Class: AbstractValue

LuCI.form. AbstractValue

The AbstractValue class serves as abstract base for the different form option styles implemented by LuCI.form. It provides the common logic for handling option input values, for dependencies among options and for validation constraints that should be applied to entered values.

This class is private and not directly accessible by user code.

new LuCI.form.AbstractValue()

form.js, line 1328

Extends

Members

datatypestring

Specifies a datatype constraint expression to validate input values against. Refer to LuCI.validation for details on the format.

If the user entered input does not match the datatype validation, the option element is marked as invalid.

Default Value:
  • null

default*

Sets a default value to use when the underlying UCI option is not set.

Default Value:
  • null

editableboolean

Mark grid section option element as editable.

Options which are displayed in the table portion of a GridSection instance are rendered as readonly text by default. By setting the editable property of a child option element to true, that element is rendered as full input widget within its cell instead of a text only preview.

This property has no effect on options that are not children of grid section elements.

Default Value:
  • false

modalonlyboolean

Move grid section option element into the table, the modal popup or both.

If this property is null (the default), the option element is displayed in both the table preview area and the per-section instance modal popup of a grid section. When it is set to false the option is only shown in the table but not the modal popup. When set to true, the option is only visible in the modal popup but not the table.

This property has no effect on options that are not children of grid section elements.

Default Value:
  • null

onchangefunction

Register a custom value change handler.

If this property is set to a function value, the function is invoked whenever the value of the underlying UI input element is changing.

The invoked handler function will receive the DOM click element as first and the underlying configuration section ID as well as the input value as second and third argument respectively.

Default Value:
  • null

optionalboolean

If set to true, the underlying ui input widget is allowed to be empty, otherwise the option element is marked invalid when no value is entered or selected by the user.

Default Value:
  • false

readonlyboolean

Make option element readonly.

This property defaults to the readonly state of the parent form element. When set to true, the underlying widget is rendered in disabled state, means its contents cannot be changed and the widget cannot be interacted with.

Default Value:
  • false

retainboolean

If set to true, the underlying ui input widget value is not cleared from the configuration on unsatisfied dependencies. The default behavior is to remove the values of all options whose dependencies are not fulfilled.

Default Value:
  • false

rmemptyboolean

If set to false, the underlying option value is retained upon saving the form when the option element is disabled due to unsatisfied dependency constraints.

Default Value:
  • true

uciconfigstring

Override the UCI configuration name to read the option value from.

By default, the configuration name is inherited from the parent Map. By setting this property, a deviating configuration may be specified.

The default is null, means inheriting from the parent form.

Default Value:
  • null

ucioptionstring

Override the UCI option name to read the value from.

By default, the elements name, which is passed as third argument to the constructor, is used as UCI option name. By setting this property, a deviating UCI option may be specified.

The default is null, means using the option element name.

Default Value:
  • null

ucisectionstring

Override the UCI section name to read the option value from.

By default, the section ID is inherited from the parent section element. By setting this property, a deviating section may be specified.

The default is null, means inheriting from the parent section.

Default Value:
  • null

validatefunction

Specifies a custom validation function to test the user input for validity. The validation function must return true to accept the value. Any other return value type is converted to a string and displayed to the user as validation error message.

If the user entered input does not pass the validation function, the option element is marked as invalid.

Default Value:
  • null

widthnumber string

Override the cell width of a table or grid section child option.

If the property is set to a numeric value, it is treated as pixel width which is set on the containing cell element of the option, essentially forcing a certain column width. When the property is set to a string value, it is applied as-is to the CSS width property.

This property has no effect on options that are not children of grid or table section elements.

Default Value:
  • null

Methods

inherited append(obj)

form.js, line 210

Add another form element as children to this element.

Name Type Description
obj AbstractElement

The form element to add.

cbid(section_id){string}

form.js, line 1752

Obtain the internal ID ("cbid") of the element instance.

Since each form section element may map multiple underlying configuration sections, the configuration section ID is required to form a fully qualified ID pointing to the specific element instance within the given specific section.

Name Type Description
section_id string

The configuration section ID
Throws:

Throws a TypeError exception when no section_id was specified.

