| Tag Link | [Lasso_TagExists] | Category | Tags |
|---|---|---|---|
| Type | Substitution | Source Available | No |
| Support | Preferred | Version | 3.0 |
| Change | Unchanged | Data Source | Any |
| Output Type | Boolean | Security | None |
| Implementation | Internal | Sets | Lasso 8.5, Lasso 8.0, Lasso 7.0, Lasso 6.0, Lasso 5.0, Lasso 3.x |
[Lasso_TagExists] returns True if the specified tag is currently defined or False otherwise.
Note: [Lasso_TagExists] will not return True for internal tags such as those listed below. These tags are implemented directly in the Lasso parser for better performance.
The internal tags include: [Abort], [Define_Tag] ... [/Define_Tag], [Define_Type] ... [/Define_Type], [Encode_Set] ... [/Encode_Set], [Fail], [Fail_If], [False], [Handle] ... [/Handle], [Handle_Error] ... [/Handle_Error], [If] ... [Else] ... [/If], [Iterate] ... [/Iterate], [Lasso_Abort], [Loop] ... [/Loop], [Loop_Abort], [Loop_Count], [NoProcess], [Params], [Protect] ... [/Protect], [Return], [Run_Children], [Select] ... [Case] ... [/Select], [Self], [True], and [While] ... [/While].
[Lasso_TagExists: 'Tag Name']
| Required Parameters | |
|---|---|
| Tag Name | The name of the tag to be checked. |
[Lasso_TagExists] will not return True for internal tags.
To check whether a tag exists before calling it:
Use the [Lasso_TagExists] tag to check that the tag exists. The following example checks that the [NSLookup] tag is defined before calling it.
[If: (Lasso_TagExists: 'NSLookup')]
[NSLookup: 'www.example.com']
[/If]
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