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schema.js 11 KB

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  1. /**
  2. * @license Copyright (c) 2003-2017, CKSource - Frederico Knabben. All rights reserved.
  3. * For licensing, see LICENSE.md.
  4. */
  5. import CKEditorError from '@ckeditor/ckeditor5-utils/src/ckeditorerror';
  6. import ObservableMixin from '@ckeditor/ckeditor5-utils/src/observablemixin';
  7. import mix from '@ckeditor/ckeditor5-utils/src/mix';
  8. /**
  9. * @module engine/model/schema
  10. */
  11. /**
  12. * @mixes module:utils/emittermixin~ObservableMixin
  13. */
  14. export default class Schema {
  15. constructor() {
  16. this._sourceRules = {};
  17. // TODO events
  18. this.decorate( 'checkChild' );
  19. this.decorate( 'checkAttribute' );
  20. this.on( 'checkAttribute', ( evt, args ) => {
  21. args[ 0 ] = normalizeContext( args[ 0 ] );
  22. }, { priority: 'highest' } );
  23. this.on( 'checkChild', ( evt, args ) => {
  24. args[ 0 ] = normalizeContext( args[ 0 ] );
  25. }, { priority: 'highest' } );
  26. }
  27. register( itemName, rules ) {
  28. if ( this._sourceRules[ itemName ] ) {
  29. // TODO docs
  30. throw new CKEditorError( 'schema-cannot-register-item-twice: A single item cannot be registered twice in the schema.' );
  31. }
  32. this._sourceRules[ itemName ] = [
  33. Object.assign( {}, rules )
  34. ];
  35. this._clearCache();
  36. }
  37. extend( itemName, rules ) {
  38. // TODO it should not throw if we want to allow e.g. adding attrs before element is registered
  39. // (which may be done by another feature).
  40. if ( !this._sourceRules[ itemName ] ) {
  41. // TODO docs
  42. throw new CKEditorError( 'schema-cannot-extend-missing-item: Cannot extend an item which was not registered yet.' );
  43. }
  44. this._sourceRules[ itemName ].push( Object.assign( {}, rules ) );
  45. this._clearCache();
  46. }
  47. getRules() {
  48. if ( !this._compiledRules ) {
  49. this._compile();
  50. }
  51. return this._compiledRules;
  52. }
  53. /**
  54. * @param {module:engine/model/node~Node|String} item
  55. */
  56. getRule( item ) {
  57. let itemName;
  58. if ( typeof item == 'string' ) {
  59. itemName = item;
  60. } else if ( item.is && item.is( 'text' ) ) {
  61. itemName = '$text';
  62. }
  63. // Element or context item.
  64. else {
  65. itemName = item.name;
  66. }
  67. return this.getRules()[ itemName ];
  68. }
  69. isRegistered( itemName ) {
  70. return !!this.getRule( itemName );
  71. }
  72. isBlock( itemName ) {
  73. const rule = this.getRule( itemName );
  74. return !!( rule && rule.isBlock );
  75. }
  76. isLimit( itemName ) {
  77. const rule = this.getRule( itemName );
  78. return !!( rule && rule.isLimit );
  79. }
  80. isObject( itemName ) {
  81. const rule = this.getRule( itemName );
  82. return !!( rule && rule.isObject );
  83. }
  84. /**
  85. * @param {module:engine/model/element~Element|module:engine/model/position~Position|Array.<String>} context
  86. * @param {module:engine/model/node~Node|String}
  87. */
  88. checkChild( context, child ) {
  89. const rule = this.getRule( child );
  90. if ( !rule ) {
  91. return false;
  92. }
  93. return this._checkContextMatch( rule, context );
  94. }
  95. /**
  96. * @param {module:engine/model/node~Node} context
  97. * @param {String}
  98. */
  99. checkAttribute( context, attributeName ) {
  100. const rule = this.getRule( context[ context.length - 1 ] );
  101. if ( !rule ) {
  102. return false;
  103. }
  104. return rule.allowAttributes.includes( attributeName );
  105. }
  106. /**
  107. * Returns the lowest {@link module:engine/model/schema~Schema#isLimit limit element} containing the entire
  108. * selection or the root otherwise.
  109. *
  110. * @param {module:engine/model/selection~Selection} selection Selection which returns the common ancestor.
  111. * @returns {module:engine/model/element~Element}
  112. */
  113. getLimitElement( selection ) {
  114. // Find the common ancestor for all selection's ranges.
