1 files changed, 18 insertions, 10 deletions
diff --git a/src/frontend/json.rs b/src/frontend/json.rs
index cd7e651..39e86f8 100644
--- a/src/frontend/json.rs
+++ b/src/frontend/json.rs
@@ -15,23 +15,34 @@ use librepology::v1::api::Api;
 
 pub struct JsonFrontend(Stdout);
 
+/// A Frontend that serializes the data to JSON
+///
+/// Useful for piping the data as structured data to another program.
+///
+/// # Warning
+///
+/// This frontend does _not_ maintain compatibility with repolocli itself. That means that piping
+/// output from repolocli to repolocli is _NOT_ supported by this frontend.
+///
 impl JsonFrontend {
     pub fn new(stdout: Stdout) -> Self {
         JsonFrontend(stdout)
     }
+
+    fn write(&self, output: String) -> Result<()> {
+        let mut outlock = self.0.lock();
+        writeln!(outlock, "{}", output).map_err(Error::from)
+    }
 }
 
 impl Frontend for JsonFrontend {
     fn list_packages(&self, packages: Vec<Package>) -> Result<()> {
-        let output = serde_json::ser::to_string_pretty(&packages).map_err(Error::from)?;
-        let mut outlock = self.0.lock();
-        writeln!(outlock, "{}", output).map_err(Error::from)
+        self.write(serde_json::ser::to_string_pretty(&packages).map_err(Error::from)?)
+
     }
 
     fn list_problems(&self, problems: Vec<Problem>) -> Result<()> {
-        let output = serde_json::ser::to_string_pretty(&problems).map_err(Error::from)?;
-        let mut outlock = self.0.lock();
-        writeln!(outlock, "{}", output).map_err(Error::from)
+        self.write(serde_json::ser::to_string_pretty(&problems).map_err(Error::from)?)
     }
 
     fn compare_packages(&self, packages: Vec<ComparePackage>, backend: &Backend, filter_repos: Vec<Repo>) -> Result<()> {
@@ -71,10 +82,7 @@ impl Frontend for JsonFrontend {
             });
         }
 
-        let output = serde_json::ser::to_string_pretty(&output)?;
-
-        let mut outlock = self.0.lock();
-        writeln!(outlock, "{}", output).map_err(Error::from)
+        self.write(serde_json::ser::to_string_pretty(&output)?)
     }
 }