list.
Use indexed fields.
If you query on a field that is not indexed, the query will be blocked whenever it would result in a scan
of more items than the query threshold (as soon as there are more items in the list than are specified
in the query threshold).
Set SPQuery.RowLimit to a value that is less than the query threshold.
If you know the URL of your list item and want to query by FileRef, use SPWeb.GetListItem(string
strUrl, string field1, params string[] fields)instead.
Using Web Controls
When you inherit and override controls in the Microsoft.SharePoint.WebControls namespace,
remember that SharePoint Web controls are templated controls.
Unlike Microsoft ASP.NET Web controls, they are defined and rendered with templates instead of
with the CreateChildControls method.
Instead of having a thickCreateChildControls method that uses the new operator to create child
controls, perform most child control creation and rendering by using the rendering templates that are
referenced in the Template, AlternateTemplate, DisplayTemplate, CustomTemplate, and
AlternateCustomTemplate properties of the SharePoint Web control.
SharePoint Web controls do inherit the CreateChildControls method, but that method should typically
do little or nothing beyond calling the parent control's CreateChildControlsmethod and perhaps a bit
of "final polish" rendering, such as assigning default values to child control properties in New mode or
assigning the current values in Edit mode.

Creating Timer Jobs
Design your timer jobs so that they consist of small, manageable pieces. Because administrators
and other events, such as system restarts, can stop timer jobs, you can minimize the amount of
rework after any interruption by breaking timer jobs into small pieces of work.
Avoiding Unnecessary Construction of SPWeb and SPSite Objects
A SPWeb or SPSite object can occupy a lot of memory.
Avoid constructing objects of these types simply to get a reference to a parent object.
Instead, to get a reference to a web application, use the static SPWebApplication.Lookup(Uri)
method, and pass it a Uri object that is created with the URI of the web application.
You can then get a reference to the farm by using the Farm property of the web application object.
(You can get a reference to a remote farm by using the static Open(String) method.)
TheContentDatabases property of the web application object contains a collection of the content
databases in the web application.
You can get a reference to a particular content database through this property if you know its index in
the collection.
For more information, see the reference topic for the SPContentDatabaseCollection class.
The following code illustrates some of these points.
SPWebApplication webApplication = SPWebApplication.Lookup(new Uri("http://localhost/");
SPFarm farm = webApplication.Farm;
SPContentDatabase content = webApplication.ContentDatabases[0];
File Naming Restrictions
For security reasons, SharePoint Foundation reads files in the %ProgramFiles%Common
FilesMicrosoft Sharedweb server extensions15TEMPLATE directory tree only if their names are
composed of ASCII letters, numbers, periods, underscores, or dashes. In addition, file names cannot
contain two or more consecutive periods. For example:
Following are permitted file names:
a) AllItems.aspx
b) Dept_1234.doc
c) Long.Name.With.Dots.txt
The following are not permitted file names:
a) Cæsar.wav
b) File Name with Spaces.avi
c) Wow...ThisIsBad.rtf
d) 揵.htm
Accessing Web and Site Objects
1) Get Current Site details using SPSite
SPSite oSiteCollection = SPContext.Current.Site;

2) Get Current Web details using SPWeb
SPWeb oWebSite = SPContext.Current.Web;
3) When your code is contained in an .aspx file or the "code behind" in an .aspx.cs file, you
can use methods to get the SPWeb.
SPWeb oWebSite = SPControl.GetContextWeb(Context);
where Context = System.Web.UI.Page.Context
4) To get reference of the current web object from .aspx page that is inherited from
LayoutsPageBase is :
SPWeb oWebSite = this.Web;
5) Use the Microsoft.SharePoint.SPSite.AllWebs property to obtain a reference to a Web site other
than the current one.
SPWeb oWebSite = SPContext.Current.Site.AllWebs["myOtherSite"];
6) Get reference of server farm or current physical server :
SPFarm oFarm = SPFarm.Local;
Access external systems
When the data source is a Web service or database, consider using the Business Data Catalog
(BDC) for SP 2007 and Business Connectivity Services (BCS) for SP 2013.
SharePoint Databases
Do not make calls directly to the SharePoint content and configuration databases.
Packaging
Structure your code project so that solution packaging is integrated into the project
Dispose Objects
We should not dispose any SPWeb, SPSite object create using SPContext.Current.Site,
SPContext.Current.Web, SPControl.GetContextWeb(Context), this.Web
We should explicitly dispose of references to objects obtained through the AllWebs property
The code should dispose any SPSite or SPWeb object obtained by using a constructor.
Do not dispose dispose of the SPWeb.ParentWeb
The SPWeb.Webs property returns a SPWebCollection object. The SPWeb objects in this collection
must be disposed.
The SPWeb.Webs.Add method (or Add) creates and returns a new SPWeb object. You should
dispose of any SPWeb object returned from this method call.
If the object is obtained from the SharePoint context objects (GetContextSite method and
GetContextWeb method), the calling application should not call the Dispose method on the object.
You should still dispose of an object that is created from these objects, for example, if a Web site is
opened from an SPSite object that you obtained by using the GetContextSite method.
Wrong Way
void CombiningCallsLeak()

