Connect to GraphQL API from MATLAB
Provided GraphQL class helps you to appropriately encode data, prepare query and call GraphQL endpoint via regular HTTP POST request under the hood according to official documentation.
Download GraphQL_Client.mltbx from releases page and open it to install toolbox.
If you want to make GraphQL Client a part of your project without installing toolbox just add GraphQL.m class to your project.
Basic GraphQL request with datetime decoding
% Define endpoint URL
url = 'https://api.graphql.jobs/';
% Compose query
query = 'query{jobs{title,locationNames,postedAt}}';
% Create GraphQL object with predefined web options
g = GraphQL(url, 'Query', query);
% Execute query
res = g.execute();
% Extract data
jobs = struct2table(res.data.jobs);
% Convert dates to datetime format
jobs.postedAt = GraphQL.datetime(jobs.postedAt);
head(jobs, 3)
| title | locationNames | postedAt | |
|---|---|---|---|
| 1 | 'Senior Fullstack En... | 'San Francisco' | 2019-08-12T20:19:52.... |
| 2 | 'Full Stack JavaScri... | 'Remote / Berlin' | 2019-08-12T12:58:28.... |
| 3 | 'Senior Software Eng... | 'London, United King... | 2019-08-12T10:47:47.... |
How to encode MATLAB structure to query string
% Define endpoint URL
url = 'https://countries-274616.ew.r.appspot.com/';
% Create filter structure
filter = struct('filter', struct('area_gt', 1e7));
% Encode filter structure to string
filterstr = GraphQL.encode(filter);
% Compose query with filter argument
query = sprintf('query{Country(%s){name,area,population}}', filterstr);
% Create GraphQL object
g = GraphQL(url, 'Query', query);
% Execute query
res = g.execute();
% Extract data
res.data.Country
| Fields | name | area | population |
|---|---|---|---|
| 1 | 'Antarctica' | 14000000 | 1000 |
| 2 | 'Russian Federation' | 17124442 | 146599183 |
How to modify HTTP request options
% Define endpoint URL
url = 'https://api.graphql.jobs/';
% Define your API key
apiKey = 'your_api_key';
% Create weboptions object (builtin in MATLAB) with specified header fields
opts = weboptions('HeaderFields', {'apiKey' apiKey});
% Optionally increase request timeout (usefull for heavy requests)
opts.Timeout = 10;
% Compose query
query = 'query{jobs{title,locationNames,postedAt}}';
% Create GraphQL object with predefined web options
g = GraphQL(url, 'Query', query, 'WebOptions', opts);
% Execute query
res = g.execute();
2020, Pavel Roslovets