Merge pull request #1 from tomchristie/docs

Docs

docs/api-guide/serializers.md

@@ -1155,6 +1155,11 @@ The [html-json-forms][html-json-forms] package provides an algorithm and seriali
 
 [DRF-Base64][drf-base64] provides a set of field and model serializers that handles the upload of base64-encoded files.
 
+## QueryFields
+
+[djangorestframework-queryfields][djangorestframework-queryfields] allows API clients to specify which fields will be sent in the response via inclusion or exclusion query paramaters.  
+
+
 [cite]: https://groups.google.com/d/topic/django-users/sVFaOfQi4wY/discussion
 [relations]: relations.md
 [model-managers]: https://docs.djangoproject.com/en/stable/topics/db/managers/
@@ -1173,3 +1178,4 @@ The [html-json-forms][html-json-forms] package provides an algorithm and seriali
 [drf-dynamic-fields]: https://github.com/dbrgn/drf-dynamic-fields
 [drf-base64]: https://bitbucket.org/levit_scs/drf_base64
 [drf-serializer-extensions]: https://github.com/evenicoulddoit/django-rest-framework-serializer-extensions
+[djangorestframework-queryfields]: http://djangorestframework-queryfields.readthedocs.io/

docs/topics/3.0-announcement.md

@@ -894,11 +894,11 @@ If the request is omitted from the context, the returned URLs will be of the for
 
 The custom `X-Throttle-Wait-Second` header has now been dropped in favor of the standard `Retry-After` header. You can revert this behavior if needed by writing a custom exception handler for your application.
 
-#### Date and time objects as ISO-8859-1 strings in serializer data.
+#### Date and time objects as ISO-8601 strings in serializer data.
 
 Date and Time objects are now coerced to strings by default in the serializer output. Previously they were returned as `Date`, `Time` and `DateTime` objects, and later coerced to strings by the renderer.
 
-You can modify this behavior globally by settings the existing `DATE_FORMAT`, `DATETIME_FORMAT` and `TIME_FORMAT` settings keys. Setting these values to `None` instead of their default value of `'iso-8859-1'` will result in native objects being returned in serializer data.
+You can modify this behavior globally by settings the existing `DATE_FORMAT`, `DATETIME_FORMAT` and `TIME_FORMAT` settings keys. Setting these values to `None` instead of their default value of `'iso-8601'` will result in native objects being returned in serializer data.
 
     REST_FRAMEWORK = {
         # Return native `Date` and `Time` objects in `serializer.data`

docs/topics/third-party-resources.md

@@ -207,6 +207,7 @@ To submit new content, [open an issue][drf-create-issue] or [create a pull reque
 * [html-json-forms][html-json-forms] - Provides an algorithm and serializer to process HTML JSON Form submissions per the (inactive) spec.
 * [django-rest-framework-serializer-extensions][drf-serializer-extensions] -
   Enables black/whitelisting fields, and conditionally expanding child serializers on a per-view/request basis.
+* [djangorestframework-queryfields][djangorestframework-queryfields] - Serializer mixin allowing clients to control which fields will be sent in the API response.
 
 ### Serializer fields
 
@@ -370,3 +371,4 @@ To submit new content, [open an issue][drf-create-issue] or [create a pull reque
 [drf_tweaks]: https://github.com/ArabellaTech/drf_tweaks
 [drf-oidc-auth]: https://github.com/ByteInternet/drf-oidc-auth
 [drf-serializer-extensions]: https://github.com/evenicoulddoit/django-rest-framework-serializer-extensions
+[djangorestframework-queryfields]: https://github.com/wimglenn/djangorestframework-queryfields

docs/tutorial/1-serialization.md

@@ -48,6 +48,8 @@ We'll need to add our new `snippets` app and the `rest_framework` app to `INSTAL
         'snippets.apps.SnippetsConfig',
     )
 
+Please note that if you're using Django <1.9, you need to replace `snippets.apps.SnippetsConfig` with `snippets`.
+
 Okay, we're ready to roll.
 
