Merge pull request jazzband#545 from chipx86/inline-compile-errors

Add error output for compiler errors within the browser.

Author: davidt

docs/configuration.rst

@@ -145,6 +145,18 @@ Defaults to ``True``
 
   this only work when PIPELINE_ENABLED is False.
 
+``SHOW_ERRORS_INLINE``
+......................
+
+``True`` if errors compiling CSS/JavaScript files should be shown inline at
+the top of the browser window, or ``False`` if they should trigger exceptions
+(the older behavior).
+
+This only applies when compiling through the ``{% stylesheet %}`` or
+``{% javascript %}`` template tags. It won't impact ``collectstatic``.
+
+Defaults to ``settings.DEBUG``.
+
 ``CSS_COMPRESSOR``
 ..................
 

pipeline/compilers/__init__.py

@@ -8,7 +8,7 @@
 from django.contrib.staticfiles.storage import staticfiles_storage
 from django.core.files.base import ContentFile
 from django.utils.encoding import smart_bytes
-from django.utils.six import string_types
+from django.utils.six import string_types, text_type
 
 from pipeline.conf import settings
 from pipeline.exceptions import CompilerError
@@ -125,7 +125,9 @@ def execute_command(self, command, cwd=None, stdout_captured=None):
             if compiling.returncode != 0:
                 stdout_captured = None  # Don't save erroneous result.
                 raise CompilerError(
-                    "{0!r} exit code {1}\n{2}".format(argument_list, compiling.returncode, stderr))
+                    "{0!r} exit code {1}\n{2}".format(argument_list, compiling.returncode, stderr),
+                    command=argument_list,
+                    error_output=stderr)
 
             # User wants to see everything that happened.
             if self.verbose:
@@ -134,7 +136,8 @@ def execute_command(self, command, cwd=None, stdout_captured=None):
                 print(stderr)
         except OSError as e:
             stdout_captured = None  # Don't save erroneous result.
-            raise CompilerError(e)
+            raise CompilerError(e, command=argument_list,
+                                error_output=text_type(e))
         finally:
             # Decide what to do with captured stdout.
             if stdout:

pipeline/conf.py

@@ -23,6 +23,8 @@
     'PIPELINE_ROOT': _settings.STATIC_ROOT,
     'PIPELINE_URL': _settings.STATIC_URL,
 
+    'SHOW_ERRORS_INLINE': _settings.DEBUG,
+
     'CSS_COMPRESSOR': 'pipeline.compressors.yuglify.YuglifyCompressor',
     'JS_COMPRESSOR': 'pipeline.compressors.yuglify.YuglifyCompressor',
     'COMPILERS': [],

pipeline/exceptions.py

@@ -10,7 +10,11 @@ class PackageNotFound(PipelineException):
 
 
 class CompilerError(PipelineException):
-    pass
+    def __init__(self, msg, command=None, error_output=None):
+        super(CompilerError, self).__init__(msg)
+
+        self.command = command
+        self.error_output = error_output.strip()
 
 
 class CompressorError(PipelineException):

pipeline/jinja2/__init__.py

@@ -34,7 +34,7 @@ def package_css(self, package_name, *args, **kwargs):
             package = self.package_for(package_name, 'css')
         except PackageNotFound:
             return ''  # fail silently, do not return anything if an invalid group is specified
-        return self.render_compressed(package, 'css')
+        return self.render_compressed(package, package_name, 'css')
 
     def render_css(self, package, path):
         template_name = package.template_name or "pipeline/css.jinja"
@@ -55,7 +55,7 @@ def package_js(self, package_name, *args, **kwargs):
             package = self.package_for(package_name, 'js')
         except PackageNotFound:
             return ''  # fail silently, do not return anything if an invalid group is specified
-        return self.render_compressed(package, 'js')
+        return self.render_compressed(package, package_name, 'js')
 
     def render_js(self, package, path):
         template_name = package.template_name or "pipeline/js.jinja"

pipeline/templates/pipeline/compile_error.html

@@ -0,0 +1,31 @@
+<div id="django-pipeline-error-{{package_name}}" class="django-pipeline-error"
+     style="display: none; border: 2px #DD0000 solid; margin: 1em; padding: 1em; background: white;">
+ <h1>Error compiling {{package_type}} package "{{package_name}}"</h1>
+ <p><strong>Command:</strong></p>
+ <pre style="white-space: pre-wrap;">{{command}}</pre>
+ <p><strong>Errors:</strong></p>
+ <pre style="white-space: pre-wrap;">{{errors}}</pre>
+</div>
+
+<script>
+document.addEventListener('readystatechange', function() {
+    var el,
+        container;
+
+    if (document.readyState !== 'interactive') {
+        return;
+    }
+
+    el = document.getElementById('django-pipeline-error-{{package_name}}');
+    container = document.getElementById('django-pipeline-errors');
+
+    if (!container) {
+        container = document.createElement('div');
+        container.id = 'django-pipeline-errors';
+        document.body.insertBefore(container, document.body.firstChild);
+    }
+
+    container.appendChild(el);
+    el.style.display = 'block';
+});
+</script>

pipeline/templatetags/pipeline.py

@@ -1,16 +1,18 @@
 from __future__ import unicode_literals
 
 import logging
+import subprocess
 
 from django.contrib.staticfiles.storage import staticfiles_storage
 
 from django import template
-from django.template.base import VariableDoesNotExist
+from django.template.base import Context, VariableDoesNotExist
 from django.template.loader import render_to_string
 from django.utils.safestring import mark_safe
 
 from ..collector import default_collector
 from ..conf import settings
+from ..exceptions import CompilerError
 from ..packager import Packager, PackageNotFound
 from ..utils import guess_type
 
