resources/src/mediawiki.action.edit/stash.js

   1 /*!
   2  * Pre-emptive page parsing edits.
   3  *
   4  * See also PageEditStash in PHP.
   5  */
   6 $( () => {
   7         const PRIORITY_LOW = 1;
   8         const PRIORITY_HIGH = 2;
   9
  10         // Do not attempt to stash "new section" edits, because for those cases the ParserOutput
  11         // varies on the edit summary field, and thus pre-parsing the page whilst that field is
  12         // being typed in would be counter-productive. (The field is re-purposed for the new
  13         // section's heading.)
  14         const $form = $( '#editform' );
  15         const section = $form.find( '[name=wpSection]' ).val();
  16         if ( !$form.length || section === 'new' ) {
  17                 return;
  18         }
  19
  20         let lastText, lastSummary, lastTextHash;
  21         let lastPriority = 0;
  22         const $text = $form.find( '#wpTextbox1' );
  23         const $summary = $form.find( '#wpSummary' );
  24         const model = $form.find( '[name=model]' ).val();
  25         const format = $form.find( '[name=format]' ).val();
  26         const revId = $form.find( '[name=parentRevId]' ).val();
  27
  28         // Whether the body text content changed since the last stashEdit()
  29         function isTextChanged() {
  30                 return lastText !== $text.textSelection( 'getContents' );
  31         }
  32
  33         // Whether the edit summary has changed since the last stashEdit()
  34         function isSummaryChanged() {
  35                 return lastSummary !== $summary.textSelection( 'getContents' );
  36         }
  37
  38         // Send a request to stash the edit to the API.
  39         // If a request is in progress, abort it since its payload is stale and the API
  40         // may limit concurrent stash parses.
  41         const api = new mw.Api();
  42         let stashReq;
  43         function stashEdit() {
  44                 const textChanged = isTextChanged();
  45                 const priority = textChanged ? PRIORITY_HIGH : PRIORITY_LOW;
  46
  47                 if ( stashReq ) {
  48                         if ( lastPriority > priority ) {
  49                                 // Stash request for summary change should wait on pending text change stash
  50                                 stashReq.then( checkStash );
  51                                 return;
  52                         }
  53                         stashReq.abort();
  54                 }
  55
  56                 // Update the "last" tracking variables
  57                 lastSummary = $summary.textSelection( 'getContents' );
  58                 lastPriority = priority;
  59                 if ( textChanged ) {
  60                         lastText = $text.textSelection( 'getContents' );
  61                         // Reset hash
  62                         lastTextHash = null;
  63                 }
  64
  65                 const params = {
  66                         formatversion: 2,
  67                         action: 'stashedit',
  68                         title: mw.config.get( 'wgPageName' ),
  69                         section: section,
  70                         sectiontitle: '',
  71                         summary: lastSummary,
  72                         contentmodel: model,
  73                         contentformat: format,
  74                         baserevid: revId
  75                 };
  76                 if ( lastTextHash ) {
  77                         params.stashedtexthash = lastTextHash;
  78                 } else {
  79                         params.text = lastText;
  80                 }
  81
  82                 const req = api.postWithToken( 'csrf', params );
  83                 stashReq = req;
  84                 req.then( ( data ) => {
  85                         if ( req === stashReq ) {
  86                                 stashReq = null;
  87                         }
  88                         if ( data.stashedit && data.stashedit.texthash ) {
  89                                 lastTextHash = data.stashedit.texthash;
  90                         } else {
  91                                 // Request failed or text hash expired;
  92                                 // include the text in a future stash request.
  93                                 lastTextHash = null;
  94                         }
  95                 } );
  96         }
  97
  98         // Check whether text or summary have changed and call stashEdit()
  99         function checkStash() {
 100                 if ( !isTextChanged() && !isSummaryChanged() ) {
 101                         return;
 102                 }
 103
 104                 stashEdit();
 105         }
 106
 107         let idleTimeout = 3000;
 108         let timer;
 109         function onKeyUp( e ) {
 110                 // Ignore keystrokes that don't modify text, like cursor movements.
 111                 // See <http://www.javascripter.net/faq/keycodes.htm> and
 112                 // <http://www.quirksmode.org/js/keys.html>. We don't have to be exhaustive,
 113                 // because the cost of misfiring is low.
 114                 // * Key code 33-40: Page Up/Down, End, Home, arrow keys.
 115                 // * Key code 16-18: Shift, Ctrl, Alt.
 116                 if ( ( e.which >= 33 && e.which <= 40 ) || ( e.which >= 16 && e.which <= 18 ) ) {
 117                         return;
 118                 }
 119
 120                 clearTimeout( timer );
 121                 timer = setTimeout( checkStash, idleTimeout );
 122         }
 123
 124         function onSummaryFocus() {
 125                 // Summary typing is usually near the end of the workflow and involves less pausing.
 126                 // Re-stash more frequently in hopes of capturing the final summary before submission.
 127                 idleTimeout = 1000;
 128                 // Stash now since the text is likely the final version. The re-stashes based on the
 129                 // summary are targeted at caching edit checks that need the final summary.
 130                 checkStash();
 131         }
 132
 133         function onTextFocus() {
 134                 // User returned to the text field... reset stash rate to default
 135                 idleTimeout = 3000;
 136         }
 137
 138         $text.on( {
 139                 keyup: onKeyUp,
 140                 focus: onTextFocus,
 141                 change: checkStash
 142         } );
 143         $summary.on( {
 144                 keyup: onKeyUp,
 145                 focus: onSummaryFocus,
 146                 focusout: checkStash
 147         } );
 148
 149         if (
 150                 // Reverts may involve use (undo) links; stash as they review the diff.
 151                 // Since the form has a pre-filled summary, stash the edit immediately.
 152                 mw.util.getParamValue( 'undo' ) !== null ||
 153                 // Pressing "show changes" and "preview" also signify that the user will
 154                 // probably save the page soon
 155                 [ 'preview', 'diff' ].indexOf( $form.find( '#mw-edit-mode' ).val() ) > -1
 156         ) {
 157                 checkStash();
 158         }
 159 } );