Initiate a SharePoint workflow from a button on the list view.

I came across a scenario recently where a project required that a list of items could have a button or link on a list view, which would cause the workflow to start.

Essentially the users involved were not happy using the OOB way that SharePoint (WSS 3.0) allows users to manually initiate workflows. They believed there were too many steps involved.

After a bit of searching and Googling, I discovered a method involving the use of a hyperlink column on the list in question, coupled with a very simple workflow. I will outline the steps involved in this process below. This is not the most graceful solution I am sure, but it is a simple solution to what can be a tricky problem.

How was it done?

Note: I am assuming that you have a simple workflow attached to a list, if not then please create a simple SharePoint Designer workflow. You can see how to do this here.

1. Add a new hyperlink column to your list, this is going to represent the button which users click on to start the workflow, so give the column an appropriate name.



2. Click on the list settings for your list and select 'Advanced settings', ensure that 'Allow management of content types' is set to 'Yes'. This will allow us to hide the hyperlink column from the forms involved, if your list is a custom list then you may be able to go to 'Form settings' within list settings and make more detailed amendments to what appears on the new, display and edit forms.



3. In the 'Content Types' section of the 'List Settings' page, click on the content type for your list. Then click on the name of your column. On the 'Change List Content Type Column' page click on the radio button for 'Hidden'. Click 'OK'and return to your list, you should see an empty space for your new column. However if you click on 'New' or try to edit an existing item your column should not display.



4. I have a simple workflow attached to this list. This basic workflow merely adds an entry to the workflow history list saying 'Workflow started OK'. I assume your workflow is going to be slightly more complex, however the principle is the same. If you click on an item in your list (if you don't have one then create a quick test entry), and select the 'Workflows' icon from the item toolbar. Now click on the name of your workflow.



5. You should now be looking at the initiation page which SharePoint Designer has created for us, now this page can be cutomised to say whatever you wish via SharePoint Designer, but I am going to leave it as the default for now. The important part here is the URL and parameters.



The URL of this page will be something similar to:

http://SITE URL/List Name/Workflows/Workflow Name/Workflow Name.aspx

and it should have 4 URL parameters, these are as follows:

List
The guid which identifies the list involved. This will not change for each link required on our list.

ID
The numerical ID of the list item involved. This is the key to making this process work.

TemplateID
The guid of the workflow to be initiated. This will not change for each link required on our list. Note: This guid, unlike the list guid above requires the braces {}, though these may be url encoded (so don't be suprised to see the guid starting %7B which is { when URL encoded).

Source
The referring URL, responses will be redirected back to here once the workflow is succesfully started.

You can probably see that we could manipulate this URL to generate a link for our new hyperlink column by simply altering the ID parameter being sent to this page. How can we do this? We simply use another workflow!

6. Ensure you have copied the URL from step 5 to the clipboard. Open SharePoint Designer and create a new workflow for this site. This simple workflow should be set to 'Automatically start this workflow when a new item is created' only.



7. Click 'Next' and then add a 'Build Dynamic String' action click on 'dynamic string' and paste your URL into the 'String Builder' window. Find the ID parameter and delete the value which you had pasted in. Leaving the cursor in this location click on 'Add Lookup' and select the 'ID' column of the 'Current Item'.



Click 'OK'. Your URL should now look similar to that shown above. At the end of the URL add a comma (,) followed by the text which you want your hyperlink column to display in the list view. For example I have added ', Start my workflow'. There must be a space between your comma and your link text. Otherwise you will get the entire URL as the text for your hyperlink!

Click 'OK' again.

8. Add another action to 'Update List Item' and with Current Item selected click on 'Add'. The 'Value Assignment' dialog will allow you to assign your new hyperlink column to the value of the URL string we have just generated. Select your new hyperlink column from the 'Set this field:' list. Next to the 'To this value:' list select the 'fx' button. In the 'Source:' drop down select 'Workflow Data' and in the 'Field:' select your variable (probably named with the default 'Variable: variable')





Click 'OK' then 'OK' again on the 'Value Assignment' dialog. The 'Update List Item' dialog should now show this field and value in the list of items to be updated. Click 'OK' again.

9. We can now click 'Finish' to complete our simple workflow. SharePoint Designer will now generate the required files and bind this workflow to your list.

