Google Blogger API error 400

Question

I'm trying to access Blogger via the JavaScript V3 API. Everything works as expected if I try to access my (public) test blog.

If I use the same code but try to access my (private) test blog I get an error.

The following is my code

        var client_id = ['WWWW', 'XXXX'];
        var api_key = ['YYYY','ZZZZ'];
        var discoveryDocs = ['https://www.googleapis.com/discovery/v1/apis/blogger/v3/rest'];
        var scope = 'https://www.googleapis.com/auth/blogger.readonly';
        var blog_id = ['BLOG0', 'BLOG1'];

        var appendResults = function(results) {
          $('#results').append(JSON.stringify(results, undefined, 2) + '<hr/>');
        };

        getBlogs = function(client, key, blog) {
            gapi.client.init({
                'apiKey': key,
                'clientId': client,
                'discoveryDocs': discoveryDocs,
                'scope': scope
            }).then(function() {
                return gapi.client.blogger.posts.list({
                    'blogId': blog
                });
            }).then(function(d) {
                return d;
            }).then(function(response) {
                appendResults(response);
            }, function(reason) {
                appendResults(reason);
            });
        };

        gapi.load('client', function() {
            for(i=0; i<api_key.length; i++) {
                getBlogs(client_id[i], api_key[i], blog_id[i]);
            }
        });

Where the second element in api_key and blog_id is my private blog.

The following is my response

{
  "result": {
    "kind": "blogger#postList",
    "items": [
      {
        "kind": "blogger#post",
        "id": "XXXX",
        "blog": {
          "id": "XXXX"
        },
        "published": "XXXX",
        "updated": "XXXX",
        "etag": "\"XXXX\"",
        "url": "http://XXXX/2017/03/blog-post.html",
        "selfLink": "https://www.googleapis.com/blogger/v3/blogs/XXXX/posts/XXXX",
        "title": "",
        "content": "XXXX",
        "author": {
          "id": "XXXX",
          "displayName": "XXXX",
          "url": "https://www.blogger.com/profile/XXXX",
          "image": {
            "url": "XXXX"
          }
        },
        "replies": {
          "totalItems": "0",
          "selfLink": "XXXX"
        }
      }
    ],
    "etag": "\"XXXX\""
  },
  "body": "{\n \"kind\": \"blogger#postList\",\n \"items\": [\n  {\n   \"kind\": \"blogger#post\",\n   \"id\": \"XXXX\",\n   \"blog\": {\n    \"id\": \"639440130428294175\"\n   },\n   \"published\": \"XXXX\",\n   \"updated\": \"XXXX\",\n   \"etag\": \"\\\"XXXX\\\"\",\n   \"url\": \"http://XXXX/2017/03/blog-post.html\",\n   \"selfLink\": \"https://www.googleapis.com/blogger/v3/blogs/XXXX/posts/XXXX\",\n   \"title\": \"\",\n   \"content\": \"XXXX\",\n   \"author\": {\n    \"id\": \"XXXX\",\n    \"displayName\": \"XXXX\",\n    \"url\": \"https://www.blogger.com/profile/XXXX\",\n    \"image\": {\n     \"url\": \"XXXX\"\n    }\n   },\n   \"replies\": {\n    \"totalItems\": \"0\",\n    \"selfLink\": \"https://www.googleapis.com/blogger/v3/blogs/XXXX/posts/XXXX/comments\"\n   }\n  }\n ],\n \"etag\": \"\\\"XXXX\\\"\"\n}\n",
  "headers": {
    "date": "XXXX",
    "content-encoding": "gzip",
    "vary": "Origin, X-Origin",
    "content-length": "576",
    "pragma": "no-cache",
    "server": "GSE",
    "etag": "\"XXXX\"",
    "content-type": "application/json; charset=UTF-8",
    "cache-control": "no-cache, no-store, max-age=0, must-revalidate",
    "expires": "XXXX"
  },
  "status": 200,
  "statusText": null
}

and

{
  "result": {
    "error": {
      "errors": [
        {
          "domain": "global",
          "reason": "invalid",
          "message": "We're sorry, but the requested resource could not be found."
        }
      ],
      "code": 400,
      "message": "We're sorry, but the requested resource could not be found."
    }
  },
  "body": "{\n \"error\": {\n  \"errors\": [\n   {\n    \"domain\": \"global\",\n    \"reason\": \"invalid\",\n    \"message\": \"We're sorry, but the requested resource could not be found.\"\n   }\n  ],\n  \"code\": 400,\n  \"message\": \"We're sorry, but the requested resource could not be found.\"\n }\n}\n",
  "headers": {
    "date": "XXXX",
    "content-encoding": "gzip",
    "vary": "Origin, X-Origin",
    "content-length": "160",
    "server": "GSE",
    "content-type": "application/json; charset=UTF-8",
    "cache-control": "private, max-age=0",
    "expires": "XXXX"
  },
  "status": 400,
  "statusText": null
}

I've setup credentials in the developer console. I'm accessing this via localhost:5000/ which I've setup localhost as a valid domain in the developer console.

The only thing I can think that might be a clue is

"result": {
    "error": {
      "errors": [
        {
          "domain": "global",
          "reason": "invalid",
          "message": "We're sorry, but the requested resource could not be found."
        }
      ],
      "code": 400,
      "message": "We're sorry, but the requested resource could not be found."
    }

This might be telling me that my requesting origin is invalid but I can't say for sure.

If I turn the same (private) blog public and re-execute, then this code works for both blog ID's.

Where am I going wrong?

Answer 1

Blogger API requires that your application has OAuth 2.0 token when accessing information on a private blog (Refer to the documentation here). Only utilizing the API key won't make the request work.

Authorization is required if the posts are on a blog that is private. If the posts are on a blog that is public, then this method can be called without authorization.

Also, the scope is different when using OAuth tokens -

Here's the OAuth 2.0 scope information for the Blogger API:

https://www.googleapis.com/auth/blogger 

To request access using OAuth 2.0, your application needs the scope information, as well as information that Google supplies during application registration (such as the client ID and/or the client secret).

You can test this API via https://developers.google.com/apis-explorer/#search/blogger.posts.list/m/blogger/v3/blogger.posts.list