Ensure to count existing images from header and footer too #113

src/Html2OpenXml/Expressions/ImageExpression.cs

@@ -11,6 +11,7 @@
  */
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Threading;
 using AngleSharp.Html.Dom;
 using DocumentFormat.OpenXml;
@@ -117,12 +118,31 @@ private Border ComposeStyles ()
 
             drawingObjId = 1; // 1 is the minimum ID set by MS Office.
             imageObjId = 1;
-            foreach (var d in context.MainPart.Document.Body!.Descendants<Drawing>())
+
+            foreach (var part in new[] { 
+                context.MainPart.Document.Body!.Descendants<Drawing>(),
+                context.MainPart.HeaderParts.SelectMany(f => f.Header.Descendants<Drawing>()),
+                context.MainPart.FooterParts.SelectMany(f => f.Footer.Descendants<Drawing>())
+            })
+            foreach (Drawing d in part)
             {
-                if (d.Inline == null) continue; // fix some rare issue where Inline is null (reported by scwebgroup)
-                if (d.Inline!.DocProperties?.Id?.Value > drawingObjId) drawingObjId = d.Inline.DocProperties.Id;
+                wp.DocProperties? docProperties = null;
+                pic.NonVisualPictureProperties? nvPr = null;
+
+                if (d.Anchor != null)
+                {
+                    docProperties = d.Anchor.GetFirstChild<wp.DocProperties>();
+                    nvPr = d.Anchor.GetFirstChild<a.Graphic>()?.GraphicData?.GetFirstChild<pic.Picture>()?.GetFirstChild<pic.NonVisualPictureProperties>();
+                }
+                else if (d.Inline != null)
+                {
+                    docProperties = d.Inline!.DocProperties;
+                    nvPr = d.Inline!.Graphic?.GraphicData?.GetFirstChild<pic.NonVisualPictureProperties>();
+                }
+
+                if (docProperties?.Id != null && docProperties.Id.Value > drawingObjId)
+                    drawingObjId = docProperties.Id.Value;
 
-                var nvPr = d.Inline!.Graphic?.GraphicData?.GetFirstChild<pic.NonVisualPictureProperties>();
                 if (nvPr != null && nvPr.NonVisualDrawingProperties?.Id?.Value > imageObjId)
                     imageObjId = nvPr.NonVisualDrawingProperties.Id;
             }

test/HtmlToOpenXml.Tests/ImgTests.cs

@@ -6,6 +6,7 @@
 namespace HtmlToOpenXml.Tests
 {
     using pic = DocumentFormat.OpenXml.Drawing.Pictures;
+    using wp = DocumentFormat.OpenXml.Drawing.Wordprocessing;
 
     /// <summary>
     /// Tests images.
@@ -86,9 +87,37 @@ public async Task LoadRemoteImage_BaseUri()
             AssertIsImg(elements.First());
         }
 
-        private void AssertIsImg (OpenXmlCompositeElement elements)
+        [Test(Description = "Image ID must be unique, amongst header, body and footer parts")]
+        public async Task UniqueImageIdAcrossPackagingParts()
         {
-            var run = elements.GetFirstChild<Run>();
+            using var generatedDocument = new MemoryStream();
+            using (var buffer = ResourceHelper.GetStream("Resources.DocWithImgHeaderFooter.docx"))
+                buffer.CopyTo(generatedDocument);
+
+            generatedDocument.Position = 0L;
+            using WordprocessingDocument package = WordprocessingDocument.Open(generatedDocument, true);
+            MainDocumentPart mainPart = package.MainDocumentPart;
+
+            var beforeMaxDocPropId = new[] {
+                mainPart.Document.Body!.Descendants<wp.DocProperties>(),
+                mainPart.HeaderParts.SelectMany(x => x.Header.Descendants<wp.DocProperties>()),
+                mainPart.FooterParts.SelectMany(x => x.Footer.Descendants<wp.DocProperties>())
+            }.SelectMany(x => x).MaxBy(x => x.Id?.Value ?? 0).Id.Value;
+
+            HtmlConverter converter = new(mainPart);
+            await converter.ParseHtml("<img src='data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO9TXL0Y4OHwAAAABJRU5ErkJggg==' width='42' height='42'>");
+            mainPart.Document.Save();
+
+            var img = mainPart.Document.Body!.Descendants<Drawing>().FirstOrDefault();
+            Assert.That(img, Is.Not.Null);
+            Assert.That(img.Inline.DocProperties.Id.Value,
+                Is.GreaterThan(beforeMaxDocPropId),
+                "New image id is incremented considering existing images in header, body and footer");
+        }
+
+        private Drawing AssertIsImg (OpenXmlCompositeElement element)
+        {
+            var run = element.GetFirstChild<Run>();
             Assert.That(run, Is.Not.Null);
             var img = run.GetFirstChild<Drawing>();
             Assert.That(img, Is.Not.Null);
@@ -99,6 +128,7 @@ private void AssertIsImg (OpenXmlCompositeElement elements)
             var imagePartId = pic.BlipFill.Blip.Embed.Value;
             var part = mainPart.GetPartById(imagePartId);
             Assert.That(part, Is.TypeOf(typeof(ImagePart)));
+            return img;
         }
     }
 }