Gravity Perks Auto List Field

Asking "how many" and then asking for their details is asking the same thing twice

A ticket form asks how many people attend and, further down, the details of each one. The visitor types a 4 in one field and fills in two rows in the other. Now your record says one thing in the price and another in the attendee list.

The number of people and the number of rows are one and the same piece of data, and while they are two separate answers they can contradict each other.

Auto List Field is a Gravity Perks perk for Gravity Forms. It ties the number of rows in a List field to the value of another field, so rows are added or removed automatically when that value changes. It also works the other way: it counts the rows in a list and hands that number to a calculation.

What it does with rows

• Syncs rows with a value: it adds or removes rows in a List field based on a Number, Quantity, Single Product or Calculated Product field.
• Counts rows: the :count modifier returns the number of rows in the list for use in a calculation. With a list of ID 1, the merge tag is {List:1:count}, and the result updates by itself.
• Real time: once the trigger field is assigned, rows change while the visitor types.
• Check on submission: when rows are added automatically, the plugin verifies that the submitted row count matches the trigger value. With :count, Gravity Forms recalculates the full calculation on submission, and the result cannot be tampered with from the browser.
• Developer hooks: there are filters for the script's initialization arguments, for showing or hiding the add and remove row buttons and for choosing which field types can trigger rows.

Each List field in the editor gets a Perks tab, and there you enable the feature and choose the trigger field.

A per-person registration form

Imagine a Number field asking how many people sign up, a list with the columns you need for each one and a calculation that multiplies the price by the number of rows. The visitor changes the number and sees rows appear or disappear, and the total changes with them. Use it as a starting idea and adjust it to your form.

The perk also offers snippets that count only rows with data and that show the row number in the first column.

Product quantity does not take the count directly

The number of rows in a list cannot go directly into the quantity field of a Single or Calculated Product. There are two workarounds. One is to add a separate Quantity field and associate it with the product. The other is to store the count in a Number field and copy it into the product quantity with Copy Cat, another Gravity Perks perk.

If the form fails, check the browser console for JavaScript errors and run a conflict test by deactivating themes and plugins.

Linking a Number field to a list

You need Gravity Forms and Gravity Perks active. Then:

1. Install and activate the perk from the plugin installer.
2. Add a Number field to the form.
3. Add a new List field or open one you already have.
4. In the list's Perks tab, check Enable Auto List Field and choose the Number field as the Trigger Field.
5. If you want to count rows, add a Number field with a calculation and put the :count modifier on the list's merge tag.

Perks that combine with it

Copy Cat copies values between fields, also from list to list, and from other field types, such as checkboxes, into a list. It is the piece that solves the product quantity limit.

If your forms need more calculations, the Gravity Perks family also has Advanced Calculations.

Answers about Auto List Field

Which fields can trigger rows?

Number, Quantity, Single Product and Calculated Product fields.

Can I use the number of rows in a price?

Yes, with the :count modifier inside the calculation of a Number field.

Can the visitor change the number of rows on their own?

There is a filter that decides whether the add and remove row buttons are shown.

Can it be translated?

Yes, with the free Loco Translate plugin.