@solid/community-server/dist/util/ResourceUtil.js

Community Solid Server: an open and modular implementation of the Solid specifications

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.addResourceMetadata = addResourceMetadata;
exports.updateModifiedDate = updateModifiedDate;
exports.addTemplateMetadata = addTemplateMetadata;
exports.cloneRepresentation = cloneRepresentation;
exports.assertReadConditions = assertReadConditions;
const n3_1 = require("n3");
const BasicRepresentation_1 = require("../http/representation/BasicRepresentation");
const RepresentationMetadata_1 = require("../http/representation/RepresentationMetadata");
const NotModifiedHttpError_1 = require("./errors/NotModifiedHttpError");
const StreamUtil_1 = require("./StreamUtil");
const TermUtil_1 = require("./TermUtil");
const Vocabularies_1 = require("./Vocabularies");
/**
 * Helper function to generate type quads for a Container or Resource.
 *
 * @param metadata - Metadata to add to.
 * @param isContainer - If the identifier corresponds to a container.
 */
function addResourceMetadata(metadata, isContainer) {
    if (isContainer) {
        metadata.add(Vocabularies_1.RDF.terms.type, Vocabularies_1.LDP.terms.Container);
        metadata.add(Vocabularies_1.RDF.terms.type, Vocabularies_1.LDP.terms.BasicContainer);
    }
    metadata.add(Vocabularies_1.RDF.terms.type, Vocabularies_1.LDP.terms.Resource);
}
/**
 * Updates the dc:modified time to the given time.
 *
 * @param metadata - Metadata to update.
 * @param date - Last modified date. Defaults to current time.
 */
function updateModifiedDate(metadata, date = new Date()) {
    // Milliseconds get lost in some serializations, potentially causing mismatches
    const lastModified = new Date(date);
    lastModified.setMilliseconds(0);
    metadata.set(Vocabularies_1.DC.terms.modified, (0, TermUtil_1.toLiteral)(lastModified.toISOString(), Vocabularies_1.XSD.terms.dateTime));
}
/**
 * Links a template file with a given content-type to the metadata using the SOLID_META.template predicate.
 *
 * @param metadata - Metadata to update.
 * @param templateFile - Path to the template.
 * @param contentType - Content-type of the template after it is rendered.
 */
function addTemplateMetadata(metadata, templateFile, contentType) {
    const templateNode = n3_1.DataFactory.namedNode(templateFile);
    metadata.add(Vocabularies_1.SOLID_META.terms.template, templateNode);
    metadata.addQuad(templateNode, Vocabularies_1.CONTENT_TYPE_TERM, contentType);
}
/**
 * Helper function to clone a representation, the original representation can still be used.
 * This function loads the entire stream in memory.
 *
 * @param representation - The representation to clone.
 *
 * @returns The cloned representation.
 */
async function cloneRepresentation(representation) {
    const data = await (0, StreamUtil_1.arrayifyStream)(representation.data);
    const result = new BasicRepresentation_1.BasicRepresentation(data, new RepresentationMetadata_1.RepresentationMetadata(representation.metadata), representation.binary);
    representation.data = (0, StreamUtil_1.guardedStreamFrom)(data);
    return result;
}
/**
 * Verify whether the given {@link Representation} matches the given conditions.
 * If true, add the corresponding ETag to the body metadata.
 * If not, destroy the data stream and throw a {@link NotModifiedHttpError} with the same ETag.
 * If `conditions` is not defined, nothing will happen.
 *
 * This uses the strict conditions check which takes the content type into account;
 * therefore, this should only be called after content negotiation, when it is certain what the output will be.
 *
 * Note that browsers only keep track of one ETag, and the Vary header has no impact on this,
 * meaning the browser could send us the ETag for a Turtle resource even though it is requesting JSON-LD;
 * this is why we have to check ETags after content negotiation.
 *
 * @param body - The representation to compare the conditions against.
 * @param eTagHandler - Used to generate the ETag to return with the 304 response.
 * @param conditions - The conditions to assert.
 */
function assertReadConditions(body, eTagHandler, conditions) {
    const eTag = eTagHandler.getETag(body.metadata);
    if (conditions && !conditions.matchesMetadata(body.metadata, true)) {
        body.data.destroy();
        const error = new NotModifiedHttpError_1.NotModifiedHttpError(eTag);
        // From RFC 9111:
        // > the cache MUST add each header field in the provided response to the stored response,
        // > replacing field values that are already present
        // So we need to make sure to send either no partial headers, or the exact same headers.
        // By adding the metadata of the original resource here, we ensure we send the same headers.
        error.metadata.identifier = body.metadata.identifier;
        error.metadata.addQuads(body.metadata.quads());
        throw error;
    }
    body.metadata.set(Vocabularies_1.HH.terms.etag, eTag);
}
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