ampache_react/app/middleware/api.js

303 lines
9.3 KiB
JavaScript

/**
* Redux middleware to perform API queries.
*
* This middleware catches the API requests and replaces them with API
* responses.
*/
import fetch from "isomorphic-fetch";
import humps from "humps";
import X2JS from "x2js";
import { assembleURLAndParams } from "../utils";
import { i18nRecord } from "../models/i18n";
import { loginUserExpired } from "../actions/auth";
export const API_VERSION = 350001; /** API version to use. */
export const BASE_API_PATH = "/server/xml.server.php"; /** Base API path after endpoint. */
// Action key that carries API call info interpreted by this Redux middleware.
export const CALL_API = "CALL_API";
// Error class to represents errors from these actions.
class APIError extends Error {}
/**
* Check the HTTP status of the response.
*
* @param response A XHR response object.
* @return The response or a rejected Promise if the check failed.
*/
function _checkHTTPStatus(response) {
if (response.status >= 200 && response.status < 300) {
return response;
} else {
return Promise.reject(response.statusText);
}
}
/**
* Parse the XML resulting from the API to JS object.
*
* @param responseText The text from the API response.
* @return The response as a JS object or a rejected Promise on error.
*/
function _parseToJSON(responseText) {
let x2js = new X2JS({
attributePrefix: "", // No prefix for attributes
keepCData: false, // Do not store __cdata and toString functions
});
if (responseText) {
return x2js.xml_str2json(responseText).root;
}
return Promise.reject(new i18nRecord({
id: "app.api.invalidResponse",
values: {},
}));
}
/**
* Check the errors returned by the API itself, in its response.
*
* @param jsonData A JS object representing the API response.
* @return The input data or a rejected Promise if errors are present.
*/
function _checkAPIErrors(jsonData) {
if (jsonData.error) {
return Promise.reject(jsonData.error);
} else if (!jsonData) {
// No data returned
return Promise.reject(new i18nRecord({
id: "app.api.emptyResponse",
values: {},
}));
}
return jsonData;
}
/**
* Apply some fixes on the API data.
*
* @param jsonData A JS object representing the API response.
* @return A fixed JS object.
*/
function _uglyFixes(jsonData) {
// Fix songs array
let _uglyFixesSongs = function (songs) {
return songs.map(function (song) {
// Fix for cdata left in artist and album
song.artist.name = song.artist.cdata;
song.album.name = song.album.cdata;
return song;
});
};
// Fix albums array
let _uglyFixesAlbums = function (albums) {
return albums.map(function (album) {
// TODO: Should go in Ampache core
// Fix for absence of distinction between disks in the same album
if (album.disk > 1) {
album.name = album.name + " [Disk " + album.disk + "]";
}
// Move songs one node top
if (album.tracks.song) {
album.tracks = album.tracks.song;
// Ensure tracks is an array
if (!Array.isArray(album.tracks)) {
album.tracks = [album.tracks];
}
// Fix tracks array
album.tracks = _uglyFixesSongs(album.tracks);
}
return album;
});
};
// Fix artists array
let _uglyFixesArtists = function (artists) {
return artists.map(function (artist) {
// Move albums one node top
if (artist.albums.album) {
artist.albums = artist.albums.album;
// Ensure albums are an array
if (!Array.isArray(artist.albums)) {
artist.albums = [artist.albums];
}
// Fix albums
artist.albums = _uglyFixesAlbums(artist.albums);
}
// Move songs one node top
if (artist.songs.song) {
artist.songs = artist.songs.song;
// Ensure songs are an array
if (!Array.isArray(artist.songs)) {
artist.songs = [artist.songs];
}
// Fix songs
artist.songs = _uglyFixesSongs(artist.songs);
}
return artist;
});
};
// Ensure items are always wrapped in an array
if (jsonData.artist && !Array.isArray(jsonData.artist)) {
jsonData.artist = [jsonData.artist];
}
if (jsonData.album && !Array.isArray(jsonData.album)) {
jsonData.album = [jsonData.album];
}
if (jsonData.song && !Array.isArray(jsonData.song)) {
jsonData.song = [jsonData.song];
}
// Fix artists
if (jsonData.artist) {
jsonData.artist = _uglyFixesArtists(jsonData.artist);
}
// Fix albums
if (jsonData.album) {
jsonData.album = _uglyFixesAlbums(jsonData.album);
}
// Fix songs
if (jsonData.song) {
jsonData.song = _uglyFixesSongs(jsonData.song);
}
// TODO: Should go in Ampache core
// Add sessionExpire information
if (!jsonData.sessionExpire) {
// Fix for Ampache not returning updated sessionExpire
jsonData.sessionExpire = (new Date(Date.now() + 3600 * 1000)).toJSON();
}
return jsonData;
}
/**
* Fetches an API response and normalizes the result.
