Added pygments_api example

4 files changed, 141 insertions, 0 deletions

diff --git a/examples/pygments_api/__init__.py b/examples/pygments_api/__init__.py
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/examples/pygments_api/__init__.py
diff --git a/examples/pygments_api/forms.py b/examples/pygments_api/forms.py
new file mode 100644
index 00000000..66446c5b
--- /dev/null
+++ b/examples/pygments_api/forms.py
@@ -0,0 +1,71 @@
+from django import forms
+
+from pygments.lexers import get_all_lexers
+from pygments.styles import get_all_styles
+
+import httplib2 as httplib
+
+
+LEXER_CHOICES = sorted([(item[1][0], item[0]) for item in get_all_lexers()])
+STYLE_CHOICES = sorted((item, item) for item in list(get_all_styles()))
+
+
+class PygmentsForm(forms.Form):
+    """A simple form with some of the most important pygments settings.
+    The code to be highlighted can be specified either in a text field, or by URL.
+    We do some additional form validation to ensure clients see helpful error responses."""
+
+    code_url = forms.URLField(required=False, label='Code URL',
+                              help_text='eg. https://bitbucket.org/tomchristie/flywheel/raw/cc266285d879/flywheel/resource.py')
+    code_text = forms.CharField(widget=forms.Textarea, required=False, label='Code Text',
+                                help_text='Either supply a URL for the code to be highlighted or copy and paste the code text here.')
+    title = forms.CharField(required=False, help_text='(Optional)')
+    linenos = forms.BooleanField(label='Show Line Numbers', required=False)
+    lexer = forms.ChoiceField(choices=LEXER_CHOICES, initial='python')
+    style = forms.ChoiceField(choices=STYLE_CHOICES, initial='friendly')
+
+    
+    def clean_code_url(self):
+        """Custom field validation.
+        Ensure that code URLs really are valid, and return the content they point to in the cleaned_data,
+        rather than returning the URL itself."""
+        cleaned_data = self.cleaned_data
+        url = cleaned_data.get('code_url')
+        if not url:
+            return ''
+
+        try:
+            http = httplib.Http('.cache')
+            resp, content = http.request(url)
+        except:
+            raise forms.ValidationError('The URL supplied cannot be reached')
+
+        if int(resp.status/100) != 2:
+            raise forms.ValidationError('The URL supplied does not return successfully')
+        if not content:
+            raise forms.ValidationError('The URL supplied returns no content')
+        
+        return content
+        
+
+    def clean(self):
+        """Custom form validation.
+        Ensure that only one of code_url and code_text is set, and return the content of whichever is set in 'code'."""
+        cleaned_data = self.cleaned_data
+        code_url = cleaned_data.get('code_url')
+        code_text = cleaned_data.get('code_text')
+
+        if not code_url and not code_text:
+            raise forms.ValidationError('Either the URL or the code text must be supplied')
+        if code_url and code_text:
+            raise forms.ValidationError('You may not specify both the URL and the code text')
+
+        if code_url:
+            cleaned_data['code'] = code_url
+            del cleaned_data['code_url']
+        else:
+            cleaned_data['code'] = code_text
+            del cleaned_data['code_text']
+
+        return cleaned_data
+
diff --git a/examples/pygments_api/urls.py b/examples/pygments_api/urls.py
new file mode 100644
index 00000000..39bcf668
--- /dev/null
+++ b/examples/pygments_api/urls.py
@@ -0,0 +1,6 @@
+from django.conf.urls.defaults import patterns
+
+urlpatterns = patterns('pygments_api.views',
+    (r'^$', 'PygmentsRoot'), 
+    (r'^([a-zA-Z0-9]+)/$', 'PygmentsInstance'),
+)
diff --git a/examples/pygments_api/views.py b/examples/pygments_api/views.py
new file mode 100644
index 00000000..01f1b4b6
--- /dev/null
+++ b/examples/pygments_api/views.py
@@ -0,0 +1,64 @@
+from django.conf import settings
+
+from flywheel.resource import Resource
+from flywheel.response import Response, status
+from flywheel.emitters import BaseEmitter
+
+from pygments.formatters import HtmlFormatter
+from pygments.lexers import get_lexer_by_name
+from pygments import highlight
+
+from forms import PygmentsForm
+
+import os
+import hashlib
+
+# We need somewhere to store the code that we highlight
+HIGHLIGHTED_CODE_DIR = os.path.join(settings.MEDIA_ROOT, 'pygments')
+
+
+class HTMLEmitter(BaseEmitter):
+    """Basic emitter which just returns the content without any further serialization."""
+    media_type = 'text/html'
+
+
+class PygmentsRoot(Resource):
+    """This example demonstrates a simple RESTful Web API aound the awesome pygments library.
+    This top level resource is used to create  """
+    form = PygmentsForm
+    allowed_methods = anon_allowed_methods = ('POST',)
+
+    def post(self, request, auth, content):
+        # Generate a unique id by hashing the input
+        input_str = ''.join(['%s%s' % (key, content[key]) for key in sorted(content.keys())])
+        hash = hashlib.md5()
+        hash.update(input_str)
+        unique_id = hash.hexdigest()
+        pathname = os.path.join(HIGHLIGHTED_CODE_DIR, unique_id)
+
+        if not os.path.exists(pathname):
+            # We only need to generate the file if it doesn't already exist.
+            title = content['title'] if content['title'] else None
+            linenos = 'table' if content['linenos'] else False
+            lexer = get_lexer_by_name(content['lexer'])
+            formatter = HtmlFormatter(style=content['style'], linenos=linenos, full=True, title=title)
+            
+            with open(pathname, 'w') as outfile:
+                highlight(content['code'], lexer, formatter, outfile)
+            
+        return Response(status.HTTP_303_SEE_OTHER, headers={'Location': self.reverse(PygmentsInstance, unique_id)})
+
+
+class PygmentsInstance(Resource):
+    """Simply return the stored highlighted HTML file with the correct mime type.
+    This Resource only emits HTML and uses a standard HTML emitter rather than FlyWheel's DocumentingHTMLEmitter class."""
+    allowed_methods = anon_allowed_methods = ('GET',)
+    emitters = (HTMLEmitter,)
+
+    def get(self, request, auth, unique_id):
+        pathname = os.path.join(HIGHLIGHTED_CODE_DIR, unique_id)
+        if not os.path.exists(pathname):
+            return Resource(status.HTTP_404_NOT_FOUND)
+        return open(pathname, 'r').read()
+
+