Template Overrides¶
Alternative templates can be used to override initial templates for use cases such as A/B testing or language variations. There are various ways to override data within the app
Case 1 - Template and data lists at runtime¶
Both template and data lists support providing override_target and override_condition columns on their contents sheet to determine under which conditions these flows will override.
Warning
Other flow types and generated flows do not currently support this feature
Example¶
In the following a template named default_template will be overidden by a template named override_template whenever the app language starts with the letters es (e.g. es_sp, es_ca)
| flow_type | flow_name | override_target | override_condition |
|---|---|---|---|
| template | default_template | ||
| template | override_template | default_template | @fields._app_language.startsWith("es") |
Google Sheet Demo
Live Preview Demo
Parameters¶
| Parameter | Description |
|---|---|
| override_target | Name of template to override |
| override_condition | Condition statement that must be satisfied for override |
Template Self-reference¶
Sometimes it might be useful to reference the original template from the override sheet, such as displaying the same original template but with different variables, or with additional content above or below.
In this case an additional is_override_target parameter is required when referencing the default template from the override.
override_template
| type | name | value | is_override_target |
|---|---|---|---|
| title | title_1 | This appears above default content | |
| begin_template | default_template | default_template | TRUE |
| end_template |
This is to prevent an infinite loop that would otherwise occur as the default_template is replaced by the override.
Case 2 - All flow types at build time¶
It is also possible to replace any other flow type during sync and build by specifying additional sheets with the same flow_type and flow_name properties. In this case the last-synced (or generated) flow will take priority.
This can be useful in cases where multiple apps share some of the same core content, and want to only apply a number of replacements/additions.
Experimental
See open issue 2081 for proposals to add multiple data sources to make this type of override system more easy to implement