Restore names of uploaded files on submit/draft restore (#65)

This involved turning the list of file IDs stored in the hidden
text field into JSON.

apps/files/models.py

@@ -19,6 +19,9 @@ class BaseFile(models.Model):
     def __str__(self):
         return self.file.name
 
+    def name(self):
+        return self.file.name
+
 
 class File(BaseFile):
     pass

apps/files/static/files/upload.js

@@ -65,10 +65,25 @@ class MultipleFilesWidget {
     }
 
     rebuildListFromField() {
-        let idList = this.element.field.value.split(",")
-        for (let id of idList) {
-            this.addFile(id, `Saved upload (id ${id})`, this.status.DONE)
+        const fieldContents = this.element.field.value
+
+        // Nothing to do
+        if (fieldContents === '') {
+            return;
         }
+
+        try {
+            let list = JSON.parse(fieldContents)
+            for (let file of list) {
+                this.addFile(file.id, file.name, this.status.DONE)
+            }
+        } catch (e) {
+            // Not JSON, let's parse as CSV
+            for (let id of fieldContents.split(",")) {
+                this.addFile(id, `Saved upload (id ${id})`, this.status.DONE)
+            }
+        }
+
         this.viewFileList()
     }
 
@@ -145,9 +160,13 @@ class MultipleFilesWidget {
 
     updateFormField() {
         let oldVal = this.element.field.value
-        this.element.field.value = this.fileList.filter(f => f.id != null)
-                                                .map(f => f.id)
-                                                .toString()
+        let fileList = this.fileList.filter(f => f.id != null)
+                                    .map(f => ({
+                                        id: f.id,
+                                        name: f.name
+                                    }))
+
+        this.element.field.value = JSON.stringify(fileList)
 
         // Mark form as dirty
         if (this.element.field.value !== oldVal) {