metadata.json support for per-table/per-database metadata

Also added support for descriptions and HTML descriptions.

Here's an example metadata.json file illustrating custom per-database and per-
table metadata:

    {
        "title": "Overall datasette title",
        "description_html": "This is a <em>description with HTML</em>.",
        "databases": {
            "db1": {
                "title": "First database",
                "description": "This is a string description & has no HTML",
                "license_url": "http://example.com/",
        		"license": "The example license",
                "queries": {
                	"canned_query": "select * from table1 limit 3;"
                },
                "tables": {
                    "table1": {
                        "title": "Custom title for table1",
                        "description": "Tables can have descriptions too",
                        "source": "This has a custom source",
                        "source_url": "http://example.com/"
                    }
                }
            }
        }
    }

Closes #165, Refs #164

datasette/app.py

@@ -242,12 +242,13 @@ class BaseView(RenderMixin):
                 **{
                     'url_json': path_with_ext(request, '.json'),
                     'url_jsono': path_with_ext(request, '.jsono'),
-                    'metadata': self.ds.metadata,
                     'extra_css_urls': self.ds.extra_css_urls(),
                     'extra_js_urls': self.ds.extra_js_urls(),
                     'datasette_version': __version__,
                 }
             }
+            if 'metadata' not in context:
+                context['metadata'] = self.ds.metadata
             r = self.render(
                 templates,
                 **context,
@@ -379,6 +380,9 @@ class DatabaseView(BaseView):
             'database_hash': hash,
             'show_hidden': request.args.get('_show_hidden'),
             'editable': True,
+            'metadata': self.ds.metadata.get(
+                'databases', {}
+            ).get(name, {}),
         }, ('database-{}.html'.format(to_css_class(name)), 'database.html')
 
 
@@ -686,7 +690,10 @@ class TableView(RowTableShared):
                     '_rows_and_columns-{}-{}.html'.format(to_css_class(name), to_css_class(table)),
                     '_rows_and_columns-table-{}-{}.html'.format(to_css_class(name), to_css_class(table)),
                     '_rows_and_columns.html',
-                ]
+                ],
+                'metadata': self.ds.metadata.get(
+                    'databases', {}
+                ).get(name, {}).get('tables', {}).get(table, {}),
             }
 
         return {
@@ -750,7 +757,10 @@ class RowView(RowTableShared):
                     '_rows_and_columns-{}-{}.html'.format(to_css_class(name), to_css_class(table)),
                     '_rows_and_columns-row-{}-{}.html'.format(to_css_class(name), to_css_class(table)),
                     '_rows_and_columns.html',
-                ]
+                ],
+                'metadata': self.ds.metadata.get(
+                    'databases', {}
+                ).get(name, {}).get('tables', {}).get(table, {}),
             }
 
         data = {

datasette/templates/_description_source_license.html

@@ -0,0 +1,25 @@
+{% if metadata.description_html or metadata.description %}
+    <div class="metadata-description">
+        {% if metadata.description_html %}
+            {{ metadata.description_html|safe }}
+        {% else %}
+            {{ metadata.description }}
+        {% endif %}
+    </div>
+{% endif %}
+{% if metadata.license or metadata.license_url or metadata.source or metadata.source_url %}
+    <p>
+    {% if metadata.license or metadata.license_url %}Data license:
+        {% if metadata.license_url %}
+            <a href="{{ metadata.license_url }}">{{ metadata.license or metadata.license_url }}</a>
+        {% else %}
+            {{ metadata.license }}
+        {% endif %}
+    {% endif %}
+    {% if metadata.source or metadata.source_url %}{% if metadata.license or metadata.license_url %}&middot;{% endif %}
+        Data source: {% if metadata.source_url %}
+            <a href="{{ metadata.source_url }}">
+        {% endif %}{{ metadata.source or metadata.source_url }}{% if metadata.source_url %}</a>{% endif %}
+    {% endif %}
+    </p>
+{% endif %}

