blockly > FieldImage > doClassValidation_
FieldImage.doClassValidation_() method
Ensure that the input value (the source URL) is a string.
Signature:
protected doClassValidation_(newValue?: any): string | null;
Parameters
| Parameter | Type | Description |
|---|---|---|
| newValue | any | (Optional) The input value. |
Returns:
string | null
A string, or null if invalid.