How to change item templates and retain existing data

Question

We are refactoring our project and are trying to clean up the usages of templates throughout the project. There are a number of templates that are very similar that could all be using the same data template, which would also mean we can better utilize the "Compatible Renderings" functionality in Sitecore making it easier for editors to change components.

The problem is we have existing content and it would be a pain have to re-create all the datasources and copy across the data manually.

For example, given the following data templates:

Template A

Title1        Single-Line Text
SubText1      Multi-Line Text
Body1         Rich Text
Image1        Image

Template B

Title2        Single-Line Text
SubText2      Rich Text
Body2         Rich Text

How can we change all items which use Template B to instead use Template A and still retain all existing data?

Answer 1

You can do this with Sitecore PowerShell Extensions.

PowerShell Extensions 4.5 or Higher

Use the Set-ItemTemplate commandlet with the -FieldsToCopy parameter.

$rootItem = Get-Item master:/content;
$sourceTemplate = Get-Item "Template-B-Path-Or-Guid-Here";
$targetTemplate = Get-Item "Template-A-Path-Or-Guid-Here";

Get-ChildItem $rootItem.FullPath -recurse | Where-Object { $_.TemplateName -eq $sourceTemplate.Name } | ForEach-Object {
    Set-ItemTemplate -Item $_ -TemplateItem $targetTemplate `
        -FieldsToCopy @{ Title2 = "Title1"; SubText2 = "SubText1"; Body2 = "Body1" }
}

The value you pass to the -FieldsToCopy parameter takes the following form: @{ OldField1 = "NewField1"; OldField2 = "NewField2"; OldField3 = "NewField3" }.

PowerShell Extensions 4.4.1 or Lower

$rootItem = Get-Item master:/content;
$sourceTemplate = Get-Item "Template-B-Path-Or-Guid-Here";
$targetTemplate = Get-Item "Template-A-Path-Or-Guid-Here";

Get-ChildItem $rootItem.FullPath -recurse | Where-Object { $_.TemplateName -eq $sourceTemplate.Name } | ForEach-Object {
    $title2 = $_.Title2;
    $subText2 = $_.SubText2;
    $body2 = $_.Body2;

    $_.ChangeTemplate($targetTemplate);
    $updatedItem = Get-Item $_.ID;

    $updatedItem.Title1 = $title2;
    $updatedItem.SubText1 = $subText2;
    $updatedItem.Body1 = $body2;
}

With PowerShell Extensions 4.4.1 or lower, be careful that you do the following or you may experience data loss:

1. Store the source field value into a variable before you change the item’s template.
2. Get the updated item out of the database before you set the target field.

Answer 2

You can rename Title2 to match name of Title1 and then simply change the template.

Sitecore will preserve data if the names of the fields match.

Template A

Title1        Single-Line Text
SubText1      Multi-Line Text
Body1         Rich Text
Image1        Image

Template B

Title2 -> Title1        Single-Line Text
SubText2 ->SubText1      Rich Text
Body2 -> Body1         Rich Text

After changes in Template B, you can change Template B to Template A and Sitecore will preserve the data

Answer 3

You can try to execute SQL script which will do the trick for you and update all the items which use particular template.

First you need to replace the field ids used in your original template with field ids used in the new template and then change the template of the item itself.

I haven't tested the script so make sure you have backups.

UPDATE VersionedFields SET [FieldId] = 'NEW_FIELD_ID' WHERE [FieldId] = 'OLD_FIELD_ID';
UPDATE UnversionedFields SET [FieldId] = 'NEW_FIELD_ID' WHERE [FieldId] = 'OLD_FIELD_ID';
UPDATE SharedFields SET [FieldId] = 'NEW_FIELD_ID' WHERE [FieldId] = 'OLD_FIELD_ID';
UPDATE Items SET [TemplateID] = 'NEW_TEMPLATE_ID' WHERE [TemplateID] = 'OLD_TEMPLATE_ID';

After the script is finished, restart the application and republished the site.

Answer 4

The Sitecore Rocks extension for VS allows you to select multiple items at once and change their template.

This is useful if all of the items, you want to change the template of, are in the same place.

UPDATE:

If the field names of the templates are different, you can change them on the new template to match the old one's, change the template of the items, and then change the field names back to the original ones.

Answer 5

I solved it using TDS(hopefully it's applicable with a unicorn & other serialization). This is a local instance approach. Similar to "adragomanov" answer.

Steps involved below, (Before do this exercise have a back up of template/content items involved here)

1. Sync all template & content items in TDS.

2. In Sitecore: Inherit a new-template(Template B) to the existing item template. So the current item will have all the fields from new-template(Template B) & old-template(Template A).

3. In TDS yaml: Replace your old-template fieldname/Id with new-template fieldname/ID. I used VS code IDE for replace, Its preferred on your own. (If your field names are same in old & new templates. Update only ID.)

4. Sync the items from TDS, Update to Sitecore. This will copy all your old-template fields to new-template fields.

5. In Sitecore: Remove the old template inheritance.

Finally , You will have the result of template change & all fields values are copied.

Answer 6

Changing the template through content editor or api will retain data where possible.

Scenario 1: Both old and new templates inherit the same base template. The data in the base template fields is retained implicitly.

Scenerio 2: Both old and new template have fields of the same field name. When ChangeTemplate() is invoked, a ChangeList is generated which captures any fields in the target template that that have the same field name as the current template.

The call to Sitecore.Data.DataProviders.Sql.SqlDataProvider.ChangeTemplate(ItemDefinition, TemplateChangeList, CallContext) acts upon the changelist and remaps the existing item fieldIds to the new fieldIds, thus retaining the data in those fields.

You can either change the target template fields to match and perhaps change the display name to what they currently are, or temporarily change the field names, change the item template, then change the template fields back to whatever they were.