Add support for media types

For some endpoints GitHub lets you request different response format
using the `Accept` header [[1]]. However, by default if the response is
not in JSON format `GhApi.__call__` will raise an error.

This commit makes it possible by adding a bit of logic to look at the
`Accept` header in the request and tell `fastcore.core.urlsend` not to
return JSON if it doesn't look like the user is requesting a JSON media
type.

[1]: https://docs.github.com/en/rest/overview/media-types

Author: lfdebrux

00_core.ipynb

@@ -202,15 +202,16 @@
     "        if path[:7] not in ('http://','https:/'): path = GH_HOST+path\n",
     "        if route:\n",
     "            for k,v in route.items(): route[k] = quote(str(route[k]))\n",
+    "        return_json = ('json' in headers['Accept'])\n",
     "        res,self.recv_hdrs = urlsend(path, verb, headers=headers or None, debug=self.debug, return_headers=True,\n",
-    "                                     route=route or None, query=query or None, data=data or None)\n",
+    "                                     route=route or None, query=query or None, data=data or None, return_json=return_json)\n",
     "        if 'X-RateLimit-Remaining' in self.recv_hdrs:\n",
     "            newlim = self.recv_hdrs['X-RateLimit-Remaining']\n",
     "            if self.limit_cb is not None and newlim != self.limit_rem:\n",
     "                self.limit_cb(int(newlim),int(self.recv_hdrs['X-RateLimit-Limit']))\n",
     "            self.limit_rem = newlim\n",
     "            \n",
-    "        return dict2obj(res)\n",
+    "        return dict2obj(res) if return_json else res\n",
     "\n",
     "    def __dir__(self): return super().__dir__() + list(self.groups)\n",
     "    def _repr_markdown_(self): return \"\\n\".join(f\"- [{o}]({_docroot + o.replace('_', '-')})\" for o in sorted(self.groups))\n",
@@ -296,18 +297,18 @@
        "- node_id: MDM6UmVmMzE1NzEyNTg4OnJlZnMvaGVhZHMvbWFzdGVy\n",
        "- url: https://api.github.com/repos/fastai/ghapi-test/git/refs/heads/master\n",
        "- object: \n",
-       "  - sha: 164355601ff88f0482d90f2e1bc7b7546a9bacef\n",
+       "  - sha: d0605f3abc070f4790501db038c24223379007a5\n",
        "  - type: commit\n",
-       "  - url: https://api.github.com/repos/fastai/ghapi-test/git/commits/164355601ff88f0482d90f2e1bc7b7546a9bacef"
+       "  - url: https://api.github.com/repos/fastai/ghapi-test/git/commits/d0605f3abc070f4790501db038c24223379007a5"
       ],
       "text/plain": [
        "- ref: refs/heads/master\n",
        "- node_id: MDM6UmVmMzE1NzEyNTg4OnJlZnMvaGVhZHMvbWFzdGVy\n",
        "- url: https://api.github.com/repos/fastai/ghapi-test/git/refs/heads/master\n",
        "- object: \n",
-       "  - sha: 164355601ff88f0482d90f2e1bc7b7546a9bacef\n",
+       "  - sha: d0605f3abc070f4790501db038c24223379007a5\n",
        "  - type: commit\n",
-       "  - url: https://api.github.com/repos/fastai/ghapi-test/git/commits/164355601ff88f0482d90f2e1bc7b7546a9bacef"
+       "  - url: https://api.github.com/repos/fastai/ghapi-test/git/commits/d0605f3abc070f4790501db038c24223379007a5"
       ]
      },
      "execution_count": null,
@@ -365,18 +366,18 @@
        "- node_id: MDM6UmVmMzE1NzEyNTg4OnJlZnMvaGVhZHMvbWFzdGVy\n",
        "- url: https://api.github.com/repos/fastai/ghapi-test/git/refs/heads/master\n",
        "- object: \n",
-       "  - sha: 164355601ff88f0482d90f2e1bc7b7546a9bacef\n",
+       "  - sha: d0605f3abc070f4790501db038c24223379007a5\n",
        "  - type: commit\n",
-       "  - url: https://api.github.com/repos/fastai/ghapi-test/git/commits/164355601ff88f0482d90f2e1bc7b7546a9bacef"
+       "  - url: https://api.github.com/repos/fastai/ghapi-test/git/commits/d0605f3abc070f4790501db038c24223379007a5"
       ],
       "text/plain": [
        "- ref: refs/heads/master\n",
        "- node_id: MDM6UmVmMzE1NzEyNTg4OnJlZnMvaGVhZHMvbWFzdGVy\n",
        "- url: https://api.github.com/repos/fastai/ghapi-test/git/refs/heads/master\n",
        "- object: \n",
-       "  - sha: 164355601ff88f0482d90f2e1bc7b7546a9bacef\n",
+       "  - sha: d0605f3abc070f4790501db038c24223379007a5\n",
        "  - type: commit\n",
-       "  - url: https://api.github.com/repos/fastai/ghapi-test/git/commits/164355601ff88f0482d90f2e1bc7b7546a9bacef"
+       "  - url: https://api.github.com/repos/fastai/ghapi-test/git/commits/d0605f3abc070f4790501db038c24223379007a5"
       ]
      },
      "execution_count": null,
@@ -388,6 +389,42 @@
     "api['/repos/{owner}/{repo}/git/ref/{ref}'](owner='fastai', repo='ghapi-test', ref='heads/master')"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Media types"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "For some endpoints GitHub lets you specify a [media type](https://docs.github.com/en/rest/overview/media-types) the for response data, using the `Accept` header. If you choose a media type that is not JSON formatted (for instance `application/vnd.github.v3.sha`) then the call to the `GhApi` object will return a string instead of an object."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "'d0605f3abc070f4790501db038c24223379007a5'"
+      ]
+     },
+     "execution_count": null,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "api('/repos/{owner}/{repo}/commits/{ref}', 'GET', route=dict(\n",
+    "    owner='fastai', repo='ghapi-test', ref='refs/heads/master'),\n",
+    "    headers={'Accept': 'application/vnd.github.VERSION.sha'})"
+   ]
+  },
   {
    "cell_type": "markdown",
    "metadata": {},