{
using (SPWeb web = new SPSite(SPContext.Current.Web.Url).OpenWeb())
{
// ... New SPSite will be leaked.
} // SPWeb object web.Dispose() automatically called.
}
Right Way
void CombiningCallsBestPractice()
{
using (SPSite siteCollection = new SPSite(SPContext.Current.Web.Url))
{
using (SPWeb web = siteCollection.OpenWeb())
{
//Perform operations on site.
} // SPWeb object web.Dispose() automatically called.
} // SPSite object siteCollection.Dispose() automatically called.
}
Exception Handling in SharePoint
1. Avoid empty Catch blocks
All the errors should be reported using error logging functionality, if not handled sufficiently.
Wrong Way
try
{
// code
}
catch { }
2. Use throw; if you’re going to throw an exception
Wrong Way
try
{
// code
}
{
throw ex;
}
Right Way
try
{
// code
}
catch
{
throw;

}
3. Handle the specific exception wherever possible
Right Way
try
{
spList = spWeb.GetList("/Path/List");
}
catch (FileNotFoundException ex)
{
// handle exception
}
catch (ArgumentException ex)
{
// handle exception
}
4. Try to check condition before it throws exception
Wrong Way
try
{
myString = listItem["MyField"].ToString();
}
{
// handle exception
}
Right Way
if (String.IsNullOrEmpty(listItem["MyField"]))
{
myString = listItem["MyField"].ToString();
}
6. Use an appropriate form of logging exception.
The most important takeaway is to ensure that the errors are logged. The 2 most logical locations to log
the errors would be the ULS or Event Log, however this may not always be appropriate. If these locations
aren’t regularly monitored or accessible by the people who need to know about the errors, then it is
essentially no better than swallowing the errors in the first place. Email, CRM, a database or even a
SharePoint list are other potential locations that could be more accessible. Logging to a file on the file
system makes little sense seeing if that is an accessible option you could just use the ULS.
7. Use a custom error page.
Nothing looks worse on a public facing internet site or even an intranet application than when you
get the SharePoint default error page. Wherever possible you should display a user friendly message
rather than an ugly generic error page.

General Principals
 All new functionality and customizations must be documented.
 Do not edit out of the box files.
o For a few well defined files such as the Web.config or docicon.xml files, the built-in files
included with SharePoint Products and Technologies should never be modified except
through official supported software updates, service packs, or product upgrades.
 Do not modify the Database Schema.
o Any change made to the structure or object types associated with a database or to the
tables included in it. This includes changes to the SQL processing of data such as triggers
and adding new User Defined Functions.
o A schema change could be performed by a SQL script, by manual change, or by code
that has appropriate permissions to access the SharePoint databases. Any custom code
or installation script should always be scrutinized for the possibility that it modifies the
SharePoint database.
 Do not directly access the databases.
o Any addition, modification, or deletion of the data within any SharePoint database using
database access commands. This would include bulk loading of data into a database,
exporting data, or directly querying or modifying data.
o Directly querying or modifying the database could place extra load on a server, or could
expose information to users in a way that violates security policies or personal
information management policies. If server- side code must query data, then the
process for acquiring that data should be through the built-in SharePoint object model,
and not by using any type of query to the database. Client-side code that needs to
modify or query data in SharePoint Products and Technologies can do this by using calls
to the built-in SharePoint Web services that in turn call the object model.
 Exception: In SharePoint 2010 the Logging database can be queried directly as
this database was designed for that purpose.
 Use best practices when accessing data using the SharePoint object model. See Working with
Large Lists, Common Coding Issues When Using the SharePoint Object Model, and Using
Disposable Windows SharePoint Services Objects
Development Decisions:
There are plenty of challenging decisions that go into defining what the right solution for a
business or technical challenge will be. What follows is a chart meant to help developers when selecting
their development approach.
Sandbox Apps Farm
When to use Deprecated. Therefore,
it’s unadvisable to build
new sandboxed
solutions.
Best practice. Create
apps whenever you can.
Create farm solutions
when you can’t do it in
an app.
Server-side code Runs under a strict CAS
policy and is limited in
what it can do.
No SharePoint server-
code. When apps are
hosted in an isolated
SharePoint site, no
Can run full trust code or
run under fine grained
custom CAS policies.

