add viewmodel for article

internal/viewmodel/ArticleViewModel.go

@@ -0,0 +1,27 @@
+package viewmodel
+
+import "crowsnest/internal/model"
+
+
+type ArticleViewModel struct {
+    Title       string
+    Author      string
+    PublishDate string
+    SourceUrl   string
+    Summary     string
+}
+
+func NewArticleViewModel(a *model.Article) *ArticleViewModel {
+    summary := a.Content
+    if len(a.Content) > 200 {
+        summary = summary[:200]
+    }
+
+    return &ArticleViewModel{
+        Title: a.Title,
+        Author: a.Author,
+        PublishDate: a.PublishDate.Local().Format("02.01.2006 03:04"),
+        SourceUrl: a.SourceUrl,
+        Summary: summary,
+    }
+}