**Background:**
Adding "soft" validation to the following fields should help users filling in templates to catch errors earlier on.
Parameter warnings by type of parameter:
|** Param type** | **Expected value** | **Text** | **Type of message** |
| Number | any combination of 0-9 | | Warning |
| Date | ISO 8601 (YYYY-MM-DD) | | Warning |
| Combobox | Suggested values as defined in TemplateData | | Notice |
| File | Filename without file: prefix | | Notice |
Situation based warnings:
|**Situation** | **Text** | **Type of Message** |
| Nested templates: When {{ }} is detected | | Notice |
| Adding undefined parameters {T117890} | | Notice |
| Required parameters | Switch current pop-up warning to inline warning | Warning |
**Requirements:**
[] Validation should appear in real time, but not before the user has stopped typing.
[] Validation should provide enough flexibility to the user to continue with the value filled in if desired (i.e. validation should not block the user from saving).
[] Investigate: if there are any other "pop-up" warnings currently in place that should be changed to inline warnings.
**Mocks:**
Messages should match MessageWidget (inline: true), but not bold.
Text and outline: Yellow30 - Warning icon: Yellow50
{F32357700}
Text and icon: Base10
{F32357703}