server-code whatsoever
is allowed.
Resource throttling Run under an advanced
resource management
system that allows
resource point allocation
and automatic shutdown
for troublesome
solutions.
Apps run isolated from a
SharePoint farm, but can
have an indirect impact
by leveraging the client
object model.
Can impact SharePoint
server-farm stability
directly.
Runs cross-domain No, and there’s no need
to since code runs within
the SharePoint farm.
Yes, which provides a
very interesting way to
distribute server loads.
No, and there’s no need
to since code runs within
Efficiency/Performance Runs on the server farm,
but in a dedicated
isolated process. The
sandbox architecture
provides overhead.
Apps hosted on separate
app servers (even cross-
domain) or in the cloud
may cause considerable
overhead.
Very efficient.
Safety Very safe. Apps rely on OAuth 2.0.
The OAuth 2.0 standard
is surrounded by some
controversy. In fact, some
SharePoint experts have
gone on the record
stating that security for
Apps will become a big
problem. We’ll just have
to wait and see how this
turns out.
Can be very safe, but
this requires additional
testing, validation and
potential monitoring.
Should IT pros worry
over it?
Due the the limited CAS
permissions and
resource throttling
system, IT pros don’t
have to worry.
Apps are able to do a lot
via the client OM. There
are some uncertainties
concerning the safety of
an App running on a page
with other Apps. For now,
this seems to be the most
worry-able option, but
we’ll have to see how this
plays out.
Definitely. This type of
solutions run on the
SharePoint farm itself
and therefore can have
a profound impact.
Manageability Easy to manage within
Can be managed on a
dedicated environment
without SharePoint.
Dedicated app admins
can take care of this.
Easy to manage within
Cloud support Yes Yes, also support for App
MarketPlace.
No, on-premises (or
dedicated) only.
App Development (SharePoint 2013):
 When developing an app select the most appropriate client API:
o Apps that offer Create/Read/Update/Delete (CRUD) actions against SharePoint or BCS
external data, and are hosted on an application server separated by a firewall benefit
most from using the JavaScript client object model.

o Server-side code in Apps that offer Create/Read/Update/Delete (CRUD) actions against
SharePoint or BCS external data, and are hosted on an application server but not
separated by a firewall mainly benefit from using the .managed client object model, but
the Silverlight client object model, JavaScript client object model or REST are also
options.
o Apps hosted on non-Microsoft technology (such as members of the LAMP stack) will
need to use REST.
o Windows phone apps need to use the mobile client object model.
o If an App contains a Silverlight application, it should use the Silverlight client object
model.
o Office Apps that also work with SharePoint need to use the JavaScript client object
model.
Quality Assurance:
 Custom code must be checked for memory leaks using SPDisposeCheck.
o False positives should be identified and commented.
 Code should be carefully reviewed and checked. As a starting point use this code review
checklist (and provide additional review as needed).
Branding:
 A consistent user interface should be leveraged throughout the site. If a custom application is
created it should leverage the same master page as the site.
 Editing out of the box master pages is not allowed. Instead, duplicate an existing master page;
make edits, then ensure you add it to a solution package for feature deployment.
 When possible you should avoid removing SharePoint controls from any design as this may
impact system behavior, or impair SharePoint functionality.
 All Master Pages should have a title, a description, and a preview image.
 All Page Layouts should have a title, a description, and a preview image.
Deployment:
 All custom SharePoint work should be deployed through SharePoint Solution (.wsp) files.
 Do not deploy directly into the SharePointRoot (15-Hive) Folders. Instead deploy into a folder
identified by Project Name.
Documentation:
 Provide an Installation Guide which contains the following items:
o Solution name and version number.
o Targeted environments for installation.
o Software and hardware Prerequisites: explicitly describes what is all needed updates,
activities, configurations, packages, etc. that should be installed or performed before
the package installation.
o Deployment steps: Detailed steps to deploy or retract the package.