 ## Creating a model to work with

rest_framework/pagination.py

@@ -294,7 +294,7 @@ class PageNumberPagination(BasePagination):
                 name=self.page_query_param,
                 required=False,
                 location='query',
-                description=force_text(self.page_query_description)
+                #description=force_text(self.page_query_description)
             )
         ]
         if self.page_size_query_param is not None:
@@ -303,7 +303,7 @@ class PageNumberPagination(BasePagination):
                     name=self.page_size_query_param,
                     required=False,
                     location='query',
-                    description=force_text(self.page_size_query_description)
+                    #description=force_text(self.page_size_query_description)
                 )
             )
         return fields
@@ -444,13 +444,13 @@ class LimitOffsetPagination(BasePagination):
                 name=self.limit_query_param,
                 required=False,
                 location='query',
-                description=force_text(self.limit_query_description)
+                #description=force_text(self.limit_query_description)
             ),
             coreapi.Field(
                 name=self.offset_query_param,
                 required=False,
                 location='query',
-                description=force_text(self.offset_query_description)
+                #description=force_text(self.offset_query_description)
             )
         ]
 

rest_framework/renderers.py

@@ -798,10 +798,30 @@ class DocumentationRenderer(BaseRenderer):
     media_type = 'text/html'
     format = 'html'
     charset = 'utf-8'
+    template = 'rest_framework/docs/index.html'
+    code_style = 'emacs'
+
+    def get_context(self, data):
+        from pygments.formatters import HtmlFormatter
+        from django.utils.html import mark_safe
+        formatter = HtmlFormatter(style=self.code_style)
+        code_style = formatter.get_style_defs('.highlight')
+        langs = ['shell', 'javascript', 'python']
+        codec = coreapi.codecs.CoreJSONCodec()
+        schema = mark_safe(codec.encode(data))
+        return {
+            'document': data,
+            'langs': langs,
+            'code_style': code_style,
+            'schema': schema
+        }
 
     def render(self, data, accepted_media_type=None, renderer_context=None):
-        from coredocs.main import render as render_docs
+        #from coredocs.main import render as render_docs
-        return render_docs(data, theme='cerulean', highlight='emacs', static=lambda path: '/static/rest_framework/docs/' + path)
+        #return render_docs(data, theme='cerulean', highlight='emacs', static=lambda path: '/static/rest_framework/docs/' + path)
+        template = loader.get_template(self.template)
+        context = self.get_context(data)
+        return template_render(template, context, request=renderer_context['request'])
 
 
 class MultiPartRenderer(BaseRenderer):

rest_framework/schemas.py

@@ -514,8 +514,8 @@ class SchemaGenerator(object):
                 name=variable,
                 location='path',
                 required=True,
-                title='' if (title is None) else title,
+                #title='' if (title is None) else title,
-                description='' if (description is None) else description
+                #description='' if (description is None) else description
             )
             fields.append(field)
 
@@ -540,7 +540,7 @@ class SchemaGenerator(object):
                     name='data',
                     location='body',
                     required=True,
-                    type='array'
+                    #type='array'
                 )
             ]
 
@@ -559,11 +559,11 @@ class SchemaGenerator(object):
                 name=field.field_name,
                 location='form',
                 required=required,
-                title=title,
+                #title=title,
-                description=description,
+                #description=description,
-                type=types_lookup[field],
+                #type=types_lookup[field],
-                input=determine_input(field),
+                #input=determine_input(field),
-                choices=getattr(field, 'choices', None)
+                #choices=getattr(field, 'choices', None)
             )
             fields.append(field)
 

rest_framework/templates/rest_framework/docs/document.html

@@ -0,0 +1,19 @@
+{% load rest_framework %}
+<div class="row">
+    <div class="col-md-6">
+        <h1 id="document-title">{{ document.title }}</h1>
+        <p>{% render_markdown document.description %}</p>
+    </div>
+    <div class="col-md-6"></div>
+</div>
+
+{% for section_key, section in document.data.items %}
+    <h1 id="{{ section_key }}" class="coredocs-section">{{ section_key }}</h1>
+    {% for link_key, link in section.links.items %}
+        {% include "rest_framework/docs/link.html" %}
+    {% endfor %}
+{% endfor %}
+
+{% for link_key, link in document.links.items %}
+    {% include "rest_framework/docs/llink.html" %}
+{% endfor %}

