Select box

Create select boxes in your forms.

Select box

Use the selectBox() function to create select boxes in your forms. It uses the HTML <select> element which provides a dropdown list of options.

---

Basic usage

import { Composer } from "formsmd";

const composer = new Composer({
  id: "my-form"
});

composer.selectBox("country", {
  question: "Which country are you from?",
  options: ["United States", "Canada", "United Kingdom"]
});

Generates the following Markdown-like syntax:

#! id = my-form

country = SelectBox(
  | question = Which country are you from?
  | options = United States, Canada, United Kingdom
)

Required

Add the required parameter to make the field mandatory:

composer.selectBox("country", {
  question: "Which country are you from?",
  options: ["United States", "Canada", "United Kingdom"],
  required: true
});

Generates the following Markdown-like syntax:

country* = SelectBox(
  | question = Which country are you from?
  | options = United States, Canada, United Kingdom
)

---

Function overview

The following is the overview of the function:

selectBox(name: string, params: object)

Arguments

Name	Type	Description
name	string	A unique name for your form field that you'll use to identify the user's response.*
params	object	An object containing all the configuration parameters for your select box field (see the parameters section below for the full list of options).

*Avoid values for the name argument which may be the names of HTML attributes, such as "name", "role", "id", etc. This is because by default, the form's template string is first sanitized using DOMPurify, and these values may be removed to prevent DOM clobbering.

---

Parameters

Shared parameters

These parameters are common to all form fields:

Name	Type	Description
question (required)	string	The main question or label of the form field.
required	true (boolean)	When set, the field becomes required.
description	string	Any extra information that the user may need to fill out the form. Appears right below the question.
fieldSize	"sm"	When set to "sm", the font sizes of the question, description, and answer are made smaller.
labelStyle	"classic"	When set to "classic", the question and description of the form field are made smaller.
subfield	true (boolean)	When set, the question and description of the form field are made smaller. Functionally the same as setting labelStyle to "classic".
disabled	true (boolean)	When set, the input is disabled.
autofocus	true (boolean)	When set, the input will be automatically focused when the parent slide becomes active, or immediately after page load.
id	string	The id attribute of the form field container.
classNames	string[]	The CSS class names of the form field. See the available CSS utility classes.
attrs	Array<{ name: string, value: string }>	Other HTML attributes of the form field. Each attribute has a name and value property.
displayCondition	{ dependencies: string[], condition: string }	Controls when the field is shown. The dependencies lists the fields to watch, and condition is the expression that must be true to show the field. The condition must be a valid Nunjucks expression. See example.

Select box specific parameters

Name	Type	Description
options (required)	Array<string | { label: string, value?: string }>	Array of options that can be either strings (e.g., ["Option 1", "Option 2"]) or objects with a label for display text and an optional value (e.g., [{ label: "Option 1", value: "opt1" }]). When using objects, if value is not provided, label is used as the value.
selected	string	Pre-selected option value.
placeholder	string	Sets the placeholder option of the select.

---

Examples

Select box with value-label pairs

Value-label pairs allow different values to be stored than what's shown to users. The label appears in the dropdown for users to select, while the value is stored in the form data. This pattern is particularly useful for storing concise identifiers in a database while displaying more descriptive text in the interface. Please note, for selected to work with value-label pairs, it must contain the value, not the label.

composer.selectBox("experience", {
  question: "Years of experience",
  options: [
    { label: "Junior (0-2 years)", value: "junior" },
    { label: "Mid-level (3-5 years)", value: "mid" },
    { label: "Senior (6+ years)", value: "senior" }
  ],
  selected: "mid",
  required: true
});

Generates the following Markdown-like syntax:

experience* = SelectBox(
  | question = Years of experience
  | options = "junior" Junior (0-2 years), "mid" Mid-level (3-5 years), "senior" Senior (6+ years)
  | selected = mid
)

Select box with custom placeholder

composer.selectBox("language", {
  question: "What's your preferred programming language?",
  description: "Choose the language you're most comfortable with",
  placeholder: "Select a language",
  options: ["JavaScript", "Python", "Java", "C++"],
  required: true
});

Generates the following Markdown-like syntax:

language* = SelectBox(
  | question = What's your preferred programming language?
  | description = Choose the language you're most comfortable with
  | placeholder = Select a language
  | options = JavaScript, Python, Java, C++
)

Styled select box with custom attributes

Add CSS classes and other HTML attributes using the classNames and attrs parameters. Please note, these class names and attributes are added to the <div> or <fieldset> container that contains the actual select field.

composer.selectBox("jobRole", {
  question: "Select your role",
  options: ["Developer", "Designer", "Manager"],
  classNames: ["col-6", "xs:col-6"],
  attrs: [
    { name: "style", value: "font-size: 18px;" }
  ]
});

Generates the following Markdown-like syntax:

[.col-6 .xs:col-6 style="font-size: 18px;"]
jobRole = SelectBox(
  | question = Select your role
  | options = Developer, Designer, Manager
)

Please see the available CSS utility classes.

Conditional display

Conditionally show or hide a select box using the displayCondition parameter. It works as follows:

• dependencies lists the fields to watch.

• condition is the expression that must be true to show the field. This must be a valid Nunjucks expression.

For instance, in the example below, the framework select will only show up if the user indicates they are a developer.

composer.selectBox("jobTitle", {
  question: "What is your job title?",
  required: true,
  options: ["Developer", "Designer", "Manager"]
});

composer.selectBox("framework", {
  question: "Which framework do you primarily use?",
  options: ["React", "Vue", "Angular"],
  displayCondition: {
    dependencies: ["jobTitle"],
    condition: "jobTitle == 'Developer'"
  }
});

Generates the following Markdown-like syntax:

jobTitle* = SelectBox(
  | question = What is your job title?
  | options = Developer, Designer, Manager
)

::: [{$ jobTitle $}]
{% if jobTitle == "Developer" %}
framework = SelectBox(
  | question = Which framework do you primarily use?
  | options = React, Vue, Angular
)
{% endif %}
:::