Blogger JSON API: Getting Started

This document explains how to get started using the Blogger JSON API.

Contents

Introduction

This document is intended for developers who want to write applications that can interact with the Blogger JSON API.

The Blogger JSON API extends version 2.0 of the Blogger Data API. If you want to retrieve data from Blogger in JSON format rather than XML, then use the Blogger JSON API. If you want to retrieve data in XML format, then use the Blogger Data API.

This version of the Blogger JSON API is currently read-only; however, we are planning on adding read/write capabilities, as well as other capabilities. Feel free to request other features on the Blogger Help Forum.

Before you start

Get a Google Account

Make sure that you have a Google Account set up. We recommend that you use a separate Google Account for development and testing purposes to protect yourself from accidental data loss. If you already have a test account, then you're all set; you can visit the Blogger user interface to set up, edit, or view your test data.

Get familiar with Blogger

If you're unfamiliar with Blogger concepts, read this document and experiment with the user interface before starting to code. This document assumes that you're familiar with Blogger, with web programming concepts, and with web data formats.

Learn about authorizing requests and identifying your application

When your application requests private data, the request must be authorized by an authenticated user who has access to that data.

When your application requests public data, the request doesn't need to be authorized, but does need to be accompanied by an identifier, such as an API key.

For information about how to authorize requests and use API keys, see Authorizing requests and identifying your application in the Using the API document.

Blogger JSON API background

Blogger concepts

Blogger is built on five basic concepts:

  • Blogs: The root concept of the API. A blog has posts and pages. This is the container for blog meta-information like Blog Name and Description.
  • Posts: A blog post is the publishable item that the blog author has created. This information is meant to be timely, reflecting what the authors want to publish to the world now. It is understood that as time passes, blog posts content ages and becomes less relevent.
  • Comments: A comment is the place where people other than the blog post author react to what the author has written. Everything from bricks to bouquets.
  • Pages: A page is a place for static content, such as biographical information, or the ways to contact the user. This is generally timeless information that doesn't change very often.
  • Users: A user is someone who interacts with Blogger, be they acting as an Author, an Administrator, or just a Reader. For public blogs, readers may be anonymous, but on private blogs a reader must be identified by Blogger.

Blogger JSON API data model

A resource is an individual data entity with a unique identifier. The Blogger JSON API operates on five types of resources:

  • Blogs Resource: Represents a blog.
  • Posts Resource: Represents a post; each Posts Resource is a child of a Blogs Resource.
  • Comments Resource: Represents a comment on a specific post; each Comments Resource is a child of a Posts Resource.
  • Pages Resource: Represents a static page; each Pages Resource is a child of a Blogs Resource.
  • Users Resource: Represents a non-anonymous user. This is used to identify the Author of a Page, Post, or Comment.
The Blogs Resource has two children resource types, Pages and Posts.
          A Posts Resource may have Comments Resource children.
Overview of the relationships between resources

The Blogger JSON API data model is based on groups of resources, called collections:

Blogs Collection
A Blogs Collection consists of all the Blogs a user has access rights to. You can list Blogs by user, or retrieve a single Blog by ID.
Posts Collection
A Posts Collection consists of all the Posts Resources within a specific Blogs Resource.
Comments Collection
A Comments Collection consists of all the Comments Resources within a specific Posts Resource.
Pages Collection
A Pages Collection consists of all the Pages Resources within a specific Blogs Resource.
Users Collection
A Users Collection consists of all the Users Resources on Blogger, and thus cannot be listed. A user can retrieve their own Users Resource (but nobody else's) by ID, or by using the identifier self.

Blogger JSON API operations

You can invoke two different methods on collections and resources in the Blogger JSON API, as described in the following table.

Operation Description REST HTTP mappings
list Lists all resources within a collection. GET on a collection URI.
get Gets a specific resource. GET on a resource URI.

The table below shows which methods are supported by each resource type. All list and get operations on private blogs require authentication.

Resource Type
Supported Methods
list get
Blogs yes yes
Posts yes yes
Comments yes yes
Pages yes yes
Users no yes

Calling styles

There are several ways to invoke the API:

REST

REST is a style of software architecture that provides a convenient and consistent approach to requesting and modifying data.

The term REST is short for "Representational State Transfer." In the context of Google APIs, it refers to using HTTP verbs to retrieve and modify representations of data stored by Google.

In a RESTful system, resources are stored in a data store; a client sends a request that the server perform a particular action (such as creating, retrieving, updating, or deleting a resource), and the server performs the action and sends a response, often in the form of a representation of the specified resource.

In Google's RESTful APIs, the client specifies an action using an HTTP verb such as POST, GET, PUT, or DELETE. It specifies a resource by a globally-unique URI of the following form:

https://www.googleapis.com/apiName/apiVersion/resourcePath?parameters

Because all API resources have unique HTTP-accessible URIs, REST enables data caching and is optimized to work with the web's distributed infrastructure.

You may find the method definitions in the HTTP 1.1 standards documentation useful; they include specifications for GET, POST, PUT, and DELETE.

REST in the Blogger JSON API

The supported Blogger operations map directly to REST HTTP verbs, as described in Blogger JSON API operations.

The specific format for Blogger JSON API URIs are:

https://www.googleapis.com/blogger/v2/users/userId
https://www.googleapis.com/blogger/v2/users/self
https://www.googleapis.com/blogger/v2/users/userId/blogs
https://www.googleapis.com/blogger/v2/users/self/blogs

https://www.googleapis.com/blogger/v2/blogs/blogId/posts
https://www.googleapis.com/blogger/v2/blogs/blogId/posts/postId
https://www.googleapis.com/blogger/v2/blogs/blogId/posts/postId/comments
https://www.googleapis.com/blogger/v2/blogs/blogId/posts/postId/comments/commentId
https://www.googleapis.com/blogger/v2/blogs/blogId/pages
https://www.googleapis.com/blogger/v2/blogs/blogId/pages/pageId

The full explanation of URIs used and the results for each supported operation in the API is summarized in the Blogger JSON API Reference document.

Here are a couple of examples of how this works in the Blogger JSON API.

List the blogs that the authenticated user has access rights to:

GET https://www.googleapis.com/blogger/v2/users/self/blogs?key=YOUR-API-KEY

Get the posts on the code.blogger.com blog (which has blog ID 3213900):

GET https://www.googleapis.com/blogger/v2/blogs/3213900?key=YOUR-API-KEY

REST from JavaScript

You can invoke the Blogger JSON API using REST from JavaScript, using the callback query parameter and a callback function. This allows you to write rich applications that display Blogger data without writing any server-side code.

The following example retrieves a post from the code.blogger.com blog (after you replace YOUR-API-KEY with your API key).

<html>
  <head>
    <title>Blogger JSON API Example</title>
  </head>
  <body>
    <div id="content"></div>
    <script>
      function handleResponse(response) {
        document.getElementById("content").innerHTML += "<h1>" + response.title + "</h1>" + response.content;
      }
    </script>
    <script
    src="https://www.googleapis.com/blogger/v2/blogs/3213900/posts/8398240586497962757?callback=handleResponse&key=YOUR-API-KEY"></script>
  </body>
</html>

Data format

JSON

JSON (JavaScript Object Notation) is a common, language-independent data format that provides a simple text representation of arbitrary data structures. For more information, see json.org.