rest_framework/templates/rest_framework/docs/index.html

@@ -0,0 +1,143 @@
+{% load staticfiles %}
+<!DOCTYPE html>
+<html lang="en">
+    <head>
+        <meta charset="utf-8">
+        <meta http-equiv="X-UA-Compatible" content="IE=edge">
+        <meta name="viewport" content="width=device-width, initial-scale=1.0">
+
+	    <title>{{ document.title }}</title>
+
+        <link href="{% static 'rest_framework/docs/css/bootstrap-custom.min.css' %}" rel="stylesheet">
+        <link href="{% static 'rest_framework/docs/css/font-awesome-4.0.3.css' %}" rel="stylesheet">
+        <link href="{% static 'rest_framework/docs/css/base.css' %}" rel="stylesheet">
+        <style>{{ code_style }}</style>
+        <style>
+        .highlight {background-color: #f7f7f9}
+        .coredocs-link {border-top: 1px solid lightgrey; margin-top: 20px}
+        .coredocs-section {border-top: 2px solid lightgrey; margin-top: 20px; padding-top: 20px}
+        .checkbox label.control-label {font-weight: bold}
+        @media (min-width: 768px) {
+            .navbar-nav.navbar-right:last-child {
+                margin-right: 0 !important;
+            }
+        }
+        </style>
+        <script src="https://unpkg.com/coreapi@0.0.17/dist/coreapi.js"></script>
+    </head>
+
+    <body>
+
+        {% include "rest_framework/docs/nav.html" %}
+
+        <div class="container-fluid">
+                <div class="col-md-2">{% include "rest_framework/docs/toc.html" %}</div>
+                <div class="col-md-10" role="main">{% include "rest_framework/docs/document.html" %}</div>
+        </div>
+
+        <script src="{% static 'rest_framework/docs/js/jquery-1.10.2.min.js' %}"></script>
+        <script src="{% static 'rest_framework/docs/js/bootstrap-3.0.3.min.js' %}"></script>
+        <script>
+            function getCookie(name) {
+                var cookieValue = null;
+                if (document.cookie && document.cookie !== '') {
+                    var cookies = document.cookie.split(';');
+                    for (var i = 0; i < cookies.length; i++) {
+                        var cookie = jQuery.trim(cookies[i]);
+                        // Does this cookie string begin with the name we want?
+                        if (cookie.substring(0, name.length + 1) === (name + '=')) {
+                            cookieValue = decodeURIComponent(cookie.substring(name.length + 1));
+                            break;
+                        }
+                    }
+                }
+                return cookieValue;
+            }
+            const csrf = {'X-CSRFToken': getCookie('csrftoken')}
+
+            const coreapi = window.coreapi
+            const codec = new coreapi.codecs.CoreJSONCodec()
+            const schema = {{ schema }}
+            const doc = codec.decode(schema, {preloaded: true})
+            const client = new coreapi.Client(null, null, csrf)
+
+            $('body').scrollspy({ target: '#toc' })
+
+            // Language Control
+            $('.language-control li a').click(function (event) {
+                event.preventDefault();
+                var button = $(this)
+                var language = button.data("language")
+
+                var languageControls = $('.language-control li a')
+                languageControls.not('[data-language="' + language +'"]').parent().removeClass("active")
+                languageControls.filter('[data-language="' + language +'"]').parent().addClass("active")
+
+                button.closest("li.dropdown").find('.dropdown-toggle span').text(language)
+
+                var codeBlocks = $('pre.highlight')
+                codeBlocks.not('[data-language="' + language +'"]').addClass("hide")
+                codeBlocks.filter('[data-language="' + language +'"]').removeClass("hide")
+            })
+
+            // API Explorer
+
+            $('form').submit(function(event) {
+                event.preventDefault();
+
+                const form = $(this).closest("form");
+                const key = form.data("key");
+                var params = {};
+
+                const formData = new FormData(form.get()[0]);
+                for (var [paramKey, paramValue] of formData.entries()) {
+                    var elem = form.find("[name=" + paramKey + "]")
+                    var dataType = elem.data('type') || 'string'
+                    var dataLocation = elem.data('location')
+
+                    if (dataType === 'integer' && paramValue) {
+                        paramValue = parseInt(paramValue)
+                    } else if (dataType === 'number' && paramValue) {
+                        paramValue = parseFloat(paramValue)
+                    } else if (dataType === 'boolean' && paramValue) {
+                        paramValue = {
+                            'true': true,
+                            'false': false
+                        }[paramValue.toLowerCase()]
+                    } else if (dataType === 'array' && paramValue) {
+                        paramValue = JSON.parse(paramValue)
+                    }
+
+                    if (dataLocation === 'query' && !paramValue) {
+                        continue
+                    }
+                    params[paramKey] = paramValue
+                }
+
+                form.find(":checkbox").each(function( index ) {
+                    var name = $(this).attr("name");
+                    if (!params.hasOwnProperty(name)) {
+                        params[name] = false
+                    }
+                })
+
+                console.log(params)
+
+                client.action(doc, key, params).then(function (data) {
+                    var response = JSON.stringify(data, null, 2);
+                    form.find(".response-data").text(response)
+                    form.find(".response-data").removeClass("hide")
+                    form.find(".response-error").addClass("hide")
+                }).catch(function (error) {
+                    var response = JSON.stringify(error.content, null, 2);
+                    form.find(".response-error").text(error.message)
+                    form.find(".response-data").text(response)
+                    form.find(".response-error").removeClass("hide")
+                    form.find(".response-data").removeClass("hide")
+
+                    /*form.find(".response-data").addClass("hide")*/
+                })
+            });
+        </script>
+    </body>
+</html>

