Update documentation. (#46)

docs/plugins/cleanupStyleAttributes.md

@@ -19,6 +19,8 @@ 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.
 
+Empty `style` attributes are removed.
+
 Style attributes are not changed if the document has attribute selectors on the `style` attribute.
 
 ### `class` Attributes

docs/plugins/createGroups.md

@@ -0,0 +1,24 @@
+# createGroups
+
+Creates `<g>` elements containing common properties for adjacent siblings.
+
+## 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 `<style>` element contains at least one rule.
+
+Groups are only created for children of `<svg>` and `<g>` elements.
+
+Adjacent siblings which have at least one common property are combined into a group. The following properties will be moved to the group if shared by all elements:
+
+- Any inheritable properties.
+- The `transform` and `transform-origin` properties, except that if both are present in the children, they are not moved to the group unless both can be moved.
+
+All common properties are written to the group element as part of the `style` attribute, except for `transform`, which is written as an attribute.
+
+The following are never put into a group:
+
+- Elements which are referenced by a `<use>` element.

docs/plugins/inlineStyles.md

@@ -2,6 +2,8 @@
 
 Moves style properties from `<style>` elements to the `style` attribute of matching elements.
 
+## Details
+
 The plugin has no effect if:
 
 - The document has scripts.

docs/plugins/removeHiddenElems.md

@@ -0,0 +1,27 @@
+# removeHiddenElems
+
+Removes [non-rendered elements](https://svgwg.org/svg2-draft/render.html#TermNeverRenderedElement) that are not used.
+
+## 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 `<style>` element has features other than simple selectors or attribute selectors.
+
+The following elements are removed, except as specified below:
+
+- Any children of `<defs>` which have no id.
+- If a non-rendering element with no `id` attribute is encountered outside of a `<defs>`, the element is changed to a `<defs>`, and its content is processed as above.
+- Empty shape elements with no id.
+- Elements with `display:none`.
+- Elements with `opacity:0`.
+
+The following are not removed:
+
+- `<style>` and `<script>` children of `<defs>`.
+- If a child of `<defs>` has no `id` attribute, it may contain descendants which have an `id` attribute. If this is the case, these descendants are moved up to become immediate children of the `<defs>` element.
+- `<marker>` elements with `display:none`.
+- `<g>` elements with `display:none` (these are converted to a `<defs>`, and their content is processed as above).
+- Elements with `opacity:0` which are within a non-rendering element which is not removed.

docs/preset-default.md

@@ -16,24 +16,21 @@ The following plugins are included in `preset-default`, in the order that they a
 - [inlineStyles](./plugins/inlineStyles.md)
 - minifyStyles
 - [cleanupIds](./plugins/cleanupIds.md)
-- removeUselessDefs
 - convertColors
 - [removeUnknownsAndDefaults](./plugins/removeUnknownsAndDefaults.md)
 - removeNonInheritableGroupAttrs
 - removeUselessStrokeAndFill
-- removeHiddenElems
+- [removeHiddenElems](./plugins/removeHiddenElems.md)
 - removeEmptyText
 - minifyTransforms
 - convertEllipseToCircle
-- moveElemsAttrsToGroup
 - moveElemsStylesToGroup
 - collapseGroups
 - convertShapeToPath
-- combinePaths
 - [minifyPathData](./plugins/minifyPathData.md)
-- removeEmptyAttrs
 - removeEmptyContainers
 - removeUnusedNS
+- [createGroups](./plugins/createGroups.md)
 
 ## Disable a Plugin
 

docs/preset-next.md

@@ -17,21 +17,18 @@ The following plugins are included in `preset-next`, in the order that they are
 - [inlineStyles](./plugins/inlineStyles.md)
 - minifyStyles
 - [cleanupIds](./plugins/cleanupIds.md)
-- removeUselessDefs
 - convertColors
 - [removeUnknownsAndDefaults](./plugins/removeUnknownsAndDefaults.md)
 - removeNonInheritableGroupAttrs
 - removeUselessStrokeAndFill
-- removeHiddenElems
+- [removeHiddenElems](./plugins/removeHiddenElems.md)
 - removeEmptyText
 - minifyTransforms
 - convertEllipseToCircle
-- moveElemsAttrsToGroup
 - moveElemsStylesToGroup
 - collapseGroups
 - convertShapeToPath
-- combinePaths
 - [minifyPathData](./plugins/minifyPathData.md)
-- removeEmptyAttrs
 - removeEmptyContainers
 - removeUnusedNS
+- [createGroups](./plugins/createGroups.md)

plugins/removeHiddenElems.js

@@ -7,6 +7,7 @@ export const description =
   'removes non-rendered elements that are not referenced';
 
 /**
+ * @see https://svgwg.org/svg2-draft/render.html#TermNeverRenderedElement
  * @type {import('./plugins-types.js').Plugin<'removeHiddenElems'>}
  */
 export const fn = (root, params, info) => {