Type
TypeError
Returns:
Type Description
string Returns the element ID.

cfgvalue(section_id){*}

form.js, line 1826

Query the underlying configuration value.

The default implementation of this method returns the cached return value of load(). It may be overwritten by user code to obtain the configuration value in a different way.

Name Type Description
section_id string

The configuration section ID
Throws:

Throws a TypeError exception when no section_id was specified.

Type
TypeError
Returns:
Type Description
* Returns the configuration value.

depends(field, value)

form.js, line 1634

Add a dependency constraint to the option.

Dependency constraints allow making the presence of option elements dependent on the current values of certain other options within the same form. An option element with unsatisfied dependencies will be hidden from the view and its current value is omitted when saving.

Multiple constraints (that is, multiple calls to depends()) are treated as alternatives, forming a logical "or" expression.

By passing an object of name => value pairs as first argument, it is possible to depend on multiple options simultaneously, allowing to form a logical "and" expression.

Option names may be given in "dot notation" which allows to reference option elements outside the current form section. If a name without dot is specified, it refers to an option within the same configuration section. If specified as configname.sectionid.optionname, options anywhere within the same form may be specified.

The object notation also allows for a number of special keys which are not treated as option names but as modifiers to influence the dependency constraint evaluation. The associated value of these special "tag" keys is ignored. The recognized tags are:

  • !reverse
    Invert the dependency, instead of requiring another option to be equal to the dependency value, that option should not be equal.
  • !contains
    Instead of requiring an exact match, the dependency is considered satisfied when the dependency value is contained within the option value.
  • !default
    The dependency is always satisfied

Examples:

  • opt.depends("foo", "test")
    Require the value of `foo` to be `test`.
  • opt.depends({ foo: "test" })
    Equivalent to the previous example.
  • opt.depends({ foo: /test/ })
    Require the value of `foo` to match the regular expression `/test/`.
  • opt.depends({ foo: "test", bar: "qrx" })
    Require the value of `foo` to be `test` and the value of `bar` to be `qrx`.
  • opt.depends({ foo: "test" })
    opt.depends({ bar: "qrx" })
    Require either foo to be set to test, or the bar option to be qrx.
  • opt.depends("test.section1.foo", "bar")
    Require the "foo" form option within the "section1" section to be set to "bar".
  • opt.depends({ foo: "test", "!contains": true })
    Require the "foo" option value to contain the substring "test".
Name Type Description
field string | Object.<string, (string|RegExp)>

The name of the option to depend on or an object describing multiple dependencies which must be satisfied (a logical "and" expression).
value string | RegExp

When invoked with a plain option name as first argument, this parameter specifies the expected value. In case an object is passed as first argument, this parameter is ignored.

formvalue(section_id){*}

form.js, line 1854

Query the current form input value.

The default implementation of this method returns the current input value of the underlying LuCI.ui widget. It may be overwritten by user code to handle input values differently.

Name Type Description
section_id string

The configuration section ID
Throws:

Throws a TypeError exception when no section_id was specified.

Type
TypeError
Returns:
Type Description
* Returns the current input value.

getUIElement(section_id){LuCI.ui.AbstractElement|null}

form.js, line 1803

Obtain the underlying LuCI.ui element instance.

Name Type Description
section_id string

The configuration section ID
Throws:

Throws a TypeError exception when no section_id was specified.

Type
TypeError
Returns:
Type Description
LuCI.ui.AbstractElement | null Returns the LuCI.ui element instance or null in case the form option implementation does not use LuCI.ui widgets.

getValidationError(section_id){string}

form.js, line 1941

Returns the current validation error for this input.

Name Type Description
section_id string

The configuration section ID
Returns:
Type Description
string The validation error at this time

isActive(section_id){boolean}

form.js, line 1959

Test whether the option element is currently active.

An element is active when it is not hidden due to unsatisfied dependency constraints.

Name Type Description
section_id string

The configuration section ID
Returns:
Type Description
boolean Returns true if the option element currently is active, otherwise it returns false.

isValid(section_id){boolean}

form.js, line 1927

Test whether the input value is currently valid.

Name Type Description
section_id string

The configuration section ID
Returns:
Type Description
boolean Returns true if the input value currently is valid, otherwise it returns false.

load(section_id){*|Promise.<*>}

form.js, line 1780

Load the underlying configuration value.

