SharePoint, Anonymous Access in FBA and SPContext issues - sharepoint

We have created a virtual directory under the root sharepoint site. This virtual directory hosts a Web Service which is accessed anonymously.
In the code we are doing the following:
using(SPSite site = new site(some uri))
{
using(SPWeb web = site.RootWeb)
{
SPList list = web.Lists["SomeList"];
SPListItem item = list.GetItemById(1); // Exception Here, COM Exception
}
}
This does not work even when using RunWithElevatedPrivileges.
However, if the HttpContext.Current is set to null, before creating the SPSite, everything works fine.
Any pointersas to why this is happening will be very helpful.
Kind regards,

On the contrary! It is considered a good practice to always check for null and dispose both your SPSite and your SPWeb explicitly, even though SPSite arguably will dispose your SPWeb for you.
And that is not part of the problem either :-)
At the worst that would cause the worker process to recycle a bit more often than usual...
Could you maybe add some more code (the whole class).
Also please include full stack trace for the error.
(details on how to enable stack trace and debugging here http://blogs.importchaos.com/alonsorobles/2008/06/09/enabling-the-sharepoint-safe-mode-call-stack-disabling-custom-errors-and-enabling-compilation-debugging/ )
Also i take it you are sure that the list and the item exists and allow anonymous access?
regards
Anders Rask

This may not be the cause of your problem, but your SPWeb does not need to be disposed of, as per Roger Lamb here, which is a distillation of Microsoft's best practices document here.

Related

Sharepoint Taxonomy Navigation

I am using taxonomy for building left navigation in the sharepoint site.
I am using below method for accessing the nodes.
NavigationTermSet navTermSet = TaxonomyNavigation.GetTermSetForWeb(SPContext.Current.Site.RootWeb, StandardNavigationProviderNames.CurrentNavigationTaxonomyProvider, true);
but its returning only two terms and not returning all the child terms under these 2 terms.
But if i logging to the site as admin i am able to get the all the child terms as well.
I tried with console appilcation and its working fine and its problem only with Annonymous user accessing the page.
I have given the Full Access to app pool account also.
Not sure what i am missing here, any lead will be really helpful.
Regards
CR
Try to use RunWithElevatedPrivileges to run with elevated rights.
SPSecurity.RunWithElevatedPrivileges(delegate()
{
using (SPSite site = new SPSite(web.Site.ID))
{
// implementation details omitted
}
});

SPSite site = new SPSite(SPContext.Current.Web.Url) vs SPContext.Current.Web.Site

Why do some SharePoint examples use
using (SPSite site = new SPSite(SPContext.Current.Web.Url))
{
...
}
and not just simply?
SPSite site = SPContext.Current.Web.Site;
...
Update
I think I have narrowed the question down to the following:
It seems that I should not use SPContent.Current directly, unless I am certain, that my code runs inside SharePoint. But when would that not be true?
Take a look at the best practices documentation on disposing objects in SharePoint 2010 from Microsoft, however there are opposing views.
There are a few key takeaways for SharePoint projects:
Always dispose your SPWeb / SPSite objects --> memory leaks
Make use of SPContext.Current... when you are sure your code is running in a SharePoint context
Unit Tests mean no Sharepoint context
External utilities mean no Sharepoint context
Powershell means no SharePoint context (e.g. activating a feature with feature receiver might fail)
Do not dispose SPContext.Current... but create your own object (again using)
You might have problems with consistency with your multiple SP.. objects.
In the end SPSite site = SPContext.Current.Web.Site; is fine in some instances, but you do not have control over this site object - that might be the problem. If you go for new SPSite(...) you will always have your SPSite and not something SharePoint created and managed for you.
Personally I almost always go for the using structure so all objects are disposed properly afterwards. Alternatively I use SPContext.Current.Web without disposing.
It depends on the context in which your code runs. For instance, you need to create a new SPSite instance if you are running within a RunWithElevatedPrivileges block.
Dennis G is correct. Disposing the SPSite/SPWeb/etc is important but make sure you do not dispose the objects that are provided to you by the API directly. It's subtle but critical otherwise your response will never get generated or cause even thread abort situations.
In my experience, if I need quick information on the SPSite or SPWeb property that I am sure available to the user context (either a content manager authorized user or anonymous), then using SPContext.Current.* object is great. Otherwise, use the RunWithElevatedPriveleges method to wrap your code and inside that lambda has the following pattern:
SPSecurity.RunWithElevatedPrivileges(() =>
{
using (SPSite site = new SPSite(SPContext.Current.Site.ID))
{
using (SPWeb web = site.OpenWeb(SPContext.Current.Web.ID))
{
// stuff goes here elevated
}
}
});

Should I dispose of this SPWeb?