  115. let element = Array.from( selection.getRanges() )
  116. .reduce( ( node, range ) => {
  117. if ( !node ) {
  118. return range.getCommonAncestor();
  119. }
  120. return node.getCommonAncestor( range.getCommonAncestor() );
  121. }, null );
  122. while ( !this.isLimit( element.name ) ) {
  123. if ( element.parent ) {
  124. element = element.parent;
  125. } else {
  126. break;
  127. }
  128. }
  129. return element;
  130. }
  131. /**
  132. * Removes attributes disallowed the schema.
  133. *
  134. * @param {Iterable.<module:engine/model/node~Node>} nodes Nodes that will be filtered.
  135. * @param {module:engine/model/writer~Writer} writer
  136. */
  137. removeDisallowedAttributes( nodes, writer ) {
  138. for ( const node of nodes ) {
  139. for ( const attribute of node.getAttributeKeys() ) {
  140. if ( !this.checkAttribute( node, attribute ) ) {
  141. writer.removeAttribute( attribute, node );
  142. }
  143. }
  144. if ( node.is( 'element' ) ) {
  145. this.removeDisallowedAttributes( node.getChildren(), writer );
  146. }
  147. }
  148. }
  149. _clearCache() {
  150. this._compiledRules = null;
  151. }
  152. _compile() {
  153. const compiledRules = {};
  154. const sourceRules = this._sourceRules;
  155. const itemNames = Object.keys( sourceRules );
  156. for ( const itemName of itemNames ) {
  157. compiledRules[ itemName ] = compileBaseItemRule( sourceRules[ itemName ], itemName );
  158. }
  159. for ( const itemName of itemNames ) {
  160. compileAllowContentOf( compiledRules, itemName );
  161. }
  162. for ( const itemName of itemNames ) {
  163. compileAllowWhere( compiledRules, itemName );
  164. }
  165. for ( const itemName of itemNames ) {
  166. compileAllowAttributesOf( compiledRules, itemName );
  167. compileInheritPropertiesFrom( compiledRules, itemName );
  168. }
  169. for ( const itemName of itemNames ) {
  170. cleanUpAllowIn( compiledRules, itemName );
  171. cleanUpAllowAttributes( compiledRules, itemName );
  172. }
  173. this._compiledRules = compiledRules;
  174. }
  175. _checkContextMatch( rule, context, contextItemIndex = context.length - 1 ) {
  176. const contextItem = context[ contextItemIndex ];
  177. if ( rule.allowIn.includes( contextItem.name ) ) {
  178. if ( contextItemIndex == 0 ) {
  179. return true;
  180. } else {
  181. const parentRule = this.getRule( contextItem );
  182. return this._checkContextMatch( parentRule, context, contextItemIndex - 1 );
  183. }
  184. } else {
  185. return false;
  186. }
  187. }
  188. }
  189. mix( Schema, ObservableMixin );
  190. function compileBaseItemRule( sourceItemRules, itemName ) {
  191. const itemRule = {
  192. name: itemName,
  193. allowIn: [],
  194. allowContentOf: [],
  195. allowWhere: [],
  196. allowAttributes: [],
  197. allowAttributesOf: [],
  198. inheritTypesFrom: []
  199. };
  200. copyTypes( sourceItemRules, itemRule );
  201. copyProperty( sourceItemRules, itemRule, 'allowIn' );
  202. copyProperty( sourceItemRules, itemRule, 'allowContentOf' );
  203. copyProperty( sourceItemRules, itemRule, 'allowWhere' );
  204. copyProperty( sourceItemRules, itemRule, 'allowAttributes' );
  205. copyProperty( sourceItemRules, itemRule, 'allowAttributesOf' );
  206. copyProperty( sourceItemRules, itemRule, 'inheritTypesFrom' );
  207. makeInheritAllWork( sourceItemRules, itemRule );
  208. return itemRule;
  209. }
  210. function compileAllowContentOf( compiledRules, itemName ) {
  211. for ( const allowContentOfItemName of compiledRules[ itemName ].allowContentOf ) {
  212. // The allowContentOf property may point to an unregistered element.
  213. if ( compiledRules[ allowContentOfItemName ] ) {
  214. const allowedChildren = getAllowedChildren( compiledRules, allowContentOfItemName );
  215. allowedChildren.forEach( allowedItem => {
  216. allowedItem.allowIn.push( itemName );
  217. } );
  218. }
  219. }
  220. delete compiledRules[ itemName ].allowContentOf;
  221. }
  222. function compileAllowWhere( compiledRules, itemName ) {
  223. for ( const allowWhereItemName of compiledRules[ itemName ].allowWhere ) {
  224. const inheritFrom = compiledRules[ allowWhereItemName ];
  225. // The allowWhere property may point to an unregistered element.