o Deployment validation: How to validate that the package is deployed successfully.
o Describe all impacted scopes in the deployment environment and the type of impact.
Features:
 Features must have a unique GUID within the farm.
 Features with event receivers should clean up all changes created in the activation as part of the
deactivation routine.
o The exception to this is if the feature creates a list or library that contains user supplied
data. Do not delete the list/library in this instance.
 Features deployed at the Farm or Web Application level should never be hidden.
 Site Collection and Site Features may be hidden if necessary.
 Ensure that all features you develop have an appropriate name, description, updated version
number and icon.
SharePoint Designer:
 SharePoint Designer 2013 updates are generally only allowed by a trained individual.
o The following is a recommended way of managing the creation of DataForm Web Parts:
Create a temporary web part page (for managing the manipulation of a data view web
part). Once the web part is ready for release and all modifications have been made
export the .webpart and then delete the page. You can now import it onto a page
elsewhere or place it in the gallery. This way none of your production pages are un-
ghosted. The other advantage is that you can place the DVWP on a publishing page (as
long as there are web part zones to accept them).
o DataForm Web Parts should be exported through the SharePoint GUI and solution
packaged for deployment as a feature.
 SharePoint Designer workflows should not be used for Business Critical Processes.
o They are not portable and cannot be packaged for solution deployment.
 Exception Note: Based on the design and approach being used it may be viable
in SharePoint 2013 for you to design a workflow that has more portability. This
should be determined on a case by case basis as to whether it is worth the
investment and is supportable in your organization.
Site Definitions:
 Site and list templates must be created through code and features (site and list definitions).
o STP files are not allowed as they are not updatable.
 Site definitions should use a minimal site definition with feature stapling.
Solutions:
 Solutions must have a unique GUID within the farm.
 Ensure that the new solution version number is incremented (format V#.#.#).
 The solution package should not contain any of the files deployed with SharePoint.
 Referenced assemblies should not be set to “Local Copy = true”

 All pre-requisites must be communicated and pre-installed as separate solution(s) for easier
administration.
Source Control:
 All source code must be under a proper source control (like TFS or SVN).
 All internal builds must have proper labels on source control.
 All releases have proper labels on source control.
InfoPath:
 If an InfoPath Form has a code behind file or requires full trust then it must be packaged as a
solution and deployed through Central Administration.
 If an InfoPath form does not have code behind and does not need full trust the form can be
manually published to a document library, but the process and location of the document library
must be documented inside the form.
o Just add the documentation text into a section control at the top of the form and set
conditional formatting on that section to always hide the section, that way users will
never see it.
WebParts
 All WebParts should have a title, a description, and an icon.
Application Configuration
 There are only a few methods in which application configuration data can be stored. When
selecting the option that is right for the situation before making the decision.
o Web.config
 APIs such as the ConfigurationSection class and SPWebConfigModification class
should always be used when making modifications to the Web.config file.
 HTTPModules, FBA membership and Role provider configuration must be made
to the Web.config.
o Property Bags
 It is recommended that you create your own _layouts page for your own
settings.
 It is also recommended that you use this codeplex tool to support this method
http://pbs2010.codeplex.com/
o Lists
 This is not a recommended option for Farm or Web Application level
configuration data.
 It is also recommended that you use this codeplex tool to support this method
http://spconfigstore.codeplex.com/

o Hierarchical Object Store (HOS) or SPPersistedObject
 Ensure that any trees or relationships you create are clearly documented.
 It is also recommended that you use the Manage Hierarchical Object Store
feature at http://features.codeplex.com/. This feature only stores values in the
Web Application. You can build a hierarchy of persisted objects but these
objects don’t necessarily map to SPSites and SPWebs.
Process:
All customizations and custom code will go through our review and release cycle.
Example of Review and Release cycle.

Share point 2013 coding standards and best practices 1.0

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