2 files changed, 63 insertions, 0 deletions
diff --git a/src/data/composite/things/content/index.js b/src/data/composite/things/content/index.js
index 474c2af2..eeedcdcd 100644
--- a/src/data/composite/things/content/index.js
+++ b/src/data/composite/things/content/index.js
@@ -1,4 +1,5 @@
 export {default as hasAnnotationPart} from './hasAnnotationPart.js';
 export {default as withAnnotationParts} from './withAnnotationParts.js';
 export {default as withSourceText} from './withSourceText.js';
+export {default as withSourceURLs} from './withSourceURLs.js';
 export {default as withWebArchiveDate} from './withWebArchiveDate.js';
diff --git a/src/data/composite/things/content/withSourceURLs.js b/src/data/composite/things/content/withSourceURLs.js
new file mode 100644
index 00000000..7c7b0ab2
--- /dev/null
+++ b/src/data/composite/things/content/withSourceURLs.js
@@ -0,0 +1,62 @@
+import {input, templateCompositeFrom} from '#composite';
+import {parseInput} from '#replacer';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
+import {withFilteredList, withMappedList} from '#composite/data';
+
+import withAnnotationParts from './withAnnotationParts.js';
+
+export default templateCompositeFrom({
+  annotation: `withSourceURLs`,
+
+  outputs: ['#sourceURLs'],
+
+  steps: () => [
+    withAnnotationParts({
+      mode: input.value('nodes'),
+    }),
+
+    raiseOutputWithoutDependency({
+      dependency: '#annotationParts',
+      output: input.value({'#sourceURLs': []}),
+    }),
+
+    {
+      dependencies: ['#annotationParts'],
+      compute: (continuation, {
+        ['#annotationParts']: annotationParts,
+      }) => continuation({
+        ['#firstPartWithExternalLink']:
+          annotationParts
+            .find(nodes => nodes
+              .some(node => node.type === 'external-link')),
+      }),
+    },
+
+    raiseOutputWithoutDependency({
+      dependency: '#firstPartWithExternalLink',
+      output: input.value({'#sourceURLs': []}),
+    }),
+
+    withMappedList({
+      list: '#firstPartWithExternalLink',
+      map: input.value(node => node.type === 'external-link'),
+    }).outputs({
+      '#mappedList': '#externalLinkFilter',
+    }),
+
+    withFilteredList({
+      list: '#firstPartWithExternalLink',
+      filter: '#externalLinkFilter',
+    }).outputs({
+      '#filteredList': '#externalLinks',
+    }),
+
+    withMappedList({
+      list: '#externalLinks',
+      map: input.value(node => node.data.href),
+    }).outputs({
+      '#mappedList': '#sourceURLs',
+    }),
+  ],
+});