| Tag Link | [Null->Invoke] | Category | Tags |
|---|---|---|---|
| Type | Member | Source Available | No |
| Support | Preferred | Version | 7.0 |
| Change | Unchanged | Data Source | Any |
| Output Type | Any | Security | None |
| Implementation | Internal | Sets | Lasso 8.5, Lasso 8.0, Lasso 7.0 |
[Null->Invoke] is a member tag which can be used with any data type. The results of calling [Null->Invoke] differ depending on what type it is called on.
Tag - [Tag->Invoke] works just like calling the tag directly. The parameters to [Tag->Invoke] are passed to the tag. For example: [\Field->(Invoke: 'Field_Name')] is equivalent to [Field: 'Field_Name'] or [\Field->(Run:
Pair - If a pair has a tag as its first element and an array as its second element then calling [Pair->Invoke] on it will execute the tag and pass the second element to the tag as its parameter array. Any other parameters passed to [Tag->Invoke] are passed after the first parameters. For example [(Pair: \Field = (Array: 'First_Name'))->Invoke] will yield the same result as [Field: 'First_Name']. This type of pair is called a "closure" and enables a method of implementing callback tags.
Others - Most other types simply return their value when [Null->Invoke] is called on them. This is true for most built
Custom Types - Custom types can override the [Type->Invoke] tag in order to provide custom behavior.
[\Tag Name->(Invoke: Parameters)]
[{Compound Expression}->(Invoke: Parameters)]
[(Pair: \Tag Name = Parameters Array->(Invoke: Additional Parameters)]
[(Pair: Compound Expression = Parameters Array->(Invoke: Additional Parameters)]
[Any Type->Invoke]
| Optional Parameters | |
|---|---|
| Parameters | All parameters are passed to the base data type. |
See the Lasso 8 Language Guide for examples of how to use this tag.