I'm hoping someone can help me out. I need to get the root web of the current site from the SPContext. It's easily done with the following
SPContext.Current.Site.RootWeb
I'm comfortable with the idea that the SPSite object here at SPContext.Current.Site.RootWeb shouldn't be disposed of, but what about the SPWeb object I'm getting from the SPSite. Will, when the SPSite get's disposed, the rootweb SPWeb get disposed to? Or do I need to dispose of it myself?
Calls to SPSite.RootWeb should not be disposed. Disposing the SPSite will also dispose the RootWeb.
There is a bug in SPDisposeCheck where it flags if you do dispose it, and if you don't (damned either way!) I detailed how I solved this in this blog post, as you can't use an SPDisposeCheckIgnore attribute in elevated privileges blocks.
No you should not. You should only dispose objects you are in control of. Because the context is something created by SharePoint you do not dispose of this as other objects may be dependent upon this.
If you were to create your own instance of an SPWeb from this objects properties than it would need to be disposed. I.e..
using (SPSite site = new SPSite(SPContext.Current.Site.RootWeb.Url))
using (SPWeb web = site.OpenWeb()) {
// do something
}
Here is an article on the best practices of disposing SharePoint objects.
http://msdn.microsoft.com/en-us/library/aa973248(v=office.12).aspx
You should normally use SPSite and SPWeb in a using clause.
using (SPSite site = new SPSite("http://mysite.sharepoint.com"))
{
using (SPWeb web = site.OpenWeb())
{
// TODO: code for using SPWeb object
}
}
This automatically will correctly release the SPWeb object after you are done with it.

How to Create a Managed Path through SharePoint Object Model

This is a question for a WSS/SharePoint guru.
Consider this scenario: I have an ASP.Net web service which links our corporate CRM system and WSS-based intranet together. What I am trying to do is provision a new WSS site collection whenever a new client is added to the CRM system. In order to make this work, I need to programmatically add the managed path to the new site collection. I know that this is possible via the Object Model, but when I try it in my own web service, it fails. Sample code extract below:
Dim _ClientSiteUrl As String = "http://myintranet/clients/sampleclient"
Using _RootWeb As SPSite = New SPSite("http://myintranet")
Dim _ManagedPaths As SPPrefixCollection = _RootWeb.WebApplication.Prefixes
If Not (_ManagedPaths.Contains(_ClientSiteUrl)) Then
_ManagedPaths.Add(_ClientSiteUrl, SPPrefixType.ExplicitInclusion)
End If
End Using
This code fails with a NullReferenceException on SPUtility.ValidateFormDigest(). Research suggested that this may be due to insufficient privileges, I tried running the code within an elevated privileges block using SPSecurity.RunWithElevatedPrivileges(AddressOf AddManagedPath), where AddManagedPath is a Sub procedure containing the above code sample.
This then fails with an InvalidOperationException, "Operation is not valid due to the current state of the object."
Where am I going wrong?
One workaround I have managed to do is to call out to STSADM.EXE via Process.Start(), supplying the requisite parameters, and this works.
Update: whilst developing the web service, I am running it using the built-in Visual Studio 2005 web server - what security context will this be running under? Can I change the security context by putting entries in web.config?
Update: I think the problem is definitely to do with not running the web service within the correct SharePoint security context. I decided to go with the workaround I suggested and shell out to STSADM, although to do this, the application pool identity that the web service runs under must be a member of the SharePoint administrators.
Update
I think you have proved that the issue is not with the code.
SPSecurity.RunWithElevatedPrivileges: Normally the code in the SharePoint web application executes with the privileges of the user taking the action. The RunWithElevatedPrivileges runs the code in the context of the SharePoint web application pools account (i think)
The description on MSDN could go into the details a tiny bit more.
The issue with the call may be that the web service is not actually running the code within a SharePoint process, so explaining why it cannot elevate (wild guess alert).
Have a crack at changing the user of your web services application pool and see if that gives any joy.
It is likely to be a permissions issue.
Maybe try:
Dim clientSiteUrl As String = "http://myintranet/clients/sampleclient"
Using SPSite = new SPSite(clientSiteUrl)
webApp As SPWebApplication = SPWebApplication.Lookup(new Uri(clientSiteUrl));
If Not (webApp.Prefixes.Contains(clientSiteUrl)) Then
webApp.Prefixes.Add(clientSiteUrl, SPPrefixType.ExplicitInclusion)
End If
End Using
This is not exact code.
Since the above code is not the exact code, here is the exact working code for a Web Application scopped feature in the Feature Activated event:
On feature activation at the Mange web application features page, activate feature will create a new Explicit managed path in the specified web application (I want to replace the hard coding, maybe with Properties.Feature.Parent, or something similar.)
using (SPSite site = new SPSite("http://dev-moss07-eric/PathHere")) {
SPWebApplication webApp = SPWebApplication.Lookup(new Uri("http://dev-moss07-eric"));
if (webApp.Prefixes.Contains("PathHere"))
{
//
}
else
{
webApp.Prefixes.Add("PathHere", SPPrefixType.ExplicitInclusion);
}
}
Code can probably be improved, but its my attempt at converting the above code.
If you want to create a managed path (explicit) and a site collection at that path, do the following:
using (SPSite site = new SPSite("http://dev-moss07-eric")) {
SPWebApplication webApp = SPWebApplication.Lookup(new Uri("http://dev-moss07-eric"));
if (webApp.Prefixes.Contains("ManagedPathHere"))
{
//
}
else
{
webApp.Prefixes.Add("ManagedPathHere", SPPrefixType.ExplicitInclusion);
}
using (SPWeb web = site.OpenWeb())
{
SPWebApplication webApplication = web.Site.WebApplication;
try
{
webApplication.Sites.Add("ManagedPathHere","Site Title Here","This site is used for hosting styling assets.", 1033, "STS#1", "6scdev\\eric.schrader", "Eric Schrader", "eric.schrader#6sc.com");
}
catch (Exception ex)
{
//ex.ToString;
}
}
}