*
* @param endpoint Base URL of your Ampache server.
* @param action API action name.
* @param auth API token to use.
* @param username Username to use in the API.
* @param extraParams An object of extra parameters to pass to the API.
*
* @return A fetching Promise.
*/
function doAPICall(endpoint, action, auth, username, extraParams) {
// Translate the API action to real API action
const APIAction = extraParams.filter ? action.rstrip("s") : action;
// Set base params
const baseParams = {
version: API_VERSION,
action: APIAction,
auth: auth,
user: username,
};
// Extend with extraParams
const params = Object.assign({}, baseParams, extraParams);
// Assemble the full URL with endpoint, API path and GET params
const fullURL = assembleURLAndParams(endpoint + BASE_API_PATH, params);
return fetch(fullURL, {
method: "get",
})
.then(_checkHTTPStatus)
.then (response => response.text())
.then(_parseToJSON)
.then(_checkAPIErrors)
.then(jsonData => humps.camelizeKeys(jsonData)) // Camelize
.then(_uglyFixes);
}
/**
* A Redux middleware that interprets actions with CALL_API info specified.
* Performs the call and promises when such actions are dispatched.
*/
export default store => next => reduxAction => {
if (reduxAction.type !== CALL_API) {
// Do not apply on other actions
return next(reduxAction);
}
// Check payload
const { endpoint, action, auth, username, dispatch, extraParams } = reduxAction.payload;
if (!endpoint || typeof endpoint !== "string") {
throw new APIError("Specify a string endpoint URL.");
}
if (!action) {
throw new APIError("Specify one of the supported API actions.");
}
if (!auth) {
throw new APIError("Specify an auth token.");
}
if (!username) {
throw new APIError("Specify a username.");
}
if (!Array.isArray(dispatch) || dispatch.length !== 3) {
throw new APIError("Expected an array of three action dispatch.");
}
if (!dispatch.every(type => typeof type === "function" || type === null)) {
throw new APIError("Expected action to dispatch to be functions or null.");
}
// Get the actions to dispatch
const [ requestDispatch, successDispatch, failureDispatch ] = dispatch;
if (requestDispatch) {
// Dispatch request action if needed
store.dispatch(requestDispatch());
}
// Run the API call
return doAPICall(endpoint, action, auth, username, extraParams).then(
response => {
if (successDispatch) {
// Dispatch success if needed
store.dispatch(successDispatch(response));
}
},
error => {
if (failureDispatch) {
// Error object from the API (in the JS object)
if (error._code && error.__cdata) {
// Format the error message
const errorMessage = error.__cdata + " (" + error._code + ")";
if (401 == error._code) {
// This is an error meaning no valid session was
// passed. We must perform a new handshake.
store.dispatch(loginUserExpired(errorMessage));
return;
}
// Else, form error message and continue
error = errorMessage;
}
// Else if exception was thrown
else if (error instanceof Error) {
// Form error message and continue
error = error.message;
}
// Dispatch a failure event
store.dispatch(failureDispatch(error));
}
}
);
};