Form controls
All KVision form controls are available in two variants. The first variant, with class name ending with "Input" (e.g.
TextInput), is a basic, fully-functional component ready to be used as a standalone widget. The second variant, with class name without "Input" (e.g. Text), is a wrapper component implementing one of FormControl interfaces and is intended primarily for use with a FormPanel container. This variant can display a label, a validation information and has some additional CSS styling consistent with Bootstrap forms components. From the developer point of view both variants have the same properties and methods (a side of label and rich properties available for second variant only). The following reference do not differentiate both variants of form controls.
All KVision form controls have the following properties:
value- allows to get or set the value of the componentname- defines anameattribute of the HTML input elementsize- allows to set the size of the form control (normal, large or small Bootstrap style)disabled- defines whether the form control is disabled
This component is rendered as a standard HTML text field and is used to get simple, textual data from the user. The
type property can be set to any of these values: TEXT, PASSWORD, EMAIL, TEL, COLOR, SEARCH, URL and is bound to the type attribute of the HTML input field. Modern browsers can render such fields with additional elements (e.g. color chooser). Other properties allow you to define a placeholder, a maximum length, autofocus or autocomplete attributes and define if the control should be read-only. Text(type = TextInputType.URL, label = "WWW") {
placeholder = "Enter the address"
maxlength = 255
autofocus = true
autocomplete = false
readonly = false
}
With an additional
kvision-imask module loaded and initialized you can use all text input mask options supported by Imask.js library.text(label = "Phone number") {
maskOptions = ImaskOptions(pattern = PatternMask("+{7}(000)000-00-00", lazy = false, eager = true))
}
This component is a direct subclass of
i.k.form.text.Text with type property set to TextInputType.PASSWORD.Password(label = "Password")
This component is rendered as a standard HTML textarea field and is used to get longer, multi-line textual data from the user. It can be sized with
cols and rows properties (mapped to standard HTML attributes).TextArea(cols = 100, rows = 5, label = "Enter some text")
Alternative way (and preferred nowadays) is to set CSS
width and height properties.TextArea(label = "Enter some text") {
width = 300.px
height = 120.px
}
Other properties allow you to define a placeholder, a maximum length, autofocus or hard wrap attributes and define if the control should be read-only.
TextArea(label = "Enter some text") {
width = 300.px
height = 120.px
placeholder = "Enter some text"
autofocus = true
wrapHard = true
readonly = true
}
The kvision-richtext module allows you to use a dedicated form control based on a modern Trix Editor component. It can be used to get rich text from the user. This component renders a text editing field with a toolbar containing basic formatting options (bold, italic, strikethrough, heading, quote, code, link and lists with indentations). The
value property contains properly formatted HTML markup. Other properties allow you to define a placeholder and autofocus attribute.RichText(
value = "<b>Bold text</b>",
label = "Rich text field with a placeholder"
) {
placeholder = "Enter some text"
autofocus = true
}
The kvision-tom-select module contains an enhanced text field with support for typeahead (autocomplete) functionality. Both local and remote data sources are supported. To use local data source pass a list of values with the
options parameter.TomTypeahead(
options = listOf("Alabama", "Alaska", "Arizona", "Arkansas", "California"),
label = "Select state"
)
To use a remote data source pass a
TomSelectCallbacks object with a load callback.TomTypeahead(
label = "Select a repository",
tsCallbacks = TomSelectCallbacks(
load = { query, callback ->
restClient.callDynamic("https://api.github.com/search/repositories") {
data = obj { q = query }
resultTransform = { it.items }
}.then { items: dynamic ->
@Suppress("UnsafeCastFromDynamic")
callback(items.map { item -> item.name })
}
}
)
)
This component is contained in the
kvision-bootstrap-typeahead-remote module and is a special version of the Typeahead control, tailored for use with KVision server side interfaces. You can find more information in part 3 of this guide.This component can be used to display a checkbox and to get true/false data from the user. The
style property can be used to render the checkbox with one of six different styles.vPanel {
checkBox(true, label = "Default checkbox") { style = CheckBoxStyle.DEFAULT }
checkBox(true, label = "Primary checkbox") { style = CheckBoxStyle.PRIMARY }
checkBox(true, label = "Success checkbox") { style = CheckBoxStyle.SUCCESS }
checkBox(true, label = "Info checkbox") { style = CheckBoxStyle.INFO }
checkBox(true, label = "Warning checkbox") { style = CheckBoxStyle.WARNING }
checkBox(true, label = "Danger checkbox") { style = CheckBoxStyle.DANGER }
}
You can layout your checkboxes horizontally using an
inline property.simplePanel {
checkBox(true, label = "First") { inline = true }
checkBox(true, label = "Second") { inline = true }
}
And you can even make the checkbox look like a radiobutton.
