The "Validation" property of a property definition specifies the mechanism for validating the values of this property.
In most cases, properties are validated while the flow is being designed or just before it is activated. If there are any invalid properties, Switch refuses to activate the flow. For performance reasons, Switch does assume that the result of design-time validation remains valid for the duration of flow activation. While this assumption is correct in most production environments, it is not strictly true for all data types; for example a file path becomes invalid when the target file is removed.
Properties that contain a variable or a script expression are validated while the flow is running, since their value cannot be determined at design time. Just before each invocation of the jobArrived entry point, Switch performs run-time validation for all properties of the flow element that contain a variable or a script expression. If a property value is invalid, Switch fails the job with an appropriate error message.
Note that there is NO run-time validation before calling the timerFired entry point (or any of the other entry points). Using non-static property values from those entry points is risky anyway since there is no job context (and referencing job context from a script expression or variable in those circumstances has undefined results).
Validation of a particular property value is performed at design time if isPropertyValueStatic() returns true for that property.
The following table describes the standard design-time validation for values entered by a particular property editor. Note that all property values are of data type string or string list.
Property editor |
Design-time validation requires that the value… |
|---|---|
Single-line text |
Is non-empty |
Password |
Is non-empty |
Number |
Is non-empty and contains only decimal digits |
Hours and minutes |
Is non-empty and has the format "hh:mm" (including the colon) where h and m stand for a decimal digit, hh and mm include leading zero if needed, hh is in range 00..23 and mm is in range 00..59 |
No-yes list |
Is one of the strings "No" or "Yes" (exact spelling and case) |
Dropdown list |
Is one of the custom strings provided for the dropdown list |
Literal |
Is the fixed string value selected from a predefined list |
Choose file |
Represents a valid absolute path and that a file exists at the path |
Choose folder |
Represents a valid absolute path and that a folder exists at the path |
Regular expression |
Is non-empty and has valid regular expression syntax |
File type |
Is non-empty and has valid filename pattern syntax |
Select from library |
Is one of the strings returned by the getLibraryForProperty entry point in the script |
Multi-line text |
Is non-empty |
Script expression |
N/A |
Single-line text with variables |
N/A (if the value contains no variables: Is non-empty) |
Multi-line text with variables |
N/A (if the value contains no variables: Is non-empty) |
Condition with variables |
N/A |
File patterns |
Has at least one item and each item has valid filename pattern syntax |
Folder patterns |
Has at least one item and each item has valid filename pattern syntax |
File types |
Has at least one item and each item has valid filename pattern syntax |
String list |
Has at least one item and each item is non-empty |
Select many from library |
Has at least one item and each item is one of the strings returned by the getLibraryForProperty entry point in the script |
External editor |
Represents a valid absolute path and that a file exists at the path |
Validation of a particular property value is performed at run time if isPropertyValueStatic() returns false for that property.
In this case the property editor used to enter the source value (example: the script expression or text with variables) is no indication for the appropriate validation scheme. Therefore, as a general principle, standard run-time validation allows the computed property value to conform to the validation scheme of ANY of the property's property editors.
Specifically, the validation algorithm works as follows:
Compile a list of validation schemes by adding the validation scheme from the following table for each of the property's property editors ("--" means do not add a scheme for this editor).
The computed property value must be non-empty AND it must comply with at least one of the validation schemes in the list compiled above (unless the list is empty).
Property editor |
Run-time validation scheme |
|---|---|
Single-line text |
-- |
Password |
-- |
Number |
Same as design-time scheme |
Hours and minutes |
Same as design-time scheme |
No-yes list |
Same as design-time scheme, or a Boolean value (*) |
Dropdown list |
Same as design-time scheme |
Literal |
Same as design-time scheme |
Choose file |
Same as design-time scheme |
Choose folder |
Same as design-time scheme |
Regular expression |
Same as design-time scheme, or a Boolean value (*) |
File type |
Same as design-time scheme |
Select from library |
Same as design-time scheme |
Multi-line text |
-- |
Script expression |
-- |
Single-line text with variables |
-- |
Multi-line text with variables |
-- |
Condition with variables |
-- |
File patterns |
Same as design-time scheme (for one item), or a Boolean value (*) |
Folder patterns |
Same as design-time scheme (for one item), or a Boolean value (*) |
File types |
Same as design-time scheme (for one item), or a Boolean value (*) |
String list |
-- |
Select many from library |
Same as design-time scheme (for one item) |
External editor |
Same as design-time scheme |
(*) a Boolean value is represented by one of the strings "true" or "false"
Consider a property that specifies a property set which can be provided as a file or it can be part of an external library. The property is set to standard validation and it has the following property editors:
Choose file
Select from library
Script expression
Single-line text with variables
For the first two editors, validation is always performed at design time. For the last two editors, validation is performed at run time (except if the single-line text does not contain any variables). In all cases, the property value is guaranteed to contain one of the following:
A valid file path that points to an existing file.
One of the library items returned for the property by the getLibraryForProperty entry point.
For most use cases it can be assumed that these values are mutually exclusive, and that the script code can tell the data types apart from looking at the value. If needed however, the script code can check which editor has been used to enter the value.