How to call external api to pull data into json format?

Question

There is an api that is used to expose data from an external website. How can I use the drupal API to call the external api and pull the data into json format?

the external api would be, for example, "api.website.com/api/get_data".

return results would be in json format "{"data":[....]}

How would I use a module to call the external api and return the data in json?

Answer 1

It depends on what you wish to do with said data.

If you are looking for a purely code approach, you could do something like:

$response = drupal_http_request($url);
$result = json_decode($response->data);

If you want a Rules based approach, you could could use the Rules HTTP Client module, which allows you to do essentially the same as the above code but via the Rules UI.

Answer 2

Drupal offers two functions for encoding and decoding JSON. To encode an array into JSON usedrupal_json_encode() and to decode a JSON object into an array use the - can you guess it? -drupal_json_decode() function.

Encoding JSON

First, let’s look at encoding an array into JSON. Take this array for example:

$array = array('Boat', 'Car', 'Ship', 'Building');

If we were to encode the above array into JSON, you will get ["Boat","Car","Ship","Building"] returned. Here is a code example:

$array = array('Boat', 'Car', 'Ship', 'Building');
$output = drupal_json_encode($array);
// $output will be ["Boat","Car","Ship","Building"]

Decoding JSON

Now let's look at decoding a JSON object. If you were to running the following code:

$json = '["Boat","Car","Ship","Building"]';  
return drupal_json_decode($json);

The drupal_json_decode() function will return an array.

Pulling In JSON Objects

The next example I want to demonstrate is how to pull in a Twitter account using Twitter's GET users/show REST API.

First, we’ll need to get the JSON object and for this we’ll use the drupal_http_request() function:

$request = drupal_http_request('https://api.twitter.com/1/users/show.json?screen_name=TwitterAPI&include_entities=true');

Within the $request variable, there will be a data property $request->data. This stores the JSON object.

The only thing left to do is decode the data property to get access to all the information.

$request = drupal_http_request('https://api.twitter.com/1/users/show.json?screen_name=TwitterAPI&include_entities=true');
return drupal_json_decode($request->data);

JSON Endpoints

The last item I want to demonstrate is how to create a JSON endpoint for content on a Drupal site. For example, if you navigate to example.com/node/1/json the website will output a JSON version of the content. This will show you how to output a full JSON page using the drupal_json_output() function.

1. First we must implement a menu item using the hook_menu. The menu item path needs to be "node/%node/json". For more details on how to use hook_menu check out the API documentation.

   /**

   • Implements hook_menu(). */ function ww_json_example_menu() { $items['node/%node/json'] = array( 'page callback' => 'ww_json_example_endpoint', 'page arguments' => array(1), 'access arguments' => array('access content'), ); return $items; }

2. Create a "page callback" function for the menu item. Also, make sure that you add a $node variable to the function signature. For this example, the page callback is "ww_json_example_endpoint". Finally, we pass the $node object through to the drupal_json_output() function. If you go to node/1/json you should just see outputted JSON code.

function ww_json_example_endpoint($node) { drupal_json_output($node); }