8129815538
This rule will help enforce slightly shorter code, especially since you can insert multiple elements at once, and according to MDN `Element.append()` is available in all browsers that we currently support. Please find additional information here: - https://developer.mozilla.org/en-US/docs/Web/API/Element/append - https://github.com/sindresorhus/eslint-plugin-unicorn/blob/main/docs/rules/prefer-dom-node-append.md
140 lines
3.6 KiB
JavaScript
140 lines
3.6 KiB
JavaScript
/* Copyright 2021 Mozilla Foundation
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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/** @typedef {import("../src/display/api").PDFPageProxy} PDFPageProxy */
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const PDF_ROLE_TO_HTML_ROLE = {
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// Document level structure types
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Document: null, // There's a "document" role, but it doesn't make sense here.
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DocumentFragment: null,
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// Grouping level structure types
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Part: "group",
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Sect: "group", // XXX: There's a "section" role, but it's abstract.
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Div: "group",
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Aside: "note",
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NonStruct: "none",
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// Block level structure types
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P: null,
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// H<n>,
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H: "heading",
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Title: null,
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FENote: "note",
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// Sub-block level structure type
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Sub: "group",
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// General inline level structure types
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Lbl: null,
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Span: null,
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Em: null,
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Strong: null,
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Link: "link",
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Annot: "note",
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Form: "form",
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// Ruby and Warichu structure types
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Ruby: null,
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RB: null,
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RT: null,
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RP: null,
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Warichu: null,
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WT: null,
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WP: null,
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// List standard structure types
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L: "list",
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LI: "listitem",
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LBody: null,
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// Table standard structure types
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Table: "table",
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TR: "row",
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TH: "columnheader",
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TD: "cell",
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THead: "columnheader",
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TBody: null,
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TFoot: null,
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// Standard structure type Caption
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Caption: null,
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// Standard structure type Figure
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Figure: "figure",
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// Standard structure type Formula
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Formula: null,
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// standard structure type Artifact
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Artifact: null,
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};
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const HEADING_PATTERN = /^H(\d+)$/;
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/**
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* @typedef {Object} StructTreeLayerBuilderOptions
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* @property {PDFPageProxy} pdfPage
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*/
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class StructTreeLayerBuilder {
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/**
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* @param {StructTreeLayerBuilderOptions} options
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*/
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constructor({ pdfPage }) {
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this.pdfPage = pdfPage;
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}
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render(structTree) {
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return this._walk(structTree);
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}
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_setAttributes(structElement, htmlElement) {
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if (structElement.alt !== undefined) {
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htmlElement.setAttribute("aria-label", structElement.alt);
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}
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if (structElement.id !== undefined) {
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htmlElement.setAttribute("aria-owns", structElement.id);
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}
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if (structElement.lang !== undefined) {
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htmlElement.setAttribute("lang", structElement.lang);
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}
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}
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_walk(node) {
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if (!node) {
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return null;
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}
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const element = document.createElement("span");
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if ("role" in node) {
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const { role } = node;
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const match = role.match(HEADING_PATTERN);
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if (match) {
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element.setAttribute("role", "heading");
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element.setAttribute("aria-level", match[1]);
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} else if (PDF_ROLE_TO_HTML_ROLE[role]) {
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element.setAttribute("role", PDF_ROLE_TO_HTML_ROLE[role]);
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}
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}
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this._setAttributes(node, element);
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if (node.children) {
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if (node.children.length === 1 && "id" in node.children[0]) {
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// Often there is only one content node so just set the values on the
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// parent node to avoid creating an extra span.
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this._setAttributes(node.children[0], element);
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} else {
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for (const kid of node.children) {
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element.append(this._walk(kid));
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}
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}
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}
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return element;
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}
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}
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export { StructTreeLayerBuilder };
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