rest_framework/templates/rest_framework/docs/langs/javascript.html

@@ -0,0 +1,18 @@
+{% load rest_framework %}
+<pre class="highlight javascript hide" data-language="javascript"><code>{% code javascript %}var coreapi = window.coreapi
+
+// Initialize a client & load the schema document
+var client = new coreapi.Client()
+var document = null
+client.get("{{ document.url }}").then(function(result) {
+    document = result
+})
+
+// Interact with the API endpoint
+var action = [{% if section_key %}"{{ section_key }}", {% endif %}"{{ link_key }}"]
+{% if link.fields %}var params = {
+{% for field in link.fields %}    {{ field.name }}: ...{% if not loop.last %},{% endif %}
+{% endfor %}}
+{% endif %}client.action(document, action, params=params).then(function(result) {
+    // Return value is in 'result'
+}){% endcode %}</code></pre>

rest_framework/templates/rest_framework/docs/langs/python.html

@@ -0,0 +1,13 @@
+{% load rest_framework %}
+<pre class="highlight python hide" data-language="python"><code>{% code python %}import coreapi
+
+# Initialize a client & load the schema document
+client = coreapi.Client()
+document = client.get("{{ document.url }}"{% if schema_format %}, format="{{ schema_format }}"{% endif %})
+
+# Interact with the API endpoint
+action = [{% if section_key %}"{{ section_key }}", {% endif %}"{{ link_key }}"]
+{% if link.fields %}params = {
+{% for field in link.fields %}    "{{ field.name }}": ...{% if not loop.last %},{% endif %}
+{% endfor %}}
+{% endif %}result = client.action(document, action{% if link.fields %}, params=params{% endif %}){% endcode %}</code></pre>

rest_framework/templates/rest_framework/docs/langs/shell.html

@@ -0,0 +1,6 @@
+{% load rest_framework %}
+<pre class="highlight shell" data-language="shell"><code>{% code bash %}# Load the schema document
+$ coreapi get {{ document.url }}{% if schema_format %} --format {{ schema_format }}{% endif %}
+
+# Interact with the API endpoint
+$ coreapi action {% if section_key %}{{ section_key }} {% endif %}{{ link_key }}{% for field in link.fields %} -p {{ field.name }}=...{% endfor %}{% endcode %}</code></pre>

