Files
dspace-angular/src/app/core/browse/browse.service.ts
2019-07-18 16:28:07 +02:00

337 lines
12 KiB
TypeScript

import { Injectable } from '@angular/core';
import { Observable, of as observableOf } from 'rxjs';
import { distinctUntilChanged, map, startWith } from 'rxjs/operators';
import {
ensureArrayHasValue,
hasValue,
hasValueOperator,
isEmpty,
isNotEmpty,
isNotEmptyOperator
} from '../../shared/empty.util';
import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
import { PaginatedList } from '../data/paginated-list';
import { RemoteData } from '../data/remote-data';
import {
BrowseEndpointRequest,
BrowseEntriesRequest,
BrowseItemsRequest,
RestRequest
} from '../data/request.models';
import { RequestService } from '../data/request.service';
import { BrowseDefinition } from '../shared/browse-definition.model';
import { BrowseEntry } from '../shared/browse-entry.model';
import { HALEndpointService } from '../shared/hal-endpoint.service';
import {
configureRequest,
filterSuccessfulResponses,
getBrowseDefinitionLinks,
getFirstOccurrence,
getRemoteDataPayload,
getRequestFromRequestHref
} from '../shared/operators';
import { URLCombiner } from '../url-combiner/url-combiner';
import { Item } from '../shared/item.model';
import { DSpaceObject } from '../shared/dspace-object.model';
import { BrowseEntrySearchOptions } from './browse-entry-search-options.model';
import { GenericSuccessResponse } from '../cache/response.models';
/**
* The service handling all browse requests
*/
@Injectable()
export class BrowseService {
protected linkPath = 'browses';
private static toSearchKeyArray(metadataKey: string): string[] {
const keyParts = metadataKey.split('.');
const searchFor = [];
searchFor.push('*');
for (let i = 0; i < keyParts.length - 1; i++) {
const prevParts = keyParts.slice(0, i + 1);
const nextPart = [...prevParts, '*'].join('.');
searchFor.push(nextPart);
}
searchFor.push(metadataKey);
return searchFor;
}
constructor(
protected requestService: RequestService,
protected halService: HALEndpointService,
private rdb: RemoteDataBuildService,
) {
}
/**
* Get all BrowseDefinitions
*/
getBrowseDefinitions(): Observable<RemoteData<BrowseDefinition[]>> {
const request$ = this.halService.getEndpoint(this.linkPath).pipe(
isNotEmptyOperator(),
distinctUntilChanged(),
map((endpointURL: string) => new BrowseEndpointRequest(this.requestService.generateRequestId(), endpointURL)),
configureRequest(this.requestService)
);
const href$ = request$.pipe(map((request: RestRequest) => request.href));
const requestEntry$ = href$.pipe(getRequestFromRequestHref(this.requestService));
const payload$ = requestEntry$.pipe(
filterSuccessfulResponses(),
map((response: GenericSuccessResponse<BrowseDefinition[]>) => response.payload),
ensureArrayHasValue(),
map((definitions: BrowseDefinition[]) => definitions
.map((definition: BrowseDefinition) => Object.assign(new BrowseDefinition(), definition))),
distinctUntilChanged()
);
return this.rdb.toRemoteDataObservable(requestEntry$, payload$);
}
/**
* Get all BrowseEntries filtered or modified by BrowseEntrySearchOptions
* @param options
*/
getBrowseEntriesFor(options: BrowseEntrySearchOptions): Observable<RemoteData<PaginatedList<BrowseEntry>>> {
return this.getBrowseDefinitions().pipe(
getBrowseDefinitionLinks(options.metadataDefinition),
hasValueOperator(),
map((_links: any) => _links.entries),
hasValueOperator(),
map((href: string) => {
// TODO nearly identical to PaginatedSearchOptions => refactor
const args = [];
if (isNotEmpty(options.scope)) {
args.push(`scope=${options.scope}`);
}
if (isNotEmpty(options.sort)) {