checkBox(true, label = "Circled checkbox") { circled = true }
A
CheckBox component has a convenient onClick method to easily bind some action to the click event.checkBox(label = "Click me").onClick {
println("Clicked")
}
By using
indeterminate property you can make the checkbox appear as neither selected nor deselected. checkBox(label = "Indeterminate checkbox") {
indeterminate = true
}
This component is similar to the
CheckBox component, but it is rendered as a radiobutton. By using the name property, you can group some radiobuttons together, with only one control selected at a time. vPanel {
radio(name = "radio", label = "First radiobutton")
radio(name = "radio", label = "Second radiobutton")
radio(name = "radio", label = "Third radiobutton")
}
The
style property can be used to render the radiobutton with one of six different styles.vPanel {
radio(name = "radio", label = "Default radiobutton") { style = RadioStyle.DEFAULT }
radio(name = "radio", label = "Primary radiobutton") { style = RadioStyle.PRIMARY }
radio(name = "radio", label = "Success radiobutton") { style = RadioStyle.SUCCESS }
radio(name = "radio", label = "Info radiobutton") { style = RadioStyle.INFO }
radio(name = "radio", label = "Warning radiobutton") { style = RadioStyle.WARNING }
radio(name = "radio", label = "Danger radiobutton") { style = RadioStyle.DANGER }
}
You can layout your radiobuttons horizontally using an
inline property.simplePanel {
radio(label = "First") { inline = true }
radio(label = "Second") { inline = true }
}
And you can even make the radiobutton look like a checkbox.
radio(name = "radio", label = "Squared radiobutton") { squared = true }
A
Radio component has a convenient onClick method to easily bind some action to the click event.radio(label = "Click me").onClick {
println("Clicked")
}
Although it is possible to use basic
Radio components to build and manage radiobutton groups (you would have to check which radio in a group is selected), KVision offers a dedicated RadioGroup component, which allows you to treat a group of radiobuttons as a single component returning a String value. It can be initialized with a list of options (key to value pairs) and the selected option can be easily set or get with the value property.val radioGroup = RadioGroup(
listOf("option1" to "First option", "option2" to "Second option"),
inline = true, label = "Radio button group"
)
radioGroup.value = "option1"
println(radioGroup.value)
This component extends the usage of
indeterminate property of the standard CheckBox component and allows you to easily use all three states of the checkbox - selected (value = true), deselected (value = false) and indeterminate (value = null).val tsc = triStateCheckBox(value = true, label = "Tri-state checkbox")
button("Make indeterminate").onClick {
tsc.value = null
}
This is a simple select box component, based on standard HTML select control. It can be used when there is no need for advanced options of the
Select component. The SimpleSelect component should be initialized with a list of options (key to values pairs).Select(
options = listOf("first" to "First option", "second" to "Second option"),
label = "Simple select"
)
The
kvision-tom-select module allows you to use a sophisticated form control based on Tom Select. It's a full-featured component, configurable with plenty of options. It can be used for a simple select picker with a few static options as well as a searchable, dynamic lists pulled over the network. The TomSelect component can be initialized with a list of options (key to values pairs).TomSelect(
options = listOf("first" to "First option", "second" to "Second option"),
label = "Select"
)
You can select many options at the same time with
multiple property. You can use tsOptions parameter to provide additional options (e.g. limit the number of selected items). See TomSelect documentation for detailed information about available options.TomSelect(
options = listOf("first" to "First option", "second" to "Second option", "third" to "Third option"),
multiple = true,
label = "Multiple select",
tsOptions = TomSelectOptions(maxItems = 2)
)
Other properties allow to define a placeholder, an autofocus attribute and to automatically generate an empty option (to be able to de-select value).
TomSelect(
options = listOf("first" to "First option", "second" to "Second option"),
label = "Styled Select"
) {
placeholder = "Select a value"
autofocus = true
emptyOption = true
}
TomSelect component can also work with a remote data source - just pass a TomSelectCallbacks object with a load callbackTomSelect(label = "Select a repository",
emptyOption = true,
tsCallbacks = TomSelectCallbacks(
load = { query, callback ->
restClient.callDynamic("https://api.github.com/search/repositories") {
data = obj { q = query }
resultTransform = { it.items }
}.then { items: dynamic ->
@Suppress("UnsafeCastFromDynamic")
callback(items.map { item ->
obj {
this.value = item.id
this.text = item.name
this.subtext = item.owner.login
}
})
}
},
shouldLoad = { it.length >= 3 }
),
tsRenders = TomSelectRenders(option = { item, escape ->
"""
<div>
<span class="title">${escape(item.text)}</span>
<small>(${escape(item.subtext)})</small>
</div>
""".trimIndent()
})
)
This component is contained in the
kvision-tom-select-remote module and is a special version of TomSelect control, tailored for use with KVision server side interfaces. You can find more information in part 3 of this guide.This is a simple integer field component, based on standard HTML input control. You can set
min and max values (default - no limits) and set the step value (default 1).Spinner(label = "Number 10 - 20",
min = 10,
max = 20,
step = 2)
This component can be used to allow a user to select numeric value with a slider. You need to configure
min (default 0), max (default 100) and step (default 1) attributes.Range(label = "Range field 10 - 20", min = 10, max = 20)
Note: the actual appearance of the control may depend on your browser.
