Some form fields in HelloID can be configured so that their value is drawn from other sources. These other sources can be another field in the form (such as a dropdown of users), or URL query string parameters. This functionality is useful in increasing the usability of your forms, thus providing a better user experience. For example, you may want to pass an arbitrary email address or other string into the form.
Enable Component Dependency
Some form field types support the Make component dependent property. For example, the Text Input Label element. When this property is enabled, you have the option to make the field's value dependent on a URL query parameter or the value of another field in the form.
In order to make the field's value depend on that of another form in the field (e.g., the selected user in a dropdown menu), choose Other field from the dropdown. Then in the next dropdown, select which form field you want to pull the value from, as seen below.
If the selected field outputs an object (like the dropdown field), then you will need to also specify which property of the object will be used for the current field's value. If, on the other hand, the specified field only outputs a string, the property field may be left blank.
URL Query Parameter
To pre-populate a form field with a value from the URL query string, select URL query parameter from the dropdown, as seen below.
You may then specify the name of the parameter that the field will depend on. You can name this whatever you want. Your provided value will be preceded by "form_" in the URL. For example, if you made the field dependent on a query parameter named "car_color", the full query string parameter would be "form_car_color".
When you send users to the form, you can then append the query string parameter to the URL like this:
This will pre-populate the fields that are dependent on that query string parameter with the value of "red".