rest_framework/templates/rest_framework/docs/link.html

@@ -0,0 +1,119 @@
+{% load rest_framework %}
+<div class="row coredocs-link">
+
+<div class="col-md-6 docs-content">
+<button class="btn btn-success" style="float: right; margin-top: 20px" data-toggle="modal" data-target="#{{ section_key }}_{{ link_key }}_modal">Interact</button>
+
+<h2 id="{{ section_key }}-{{ link_key }}">{{ link.title|default:link_key }}</h2>
+    <p>
+        <span class="label label-primary">{{ link.action|upper }}</span> <code>{{ link.url }}</code>
+    </p>
+
+    <p>{% render_markdown link.description %}</p>
+
+{% if link.fields|with_location:'path' %}
+    <h4>Path Parameters</h4>
+    <p>The following parameters should be included in the URL path.</p>
+    <table class="parameters table table-bordered table-striped">
+        <thead>
+            <tr><th>Parameter</th><th>Description</th></tr>
+        </thead>
+        <tbody>
+            {% for field in link.fields|with_location:'path' %}
+            <tr><td class="parameter-name"><code>{{ field.name }}</code>{% if field.required %} <span class="label label-warning">required</span>{% endif %}</td><td>{% if field.description %}{{ field.description }}{% endif %}</td></tr>
+            {% endfor %}
+        </tbody>
+    </table>
+{% endif %}
+{% if link.fields|with_location:'query' %}
+    <h4>Query Parameters</h4>
+    <p>The following parameters should be included as part of a URL query string.</p>
+    <table class="parameters table table-bordered table-striped">
+        <thead>
+            <tr><th>Parameter</th><th>Description</th></tr>
+        </thead>
+        <tbody>
+            {% for field in link.fields|with_location:'query' %}
+            <tr><td class="parameter-name"><code>{{ field.name }}</code>{% if field.required %} <span class="label label-warning">required</span>{% endif %}</td><td>{% if field.description %}{{ field.description }}{% endif %}</td></tr>
+            {% endfor %}
+        </tbody>
+    </table>
+{% endif %}
+{% if link.fields|with_location:'header' %}
+    <h4>Header Parameters</h4>
+    <p>The following parameters should be included as HTTP headers.</p>
+    <table class="parameters table table-bordered table-striped">
+        <thead>
+            <tr><th>Parameter</th><th>Description</th></tr>
+        </thead>
+        <tbody>
+            {% for field in link.fields|with_location:'header' %}
+            <tr><td class="parameter-name"><code>{{ field.name }}</code>{% if field.required %} <span class="label label-warning">required</span>{% endif %}</td><td>{% if field.description %}{{ field.description }}{% endif %}</td></tr>
+            {% endfor %}
+        </tbody>
+    </table>
+{% endif %}
+{% if link.fields|with_location:'body' %}
+    <h4>Request Body</h4>
+    <p>The request body should be <code>"{{ link.encoding }}"</code> encoded, and should contain a single item.</p>
+    <table class="parameters table table-bordered table-striped">
+        <thead>
+            <tr><th>Parameter</th><th>Description</th></tr>
+        </thead>
+        <tbody>
+            {% for field in link.fields|with_location:'body' %}
+            <tr><td class="parameter-name"><code>{{ field.name }}</code>{% if field.required %} <span class="label label-warning">required</span>{% endif %}</td><td>{% if field.description %}{{ field.description }}{% endif %}</td></tr>
+            {% endfor %}
+        </tbody>
+    </table>
+{% elif link.fields|with_location:'form' %}
+    <h4>Request Body</h4>
+    <p>The request body should be a <code>"{{ link.encoding }}"</code> encoded object, containing the following&nbsp;items.</p>
+    <table class="parameters table table-bordered table-striped">
+        <thead>
+            <tr><th>Parameter</th><th>Description</th></tr>
+        </thead>
+        <tbody>
+            {% for field in link.fields|with_location:'form' %}
+            <tr><td class="parameter-name"><code>{{ field.name }}</code>{% if field.required %} <span class="label label-warning">required</span>{% endif %}</td><td>{% if field.description %}{{ field.description }}{% endif %}</td></tr>
+            {% endfor %}
+        </tbody>
+    </table>
+{% endif %}
+
+</div>
+
+    <div class="col-md-6 code-samples">
+        {% if 'shell' in langs %}{% include "rest_framework/docs/langs/shell.html" %}{% endif %}
+        {% if 'python' in langs %}{% include "rest_framework/docs/langs/python.html" %}{% endif %}
+        {% if 'javascript' in langs %}{% include "rest_framework/docs/langs/javascript.html" %}{% endif %}
+    </div>
+</div>
+
+<!-- Modal -->
+<div class="modal fade api-modal" id="{{ section_key }}_{{ link_key }}_modal" tabindex="-1" role="dialog" aria-labelledby="api explorer modal">
+<div class="modal-dialog modal-lg" role="document">
+  <div class="modal-content">
+    <div class="modal-header">
+      <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>
+      <h4 class="modal-title">{{ link.title|default:link_key }}</h4>
+    </div>
+
+    <div class="modal-body">
+        <form data-key='["{{ section_key }}", "{{ link_key }}"]'>
+            {% form_for_link link %}
+
+            <div id="response">
+                <div class="response-error alert alert-danger hide"></div>
+                <pre class="response-data hide"></pre>
+            </div>
+
+            <div class="text-right">
+                <button type="submit" class="btn btn-primary">Submit</button>
+            </div>
+        </form>
+    </div>
+
+  </div>
+</div>
+</div>

