| 1 | /** |
| 2 | * Reads and writes the URL based on reveal.js' current state. |
| 3 | */ |
| 4 | export default class Location { |
| 5 | |
| 6 | // The minimum number of milliseconds that must pass between |
| 7 | // calls to history.replaceState |
| 8 | MAX_REPLACE_STATE_FREQUENCY = 1000 |
| 9 | |
| 10 | constructor( Reveal ) { |
| 11 | |
| 12 | this.Reveal = Reveal; |
| 13 | |
| 14 | // Delays updates to the URL due to a Chrome thumbnailer bug |
| 15 | this.writeURLTimeout = 0; |
| 16 | |
| 17 | this.replaceStateTimestamp = 0; |
| 18 | |
| 19 | this.onWindowHashChange = this.onWindowHashChange.bind( this ); |
| 20 | |
| 21 | } |
| 22 | |
| 23 | bind() { |
| 24 | |
| 25 | window.addEventListener( 'hashchange', this.onWindowHashChange, false ); |
| 26 | |
| 27 | } |
| 28 | |
| 29 | unbind() { |
| 30 | |
| 31 | window.removeEventListener( 'hashchange', this.onWindowHashChange, false ); |
| 32 | |
| 33 | } |
| 34 | |
| 35 | /** |
| 36 | * Returns the slide indices for the given hash link. |
| 37 | * |
| 38 | * @param {string} [hash] the hash string that we want to |
| 39 | * find the indices for |
| 40 | * |
| 41 | * @returns slide indices or null |
| 42 | */ |
| 43 | getIndicesFromHash( hash=window.location.hash, options={} ) { |
| 44 | |
| 45 | // Attempt to parse the hash as either an index or name |
| 46 | let name = hash.replace( /^#\/?/, '' ); |
| 47 | let bits = name.split( '/' ); |
| 48 | |
| 49 | // If the first bit is not fully numeric and there is a name we |
| 50 | // can assume that this is a named link |
| 51 | if( !/^[0-9]*$/.test( bits[0] ) && name.length ) { |
| 52 | let slide; |
| 53 | |
| 54 | let f; |
| 55 | |
| 56 | // Parse named links with fragments (#/named-link/2) |
| 57 | if( /\/[-\d]+$/g.test( name ) ) { |
| 58 | f = parseInt( name.split( '/' ).pop(), 10 ); |
| 59 | f = isNaN(f) ? undefined : f; |
| 60 | name = name.split( '/' ).shift(); |
| 61 | } |
| 62 | |
| 63 | // Ensure the named link is a valid HTML id or data-id attribute |
| 64 | try { |
| 65 | const decodedName = decodeURIComponent( name ); |
| 66 | slide = ( |
| 67 | document.getElementById( decodedName ) || |
| 68 | document.querySelector( `[data-id="${decodedName}"]` ) |
| 69 | ).closest('.slides section'); |
| 70 | } |
| 71 | catch ( error ) { } |
| 72 | |
| 73 | if( slide ) { |
| 74 | return { ...this.Reveal.getIndices( slide ), f }; |
| 75 | } |
| 76 | } |
| 77 | else { |
| 78 | const config = this.Reveal.getConfig(); |
| 79 | let hashIndexBase = config.hashOneBasedIndex || options.oneBasedIndex ? 1 : 0; |
| 80 | |
| 81 | // Read the index components of the hash |
| 82 | let h = ( parseInt( bits[0], 10 ) - hashIndexBase ) || 0, |
| 83 | v = ( parseInt( bits[1], 10 ) - hashIndexBase ) || 0, |
| 84 | f; |
| 85 | |
| 86 | if( config.fragmentInURL ) { |
| 87 | f = parseInt( bits[2], 10 ); |
| 88 | if( isNaN( f ) ) { |
| 89 | f = undefined; |
| 90 | } |
| 91 | } |
| 92 | |
| 93 | return { h, v, f }; |
| 94 | } |
| 95 | |
| 96 | // The hash couldn't be parsed or no matching named link was found |
| 97 | return null |
| 98 | |
| 99 | } |
| 100 | |
| 101 | /** |
| 102 | * Reads the current URL (hash) and navigates accordingly. |
| 103 | */ |
| 104 | readURL() { |
| 105 | |
| 106 | const currentIndices = this.Reveal.getIndices(); |
| 107 | const newIndices = this.getIndicesFromHash(); |
| 108 | |
| 109 | if( newIndices ) { |
| 110 | if( ( newIndices.h !== currentIndices.h || newIndices.v !== currentIndices.v || newIndices.f !== undefined ) ) { |
| 111 | this.Reveal.slide( newIndices.h, newIndices.v, newIndices.f ); |
| 112 | } |
| 113 | } |
| 114 | // If no new indices are available, we're trying to navigate to |
| 115 | // a slide hash that does not exist |
| 116 | else { |
| 117 | this.Reveal.slide( currentIndices.h || 0, currentIndices.v || 0 ); |
| 118 | } |
| 119 | |
| 120 | } |
| 121 | |
| 122 | /** |
| 123 | * Updates the page URL (hash) to reflect the current |
| 124 | * state. |
| 125 | * |
| 126 | * @param {number} delay The time in ms to wait before |
| 127 | * writing the hash |
| 128 | */ |
| 129 | writeURL( delay ) { |
| 130 | |
| 131 | let config = this.Reveal.getConfig(); |