The default implementation of this method reads and returns the underlying UCI option value (or the related JavaScript property for JSONMap instances). It may be overwritten by user code to load data from nonstandard sources.

Name Type Description
section_id string

The configuration section ID
Throws:

Throws a TypeError exception when no section_id was specified.

Type
TypeError
Returns:
Type Description
* | Promise.<*> Returns the configuration value to initialize the option element with. The return value of this function is filtered through Promise.resolve() so it may return promises if overridden by user code.

parse(section_id){Promise.<void>}

form.js, line 2000

Parse the option element input.

The function is invoked when the parse() method has been invoked on the parent form and triggers input value reading and validation.

Name Type Description
section_id string

The configuration section ID
Returns:
Type Description
Promise.<void> Returns a promise resolving once the input value has been read and validated or rejecting in case the input value does not meet the validation constraints.

remove(section_id)

form.js, line 2080

Remove the corresponding value from the configuration.

This function is invoked upon saving the parent form when the option element has been hidden due to unsatisfied dependencies or when the user cleared the input value and the option is marked optional.

The default implementation simply removes the associated option from the UCI configuration (or the associated JavaScript object property in case of JSONMap forms). It may be overwritten by user code to implement alternative removal logic, e.g. to retain the original value.

Name Type Description
section_id string

The configuration section ID

inherited abstractrender(){Node|Promise.<Node>}

form.js, line 246

Render the form element.

The render() function recursively walks the form element tree and renders the markup for each element, returning the assembled DOM tree.

Returns:
Type Description
Node | Promise.<Node> May return a DOM Node or a promise resolving to a DOM node containing the form element's markup, including the markup of any child elements.

inherited stripTags(s){string}

form.js, line 288

Strip any HTML tags from the given input string, and decode HTML entities.

Name Type Description
s string

The input string to clean.
Returns:
Type Description
string The cleaned input string with HTML tags removed, and HTML entities decoded.

textvalue(section_id){string}

form.js, line 1878

Obtain a textual input representation.

The default implementation of this method returns the HTML escaped current input value of the underlying LuCI.ui widget. User code or specific option element implementations may overwrite this function to apply a different logic, e.g. to return Yes or No depending on the checked state of checkbox elements.

Name Type Description
section_id string

The configuration section ID
Throws:

Throws a TypeError exception when no section_id was specified.

Type
TypeError
Returns:
Type Description
string Returns the text representation of the current input value.

inherited titleFn(property, fmt_args){string|null}

form.js, line 327

Format the given named property as title string.

This function looks up the given named property and formats its value suitable for use as element caption or description string. It also strips any HTML tags from the result.

If the property value is a string, it is passed to String.format() along with any additional parameters passed to titleFn().

If the property value is a function, it is invoked with any additional titleFn() parameters as arguments and the obtained return value is converted to a string.

In all other cases, null is returned.

Name Type Description
property string

The name of the element property to use.
fmt_args * repeatable

Extra values to format the title string with.
Returns:
Type Description
string | null The formatted title string or null if the property did not exist or was neither a string nor a function.

abstractvalidate(section_id, value){*}

form.js, line 1913

Apply custom validation logic.

This method is invoked whenever incremental validation is performed on the user input, e.g. on keyup or blur events.

The default implementation of this method does nothing and always returns true. User code may overwrite this method to provide additional validation logic which is not covered by data type constraints.

Name Type Description
section_id string

The configuration section ID
value *

The value to validate
Returns:
Type Description
* The method shall return true to accept the given value. Any other return value is treated as failure, converted to a string and displayed as error message to the user.

write(section_id, formvalue)

form.js, line 2057

Write the current input value into the configuration.

This function is invoked upon saving the parent form when the option element is valid and when its input value has been changed compared to the initial value returned by cfgvalue().

The default implementation simply sets the given input value in the UCI configuration (or the associated JavaScript object property in case of JSONMap forms). It may be overwritten by user code to implement alternative save logic, e.g. to transform the input value before it is written.

Name Type Description
section_id string

The configuration section ID
formvalue string | Array.<string>

The input value to write.