@@ -51,7 +53,7 @@ def render(self, context):
         except VariableDoesNotExist:
             pass
 
-    def render_compressed(self, package, package_type):
+    def render_compressed(self, package, package_name, package_type):
         if settings.PIPELINE_ENABLED:
             method = getattr(self, "render_{0}".format(package_type))
             return method(package, package.output_filename)
@@ -61,10 +63,29 @@ def render_compressed(self, package, package_type):
 
             packager = Packager()
             method = getattr(self, "render_individual_{0}".format(package_type))
-            paths = packager.compile(package.paths)
+
+            try:
+                paths = packager.compile(package.paths)
+            except CompilerError as e:
+                if settings.SHOW_ERRORS_INLINE:
+                    method = getattr(self, 'render_error_{0}'.format(
+                        package_type))
+
+                    return method(package_name, e)
+                else:
+                    raise
+
             templates = packager.pack_templates(package)
             return method(package, paths, templates=templates)
 
+    def render_error(self, package_type, package_name, e):
+        return render_to_string('pipeline/compile_error.html', Context({
+            'package_type': package_type,
+            'package_name': package_name,
+            'command': subprocess.list2cmdline(e.command),
+            'errors': e.error_output,
+        }))
+
 
 class StylesheetNode(PipelineMixin, template.Node):
     def __init__(self, name):
@@ -79,7 +100,7 @@ def render(self, context):
         except PackageNotFound:
             logger.warn("Package %r is unknown. Check PIPELINE_CSS in your settings.", package_name)
             return ''  # fail silently, do not return anything if an invalid group is specified
-        return self.render_compressed(package, 'css')
+        return self.render_compressed(package, package_name, 'css')
 
     def render_css(self, package, path):
         template_name = package.template_name or "pipeline/css.html"
@@ -94,6 +115,10 @@ def render_individual_css(self, package, paths, **kwargs):
         tags = [self.render_css(package, path) for path in paths]
         return '\n'.join(tags)
 
+    def render_error_css(self, package_name, e):
+        return super(StylesheetNode, self).render_error(
+            'CSS', package_name, e)
+
 
 class JavascriptNode(PipelineMixin, template.Node):
     def __init__(self, name):
@@ -108,7 +133,7 @@ def render(self, context):
         except PackageNotFound:
             logger.warn("Package %r is unknown. Check PIPELINE_JS in your settings.", package_name)
             return ''  # fail silently, do not return anything if an invalid group is specified
-        return self.render_compressed(package, 'js')
+        return self.render_compressed(package, package_name, 'js')
 
     def render_js(self, package, path):
         template_name = package.template_name or "pipeline/js.html"
@@ -132,6 +157,10 @@ def render_individual_js(self, package, paths, templates=None):
             tags.append(self.render_inline(package, templates))
         return '\n'.join(tags)
 
+    def render_error_js(self, package_name, e):
+        return super(JavascriptNode, self).render_error(
+            'JavaScript', package_name, e)
+
 
 @register.tag
 def stylesheet(parser, token):

tests/tests/test_compiler.py

@@ -156,7 +156,16 @@ def setUp(self):
         self.compiler = Compiler()
 
     def test_compile(self):
-        self.assertRaises(CompilerError, self.compiler.compile, [_('pipeline/js/dummy.coffee')])
+        with self.assertRaises(CompilerError) as cm:
+            self.compiler.compile([_('pipeline/js/dummy.coffee')])
+
+            e = cm.exception
+            self.assertEqual(
+                e.command,
+                ['this-exists-nowhere-as-a-command-and-should-fail',
+                 'pipeline/js/dummy.coffee',
+                 'pipeline/js/dummy.junk'])
+            self.assertEqual(e.error_output, '')
 
     def tearDown(self):
         default_collector.clear()
@@ -170,7 +179,12 @@ def setUp(self):
         self.compiler = Compiler()
 
     def test_compile(self):
-        self.assertRaises(CompilerError, self.compiler.compile, [_('pipeline/js/dummy.coffee')])
+        with self.assertRaises(CompilerError) as cm:
+            self.compiler.compile([_('pipeline/js/dummy.coffee')])
+
+            e = cm.exception
+            self.assertEqual(e.command, ['/usr/bin/env', 'false'])
+            self.assertEqual(e.error_output, '')
 
     def tearDown(self):
         default_collector.clear()