Create list columns via Web Services

I have just spent a day up to my armpits in JavaScript, specifically JavaScript for creating columns on custom lists for a site configuration utility (where the team I was working in doesn't have developer level access to the farm).

The bulk of the work for creating lists and libraries was done by my predecessor but the scope for adding columns to a list was restricted to adding existing site columns. I need to be able to automatically create new list columns.

Using the UpdateList method of the Lists web service makes this quite simple. The tricky part is working out what parameters you use to create the fields (also applies to updating).

The CAML query for creating a field is of the format:

<Fields><Method ID="1"><Field [attributes]/><Field [attributes]/></Method></Fields>

There are lots of attributes to use for the node, but these are the common ones:

• Type: Corresponds to the column type in the Create Column screen (more details below)
• Name: Internal name of the field (replaced with the internalised version of the Display Name, see this post).
• Display Name: The visible name of the column
• Required: "TRUE" or "FALSE", whether or not this column must contain information (not applicable to Yes/No or Calculated columns)
• Description: The column description

Other attributes are used depending on the column type (with typical examples):

• Single line of text
  
  
  • Type="Text"
• Multiple lines of text
  
  
  • Type="Note"
  • AppendOnly="TRUE" (append changes to the field, but only if versioning on the list is enabled)
  • RestrictedMode="TRUE" (defines whether users can use normal rich text, or enhanced rich text)
  • RichText="TRUE" (rich or plain text)
  • NumLines="6" (number of lines to display to the user while editing)
• Choice
  
  
  • Type="Choice"
  • Format="Dropdown"
  • FillInChoice="FALSE"
  • Mult="FALSE" (sets multiple selection)
  • <CHOICES><CHOICE>Choice 1</CHOICE><CHOICE>Choice 2</CHOICE></CHOICES>
  • <Default>Choice 2</Default>
• Currency
  
  
  • Type="Currency"
  • Max="321" (maximum value)
  • Min="123" (minimum value)
  • Decimals="0" (number of decimal places)
  • LCID="1033/5129" (currency format, 1033 is USA, 5129 is NZ)
• Date and Time
  
  
  • Type="DateTime"
  • Format="DateOnly"
  • <Default>[today]</Default>
• Lookup
  
  
  • Type="Lookup"
  • List="Lists/[List Name]"
  • ShowField="Title"
  • Mult="FALSE"
• Yes/No
  
  
  • Type="Boolean"
  • <Default>Yes</Default>
• Person or Group
  
  
  • Type="User"
  • UserSelectionMode="0" (all people)
  • ShowField="ImnName" (Name with presence)
• Calculated
  
  
  • Type="Calculated"
  • ResultType="Text"
  • ReadOnly="TRUE"
  • <Formula>=If([ECM Status]="Draft","Work in progress","Submitted")</Formula>
  • <FieldRefs><FieldRef Name="ECM_x0020_Status"/></FieldRefs>

Use friendly 'developer' column names

When you create new columns in your SharePoint site, an internal name is created from the entered display name. SharePoint uses this internally for what it does and if you use SharePoint Designer to create custom pages for your lists, document libraries, etc. then this internal name is what you interact with.

The internal name (FieldName) is generated by replacing any spaces with _x0020_, so for example, if you create a column called Registration of Interest, the generated FieldName will be Registration_x0020_of_x0020_Interest. You can see this by looking at the field parameter in the URL when editing the column:

In this case, SharePoint encodes the '_' as %5F, which makes it even more messy.

Now if you only work with out of the box configuration through the browser then that's fine, you don't need to worry about the FieldName. But if you work with SharePoint Designer then it becomes horrible to look at, less than to use.

What can you do? If you rename a site column, all you are doing is changing the display name, the FieldName remains the same. So when you create a new column, give it the name you want to use internally, then change it afterwards to what you want it to display. In our above example, we would create the column by calling it RegistrationOfInterest (alternatively RegOfInterest or even RoI). Once the column is created we can then rename it to Registration of Interest but the FieldName will still be RegistrationOfInterest. A lot easier to use.

You can also use this trick when creating lists and libraries to create friendlier URLs. A list called Training Providers will display /Training%20Providers/ in the URL, but if you name the list TrainingProviders on creation, then rename it, the URL portion will remain /TrainingProviders/.