rest_framework/templates/rest_framework/docs/nav.html

@@ -0,0 +1,34 @@
+<div class="navbar navbar-default navbar-fixed-top" role="navigation">
+    <div class="container-fluid">
+
+        <!-- Collapsed navigation -->
+        <div class="navbar-header">
+            <!-- Expander button -->
+            <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse">
+                <span class="sr-only">Toggle navigation</span>
+                <span class="icon-bar"></span>
+                <span class="icon-bar"></span>
+                <span class="icon-bar"></span>
+            </button>
+
+            <!-- Main title -->
+            <a class="navbar-brand" href="{{ homepage_url }}">{{ document.title }}</a>
+        </div>
+
+
+        <div class="navbar-collapse">
+            <ul class="nav navbar-nav navbar-right">
+                <li class="dropdown">
+                    <a href="#" class="dropdown-toggle" data-toggle="dropdown"><span>shell</span> <b class="caret"></b></a>
+                    <ul class="dropdown-menu language-control">
+                        <li class="active"><a href="#" data-language="shell">shell</a></li>
+                        <li><a href="#" data-language="javascript">javascript</a></li>
+                        <li><a href="#" data-language="python">python</a></li>
+                    </ul>
+                </li>
+            </ul>
+        </div>
+
+    </div>
+</div>
+

rest_framework/templates/rest_framework/docs/toc.html

@@ -0,0 +1,17 @@
+<div id="toc" class="bs-sidebar hidden-print affix" role="complementary">
+    <ul class="nav bs-sidenav">
+        <li class="active">
+            <a href="#document-title">{{ document.title }}</a>
+        </li>
+        {% for section_key, section in document.data.items %}
+        <li>
+            <a href="#{{ section_key }}">{{ section_key }}</a>
+            <ul class="nav">
+                {% for link_key, link in section.links.items %}
+                <li><a href="#{{ section_key }}-{{ link_key }}">{{ link.title|default:link_key }}</a></li>
+                {% endfor %}
+            </ul>
+        </li>
+        {% endfor %}
+    </ul>
+</div>

rest_framework/templatetags/rest_framework.py

@@ -13,12 +13,89 @@ from rest_framework.compat import NoReverseMatch, reverse, template_render
 from rest_framework.renderers import HTMLFormRenderer
 from rest_framework.utils.urls import replace_query_param
 
+from markdown.extensions.fenced_code import FencedBlockPreprocessor
+import markdown
+
+
 register = template.Library()
 
 # Regex for adding classes to html snippets
 class_re = re.compile(r'(?<=class=["\'])(.*)(?=["\'])')
 
 
+class CustomFencedBlockPreprocessor(FencedBlockPreprocessor):
+    CODE_WRAP = '<pre%s><code>%s</code></pre>'
+    LANG_TAG = ' class="highlight %s"'
+
+
+class FencedCodeExtension(markdown.Extension):
+
+    def extendMarkdown(self, md, md_globals):
+        """ Add FencedBlockPreprocessor to the Markdown instance. """
+        md.registerExtension(self)
+
+        md.preprocessors.add('fenced_code_block',
+                             CustomFencedBlockPreprocessor(md),
+                             ">normalize_whitespace")
+
+
+from pygments import highlight
+from pygments.lexers import get_lexer_by_name
+from pygments.formatters import HtmlFormatter
+
+
+@register.tag(name='code')
+def do_code(parser,token):
+    code = token.split_contents()[-1]
+    nodelist = parser.parse(('endcode',))
+    parser.delete_first_token()
+    return CodeNode(code, nodelist)
+
+
+class CodeNode(template.Node):
+    style = 'emacs'
+
+    def __init__(self, lang, code):
+        self.lang = lang
+        self.nodelist = code
+
+    def render(self, context):
+        body = self.nodelist.render(context)
+        lexer = get_lexer_by_name(self.lang, stripall=False)
+        formatter = HtmlFormatter(nowrap=True, style=self.style)
+        code = highlight(body, lexer, formatter)
+        return code
+
+
+@register.filter()
+def with_location(fields, location):
+    return [
+        field for field in fields
+        if field.location == location
+    ]
+
+
+@register.simple_tag
+def form_for_link(link):
+    import coreschema
+    properties = {
+        field.name: field.schema or coreschema.String()
+        for field in link.fields
+    }
+    required = [
+        field.name
+        for field in link.fields
+        if field.required
+    ]
+    schema = coreschema.Object(properties=properties, required=required)
+    return coreschema.render_to_form(schema)
+
+
+@register.simple_tag
+def render_markdown(markdown_text):
+    return markdown.markdown(markdown_text, extensions=[FencedCodeExtension(), "tables"])
+
+
 @register.simple_tag
 def get_pagination_html(pager):
     return pager.to_html()