Warn when referenced style is not defined

4 files changed, 55 insertions, 7 deletions

diff --git a/src/main/java/org/zwobble/mammoth/docx/BodyXmlReader.java b/src/main/java/org/zwobble/mammoth/docx/BodyXmlReader.java
index 26958dd..a9e99f1 100644
--- a/src/main/java/org/zwobble/mammoth/docx/BodyXmlReader.java
+++ b/src/main/java/org/zwobble/mammoth/docx/BodyXmlReader.java
@@ -1,6 +1,7 @@
 package org.zwobble.mammoth.docx;
 
 import org.zwobble.mammoth.documents.*;
+import org.zwobble.mammoth.results.Result;
 import org.zwobble.mammoth.util.MammothOptionals;
 import org.zwobble.mammoth.xml.XmlElement;
 import org.zwobble.mammoth.xml.XmlElementLike;
@@ -12,6 +13,8 @@ import static com.google.common.collect.Iterables.filter;
 import static com.google.common.collect.Iterables.transform;
 import static org.zwobble.mammoth.docx.ReadResult.EMPTY_SUCCESS;
 import static org.zwobble.mammoth.docx.ReadResult.success;
+import static org.zwobble.mammoth.results.Warning.warning;
+import static org.zwobble.mammoth.util.MammothLists.list;
 
 public class BodyXmlReader {
     private final Styles styles;
@@ -49,16 +52,28 @@ public class BodyXmlReader {
 
     private ReadResult readParagraph(XmlElement element) {
         XmlElementLike properties = element.findChildOrEmpty("w:pPr");
-        Optional<Style> paragraphStyle = readParagraphStyle(properties);
         Optional<NumberingLevel> numbering = readNumbering(properties);
-        return readElements(element.children())
-            .map(children -> new Paragraph(paragraphStyle, numbering, children));
+        return ReadResult.map(
+            readParagraphStyle(properties),
+            readElements(element.children()),
+            (paragraphStyle, children) -> new Paragraph(paragraphStyle, numbering, children));
     }
 
-    private Optional<Style> readParagraphStyle(XmlElementLike properties) {
+    private Result<Optional<Style>> readParagraphStyle(XmlElementLike properties) {
         return readVal(properties, "w:pStyle")
-            .map(styleId -> styles.findParagraphStyleById(styleId)
-                .orElse(new Style(styleId, Optional.empty())));
+            .map(this::findParagraphStyleById)
+            .orElse(Result.empty());
+    }
+
+    private Result<Optional<Style>> findParagraphStyleById(String styleId) {
+        Optional<Style> style = styles.findParagraphStyleById(styleId);
+        if (style.isPresent()) {
+            return Result.success(style);
+        } else {
+            return new Result<>(
+                Optional.of(new Style(styleId, Optional.empty())),
+                list(warning("Paragraph style with ID " + styleId + " was referenced but not defined in the document")));
+        }
     }
 
     private Optional<NumberingLevel> readNumbering(XmlElementLike properties) {
diff --git a/src/main/java/org/zwobble/mammoth/docx/ReadResult.java b/src/main/java/org/zwobble/mammoth/docx/ReadResult.java
index 9fd2e6c..7c672b2 100644
--- a/src/main/java/org/zwobble/mammoth/docx/ReadResult.java
+++ b/src/main/java/org/zwobble/mammoth/docx/ReadResult.java
@@ -1,11 +1,12 @@
 package org.zwobble.mammoth.docx;
 
 import com.google.common.collect.ImmutableList;
-import org.zwobble.mammoth.results.Result;
 import org.zwobble.mammoth.documents.DocumentElement;
+import org.zwobble.mammoth.results.Result;
 import org.zwobble.mammoth.results.Warning;
 
 import java.util.List;
+import java.util.function.BiFunction;
 import java.util.function.Function;
 
 import static org.zwobble.mammoth.util.MammothLists.list;
@@ -23,6 +24,20 @@ public class ReadResult {
         return new ReadResult(elements.build(), warnings.build());
     }
 
+    public static <T> ReadResult map(
+        Result<T> first,
+        ReadResult second,
+        BiFunction<T, List<DocumentElement>, DocumentElement> function)
+    {
+        ImmutableList.Builder<Warning> warnings = ImmutableList.builder();
+        warnings.addAll(first.getWarnings());
+        warnings.addAll(second.warnings);
+
+        return new ReadResult(
+            list(function.apply(first.getValue(), second.elements)),
+            warnings.build());
+    }
+
     public static ReadResult success(DocumentElement element) {
         return success(list(element));
     }
diff --git a/src/main/java/org/zwobble/mammoth/results/Result.java b/src/main/java/org/zwobble/mammoth/results/Result.java
index 846841e..be0819a 100644
--- a/src/main/java/org/zwobble/mammoth/results/Result.java
+++ b/src/main/java/org/zwobble/mammoth/results/Result.java
@@ -1,8 +1,10 @@
 package org.zwobble.mammoth.results;
 
 import com.google.common.collect.ImmutableList;
+import org.zwobble.mammoth.documents.Style;
 
 import java.util.List;
+import java.util.Optional;
 import java.util.function.Function;
 
 import static org.zwobble.mammoth.util.MammothLists.list;
@@ -18,6 +20,10 @@ public class Result<T> {
         return new Result<>(elements.build(), warnings.build());
     }
 
+    public static Result<Optional<Style>> empty() {
+        return new Result<>(Optional.empty(), list());
+    }
+
     public static <T> Result<T> success(T value) {
         return new Result<>(value, list());
     }
diff --git a/src/main/java/org/zwobble/mammoth/results/Warning.java b/src/main/java/org/zwobble/mammoth/results/Warning.java
index c1b4e4b..25579c2 100644
--- a/src/main/java/org/zwobble/mammoth/results/Warning.java
+++ b/src/main/java/org/zwobble/mammoth/results/Warning.java
@@ -1,4 +1,16 @@
 package org.zwobble.mammoth.results;
 
 public class Warning {
+    public static Warning warning(String message) {
+        return new Warning(message);
+    }
+    private final String message;
+
+    private Warning(String message) {
+        this.message = message;
+    }
+
+    public String getMessage() {
+        return message;
+    }
 }