Conditions
Introduction
A condition is a rule about other answers: "Country is any of Canada, United States", or "Age is less than 18". Formidable uses one condition builder everywhere you need one:
- a field's Conditions tab: show or hide the field, and make it required;
- page and section settings: skip a page, hide a section;
- a workflow's conditions: run the workflow only when they hold;
- the Submissions filter, and the filters on other control panel listings.
Fields
A field's Conditions tab has two parts:
- Show if or Hide if (the mode), with a set of rules. While the rules decide the field is hidden, it is not shown, not validated, and its answer is blanked before the submission is stored.
- Require if, with its own rules. While they hold, the field is required, even if it is not normally.
Rules combine with and and or, and can be grouped.
Pages and sections
A page can be skipped and a section hidden by the same kind of rules. To keep the order of the form well defined, a page condition can only use fields on earlier pages, and a section condition can only use fields on earlier pages or in earlier sections of its own page. The builder only offers those fields, and the server refuses to save anything else, so circular conditions are impossible.
On a multi-page form, a skipped page is skipped by Next, Back and the step indicator alike. Its answers are blanked, so an answer on a skipped page can never switch on a later page. The last page that applies shows Submit in place of Next.
Operators
What a rule offers depends on the field it reads:
| The field is | Operators |
|---|---|
| Text | equals, not equals, contains, does not contain, starts with, ends with, is empty, is not empty |
| A number (Number, Range, or a field cast to a number) | equals, not equals, greater than, greater than or equal, less than, less than or equal, between |
| A date (Dates & Times fieldtypes) | on, not on, after, on or after, before, on or before, between |
| True or false (a field cast to true/false) | is, is not |
| Has choices (Select, Radio Buttons, Checkboxes, …) | is any of, is none of |
- Date operators work by the day. "On or after the 3rd" includes 3 pm on the 3rd.
- Between takes two numbers or two dates and includes both ends.
- A Computed field compares as what it produces: a number for arithmetic and lengths of time, a date for "date plus days", text for joined text.
- Fields that hold several answers (Checkboxes, multiple files) compare each answer in turn, so "is any of" works. In the Submissions filter, where the answers are searched in the database, these fields use "contains".
Repeating sections
Inside a repeating section, a condition on another field in the same section reads that row's answer. "Show School when Age is under 18" works row by row. A field outside the section reads as itself.
From outside the section, a condition on one of its fields asks about any row:
- A positive operator holds when any row matches. A later section shown when Age is under 18 appears if any row's age is.
- A negative operator means no row matches. "Name is not Smith" holds when nobody is called Smith.
- is empty holds when every row is empty.
Page, section and workflow conditions follow the same rules.
Where conditions run
Conditions run in two places: in the browser, by formidable.js, so fields appear and disappear as the visitor types, and on the server when the form is submitted. The server does not trust the browser. It works out what is visible and required from the submitted answers, whatever the page claimed. Turning scripts off, editing the page or posting by hand cannot get around a condition. Both use one shared set of test cases, so a condition cannot hold on the page and fail on the server.
formidable.js is added to the page only when the form needs it. See Troubleshooting if conditions do not respond.