From 37c2094a9c039e80aa4a8ce2ba38e9c9dfb3b70d Mon Sep 17 00:00:00 2001
From: Karl Kroening <karlk@kralnet.us>
Date: Wed, 5 Jul 2017 22:30:00 -0600
Subject: [PATCH] Rename graph.py to _view.py; handle graphviz import errors;
 use tempfile

---
 ffmpeg/__init__.py            |  3 ++-
 ffmpeg/{graph.py => _view.py} | 22 +++++++++++++++++++---
 2 files changed, 21 insertions(+), 4 deletions(-)
 rename ffmpeg/{graph.py => _view.py} (80%)

diff --git a/ffmpeg/__init__.py b/ffmpeg/__init__.py
index 1953609..9f1bed7 100644
--- a/ffmpeg/__init__.py
+++ b/ffmpeg/__init__.py
@@ -3,4 +3,5 @@ from . import _filters, _ffmpeg, _run
 from ._filters import *
 from ._ffmpeg import *
 from ._run import *
-__all__ = _filters.__all__ + _ffmpeg.__all__ + _run.__all__
+from ._view import *
+__all__ = _filters.__all__ + _ffmpeg.__all__ + _run.__all__ + _view.__all__
diff --git a/ffmpeg/graph.py b/ffmpeg/_view.py
similarity index 80%
rename from ffmpeg/graph.py
rename to ffmpeg/_view.py
index 9e220df..aec939c 100644
--- a/ffmpeg/graph.py
+++ b/ffmpeg/_view.py
@@ -2,8 +2,8 @@ from __future__ import unicode_literals
 
 from .dag import get_outgoing_edges
 from ._run import topo_sort
-import graphviz
 import os
+import tempfile
 
 from ffmpeg.nodes import (
     InputNode,
@@ -15,10 +15,20 @@ from ffmpeg.nodes import (
 
 @operator()
 def view(*downstream_nodes, **kwargs):
+    try:
+        import graphviz
+    except ImportError:
+        raise ImportError('failed to import graphviz; please make sure graphviz is installed (e.g. `pip install '
+            'graphviz`)')
+
+    filename = kwargs.pop('filename', None)
+    show_labels = kwargs.pop('show_labels', False)
+    if filename is None:
+        filename = tempfile.mktemp()
+
     sorted_nodes, outgoing_edge_maps = topo_sort(downstream_nodes)
     graph = graphviz.Digraph()
     graph.attr(rankdir='LR')
-    show_labels = kwargs.pop('show_labels', False)
     if len(kwargs.keys()) != 0:
         raise ValueError('Invalid kwargs key(s): {}'.format(', '.join(kwargs.keys())))
 
@@ -44,4 +54,10 @@ def view(*downstream_nodes, **kwargs):
             downstream_node_id = str(hash(edge.downstream_node))
             graph.edge(upstream_node_id, downstream_node_id, **kwargs)
 
-    graph.view('graph.png')
+    graph.view(filename)
+
+
+
+__all__ = [
+    'view',
+]