10. Go to your list and click on 'New' in the list toolbar, complete a test item (noting that your hyperlink column is not listed). Click 'OK' and you should return to your list view and your hyperlink column should be populated with the display value you entered in stage 7.



Clicking on this hyperlink should take you to the initiation page that SharePoint Designer created for you, but (crucially) the ID will be the ID for the item which the hyperlink column exists on.

Clicking 'Start' on this page will start your workflow as designed in SharePoint Designer.

So there you go! Wait for it...There are a few buts...

Issues

1. Document Libraries with check in/out enabled
This is the same as designing any workflow which is going to update these items, you must handle checking in/out. Because our workflow is only initiated on creation then this is not a major issue, but I did come across some problems in this scenario, but they were overcome by having the workflow check the item back in before updating.

2. Custom Workflow
This workaround is designed for dealing with either SharePoint Designer workflows or custom workflows which use an initiation form as SPD always creates a workflow initiation form anyway. It will not work for custom workflows that do not require an initiation form as there is no URL to link to (This is a scenario that I am interested in so if anyone has any recommendations then please post a comment). If your custom workflow uses an InfoPath form to initiate then you might want to look at creating links to the following URL:

http://SITE URL/_layouts/IniWrkflIP.aspx

This page takes similar parameters to the SPD generated page except you can supply an xsn location for your infopath form too. More information can be found here. The above technique should work perfectly well in this scenario, I just haven't tried it.

Credit: Thanks to Laura Rogers from the sharepointdiscussions Yahoo group for pointing me in the direction of this method.

Microsoft.SharePoint.SoapServer.SoapServerException whilst using the SharePoint web services

Whilst trying out some development concepts using the SharePoint Lists.asmx web service I came across the above error message everytime I tried to call the GetList or GetListItems method. My code was simple:

Dim serLists as New myService.Lists
serLists.Credentials = System.Net.CredentialCache.DefaultCredentials
Dim myItems as XmlNode = serLists.GetListItems("MyList", Nothing, Nothing, Nothing, Nothing, Nothing, Nothing)

However whenever I ran this through I got the mysterious error:

Microsoft.SharePoint.SoapServer.SoapServerException

Visual Studio debugging did not report any inner exceptions so I could not find out what the problem was.

The solution is a simple one. The Lists web service will execute methods on the root web (SPWeb as in site) on the Site Collection, even if your web service reference is to a site further down the site collection.

There is a URL property on the proxy class generated for the web service, you need to set this to the url of the web service within your sub site. This must be set BEFORE you use the service proxy class to call the method.

Example

'Set the Url property of the service for the path to a subsite.
'Not setting this property will return the lists in the root web site.
serLists.Url = http://Server_Name/Subsite_Name/_vti_bin/Lists.asmx

Hope this helps!

Keeping Up - SharePoint

For those of you interested in the best ways of keeping up to date with information and developments with SharePoint then the SharePoint Product Team have posted a great blog article with links to a load of really useful RSS feeds.

Suck 'em up and keep updated!

Microsoft SharePoint Team Blog - A much easier way to keep track of new SharePoint content published on MSDN and TechNet

SharePoint Developer Training

This post comes as I am undertaking a SharePoint developer course with Combined Knowledge. The training is being delivered by Todd Bleeker a SharePoint MVP from US firm Mindsharp. Todd's enthusiasm for SharePoint is infectious and the training is highly detailed and relevant.

I hope to post some articles on tips for SharePoint developers once the course is complete.

For further info see Combined Knowledge, Mindsharp, Todd Bleeker

Update

I appreciate that I have not updated my blog for a while, I have been busy learning new stuff...

I am looking to write some interesting stuff on my experiences with SharePoint thus far as I am off to Ullesthorpe in Leicester next week to do the SharePoint developer training with Combined Knowledge.

I also have some potings re: BizTalk developer tips that I will get on here next week. So keepa lookout.

System.Net.Mail and locked files

For many years now I have had a functional class for making it easy to create and send emails. I have over the years tweaked this class to support lots of additional features such as html and plain text templates, sending emails using alternate views, file attachments etc.

However just recently I noticed that if I tried to do anything with a file after I had attached it to an email using my mailmanager class then I got problems as Windows was always retaining a file lock on the file.