SharePoint Development Permissions

Hi I am using the SharePoint namespace to pull items from various lists throughout the site. My web part works, but only on my account. When I try it on another account it gives me "Error: Access Denied" for the page. I have taken all web parts out and have only this web part on the page. When I remove the following lines the page loads for everyone, when I add it back in however it does not work. I am guessing this is some permission problem. I was wondering is there away to programatically query different lists on SharePoint by assigning a user id to use? Thank you for any help
...
SPSite site = new SPSite(_SPSite);
SPWeb eachWeb = site.AllWebs[0];
SPListItemCollection myItemCollection = eachWeb.Lists["Listings"].Items;
...
You're correct, the access denied error is occurring when you're using an account which does not have access to the "Listings" list in the current website.
The easiest way around the issue is to use a SPSecurity.RunWithElevatedPrivleges call:
SPSecurity.RunWithElevatedPrivleges(delegate()
{
//Your code here
});
which will run whatever code is contained in the anonymous method using the SharePoint/System account, granting complete control. Be careful when using this technique though, as it equivalent to running code at full trust with a super user account. There are other caveats to be aware of as well.
Try:
SPWeb eachWeb = SPContext.Current.Site.RootWeb.Webs[0];
SPListItemCollection myItemCollection = eachWeb.Lists["Listings"].Items;
Remember that SPWeb should be used in a using block, or disposed of explicitly after use.
As regards the first caveat from EvilGoatBob, I quote:
"If you're manipulating any Object Model elements within your elevated method, you need to get a fresh SPSite reference inside this call. For example
SPSecurity.RunWithElevatedPrivileges(delegate(){
SPSite mySite = new SPSite(http://sharepoint/);
SPWeb myWeb = SPSite.OpenWeb();
// further implementation omitted
});"
Notice that the site parameter is hard-coded - this is because of a bug. If you instead had tried:
using (SPSite site = new SPSite("http://" + System.Environment.MachineName)) {}
You would get the rather generic "No SharePoint Site exists at the specified URL..." error. This caused me no end of grief. Bottom line is that you have to hard-code the server name (unless anyone has an alternative). You can also get a similar error message when debugging Web Parts for the first time with VSeWSS 1.3.
You do not need to hardcode the server name in this case because your requirement is to retrieve items from list inside the same site as your webpart. You are correct, if you do not have enough privileges with your account, then you get the Access Denied. The solution is to create a new SPSite object within a different security context, and do your work:
SPSecurity.RunWithElevatedPrivileges(delegate()
{
using (SPSite site = new SPSite(SPContext.Current.Site.Url))
{
using (SPWeb web = site.OpenWeb())
{
//the web object was retrieved with elevated privileges under the system account.
//do your work here:
SPListItemCollection myItemCollection = web.Lists["Listings"].Items;
//...
}
}
}
);
With the code above, your webpart is portable because there's no hardcoding, and runs in the correct security context while disposing of all unmanaged SPRequest objects created by the SPSite and SPWeb constructors.

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