This component can be used for fixed precision decimal numbers (e.g. currency). You need do set a number of decimal digits (default 2) and the component will automatically format the number. You can set
min and max values (default - no limits). You can also specify a decimal digit character or just use the auto-detected default.Numeric(label = "Product price", min = 0)
With
kvision-imask module you can use the advanced numeric component, which allows you to work with all decimal numbers (with or without fixed number of decimal digits) and fully controls the characters entered by the user. By setting decimals property to a larger value (up to 15) you can support inputs with different number of decimal digits.ImaskNumeric(label = "Enter number", decimals = 15)
If you want to support fixed decimals, set
padFractionalZeros = true - the component will automatically format the number.ImaskNumeric(label = "Product price", min = 0, padFractionalZeros = true)
You can also use decimals and thousands separator chars (both are automatically detected from the current locale).
Note: All numeric components are based on JavaScript
Number type, which is double-precision 64-bit binary format IEEE 754. The range and precision of represented numbers is limited. To prevent rounding errors KVision limits the range of supported numbers to about 14 digits. Both
kvision-datetime module allows you to use a sophisticated form control based on Tempus-dominus library. Is It's a full-featured component, configurable with plenty of options. It can be used to display date and/or time picker, based on the date format specified with Fecha library formatting tokens. The default format is "YYYY-MM-DD HH:mm", which means the control will display date and time picker.DateTime(format = "YYYY-MM-DD", label = "Date field") {
placeholder = "Enter date"
}
DateTime(format = "HH:mm", label = "Time field") {
placeholder = "Enter time"
}
DateTime(label = "Date and time field") {
placeholder = "Enter date and time"
}
Other properties allow you to set days of the week that should be disabled, visibility of "Clear", "Close" and "Today" buttons and also the increment used to build the hour view (default - 5 minutes).
DateTime(label = "Date and time field") {
placeholder = "Enter date and time"
daysOfWeekDisabled = arrayOf(0, 6) // Saturday, Sunday
showClear = false
showClose = false
showTodayButton = false
stepping = 30
}
You can also use
minDate, maxDate, enabledDates and disabledDates properties to control which dates the user is allowed to choose.The kvision-bootstrap-upload module allows you to use a form component based on Bootstrap fileinput, which allows the user to select and upload files. It can be used as a standard file input element, with files being sent as a multi-part form submission or as an AJAX submission and it can be also used as a client-side file selection tool to be used with FileReader API available in modern browsers. The
Upload component has a lot of options to customize its appearance and functionality - see API documentation for more details. You can use the
Upload component to upload files to the server with standard multi-part form action. You should create the FormPanel container with additional parameters (FormMethod.POST, FormEnctype.MULTIPART). In this mode you will be able to upload only one file at a time (unless you add more Upload controls). You should also add a button with type SUBMIT.formPanel<Form>(FormMethod.POST, "/upload", FormEnctype.MULTIPART) {
add(Form::text, Text(label = "Text", name = "text_field"))
add(Form::upload, BootstrapUpload(label = "Upload file").apply {
name = "file_field"
})
hPanel {
button("Submit", type = ButtonType.SUBMIT)
}
}
To use this mode you have to create a server endpoint responsible for processing an AJAX request and returning the correctly formatted response (at least an empty JSON object {}). More information can be found on this Bootstrap fileinput page. On the client side you can use all available options including multiple file uploads. There is no need to add any form parameters or submit buttons.
formPanel<Form> {
add(Form::text, Text(label = "Text"))
add(Form::upload, BootstrapUpload("/ajax-upload", label = "Upload file").apply {
multiple = true
explorerTheme = true
dropZoneEnabled = false
allowedFileTypes = setOf("image")
})
}
In this mode you have to handle your uploaded files and the rest of your form data separately. Alternatively you can use
uploadExtraData property and add your form data directly to your AJAX request.formPanel<Form> {
add(Form::text, Text(label = "Text"))
add(Form::upload, BootstrapUpload("/ajax-upload", label = "Upload file").apply {
uploadExtraData = { _, _ -> this@formPanel.getDataJson() }
})
}
Modern browsers support FileReader API and allow you to work with files entirely on the client side. The
FormPanel<K> class has a suspending getDataWithFileContent extension function, which is using Kotlin coroutines to read the content of all uploaded files as BASE64 dataURL strings. It makes it very easy to use such content in other KVision components (e.g. images or any HTML formatted text).formPanel<Form> {
add(Form::text, Text(label = "Caption"))
add(Form::upload, BootstrapUpload("/", label = "Image").apply {
showUpload = false
showCancel = false
explorerTheme = true
allowedFileTypes = setOf("image")
})
hPanel {
button("Use form data").onClickLaunch {
val fdata = this@formPanel.getDataWithFileContent()
val firstImage = fdata.upload?.firstOrNull()?.content
if (firstImage != null) {
Alert.show(fdata.text, "<img src=\"$firstImage\">", rich = true)
}
}
}
}
Note: You need to set
uploadUrl parameter (e.g. to "/" value), even though it's not directly used in this mode.Last modified 3mo ago