Updated docs. (#32)

docs/plugins/cleanupStyleAttributes.md

@@ -0,0 +1,28 @@
+# cleanupStyleAttributes
+
+Removes invalid style properties and unreferenced class attribute names.
+
+## Details
+
+The plugin has no effect if:
+
+- The document has scripts.
+- The document has `<style>` elements with CSS which **svgo-ll** is not able to process.
+
+### `style` Attributes
+
+Properties that are not valid for a particular element are removed.
+
+For `<g>` elements whose only children are shapes, properties relating to text and fonts are removed.
+
+The `style` attribute is removed from all animation elements.
+
+The list of allowable properties comes from https://www.w3.org/TR/SVG2/styling.html#PresentationAttributes, and also includes the `font` shorthand property.
+
+Style attributes are not changed if the document has attribute selectors on the `style` attribute.
+
+### `class` Attributes
+
+Any class names in the `class` attribute which are not referenced by a style selector are removed. If all class names are removed, the class attribute is removed.
+
+Class attributes are not changed if the document has attribute selectors on the `class` attribute.

docs/plugins/removeUnknownsAndDefaults.md

@@ -3,25 +3,44 @@
 Removes unknown elements and attributes, as well as attributes that are set to their default value.
 It also removes the the `standalone` declaration from the DTD if [`standalone`](https://www.w3.org/TR/REC-xml/#sec-rmd) is set to `no`.
 
+## Details
+
 The plugin has no effect if:
 
 - The document has scripts.
 - The document has `<style>` elements with CSS which **svgo-ll** is not able to process.
 
-The following elements are not processed:
+The following elements and attributes are not processed:
 
 - Any element with a namespace prefix.
 - Any `<foreignObject>` elements and their children.
 - Any attributes whose name starts with `aria-` or `data-i`.
 - `xmlns` attributes are never removed.
-- Attribues with a namespace prefix are never removed unless the prefix is `xml` or `xlink`.
+- Attributes with a namespace prefix are never removed unless the prefix is `xml` or `xlink`.
+
+### Elements
 
 Elements are removed if:
 
 - They are not allowed as children of their parents.
 
-Attributes set to a default value are removed if:
+### `style` attributes
+
+Style attribute properties are removed if they are not in an element which is referenced by a `<use>` element (or are a child of any such element), and removing the property does not change the effective style on the element.
+
+### Other attributes
+
+Attributes are always removed if there is a `style` attribute property which overrides the attribute.
+
+Attributes are removed if they are not valid for the element.
+
+Otherwise attributes are removed if both:
+
+- They are either
+
+  - not inheritable, and are set to a default value, or
+  - inheritable, and either have the same value as the parent element, or have a default value, and are not overriding the value of the parent element
+
+  and
 
-- They are not overriding a value set by an ancestor, and
-- they are not in an element that has an id (e.g., a `linearGradient` or similar element which may be referenced elsewhere)
-- they are not in an element which is referenced by a `<use>` element (or a child of any such element).
+- they are not in an element which is referenced by a `<use>` element (or are a child of any such element).

docs/preset-default.md

@@ -2,17 +2,16 @@
 
 ## Plugins List
 
-The following plugins are included in `preset-default`, in the order that they're executed:
+The following plugins are included in `preset-default`, in the order that they are executed:
 
 - removeDoctype
 - removeXMLProcInst
 - removeComments
 - removeMetadata
 - removeEditorsNSData
 - removeDesc
-- cleanupAttrs
 - [cleanupXlink](./plugins/cleanupXlink.md)
-- cleanupStyleAttributes
+- [cleanupStyleAttributes](./plugins/cleanupStyleAttributes.md)
 - combineStyleElements
 - [inlineStyles](./plugins/inlineStyles.md)
 - minifyStyles

docs/preset-next.md

@@ -3,17 +3,16 @@
 
 ## Plugins List
 
-The following plugins are included in `preset-next`, in the order that they're executed:
+The following plugins are included in `preset-next`, in the order that they are executed:
 
 - removeDoctype
 - removeXMLProcInst
 - removeComments
 - removeMetadata
 - removeEditorsNSData
 - removeDesc
-- cleanupAttrs
 - [cleanupXlink](./plugins/cleanupXlink.md)
-- cleanupStyleAttributes
+- [cleanupStyleAttributes](./plugins/cleanupStyleAttributes.md)
 - combineStyleElements
 - [inlineStyles](./plugins/inlineStyles.md)
 - minifyStyles

plugins/preset-default.js

@@ -1,5 +1,4 @@
 import { createPreset } from '../lib/svgo/plugins.js';
-import * as cleanupAttrs from './cleanupAttrs.js';
 import * as cleanupIds from './cleanupIds.js';
 import * as cleanupStyleAttributes from './cleanupStyleAttributes.js';
 import * as cleanupXlink from './cleanupXlink.js';
@@ -40,7 +39,6 @@ const presetDefault = createPreset({
     removeMetadata,
     removeEditorsNSData,
     removeDesc,
-    cleanupAttrs,
     cleanupXlink,
     cleanupStyleAttributes,
     combineStyleElements,