Handling Errors

WARNING

This API is frozen and deprecated. Please use the fluent API from 0.9.4 on

All requests are made over the network. As the first fallacy of distributed computing reminds us, the network is not reliable. More often than network failures are other server-side issues that may prevent your requests from being handled as you expect. For simplicity, most of the examples in this doc do not include exception handling, but of course your client code should always.

When halchemy encounters an issue when submitting your request it does two things:

• records the details in a public member called last error
• throws an exception

Here is an example of how to handle the exception:

import json
from halchemy import Api

api = Api('http://example.org/api')

try:
    root = api.get()
    customer = api.get_from_rel(root, 'customers')
except RuntimeError as ex:
    print(f'Could not fetch the list of customers: {api.last_error["status_code"]} {api.last_error["reason"]}')
    print(json.dumps(api.last_error["details"], indent=4}))
    # handle accordingly...

Details for last_error:

key	Description
method	The method of the request sent to the server, e.g. GET, POST, etc.
url	The URL the request was sent to.
status_code	The http status code returned by the server.
reason	The reason phrase returned by the server.
details	The body of the response, hopefully providing additional details about the error.
response	The response object returned by the requests library method.
error	The exception that was caught by halchemy before rethrowing.

const {Api} = require('halchemy')

async function errorHandlingExample() {
    const api = new Api('http://example.org/api')

    try {
        const root = await api.get()  // get the root resource

        const customer = await api.getFromRel({
            resource: root,
            rel: 'customers'
        })
    } catch(error) {
        console.log(`Could not fetch the list of customers: ${api.last_error.statusCode} ${api.last_error.reason}`)
        console.log(api.lastError.details)
    }
}
errorHandlingExample()

Details for lastError

member	Description
method	The method of the request sent to the server, e.g. GET, POST, etc.
url	The URL the request was sent to.
statusCode	The http status code returned by the server.
reason	The reason phrase returned by the server.
details	The body of the response, hopefully providing additional details about the error.
response	The response object returned by the axios library method.
error	The exception that was caught by halchemy before rethrowing.