datasette/templates/base.html

@@ -20,19 +20,17 @@
 <div class="ft">
     Powered by <a href="https://github.com/simonw/datasette" title="Datasette v{{ datasette_version }}">Datasette</a>
     {% if query_ms %}&middot; Query took {{ query_ms|round(3) }}ms{% endif %}
-    {% if metadata.license %}&middot; Data license:
+    {% if metadata.license or metadata.license_url %}&middot; Data license:
         {% if metadata.license_url %}
-            <a href="{{ metadata.license_url }}">{{ metadata.license }}</a>
+            <a href="{{ metadata.license_url }}">{{ metadata.license or metadata.license_url }}</a>
         {% else %}
             {{ metadata.license }}
         {% endif %}
     {% endif %}
-    {% if metadata.source_url %}&middot;
+    {% if metadata.source or metadata.source_url %}&middot;
-        {% if metadata.source %}
+        Data source: {% if metadata.source_url %}
-            Data source: <a href="{{ metadata.source_url }}">{{ metadata.source }}</a>
+            <a href="{{ metadata.source_url }}">
-        {% else %}
+        {% endif %}{{ metadata.source or metadata.source_url }}{% if metadata.source_url %}</a>{% endif %}
-            <a href="{{ metadata.source_url }}">Data source</a>
-        {% endif %}
     {% endif %}
 </div>
 

datasette/templates/database.html

@@ -12,7 +12,9 @@
 {% block content %}
 <div class="hd"><a href="/">home</a></div>
 
-<h1 style="padding-left: 10px; border-left: 10px solid #{{ database_hash[:6] }}">{{ database }}</h1>
+<h1 style="padding-left: 10px; border-left: 10px solid #{{ database_hash[:6] }}">{{ metadata.title or database }}</h1>
+
+{% block description_source_license %}{% include "_description_source_license.html" %}{% endblock %}
 
 <form class="sql" action="/{{ database }}-{{ database_hash }}" method="get">
     <h3>Custom SQL query</h3>

datasette/templates/index.html

@@ -6,24 +6,8 @@
 
 {% block content %}
 <h1>{{ metadata.title or "Datasette" }}</h1>
-{% if metadata.license or metadata.source_url %}
+
-    <p>
+{% block description_source_license %}{% include "_description_source_license.html" %}{% endblock %}
-    {% if metadata.license %}Data license:
-        {% if metadata.license_url %}
-            <a href="{{ metadata.license_url }}">{{ metadata.license }}</a>
-        {% else %}
-            {{ metadata.license }}
-        {% endif %}
-    {% endif %}
-    {% if metadata.source_url %}{% if metadata.license %}&middot;{% endif %}
-        {% if metadata.source %}
-            Data source: <a href="{{ metadata.source_url }}">{{ metadata.source }}</a>
-        {% else %}
-            <a href="{{ metadata.source_url }}">Data source</a>
-        {% endif %}
-    {% endif %}
-    </p>
-{% endif %}
 
 {% for database in databases %}
     <h2 style="padding-left: 10px; border-left: 10px solid #{{ database.hash[:6] }}"><a href="{{ database.path }}">{{ database.name }}</a></h2>

datasette/templates/row.html

@@ -20,6 +20,8 @@
 
 <h1 style="padding-left: 10px; border-left: 10px solid #{{ database_hash[:6] }}">{{ table }}: {{ ', '.join(primary_key_values) }}</a></h1>
 
+{% block description_source_license %}{% include "_description_source_license.html" %}{% endblock %}
+
 <p>This data as <a href="{{ url_json }}">.json</a>, <a href="{{ url_jsono }}">.jsono</a></p>
 
 {% include custom_rows_and_columns_templates %}

datasette/templates/table.html

@@ -19,7 +19,9 @@
 {% block content %}
 <div class="hd"><a href="/">home</a> / <a href="/{{ database }}-{{ database_hash }}">{{ database }}</a></div>
 
-<h1 style="padding-left: 10px; border-left: 10px solid #{{ database_hash[:6] }}">{{ table }}{% if is_view %} (view){% endif %}</h1>
+<h1 style="padding-left: 10px; border-left: 10px solid #{{ database_hash[:6] }}">{{ metadata.title or table }}{% if is_view %} (view){% endif %}</h1>
+
+{% block description_source_license %}{% include "_description_source_license.html" %}{% endblock %}
 
 {% if filtered_table_rows or human_filter_description %}
     <h3>{% if filtered_table_rows or filtered_table_rows == 0 %}{{ "{:,}".format(filtered_table_rows) }} row{% if filtered_table_rows == 1 %}{% else %}s{% endif %}{% endif %}