blob: 4c7dea010e1968643d2fbcee548d76aae70cf4a2 [file] [log] [blame]
/*
* Pipe viewer manager is used to load and get an instance of a pipe viewer
* given its name.
*
* Manager handles on-demand loading and caching of pipe viewers.
* @fileoverview
*/
import { isAbsoulteUrl } from 'libs/utils/url'
import { Logger } from 'libs/logs/logger'
/*
* Preload certain common builtin plugins.
* Plugins are normally loaded on demand and this makes the initial bundle larger
* but common plugins should be preloaded for better performance.
* This is kind of a hack as it simply exposes a path to these
* plugins so that build bundler finds them and bundles them with the reset of the app
*/
import { default as plugin } from './builtin/vlog/plugin'
import { default as plugin } from './builtin/image/plugin'
import { default as plugin } from './builtin/console/plugin'
var log = new Logger('pipe-viewer/manager');
// cache loaded viewers
var loadedPipeViewers = {};
/*
* Asynchronously loads and returns a PipeViewer plugin instance given its name.
* @param {string} name Unique name of the viewer.
* @return {Promise<PipeViewer>} pipe viewer for the given name
*/
export function get(name) {
if(isLoaded(name)) {
return Promise.resolve(new loadedPipeViewers[name]());
}
return loadViewer(name).then((viewerClass) => {
return new viewerClass();
}).catch((e) => { return Promise.reject(e); });
}
/*
* Tests whether the viewer plugin is already loaded or not.
* @param {string} name Unique name of the viewer.
* @return {string} Whether the viewer plugin is already loaded or not.
*
* @private
*/
function isLoaded(name) {
return loadedPipeViewers[name] !== undefined
}
/*
* Registers a pipeViewer under a unique name and make it available to be called
* @param {string} name Unique name of the viewer.
* @return {Promise} when import completes.
*
* @private
*/
function loadViewer(name) {
log.debug('loading viewer:', name);
var path = getPath(name);
return System.import(path).then((module) => {
var pipeViewerClass = module.default;
loadedPipeViewers[name] = pipeViewerClass;
return pipeViewerClass;
}).catch((e) => {
var errMessage = 'could not load viewer for: ' + name;
log.debug(errMessage, e);
return Promise.reject(new Error(errMessage));
})
}
/*
* Returns the path to a pipe viewer module location based on its name.
* @param {string} name Unique name of the viewer.
* @return {string} path to a pipe viewer module location.
*
* @private
*/
function getPath(name) {
if(isAbsoulteUrl(name)) {
var encodedName = encodeURIComponent(name);
System.paths[encodedName] = name;
return encodedName;
} else {
return 'pipe-viewers/builtin/' + name + '/plugin';
}
}