@siteimprove/alfa-css
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@siteimprove/alfa-cssThis package implements support for CSS syntax and values.
(all paths are relative to src/)
syntax: Support for the CSS syntax and parsers for the basic tokens.unit: Model of CSS units. We currently only support angle and length.calculation: Model of CSS calculations. This contains base (non calculated) numeric types, and calculations themselves.value: Model for the CSS values themselves. This includes another copy of the numeric types, but this time including potential calculation. Most of the actual work is likely to involve this directory. It is further split into the various types.The Value type contains the shared structure of CSS values. Most notably:
Value have a type string parameter that can be used as a discriminating union field (e.g. in a switch statement). However, it may sometimes be more convenient to use the Foo.isFoo type predicates, notably in combination with a Selective construct.Value have a CALC type parameter that indicates whether they may contain calculations (i.e. if CALC is false, we guarantee there is no calculation, but if CALC is true, we do not guarantee the presence of a calculation). This parameter can be accessed programmatically with the Value#hasCalculation() type predicate.Value have a Foo.Canonical subtype representing the canonical form of the value. This includes resolving calculations, converting units to their canonical units (e.g. px for lengths), and otherwise converting formats (e.g. canonical colors are in RGB format).Value have a #resolve() method to resolve calculations and provide the same value in its canonical form. These may need a resolver to help with some types (mostly lengths and percentages). The type system should ensure that #resolve() is always called with the correct resolver. Value that need a resolver also have a Foo.Resolver type to declare it.Value, percentage resolution depends on data Alfa does not always have (usually, size of boxes). These also have a Foo.PartiallyResolved type, and a Foo.partiallyResolve() function (with its Foo.PartialResolver interface). Note that partially resolved values will possibly include calculations, including mixed ones (length-percentage) and that needs to be handled downstream (e.g. with the computed values of the CSS properties using these).Value implement the Resolvable interface, which state into what they resolve, and which resolver they need.0.93.0 (2024-10-03)
@siteimprove/alfa-dom: Element.hasDisplaySize() now builds a Predicate<Element<"select">> instead of a Predicate<Element>. (#1683)
@siteimprove/alfa-dom: The helper Element.inputType(element) has been replaced by a method element.inputType(). (#1683)
@siteimprove/alfa-style, @siteimprove/alfa-css: Support for CSS properties scale and translate was added. (#1688)
@siteimprove/alfa-parser: A Parser.doubleBar combinator is now available, to parse CSS "double bar". (#1691)
@siteimprove/alfa-style: A Style.hasUsedStyle predicate builder is now available. (#1694)
@siteimprove/alfa-style: Style properties container-type, mix-blend-mode and isolation are now supported. (#1675)
@siteimprove/alfa-style, @siteimprove/alfa-css: Style property contain is now supported. (#1679)
@siteimprove/alfa-css: A Keyword#is predicate is now available. (#1694)
@siteimprove/alfa-option: An Option.conditional builder is now available, returning None if the predicate is false. (#1694)
@siteimprove/alfa-dom: A method Element<"select">#displaySize() is now available. (#1683)
@siteimprove/alfa-selector: The :checked pseudo-class is now supported. (#1684)
@siteimprove/alfa-rules: Experimental rule SIA-ER8. It adds support for type="password" and more. (#1667)
@siteimprove/alfa-style: Style objects now have an optional owner pointing to the element whose style it is. (#1694)
@siteimprove/alfa-dom: An Element<"select">#optionsList() helper is now available. (#1683)
@siteimprove/alfa-style: Basic support for used values is now available. (#1689)
@siteimprove/alfa-css: Transform functions scale3d() and scaleZ() have been added and the scale transformation functions now accept percentages. (#1688)
@siteimprove/alfa-string: A String.hasWhitespace predicate is now available. (#1694)
@siteimprove/alfa-rules: SIA-R83 is now better at handling white-space and text-overflow. (#1694)
@siteimprove/alfa-style: flex-wrap now has a used value of None on elements that are not flex containers. (#1694)
@siteimprove/alfa-style: <option> elements that are hidden by their <select> are now correctly considered as invisible. (#1683)
@siteimprove/alfa-style: overflow and text-overflow now have no used value on elements where they don't apply. (#1689)
@siteimprove/alfa-style: The computed value of display for <button> elements now correctly handles button layout. (#1694)
FAQs
Implementations of the core CSS syntax and value types
The npm package @siteimprove/alfa-css receives a total of 309 weekly downloads. As such, @siteimprove/alfa-css popularity was classified as not popular.
We found that @siteimprove/alfa-css demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 2 open source maintainers collaborating on the project.
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