  226. if ( inheritFrom ) {
  227. const allowedIn = inheritFrom.allowIn;
  228. compiledRules[ itemName ].allowIn.push( ...allowedIn );
  229. }
  230. }
  231. delete compiledRules[ itemName ].allowWhere;
  232. }
  233. function compileAllowAttributesOf( compiledRules, itemName ) {
  234. for ( const allowAttributeOfItem of compiledRules[ itemName ].allowAttributesOf ) {
  235. const inheritFrom = compiledRules[ allowAttributeOfItem ];
  236. if ( inheritFrom ) {
  237. const inheritAttributes = inheritFrom.allowAttributes;
  238. compiledRules[ itemName ].allowAttributes.push( ...inheritAttributes );
  239. }
  240. }
  241. delete compiledRules[ itemName ].allowAttributesOf;
  242. }
  243. function compileInheritPropertiesFrom( compiledRules, itemName ) {
  244. const item = compiledRules[ itemName ];
  245. for ( const inheritPropertiesOfItem of item.inheritTypesFrom ) {
  246. const inheritFrom = compiledRules[ inheritPropertiesOfItem ];
  247. if ( inheritFrom ) {
  248. const typeNames = Object.keys( inheritFrom ).filter( name => name.startsWith( 'is' ) );
  249. for ( const name of typeNames ) {
  250. if ( !( name in item ) ) {
  251. item[ name ] = inheritFrom[ name ];
  252. }
  253. }
  254. }
  255. }
  256. delete item.inheritTypesFrom;
  257. }
  258. // Remove items which weren't registered (because it may break some checks or we'd need to complicate them).
  259. // Make sure allowIn doesn't contain repeated values.
  260. function cleanUpAllowIn( compiledRules, itemName ) {
  261. const itemRule = compiledRules[ itemName ];
  262. const existingItems = itemRule.allowIn.filter( itemToCheck => compiledRules[ itemToCheck ] );
  263. itemRule.allowIn = Array.from( new Set( existingItems ) );
  264. }
  265. function cleanUpAllowAttributes( compiledRules, itemName ) {
  266. const itemRule = compiledRules[ itemName ];
  267. itemRule.allowAttributes = Array.from( new Set( itemRule.allowAttributes ) );
  268. }
  269. function copyTypes( sourceItemRules, itemRule ) {
  270. for ( const sourceItemRule of sourceItemRules ) {
  271. const typeNames = Object.keys( sourceItemRule ).filter( name => name.startsWith( 'is' ) );
  272. for ( const name of typeNames ) {
  273. itemRule[ name ] = sourceItemRule[ name ];
  274. }
  275. }
  276. }
  277. function copyProperty( sourceItemRules, itemRule, propertyName ) {
  278. for ( const sourceItemRule of sourceItemRules ) {
  279. if ( typeof sourceItemRule[ propertyName ] == 'string' ) {
  280. itemRule[ propertyName ].push( sourceItemRule[ propertyName ] );
  281. } else if ( Array.isArray( sourceItemRule[ propertyName ] ) ) {
  282. itemRule[ propertyName ].push( ...sourceItemRule[ propertyName ] );
  283. }
  284. }
  285. }
  286. function makeInheritAllWork( sourceItemRules, itemRule ) {
  287. for ( const sourceItemRule of sourceItemRules ) {
  288. const inheritFrom = sourceItemRule.inheritAllFrom;
  289. if ( inheritFrom ) {
  290. itemRule.allowContentOf.push( inheritFrom );
  291. itemRule.allowWhere.push( inheritFrom );
  292. itemRule.allowAttributesOf.push( inheritFrom );
  293. itemRule.inheritTypesFrom.push( inheritFrom );
  294. }
  295. }
  296. }
  297. function getAllowedChildren( compiledRules, itemName ) {
  298. const itemRule = compiledRules[ itemName ];
  299. return getValues( compiledRules ).filter( rule => rule.allowIn.includes( itemRule.name ) );
  300. }
  301. function normalizeContext( ctx ) {
  302. if ( Array.isArray( ctx ) ) {
  303. return ctx.map( mapContextItem );
  304. }
  305. // Item or position (PS. It's ok that Position#getAncestors() doesn't accept params).
  306. else {
  307. return ctx.getAncestors( { includeSelf: true } ).map( mapContextItem );
  308. }
  309. }
  310. function mapContextItem( ctxItem ) {
  311. if ( typeof ctxItem == 'string' ) {
  312. return {
  313. name: ctxItem,
  314. * getAttributes() {}
  315. };
  316. } else {
  317. return {
  318. name: ctxItem.is( 'text' ) ? '$text' : ctxItem.name,
  319. * getAttributes() {
  320. yield* ctxItem.getAttributes();
  321. }
  322. };
  323. }
  324. }
  325. function getValues( obj ) {
  326. return Object.keys( obj ).map( key => obj[ key ] );
  327. }