A clean, minimal, and extensible DSL for defining structured, dynamic forms in Elixir.
FormBuilderDSL helps teams write intuitive, maintainable forms with metadata structures that can power:
- Web-based LiveView and HTML rendering
- JSON-serializable form schemas for APIs
- Dynamic admin and internal tool UIs
- Declarative definitions for form fields
- Support for all common form input types
- Reusable
defenum/2macro for dropdown/select support - Generates metadata as
FormBuilderDSL.Fieldstructs - Runtime-safe enum management using
ETS - Clean rendering logic that plays well with Phoenix Components
- Comprehensive validation support
- Default values and field attributes
- Form context and state management
defmodule MyForm do
use FormBuilderDSL
defenum :status, [:approved, :rejected, :pending]
form :user do
text :name
email(:email)
password(:password)
select :status, options: status_labeled_options()
end
enddefmodule UserForm do
use FormBuilderDSL
form :user do
text :name, required: true, validations: [min_length: 3, max_length: 50]
email(:email, required: true, validations: [format: :email])
number(:age, required: true, validations: [min: 18, max: 100])
select :role, required: true, options: role_labeled_options()
end
end
# Using the form with validation
form = UserForm.fields()
context = FormBuilderDSL.Context.new(:user, form)
# Validate the form
context = FormBuilderDSL.Context.validate(context)
# Check for errors
if FormBuilderDSL.Context.valid?(context) do
# Form is valid, process the data
values = context.values
else
# Form has errors
errors = context.errors
enddefmodule ProductForm do
use FormBuilderDSL
defenum :categories, [:tech, :science, :arts]
form :product do
# Text inputs
text :name, required: true, placeholder: "Enter product name"
email(:contact_email, required: true)
password(:admin_password)
number(:price, min: 0, max: 1000, step: 0.01)
tel(:phone_number)
url(:website)
search(:keywords)
# Date and time inputs
date(:release_date)
time(:available_time)
date_time :last_updated
month(:target_month)
week(:target_week)
# Selection inputs
select :category, options: categories_labeled_options()
multi_select(:tags, options: categories_labeled_options())
radio(:status, options: status_labeled_options())
checkbox(:featured)
switch(:active)
# File inputs
file(:document, accept: ".pdf,.doc,.docx")
image(:product_image)
# Special inputs
color(:theme_color)
range(:rating, min: 1, max: 5, step: 1)
hidden(:internal_id)
end
enddefmodule SettingsForm do
use FormBuilderDSL
form :settings do
text :name, default: "John Doe"
email(:email, default: "john@example.com")
select :role, default: "user", options: role_labeled_options()
end
enddefmodule ReadOnlyForm do
use FormBuilderDSL
form :user do
text :name, disabled: true
email(:email, disabled: true)
select :role, disabled: true, options: role_labeled_options()
end
endThe DSL supports various validation rules:
form :user do
# Required field
text :name, required: true
# String length validations
text :description, validations: [min_length: 10, max_length: 1000]
# Numeric range validations
number :age, validations: [min: 18, max: 100]
# Email format validation
email :email, validations: [format: :email]
# Value inclusion validation
select :role, validations: [in: ["admin", "user", "guest"]]
endAdd the dependency to your mix.exs:
def deps do
[
{:form_builder_dsl, "~> 0.1.0"}
]
endThen run:
mix deps.getTo keep the DSL syntax clean and bracket-free, add the following to your .formatter.exs:
[
import_deps: [:form_builder_dsl],
locals_without_parens: [
form: 2,
defenum: 2,
text: 1,
text: 2,
select: 1,
select: 2,
date_time: 1,
date_time: 2,
email: 1,
email: 2,
password: 1,
password: 2,
number: 1,
number: 2,
tel: 1,
tel: 2,
url: 1,
url: 2,
search: 1,
search: 2,
date: 1,
date: 2,
time: 1,
time: 2,
month: 1,
month: 2,
week: 1,
week: 2,
multi_select: 1,
multi_select: 2,
radio: 1,
radio: 2,
checkbox: 1,
checkbox: 2,
switch: 1,
switch: 2,
file: 1,
file: 2,
image: 1,
image: 2,
color: 1,
color: 2,
range: 1,
range: 2,
hidden: 1,
hidden: 2
]
]This tells the formatter not to wrap parentheses around common DSL macros.
MIT ยฉ Pranav J