args.push(`sort=${options.sort.field},${options.sort.direction}`);
}
if (isNotEmpty(options.pagination)) {
args.push(`page=${options.pagination.currentPage - 1}`);
args.push(`size=${options.pagination.pageSize}`);
}
if (isNotEmpty(options.startsWith)) {
args.push(`startsWith=${options.startsWith}`);
}
if (isNotEmpty(args)) {
href = new URLCombiner(href, `?${args.join('&')}`).toString();
}
return href;
}),
getBrowseEntriesFor(this.requestService, this.rdb)
);
}
/**
* Get all items linked to a certain metadata value
* @param {string} filterValue metadata value to filter by (e.g. author's name)
* @param options Options to narrow down your search
* @returns {Observable<RemoteData<PaginatedList<Item>>>}
*/
getBrowseItemsFor(filterValue: string, options: BrowseEntrySearchOptions): Observable<RemoteData<PaginatedList<Item>>> {
return this.getBrowseDefinitions().pipe(
getBrowseDefinitionLinks(options.metadataDefinition),
hasValueOperator(),
map((_links: any) => _links.items),
hasValueOperator(),
map((href: string) => {
const args = [];
if (isNotEmpty(options.scope)) {
args.push(`scope=${options.scope}`);
}
if (isNotEmpty(options.sort)) {
args.push(`sort=${options.sort.field},${options.sort.direction}`);
}
if (isNotEmpty(options.pagination)) {
args.push(`page=${options.pagination.currentPage - 1}`);
args.push(`size=${options.pagination.pageSize}`);
}
if (isNotEmpty(options.startsWith)) {
args.push(`startsWith=${options.startsWith}`);
}
if (isNotEmpty(filterValue)) {
args.push(`filterValue=${filterValue}`);
}
if (isNotEmpty(args)) {
href = new URLCombiner(href, `?${args.join('&')}`).toString();
}
return href;
}),
getBrowseItemsFor(this.requestService, this.rdb)
);
}
/**
* Get the first item for a metadata definition in an optional scope
* @param definition
* @param scope
*/
getFirstItemFor(definition: string, scope?: string): Observable<RemoteData<Item>> {
return this.getBrowseDefinitions().pipe(
getBrowseDefinitionLinks(definition),
hasValueOperator(),
map((_links: any) => _links.items),
hasValueOperator(),
map((href: string) => {
const args = [];
if (hasValue(scope)) {
args.push(`scope=${scope}`);
}
args.push('page=0');
args.push('size=1');
if (isNotEmpty(args)) {
href = new URLCombiner(href, `?${args.join('&')}`).toString();
}
return href;
}),
getBrowseItemsFor(this.requestService, this.rdb),
getFirstOccurrence()
);
}
/**
* Get the previous page of items using the paginated list's prev link
* @param items
*/
getPrevBrowseItems(items: RemoteData<PaginatedList<Item>>): Observable<RemoteData<PaginatedList<Item>>> {
return observableOf(items.payload.prev).pipe(
getBrowseItemsFor(this.requestService, this.rdb)
);
}
/**
* Get the next page of items using the paginated list's next link
* @param items
*/
getNextBrowseItems(items: RemoteData<PaginatedList<Item>>): Observable<RemoteData<PaginatedList<Item>>> {
return observableOf(items.payload.next).pipe(
getBrowseItemsFor(this.requestService, this.rdb)
);
}
/**
* Get the previous page of browse-entries using the paginated list's prev link
* @param entries
*/
getPrevBrowseEntries(entries: RemoteData<PaginatedList<BrowseEntry>>): Observable<RemoteData<PaginatedList<BrowseEntry>>> {
return observableOf(entries.payload.prev).pipe(
getBrowseEntriesFor(this.requestService, this.rdb)
);
}
/**
* Get the next page of browse-entries using the paginated list's next link
* @param entries
*/
getNextBrowseEntries(entries: RemoteData<PaginatedList<BrowseEntry>>): Observable<RemoteData<PaginatedList<BrowseEntry>>> {
return observableOf(entries.payload.next).pipe(
getBrowseEntriesFor(this.requestService, this.rdb)
);
}
/**
* Get the browse URL by providing a metadatum key and linkPath
