I like to make use of web properties to make
my solutions more flexible and configurable. For instance, a client of mine
likes to request automated emails from SharePoint. But experience has taught me
that these emails can get overwhelming and it’s not uncommon for a customer to
come back later and request that I stop the emails or reduce their frequency.
If the sending and frequency of emails is hard coded into a deployed solution,
then the process to change the emails involves a code change and a redeployment
which takes time and always has an element of risk to it. Therefore, in cases
like these I will code my solution to read web properties to drive these behaviors.
For example, I might create a web property
named “Customer_SendEmails_OnOff” which can have a value of “On” or “Off”, and
another one named “Customer_Email_FrequencyHours” which would have a value of
the number of hours between emails, like “6”. My deployed solution reads in
these property values and behaves accordingly. If it reads the “Customer_SendEmail_OnOff”
property and the value is “Off” then it sends no emails, if it is “On” then it
reads the “Customer_Email_FrequencyHours” property value to determine the minimum
number of hours between emails. This
way, I can use a few PowerShell commands to alter these property values and
correspondingly change the behavior of my deployed solution immediately.
Here are some useful code samples
related to this process:
PowerShell (add or update a web property)
# Make sure the SharePoint namespace
is loaded
Add-pssnapin Microsoft.SharePoint.PowerShell –erroraction silentlycontinue;
# Set some sample variables
$yourservername = "contoso.local";
$yoursitepath = "sites/Accounting/Audits";
$yourpropname = "Customer_Email_OnOff";
$yourpropvalue = "On";
# Get an SPWeb object
$web = get-spweb ("http://{0}/{1}"
–f $yourservername, $yoursitepath);
# Get a hashtable of all the
properties on the SPWeb
$props = $web.AllProperties;
# Add or update the property
# NOTE: Add "" to ensure
PowerShell interprets value as a string
if ($props.ContainsKey($yourpropname)
{
$props[$yourpropname] = "" + $yourpropvalue;
}
else
{
$props.Add($yourpropname, "" + $yourpropvalue);
}
# Commit updates to the SPWeb
$web.update();
# Release SPWeb from memory
$web.dispose();
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PowerShell (iterate all existing properties)
# Make sure the SharePoint namespace
is loaded
Add-pssnapin Microsoft.SharePoint.PowerShell –erroraction silentlycontinue;
# Set some sample variables
$yourservername = "contoso.local";
$yoursitepath = "sites/Accounting/Audits";
# Get an SPWeb object
$web = get-spweb ("http://{0}/{1}"
–f $yourservername, $yoursitepath);
# Get a hashtable of all the
properties on the SPWeb
$props = $web.AllProperties;
# Iterate the property names and
values
foreach
($p in $props.Keys)
{
write-host –f green "PropertyName:
" -nonewline;
write-host –f yellow $p;
write-host –f green " Value: " -nonewline;
write-host –f yellow $props[$p];
write-host;
}
# Release SPWeb from memory
$web.dispose();
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PowerShell (cleanup/delete selected existing properties, full script)
param(
[Parameter(Mandatory=$true,HelpMessage='Target subweb for properties
(e.g. http://contoso.local/sites/accounting/audits)')][System.String]$weburl)
# Get our web object
$web = get-spweb $weburl;
# Create an empty array to hold the
keys to be deleted
$deleteKeys = @();
# Iterate through each property
$props =
[System.Collections.HashTable]$web.allproperties;
foreach ($p in $props.keys)
{
write-host
-f green " PropertyName: " -nonewline;
write-host
-f yellow $p -nonewline;
write-host
-f red " <- Delete? " -nonewline;
# Read key input until "Y" or "N" pressed
do {
$key =
$host.UI.RawUI.ReadKey("NoEcho,IncludeKeyDown");
}
until
(($key.Character -eq "Y") -or ($key.Character -eq "N"))
# Echo the key pressed
write-host
-f White $key.Character;
# Since we cannot update a collection we are iterating through,
# add the keys to delete into our array
if
($key.Character -eq "Y")
{
$deleteKeys += $p;
}
}
# Delete the property keys that were
marked for deletion
write-host;
foreach ($propkey in $deleteKeys)
{
$web.allproperties.remove($propkey);
write-host
-f red " Deleted: "
-nonewline;
write-host
-f yellow $propkey;
}
write-host;
# Commit our changes
$web.update();
# Release the SPWeb object from
memory
$web.dispose();
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C# (read a property value)
// Set some sample variables
string yourservername = "contoso.local";
string yoursitepath = "sites/Accounting/Audits";
string yourpropname = "Customer_Email_OnOff";
string yourpropvalue = string.Empty();
object property = null;
// Access the site object
using (SPSite site = new SPSite(string.Format("http://{0}/{1}", yourservername, yoursitepath)))
{
// Access the web object
using (SPWeb web = site.OpenWeb())
{
// Attempt to get the property
property = web.AllProperties[yourpropname];
// Check for null
if (property !=
null)
{
// Populate your
variable with the value that was read
yourpropvalue =
property.ToString();
}
else
{
// Handle error
throw
new ArgumentNullException(yourpropname, "Property returned null.");
}
} // end using web
} // end using
site
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