[PostCondition]
[PostCondition] evaluates a conditional expression and throws an error if the expression does not return True. The error is equivalent to a syntax error in LDML code.
Most custom tags should deal with errors by outputting appropriate error messages or default values. The [PostCondition] tag can be used as a safety mechanism to ensure that the type or range of output from a tag is strictly enforced.
The tag [Return_Value] can be used to retrieve the current value that is being returned by the tag.
This tag can only be called within [Define_Tag] ... [/Define_Tag] tags. The [PostCondition] tags will be evaluated after all other tags within the [Define_Tag] ... [/Define_Tag] tags.
- Syntax
- Parameters
[PostCondition]Examples
To define a tag that only returns values of a certain data type:
Use the [PostCondition] tag. The following example returns the first parameter to the tag and throws an error if that value is not an array.
[Define_Tag: 'ArrayOnly']
[PostCondition: (Return_Value)->Type == 'array']
[Return: (Params)->(Get: 1)]
[/Define_Tag]| Tag Link | [PostCondition] | Category | Custom Tag |
|---|---|---|---|
| Type | Process | Data Source | Any |
| Support | Preferred | Version | 5.0 |
| Output Type | None | Security | Tag |
| Implementation | LCAPI | Sets | Lasso 7.0, Lasso 6.0, Lasso 5.0 |
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