* @param metadatumKey
* @param linkPath
*/
getBrowseURLFor(metadataKey: string, linkPath: string): Observable<string> {
const searchKeyArray = BrowseService.toSearchKeyArray(metadataKey);
return this.getBrowseDefinitions().pipe(
getRemoteDataPayload(),
map((browseDefinitions: BrowseDefinition[]) => browseDefinitions
.find((def: BrowseDefinition) => {
const matchingKeys = def.metadataKeys.find((key: string) => searchKeyArray.indexOf(key) >= 0);
return isNotEmpty(matchingKeys);
})
),
map((def: BrowseDefinition) => {
if (isEmpty(def) || isEmpty(def._links) || isEmpty(def._links[linkPath])) {
throw new Error(`A browse endpoint for ${linkPath} on ${metadataKey} isn't configured`);
} else {
return def._links[linkPath];
}
}),
startWith(undefined),
distinctUntilChanged()
);
}
}
/**
* Operator for turning a href into a PaginatedList of BrowseEntries
* @param requestService
* @param responseCache
* @param rdb
*/
export const getBrowseEntriesFor = (requestService: RequestService, rdb: RemoteDataBuildService) =>
(source: Observable<string>): Observable<RemoteData<PaginatedList<BrowseEntry>>> =>
source.pipe(
map((href: string) => new BrowseEntriesRequest(requestService.generateRequestId(), href)),
configureRequest(requestService),
toRDPaginatedBrowseEntries(requestService, rdb)
);
/**
* Operator for turning a href into a PaginatedList of Items
* @param requestService
* @param responseCache
* @param rdb
*/
export const getBrowseItemsFor = (requestService: RequestService, rdb: RemoteDataBuildService) =>
(source: Observable<string>): Observable<RemoteData<PaginatedList<Item>>> =>
source.pipe(
map((href: string) => new BrowseItemsRequest(requestService.generateRequestId(), href)),
configureRequest(requestService),
toRDPaginatedBrowseItems(requestService, rdb)
);
/**
* Operator for turning a RestRequest into a PaginatedList of Items
* @param requestService
* @param responseCache
* @param rdb
*/
export const toRDPaginatedBrowseItems = (requestService: RequestService, rdb: RemoteDataBuildService) =>
(source: Observable<RestRequest>): Observable<RemoteData<PaginatedList<Item>>> => {
const href$ = source.pipe(map((request: RestRequest) => request.href));
const requestEntry$ = href$.pipe(getRequestFromRequestHref(requestService));
const payload$ = requestEntry$.pipe(
filterSuccessfulResponses(),
map((response: GenericSuccessResponse<Item[]>) => new PaginatedList(response.pageInfo, response.payload)),
map((list: PaginatedList<Item>) => Object.assign(list, {
page: list.page ? list.page.map((item: DSpaceObject) => Object.assign(new Item(), item)) : list.page
})),
distinctUntilChanged()
);
return rdb.toRemoteDataObservable(requestEntry$, payload$);
};
/**
* Operator for turning a RestRequest into a PaginatedList of BrowseEntries
* @param requestService
* @param responseCache
* @param rdb
*/
export const toRDPaginatedBrowseEntries = (requestService: RequestService, rdb: RemoteDataBuildService) =>
(source: Observable<RestRequest>): Observable<RemoteData<PaginatedList<BrowseEntry>>> => {
const href$ = source.pipe(map((request: RestRequest) => request.href));
const requestEntry$ = href$.pipe(getRequestFromRequestHref(requestService));
const payload$ = requestEntry$.pipe(
filterSuccessfulResponses(),
map((response: GenericSuccessResponse<BrowseEntry[]>) => new PaginatedList(response.pageInfo, response.payload)),
map((list: PaginatedList<BrowseEntry>) => Object.assign(list, {
page: list.page ? list.page.map((entry: BrowseEntry) => Object.assign(new BrowseEntry(), entry)) : list.page
})),
distinctUntilChanged()
);
return rdb.toRemoteDataObservable(requestEntry$, payload$);
};