@rdfine/hydra/extensions/TemplateExpander.js

> ## @rdfine/hydra > ### Generated JavaScript types for Hydra Core Vocabulary

import URITemplate from 'es6-url-template';
export class TemplateExpander {
    constructor(template) {
        this.__template = template;
    }
    expand(baseOrFirst, ...models) {
        if (!this.__template.template) {
            return '';
        }
        let base = '';
        let expansionModels;
        if (typeof baseOrFirst === 'string') {
            base = baseOrFirst;
            expansionModels = models;
        }
        else {
            const parent = this.findNamedParent();
            if (parent) {
                base = parent.id.value;
            }
            expansionModels = baseOrFirst ? [baseOrFirst, ...models] : models;
        }
        const uriTemplate = new URITemplate(this.__template.template);
        const variables = expansionModels.reduce((variables, model) => {
            return {
                ...variables,
                ...this.buildExpansionModel(this.__template.mapping, 'id' in model ? model.pointer : model),
            };
        }, {});
        const expanded = uriTemplate.expand(variables);
        if (base) {
            return new URL(expanded, base).toString();
        }
        return expanded;
    }
    findNamedParent() {
        let parent = this.__template._parent;
        do {
            if (parent && !parent.isAnonymous) {
                return parent;
            }
            parent = parent?._parent;
        } while (parent);
        return undefined;
    }
    buildExpansionModel(mappings, templateValues) {
        return mappings.reduce((model, mapping) => {
            const { property, variable } = mapping;
            if (!property || !variable) {
                return model;
            }
            const values = templateValues.out(property.id)
                .map(({ term }) => {
                const variableRepresentation = mapping.variableRepresentation || this.__template.variableRepresentation;
                return variableRepresentation?.mapValue(term) || term.value;
            });
            if (values.length === 0) {
                return model;
            }
            return {
                ...model,
                [variable]: values,
            };
        }, {});
    }
}