Theme

List

The list input allows you to structure data from child inputs as an array. The list itself outputs no markup (by default) and can be used in conjunction with any other type of input — including nested groups and lists.

The value of a list input is an array where each item is the value of the input at that index. Sub-inputs do not need to be of the same type. In addition to structuring data, lists can determine the validation state, provide initial values, and supply plugins and configuration to all of its children.

Basic example

Load live example
Performance

Vue’s handy v-model is fully supported in FormKit with bi-directional data flow even on lists and groups. However, if your form needs extremely high performance consider using the core node to read/write instead of v-model.

List types

There are 2 flavors of lists:

  • Static lists (default) have pre-determined children. They should not be used for iterating over values or adding/removing items.
  • Dynamic lists allow iteration over the list’s value to create its children. They are useful for creating dynamic-length lists like repeaters.

Static lists

Static lists are the simplest type of list to create. Wrap any inputs in a <FormKit type="list"> and those inputs will automatically be set as values of their array. Immediate children of lists do not have a name (even if specified) instead they are always identified by their index. In a static list, this index is stable and is based on the order of the inputs.

Load live example
Iterating over the list values

Static lists should not be used for iterating over their own value. While it is safe to iterate over other arbitrary data iterating over the value of the list itself will cause recursive rendering and infinite loops. Instead use a dynamic list.

Dynamic lists

Dynamic lists allow you to iterate over the values of the list to create and hydrate the inputs inside the list. Dynamic lists are useful for creating dynamic array structures like repeaters.

You can mutate the structure of your dynamic list by adding and removing items from the value array. FormKit will automatically update the underlying form structure to match the new value.

In order for dynamic lists to keep your data in sync, you must use items from the default slot to create your v-for and you must also pass the index of the v-for as the index prop to each item in of the list.

FormKit Pro Repeater

To use a prebuilt repeater, check out the free FormKit Pro repeater input.

Dynamic list example

Load live example

Dynamic list with a nested group

Load live example

Dynamic list using v-model

Load live example

Dynamic list in schema

Load live example

Validity of children

Lists (and groups) are always aware of the validation state of their children (including nested children). You can access this data in the context object of the input (context.state.valid).

Load live example

Showing error & validation messages

Even though a list can have validation rules and input errors, it does not include any functionality to show validation messages and errors by default. The list ships no HTML at all. If you’d like to display those errors — you can add the <FormKitMessages /> as a child of the list.

Configuration

Further documentation on the FormKitMessages component can be found on the form documentation page.

Props & Attributes

PropTypeDefaultDescription
disabledBooleanfalseDisables all the inputs in the list.
dynamicBooleanfalseEnables dynamic mode for the list and provides items in the default slot creating an iterator (v-for).
Show Universal props
configObject{}Configuration options to provide to the input’s node and any descendent node of this input.
delayNumber20Number of milliseconds to debounce an input’s value before the commit hook is dispatched.
dirtyBehaviorstringtouchedDetermines how the "dirty" flag of this input is set. Can be set to touched or comparetouched (the default) is more performant, but will not detect when the form is once again matching its initial state.
errorsArray[]Array of strings to show as error messages on this field.
helpString''Text for help text associated with the input.
idStringinput_{n}The unique id of the input. Providing an id also allows the input’s node to be globally accessed.
ignoreBooleanfalsePrevents an input from being included in any parent (group, list, form etc). Useful when using inputs for UI instead of actual values.
indexNumberundefinedAllows an input to be inserted at the given index if the parent is a list. If the input’s value is undefined, it inherits the value from that index position. If it has a value it inserts it into the lists’s values at the given index.
labelString''Text for the label element associated with the input.
nameStringinput_{n}The name of the input as identified in the data object. This should be unique within a group of fields.
parentFormKitNodecontextualBy default the parent is a wrapping group, list or form — but this props allows explicit assignment of the parent node.
prefix-iconString''Specifies an icon to put in the prefixIcon section.
preservebooleanfalsePreserves the value of the input on a parent group, list, or form when the input unmounts.
preserve-errorsbooleanfalseBy default errors set on inputs using setErrors are automatically cleared on input, setting this prop to true maintains the error until it is explicitly cleared.
sections-schemaObject{}An object of section keys and schema partial values, where each schema partial is applied to the respective section.
suffix-iconString''Specifies an icon to put in the suffixIcon section.
typeStringtextThe type of input to render from the library.
validationString, Array[]The validation rules to be applied to the input.
validation-visibilityStringblurDetermines when to show an input's failing validation rules. Valid values are blur, dirty, and live.
validation-labelString{label prop}Determines what label to use in validation error messages, by default it uses the label prop if available, otherwise it uses the name prop.
validation-rulesObject{}Additional custom validation rules to make available to the validation prop.
valueAnyundefinedSeeds the initial value of an input and/or its children. Not reactive. Can seed entire groups (forms) and lists..

Sections

Section-keyDescription
outerThe outermost wrapping element.
wrapperA wrapper around the label and input.
labelThe label of the input.
prefixHas no output by default, but allows content directly before an input element.
prefixIconAn element for outputting an icon before the prefix section.
innerA wrapper around the actual input element.
suffixHas no output by default, but allows content directly after an input element.
suffixIconAn element for outputting an icon after the suffix section.
inputThe input element itself.
helpThe element containing help text.
messagesA wrapper around all the messages.
messageThe element (or many elements) containing a message — most often validation and error messages.