Set alt in data-mw for non-img media

Follow up to I02ea8421e468635ba6297bb5cda488a5a79c9a1d the depends on
I7a5c24f6ffc15ff0455adf5b025b695ee71501b6 in Parsoid.

Note that the mediaTag isn't currently being passed around for gallery
image nodes so, for example, a <video> becomes an <img> as is.  But,
that's independent of this patch, and a follow up will fix it.
Noted in T348703#9278332

Bug: T348703
Bug: T214603
Change-Id: I5f7d3dfe0a41fac1568c97dccc41209c14e741d0

modules/ve-mw/dm/nodes/ve.dm.MWGalleryImageNode.js

@@ -41,7 +41,7 @@ ve.dm.MWGalleryImageNode.static.matchFunction = function ( element ) {
 ve.dm.MWGalleryImageNode.static.parentNodeTypes = [ 'mwGallery' ];
 
 ve.dm.MWGalleryImageNode.static.preserveHtmlAttributes = function ( attribute ) {
-	var attributes = [ 'typeof', 'class', 'src', 'resource', 'width', 'height', 'href', 'rel', 'alt' ];
+	var attributes = [ 'typeof', 'class', 'src', 'resource', 'width', 'height', 'href', 'rel', 'alt', 'data-mw' ];
 	return attributes.indexOf( attribute ) === -1;
 };
 // By handling our own children we ensure that original DOM attributes
@@ -152,6 +152,7 @@ ve.dm.MWGalleryImageNode.static.toDataElement = function ( domElements, converte
 			height: height !== null && height !== '' ? +height : null,
 			isError: isError,
 			errorText: errorText,
+			mw: mwData,
 			imageClassAttr: img.getAttribute( 'class' ),
 			imgWrapperClassAttr: a.getAttribute( 'class' )
 		}
@@ -176,7 +177,8 @@ ve.dm.MWGalleryImageNode.static.toDomElements = function ( data, doc, converter
 		container = doc.createElement( 'span' ),
 		a = doc.createElement( 'a' ),
 		img = doc.createElement( attributes.isError ? 'span' : ( attributes.mediaTag || 'img' ) ),
-		alt = attributes.altText;
+		alt = attributes.altText,
+		mwData = ve.copy( attributes.mw ) || {};
 
 	// FIXME: attributes.mediaTag and attributes.mediaClass aren't set after edit
 
@@ -225,10 +227,30 @@ ve.dm.MWGalleryImageNode.static.toDomElements = function ( data, doc, converter
 		li.appendChild( captionWrapper.firstChild );
 	}
 
-	if ( attributes.altTextSame ) {
-		img.setAttribute( 'alt', ve.dm.MWGalleryImageNode.static.textContentFromCaption( li ).trim() );
-	} else if ( typeof alt === 'string' ) {
-		img.setAttribute( 'alt', alt );
+	// Meh, see the FIXME above about the mediaTag not being set
+	if ( img.nodeName.toLowerCase() === 'img' ) {
+		if ( attributes.altTextSame ) {
+			img.setAttribute( 'alt', ve.dm.MWGalleryImageNode.static.textContentFromCaption( li ).trim() );
+		} else if ( typeof alt === 'string' ) {
+			img.setAttribute( 'alt', alt );
+		}
+	} else {
+		var mwAttribs = mwData.attribs || [];
+		mwAttribs = mwAttribs.filter(
+			function ( attr ) { return attr[ 0 ] !== 'alt'; }
+		);
+		// Parsoid only sets an alt in the data-mw.attribs if it's explicit
+		// in the source
+		if ( !attributes.altTextSame && typeof alt === 'string' ) {
+			mwAttribs.push( [ 'alt', { txt: alt } ] );
+		}
+		if ( mwData.attribs || mwAttribs.length ) {
+			mwData.attribs = mwAttribs;
+		}
+	}
+
+	if ( !ve.isEmptyObject( mwData ) ) {
+		container.setAttribute( 'data-mw', JSON.stringify( mwData ) );
 	}
 
 	return [ li ];

