From b6be1cdc99e08c90f8f9bc32c9e9aa0c9686c4d5 Mon Sep 17 00:00:00 2001
From: Paul Beckingham <paul@beckingham.net>
Date: Sat, 18 Oct 2014 16:55:26 -0400
Subject: [PATCH] Hooks

- Factored out the code that determines if the JSON output from a hook script is
  actually JSON.
---
 src/Hooks.cpp | 47 ++++++++++++++++++++++++++++++++++++++++-------
 src/Hooks.h   |  1 +
 2 files changed, 41 insertions(+), 7 deletions(-)

diff --git a/src/Hooks.cpp b/src/Hooks.cpp
index dee6da11f..f848192e3 100644
--- a/src/Hooks.cpp
+++ b/src/Hooks.cpp
@@ -36,6 +36,7 @@
 #include <sys/wait.h>
 #include <sys/types.h>
 #include <Context.h>
+#include <JSON.h>
 #include <Hooks.h>
 #include <text.h>
 #include <util.h>
@@ -133,7 +134,7 @@ void Hooks::onLaunch ()
     {
       for (line = lines.begin (); line != lines.end (); ++line)
       {
-        if (line->length () && (*line)[0] == '{')
+        if (isJSON (*line))
         {
           if (_debug >= 2)
             context.debug ("Hook output: " + *line);
@@ -149,7 +150,7 @@ void Hooks::onLaunch ()
     else
     {
       for (line = lines.begin (); line != lines.end (); ++line)
-        if (line->length () && (*line)[0] != '{')
+        if (! isJSON (*line))
           context.error (*line);
 
       throw 0;  // This is how hooks silently terminate processing.
@@ -215,7 +216,7 @@ void Hooks::onExit ()
       if (_debug >= 2)
         context.debug ("Hook output: " + *line);
 
-      if (line->length () && (*line)[0] != '{')
+      if (! isJSON (*line))
       {
         if (status == 0)
           context.footnote (*line);
@@ -280,7 +281,7 @@ void Hooks::onAdd (std::vector <Task>& changes)
         if (_debug >= 2)
           context.debug ("Hook output: " + *line);
 
-        if (line->length () && (*line)[0] == '{')
+        if (isJSON (*line))
           changes.push_back (Task (*line));
         else
           context.footnote (*line);
@@ -289,7 +290,7 @@ void Hooks::onAdd (std::vector <Task>& changes)
     else
     {
       for (line = lines.begin (); line != lines.end (); ++line)
-        if (line->length () && (*line)[0] != '{')
+        if (! isJSON (*line))
           context.error (*line);
 
       throw 0;  // This is how hooks silently terminate processing.
@@ -359,7 +360,7 @@ void Hooks::onModify (const Task& before, std::vector <Task>& changes)
         if (_debug >= 2)
           context.debug ("Hook output: " + *line);
 
-        if (line->length () && (*line)[0] == '{')
+        if (isJSON (*line))
           changes.push_back (Task (*line));
         else
           context.footnote (*line);
@@ -368,7 +369,7 @@ void Hooks::onModify (const Task& before, std::vector <Task>& changes)
     else
     {
       for (line = lines.begin (); line != lines.end (); ++line)
-        if (line->length () && (*line)[0] != '{')
+        if (! isJSON (*line))
           context.error (*line);
 
       throw 0;  // This is how hooks silently terminate processing.
@@ -403,3 +404,35 @@ std::vector <std::string> Hooks::scripts (const std::string& event)
 }
 
 ////////////////////////////////////////////////////////////////////////////////
+bool Hooks::isJSON (const std::string& input) const
+{
+  if (input.length () &&
+      input[0] == '{' &&
+      input[input.length () - 1] == '}')
+  {
+    try
+    {
+      Task maybe (input);
+      return true;
+    }
+
+    catch (const std::string& e)
+    {
+      if (_debug >= 1)
+        context.debug ("Hook output looks like JSON, but is not a valid task.");
+
+      if (_debug >= 2)
+        context.debug ("JSON parser error: " + e);
+    }
+
+    catch (...)
+    {
+      if (_debug >= 1)
+        context.debug ("Hook output looks like JSON, but fails to parse.");
+    }
+  }
+
+  return false;
+}
+
+////////////////////////////////////////////////////////////////////////////////
diff --git a/src/Hooks.h b/src/Hooks.h
index ae0d9d27c..e0b713c3c 100644
--- a/src/Hooks.h
+++ b/src/Hooks.h
@@ -51,6 +51,7 @@ public:
 
 private:
   std::vector <std::string> scripts (const std::string&);
+  bool isJSON (const std::string&) const;
 
 private:
   bool                      _enabled;