| 132 | let currentSlide = this.Reveal.getCurrentSlide(); |
| 133 | |
| 134 | // Make sure there's never more than one timeout running |
| 135 | clearTimeout( this.writeURLTimeout ); |
| 136 | |
| 137 | // If a delay is specified, timeout this call |
| 138 | if( typeof delay === 'number' ) { |
| 139 | this.writeURLTimeout = setTimeout( this.writeURL, delay ); |
| 140 | } |
| 141 | else if( currentSlide ) { |
| 142 | |
| 143 | let hash = this.getHash(); |
| 144 | |
| 145 | // If we're configured to push to history OR the history |
| 146 | // API is not available. |
| 147 | if( config.history ) { |
| 148 | window.location.hash = hash; |
| 149 | } |
| 150 | // If we're configured to reflect the current slide in the |
| 151 | // URL without pushing to history. |
| 152 | else if( config.hash ) { |
| 153 | // If the hash is empty, don't add it to the URL |
| 154 | if( hash === '/' ) { |
| 155 | this.debouncedReplaceState( window.location.pathname + window.location.search ); |
| 156 | } |
| 157 | else { |
| 158 | this.debouncedReplaceState( '#' + hash ); |
| 159 | } |
| 160 | } |
| 161 | // UPDATE: The below nuking of all hash changes breaks |
| 162 | // anchors on pages where reveal.js is running. Removed |
| 163 | // in 4.0. Why was it here in the first place? ¯\_(ツ)_/¯ |
| 164 | // |
| 165 | // If history and hash are both disabled, a hash may still |
| 166 | // be added to the URL by clicking on a href with a hash |
| 167 | // target. Counter this by always removing the hash. |
| 168 | // else { |
| 169 | // window.history.replaceState( null, null, window.location.pathname + window.location.search ); |
| 170 | // } |
| 171 | |
| 172 | } |
| 173 | |
| 174 | } |
| 175 | |
| 176 | replaceState( url ) { |
| 177 | |
| 178 | window.history.replaceState( null, null, url ); |
| 179 | this.replaceStateTimestamp = Date.now(); |
| 180 | |
| 181 | } |
| 182 | |
| 183 | debouncedReplaceState( url ) { |
| 184 | |
| 185 | clearTimeout( this.replaceStateTimeout ); |
| 186 | |
| 187 | if( Date.now() - this.replaceStateTimestamp > this.MAX_REPLACE_STATE_FREQUENCY ) { |
| 188 | this.replaceState( url ); |
| 189 | } |
| 190 | else { |
| 191 | this.replaceStateTimeout = setTimeout( () => this.replaceState( url ), this.MAX_REPLACE_STATE_FREQUENCY ); |
| 192 | } |
| 193 | |
| 194 | } |
| 195 | |
| 196 | /** |
| 197 | * Return a hash URL that will resolve to the given slide location. |
| 198 | * |
| 199 | * @param {HTMLElement} [slide=currentSlide] The slide to link to |
| 200 | */ |
| 201 | getHash( slide ) { |
| 202 | |
| 203 | let url = '/'; |
| 204 | |
| 205 | // Attempt to create a named link based on the slide's ID |
| 206 | let s = slide || this.Reveal.getCurrentSlide(); |
| 207 | let id = s ? s.getAttribute( 'id' ) : null; |
| 208 | if( id ) { |
| 209 | id = encodeURIComponent( id ); |
| 210 | } |
| 211 | |
| 212 | let index = this.Reveal.getIndices( slide ); |
| 213 | if( !this.Reveal.getConfig().fragmentInURL ) { |
| 214 | index.f = undefined; |
| 215 | } |
| 216 | |
| 217 | // If the current slide has an ID, use that as a named link, |
| 218 | // but we don't support named links with a fragment index |
| 219 | if( typeof id === 'string' && id.length ) { |
| 220 | url = '/' + id; |
| 221 | |
| 222 | // If there is also a fragment, append that at the end |
| 223 | // of the named link, like: #/named-link/2 |
| 224 | if( index.f >= 0 ) url += '/' + index.f; |
| 225 | } |
| 226 | // Otherwise use the /h/v index |
| 227 | else { |
| 228 | let hashIndexBase = this.Reveal.getConfig().hashOneBasedIndex ? 1 : 0; |
| 229 | if( index.h > 0 || index.v > 0 || index.f >= 0 ) url += index.h + hashIndexBase; |
| 230 | if( index.v > 0 || index.f >= 0 ) url += '/' + (index.v + hashIndexBase ); |
| 231 | if( index.f >= 0 ) url += '/' + index.f; |
| 232 | } |
| 233 | |
| 234 | return url; |
| 235 | |
| 236 | } |
| 237 | |
| 238 | /** |
| 239 | * Handler for the window level 'hashchange' event. |
| 240 | * |
| 241 | * @param {object} [event] |
| 242 | */ |
| 243 | onWindowHashChange( event ) { |
| 244 | |
| 245 | this.readURL(); |
| 246 | |
| 247 | } |
| 248 | |
| 249 | } |