modules/ve-mw/tests/dm/ve.dm.mwExample.js

@@ -946,7 +946,15 @@ ve.dm.mwExample.domToDataCases = {
 					imgWrapperClassAttr: null,
 					src: null,
 					isError: true,
-					errorText: 'File:!Example.jpg'
+					errorText: 'File:!Example.jpg',
+					mw: {
+						errors: [
+							{
+								key: 'apierror-filedoesnotexist',
+								message: 'This image does not exist.'
+							}
+						]
+					}
 				}
 			},
 			{ type: 'mwGalleryImageCaption' },
@@ -967,7 +975,7 @@ ve.dm.mwExample.domToDataCases = {
 			<ul typeof="mw:Extension/gallery" about="#mwt2" data-mw='{"name":"gallery","attrs":{},"body":{}}'>
 				<li class="gallerybox">
 					<div class="thumb">
-						<span typeof="mw:Error mw:File">
+						<span typeof="mw:Error mw:File" data-mw='{"errors":[{"key":"apierror-filedoesnotexist","message":"This image does not exist."}]}'>
 							<a href="./Special:FilePath/!Example.jpg">
 								<span class="mw-file-element mw-broken-media" resource="./File:!Example.jpg" data-width="120" data-height="120">File:!Example.jpg</span>
 							</a>
@@ -1023,7 +1031,8 @@ ve.dm.mwExample.domToDataCases = {
 					imgWrapperClassAttr: 'mw-file-description',
 					src: ve.ce.minImgDataUri,
 					isError: false,
-					errorText: null
+					errorText: null,
+					mw: {}
 				}
 			},
 			{ type: 'mwGalleryImageCaption' },
@@ -1099,7 +1108,8 @@ ve.dm.mwExample.domToDataCases = {
 					imgWrapperClassAttr: 'mw-file-description',
 					src: ve.ce.minImgDataUri,
 					isError: false,
-					errorText: null
+					errorText: null,
+					mw: {}
 				}
 			},
 			{ type: 'mwGalleryImageCaption' },

modules/ve-mw/ui/dialogs/ve.ui.MWGalleryDialog.js

@@ -428,7 +428,8 @@ ve.ui.MWGalleryDialog.prototype.getSetupProcess = function ( data ) {
 						isError: image.getAttribute( 'isError' ),
 						errorText: image.getAttribute( 'errorText' ),
 						imageClassAttr: image.getAttribute( 'imageClassAttr' ),
-						imgWrapperClassAttr: image.getAttribute( 'imgWrapperClassAttr' )
+						imgWrapperClassAttr: image.getAttribute( 'imgWrapperClassAttr' ),
+						mw: image.getAttribute( 'mw' )
 					} );
 				}
 
@@ -676,7 +677,8 @@ ve.ui.MWGalleryDialog.prototype.onRequestImagesSuccess = function ( response ) {
 					captionDocument: this.createCaptionDocument( null ),
 					isError: false,
 					errorText: null,
-					imageClassAttr: 'mw-file-element'
+					imageClassAttr: 'mw-file-element',
+					mw: {}
 				}, config ) );
 				delete this.selectedFilenames[ title ];
 			}
@@ -1040,7 +1042,8 @@ ve.ui.MWGalleryDialog.prototype.insertOrUpdateNode = function () {
 			isError: galleryItem.isError,
 			errorText: galleryItem.errorText,
 			imageClassAttr: galleryItem.imageClassAttr,
-			imgWrapperClassAttr: galleryItem.imgWrapperClassAttr
+			imgWrapperClassAttr: galleryItem.imgWrapperClassAttr,
+			mw: galleryItem.mw
 		};
 
 		return [

modules/ve-mw/ui/widgets/ve.ui.MWGalleryItemWidget.js

@@ -35,6 +35,7 @@ ve.ui.MWGalleryItemWidget = function VeUiMWGalleryItemWidget( imageInfo, config
 	this.isError = imageInfo.isError;
 	this.imageClassAttr = imageInfo.imageClassAttr;
 	this.imgWrapperClassAttr = imageInfo.imgWrapperClassAttr;
+	this.mw = imageInfo.mw;
 
 	// Configuration initialization
 	config = config || {};