Skip to content

Latest commit

 

History

History
349 lines (230 loc) · 9.37 KB

jsonFetch.md

File metadata and controls

349 lines (230 loc) · 9.37 KB

elections-cpl.api.hscc.bdpa.org • Docs

elections-cpl.api.hscc.bdpa.org / lib/json-unfetch / jsonFetch

Function: jsonFetch()

jsonFetch(url, init)

jsonFetch<JsonType, ErrorType>(url, init?): Promise<object>

Fetches a resource and returns an object containing two items: the response itself under res and the response body parsed as JSON under either error (if the response has a non-2xx status) or json.

If the response was not received with an application/json content-type header or has a non-2xx status and unparseable response body, json will be undefined and error will be an empty object.

This function rejects if 1) the request body cannot be parsed as JSON but is being sent with an application/json content-type header or 2) the response body cannot be parsed as JSON but was received with an application/json content-type header.

Type parameters

• JsonType extends JsonObject = JsonObject

• ErrorType extends JsonObject = JsonType

Parameters

• url: string

• init?: Omit<JsonRequestInit, "rejectIfNotOk" | "rejectIfNonJsonContentType" | "swr"> & object

Returns

Promise<object>

error

error: Partial<ErrorType> | undefined

json

json: JsonType | undefined

res

res: Response

Example

type ResJson = { myNumber: number };
type ResErr = { reason: string };
const { res, json, error } = await jsonFetch<ResJson, ResErr>(
  'api/endpoint',
  {
    method: 'POST',
    headers: { authorization: `Bearer ${apiKey}` },
    body: requestData
  }
);

if (error) {
  console.error(error?.reason ?? (res.ok
      ? 'bad json'
      : res.statusText));
} else {
  console.log(`number is: ${json?.myNumber}`);
}

Source

lib/json-unfetch/index.ts:124

jsonFetch(url, init)

jsonFetch<JsonType, ErrorType>(url, init): Promise<object>

Fetches a resource and returns an object containing two items: the response itself under res and the response body parsed as JSON under either error (if the response has a non-2xx status) or json.

If the response was received with a non-2xx status and unparseable response body, json will be undefined and error will be an empty object.

This function rejects if 1) the request body cannot be parsed as JSON but is being sent with an application/json content-type header, 2) the response body cannot be parsed as JSON but was received with an application/json content-type header, or 3) the response was received with a content-type header other than application/json.

Type parameters

• JsonType extends JsonObject = JsonObject

• ErrorType extends JsonObject = JsonType

Parameters

• url: string

• init: Omit<JsonRequestInit, "rejectIfNotOk" | "rejectIfNonJsonContentType" | "swr"> & object

Returns

Promise<object>

error

error: Partial<ErrorType> | undefined

json

json: JsonType | undefined

res

res: Response

Example

type ResJson = { myNumber: number };
type ResErr = { reason: string };

try {
  const { res, json, error } = await jsonFetch<ResJson, ResErr>(
    'api/endpoint',
    { rejectIfNonJsonContentType: true }
  );

  if (error) {
    console.error(error?.reason ?? res.statusText);
  } else {
    console.log(`number is: ${json?.myNumber}`);
  }
} catch(e) {
  if(e instanceof JsonFetchError) {
    // Special handling for non-json response bodies
    specialHandler(e.res.status, e.json);
  } else {
    throw e;
  }
}

Source

lib/json-unfetch/index.ts:182

jsonFetch(url, init)

jsonFetch<JsonType, ErrorType>(url, init): Promise<object>

Fetches a resource and returns an object containing two items: the response itself under res and either the response body parsed as JSON under json or, if the response was received with a content-type header other than application/json, an empty object under error.

This function rejects if 1) the request body cannot be parsed as JSON but is being sent with an application/json content-type header, 2) the response body cannot be parsed as JSON but was received with an application/json content-type header, or 3) the response was received with a non-2xx status.

Type parameters

• JsonType extends JsonObject = JsonObject

• ErrorType extends JsonObject = JsonType

Parameters

• url: string

• init: Omit<JsonRequestInit, "rejectIfNotOk" | "rejectIfNonJsonContentType" | "swr"> & object

Returns

Promise<object>

error

error: Partial<ErrorType> | undefined

json

json: JsonType | undefined

res

res: Response

Example

type ResJson = { myNumber: number };
type ResErr = { reason: string };

try {
  const { res, json, error } = await jsonFetch<ResJson, ResErr>(
    'api/endpoint',
    { rejectIfNotOk: true }
  );

  if (error) {
    console.error(error?.reason ?? 'bad json');
  } else {
    console.log(`number is: ${json?.myNumber}`);
  }
} catch(e) {
  if(e instanceof JsonFetchError) {
    // Special handling for non-2xx responses
    specialHandler(e.res.status, e.json);
  } else {
    throw e;
  }
}

Source

lib/json-unfetch/index.ts:237

jsonFetch(url, init)

jsonFetch<JsonType, ErrorType>(url, init): Promise<object>

Fetches a resource and returns an object containing two items: the response itself under res and and the response body parsed as JSON under json.

This function rejects if 1) the request body cannot be parsed as JSON but is being sent with an application/json content-type header, 2) the response body cannot be parsed as JSON but was received with an application/json content-type header, 3) the response was received with a content-type header other than application/json, or 4) the response was received with a non-2xx status.

Hence, when jsonFetch is called in this way, json will always be defined and error will always be undefined.

Type parameters

• JsonType extends JsonObject = JsonObject

• ErrorType extends JsonObject = JsonType

Parameters

• url: string

• init: Omit<JsonRequestInit, "rejectIfNotOk" | "rejectIfNonJsonContentType" | "swr"> & object

Returns

Promise<object>

error

error: undefined

json

json: JsonType

res

res: Response

Example

try {
  const url = 'https://some.resource.com/data.json';
  const { json } = await jsonFetch(url, {
    rejectIfNotOk: true,
    rejectIfNonJsonContentType: true
  });
  doSomethingWith(json);
} catch(e) {
  if(e instanceof JsonFetchError) {
    // Special handling for non-2xx/non-json response bodies
    specialHandler(e.res.status, e.json);
  } else {
    throw e;
  }
}

Source

lib/json-unfetch/index.ts:288

jsonFetch(url, init)

jsonFetch<JsonType, ErrorType>(url, init): Promise<JsonType>

Fetches a resource and returns the response body parsed as a JSON object.

This function rejects if 1) the request body cannot be parsed as JSON but is being sent with an application/json content-type header, 2) the response body cannot be parsed as JSON but was received with an application/json content-type header, 3) the response was received with a content-type header other than application/json, or 4) the response was received with a non-2xx status.

The object SWR returns will contain the rejection reason under the error property. Usually, error is as an instance of JsonUnfetchError complete with json and res properties. If unfetch itself fails, the error object returned will not have these properties.

Type parameters

• JsonType extends JsonObject = JsonObject

• ErrorType extends JsonObject = JsonType

Parameters

• url: string

• init: Omit<JsonRequestInit, "swr"> & object

Returns

Promise<JsonType>

Example

  const { data: json, error } = useSwr('api/endpoint', swrFetch);
  // Or:                  ... = useSwr('api/endpoint', key => jsonFetch(key, { swr: true }));

  if(error) <div>Error: {error.message}</div>;
  return <div>Hello, your data is: {json.data}</div>;

See

https://swr.vercel.app

Source

lib/json-unfetch/index.ts:333