The solution was a simple one...write better code. Essentially I was not correctly disposing of the System.Net.Mail.MailMessage after attaching files and sending the email. Its a lesson in diligence that sometimes it doesn't matter how many times you have revised a piece of code over the years. It can be the simplest of things that bites you!

Calling an External Assemby from a Scripting Functoid

Having completed the official Microsoft course on developing with BizTalk (credit to QA-IQ for adding some great additional content to the course), I have been working on some projects in anger.

The most recent issue I had was around testing a map which used a scripting functoid to call my data layer to get some data out of a database.

I built a class library project which provides various methods to retrieve the data I need using the data layer. However when I referenced the project in my maps project (note that I keep all BizTalk file types e.g. schemas, orchestrations, maps etc in their own project for ease of deployment) I got an error essentially saying that the assembly could not be loaded. After some rooting around I found the problems.

The following is my checklist for things to look for if you are having problems with this:

• Make sure that all functions used on your assembly are working correctly first. Its much easier to know that you can rule out problems with your referenced code prior to using it in BizTalk.
  
  
• DO NOT set-up shared (static in C#) functions on your referenced assembly if you want to call them from a scripting functoid. BizTalk will natively try to instantiate your class so these will not work.
  
  
• Restart VS to ensure that all references have been freshly loaded.
  
  
• Ensure that the dll for your referenced project is installed in the GAC on your development machine.
  
  
• If you are using the 'Test Map' functionality from within VS then you will also need to ensure that any config settings that are required for your assembly (e.g AppSettings) are included in the devenv.exe.config file. At runtime these settings will need to be put into btsntsvc.config on your live configuration.
  
  
• If you have updated your assembly then ensure that VS is trying to use the correct version, remove all references to your assembly and add them again.
  
  
• Refresh the GAC.
  
  
• If you wish to debug your referenced assembly then you will have to setup a test project to do this, however ensure that you un-install your dll from the GAC if you have already installed it as VS will try to use the GAC version first and this will not have a debug file associated with it. You will get an error saying that no debug information has been generated if VS is using the reference from the GAC.
  

I hope that this has been helpful. I suspect I will be adding a few more BizTalk related posts as I get to grips with some of the finer points of the technology.

BizTalk

I am heading off to London in a few short days to undertake the MS training for BizTalk Server 2006. I am hoping that my experiences will be a shade better than other times I have taken the official MS courses on new subjects.

The idea of BizTalk is very new to me and it will be interesting to see how it all fits together. I have heard all kinds of comments on BizTalk so it remains to be seen how this pans out for me.

I'll let you know how it goes.

Auditing tables with ntext fields

I need to track and audit changes to a field on a SQL Server 2000 database. Not difficult? I thought not. The first problem was with data typing, the field in question is an ntext field which is a problem.

Normally I would use:

CREATE TRIGGER xxx ON xxx FOR Insert/Update/Delete

This can't work in my scenario as neither the 'Inserted' nor the 'Deleted' tables will store the values of text, ntext or image fields in the case of a FOR trigger, otherwise known as an AFTER trigger as it takes place after the table change which triggered it.

Enter the INSTEAD OF trigger. This trigger bought in from SQL 2000 onwards supports the use of ntext, text and image fields in the 'deleted' and 'inserted' tables. However I have now discovered that you cannot use the values from these fields in local variables or sub-queries so I cannot get them out of the 'inserted' table and record them into my audit table.

The other problem with this approach is that the INSTEAD OF trigger (as the name rather handily implies) actually replaces the table change action which triggered it e.g. the original insert or update will be replaced by the trigger code. I could write code to re-perform the original action after my custom code, but this all sounds rather messy.

In short I am still stumped, auditing changes to an ntext field cannot be a rare occurence, and yet the answer evades me.

I should really say that I am not a SQL Server developer, but I am trying to debug a 3rd party application and suspect that there are problems when saving fields back to the database. Hence the need for an audit table.

Determining data types at runtime in VB.Net

I always forget how this should work. So here its is quick and easy...

To determine the data type of an object at runtime you can use the TypeOf() function.

For example :

If TypeOf(Control) is TextBox Then

'Some function here

End If