selfVM gives you access to the running ViewModel from an OCL expression or action. Use it when you need to save, refresh, invoke ViewModel behavior, inspect ViewModel state, or work with the ViewModel rather than the current business object.

What selfVM refers to

selfVM is a built-in ViewModel variable. It references the ViewModel that holds the objects currently being worked with.

Do not confuse it with self:

Expression	Refers to	Use it for
self	The object in the current expression context.	Reading or changing attributes and associations of that object.
selfVM	The running ViewModel.	Running ViewModel operations, saving, refreshing, inspecting state, and accessing the object that opened a rooted ViewModel.

For example, an action column placed in a detail nesting has a self that refers to that detail object. selfVM still refers to the ViewModel containing that nesting.

You can inspect the variables and members available in a particular expression context in the OCL editor or Action Editor. This matters because available variables can differ when a ViewModel is used for a user interface, an API, or a report. For a broader explanation of self, vCurrent, and other variables, see Documentation:ViewModel variables.

Common tasks

Save the changes made in the ViewModel

Use selfVM.Save to commit changes made in the ViewModel to persistent storage.

selfVM.Save

Before saving, you can inspect the objects that will be saved through selfVM.DirtyList. To abandon all changes made through the ViewModel, use:

selfVM.DirtyList->DiscardChanges

See Documentation:OCLOperators Save and Documentation:SelfVM.DirtyList for the save and discard behavior.

Run fetch hints for a list

Use selfVM.ExecuteFetchHints(aList) after you have populated a list outside the normal seeker flow and want its fetch hints applied.

A ViewModel nesting whose name starts with FetchHints provides the fetching hints. The columns in that nesting are executed for lists returned through seeker logic. Call ExecuteFetchHints explicitly when you create the result list yourself.

For example, this action clears a result list, adds the selected sales articles, and then applies the fetch hints to that list:

vSeekerResult->Clear;
Singleton.oclSingleton.User.FavoriteArticle->select(fa|
  fa.Filter.SqlLike(vFavFilter+'%') or vFavFilter.IsNullOrEmpty
).FavoriteArticles->collect(a|
  let sa=a.SalesArticles->select(sa|sa.MarketingCompany=self)->first in
  (
    if sa.isnull then
      vSeekerResult
    else
      vSeekerResult.Add(sa)
    endif
  )
);
selfVM.ExecuteFetchHints(vSeekerResult)

See Documentation:Efficient ViewModel fetch for the complete pattern and its purpose.

Execute ViewModel actions

Use selfVM.ExecuteAction when an OCL action needs to invoke an action on the running ViewModel. Use selfVM.CanExecuteAction when you need to determine whether an action can execute before invoking it.

The exact members available depend on the expression context. Use the Action Editor to select the operation and supply its arguments rather than assuming an action signature.

Access the object that opened a rooted ViewModel

selfVM.RootObject returns the object instance used to open the current rooted ViewModel. The root reference cannot be changed while the ViewModel is open, but you can change attributes on that object.

Because selfVM is available in every ViewModel, the root object has no fixed static type. Cast it to the type you expect before accessing its attributes.

selfVM.RootObject->notEmpty

The expression above checks whether the ViewModel has a root object.

selfVM.RootObject->safeCast(Thing).SomeString:='a new value'

See Documentation:OCLOperators RootObject for details.

Identify how the ViewModel is being used

selfVM.DisplayMode identifies the current usage of the ViewModel. It can have these values:

enum DisplayModeEnum {
  UINormal, UIModal, UIPopup, Technical,
  RestPost, RestGet, RestPatch, RestPut, RestDelete
};

For example, ViewModels used by templates, transforms, deep clones, server-side execution, asynchronous tickets, reports, or Tajson use Technical. MVC-rendered pages also use Technical. WPF and Turnkey user interfaces use UINormal, UIModal, or UIPopup.

See Documentation:OCLOperators DisplayMode for the full usage guidance.

selfVM members

The following operations and properties are available on selfVM. Availability and accepted arguments are context-sensitive; use the OCL editor or Action Editor to inspect the member in the place where you will use it.

Member	Category	Purpose
ExecuteFetchHints	Operation	Applies configured fetch hints to a list. See Documentation:Efficient ViewModel fetch.
Save	Operation	Commits ViewModel changes to persistent storage. See Documentation:OCLOperators Save.
ExecuteAction	Operation	Executes a ViewModel action programmatically.
CanExecuteAction	Operation	Checks whether a ViewModel action can execute.
Search	Operation	Runs ViewModel search behavior.
ImportTabSepData	Operation	Imports tab-separated data.
Refresh	Operation	Refreshes the ViewModel.
ExecutePS	Operation	Legacy persistent-storage evaluation operation. Use <Class>.PSEval instead. See Documentation:How to use the ExecutePS function in selfVM.
PSExpression_Refresh	Operation	Refreshes a persistent-storage expression.
RestGet, RestPost, RestPatch, RestPut, RestDelete, RestDownload	Operations	REST-related ViewModel operations.
JSonToObjects, XmlToObjects	Operations	Converts JSON or XML to objects.
XsltTransformXml, XmlValidateWithSchemas	Operations	Transforms or validates XML.
ViewModelAsJSon	Operation	Produces a JSON representation of the ViewModel.
GetGridAsTabSepData	Operation	Produces tab-separated data from a grid.
SuspectExternalUpdateInvalidate	Operation	Invalidates the ViewModel when an external update is suspected.
RunServerSideViewModelNow	Operation	Runs a server-side ViewModel immediately.
Navigate	Operation	Performs ViewModel navigation.
ShowActionMenuForCurrentInNesting	Operation	Shows the action menu for the current object in a nesting.
ExecuteCurrentActionAgainOnce	Operation	Requests one repeat execution of the current action.
SysDocBatchZip	Operation	Creates a system-document batch ZIP operation.
Download(filename:string,blob)	Operation	Downloads a blob using the specified file name.
ViewModelName	Property	The ViewModel name.
DirtyList	Property	Changed objects that selfVM.Save will save. See Documentation:SelfVM.DirtyList.
ListActions, Nestings, Styles	Properties	ViewModel action, nesting, and style collections.
DisplayMode	Property	The current ViewModel usage mode. See Documentation:OCLOperators DisplayMode.
LogEntry	Property	The ViewModel log entry.
RootObject	Property	The object used to open a rooted ViewModel. See Documentation:OCLOperators RootObject.

See also

• Documentation:Built in ViewModel variables
• Documentation:ViewModel variables
• Documentation:Efficient ViewModel fetch
• Documentation:SelfVM.DirtyList
• Documentation:OCLOperators Save
• Documentation:OCLOperators DisplayMode