From 1f06058af1e4c76a69276a6113eaf02f2bc4ab2f Mon Sep 17 00:00:00 2001
From: john gravois <jgravois@esri.com>
Date: Fri, 21 Sep 2018 11:39:56 -0700
Subject: [PATCH] docs(:book:): adapt built in acetate helper to fix sticky
 links

ISSUES CLOSED: #284
---
 docs/acetate.config.js | 109 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 107 insertions(+), 2 deletions(-)

diff --git a/docs/acetate.config.js b/docs/acetate.config.js
index 4d4c7fcabc..3c9553e70a 100644
--- a/docs/acetate.config.js
+++ b/docs/acetate.config.js
@@ -2,10 +2,35 @@ const path = require("path");
 const fs = require("fs");
 const { inspect } = require("util");
 const _ = require("lodash");
-const slug = require("slug");
 
 const IS_DEV = process.env.ENV !== "prod";
-const BASE_URL = process.env.ENV === "prod" ? "/arcgis-rest-js" : "";
+const BASE_URL = IS_DEV ? "" : "/arcgis-rest-js";
+
+const url = require("url");
+const PROTOCOL_REGEX = /^(.+:)?\/\//;
+const HASH_REGEX = /^#/;
+
+function stripSlashes(string = "") {
+  var count = string.length - 1;
+  var index = 0;
+
+  while (string.charCodeAt(index) === 47 && ++index);
+  while (string.charCodeAt(count) === 47 && --count);
+
+  string = string.slice(index, count + 1);
+
+  return string;
+}
+
+function ensureTrailingSlash(baseUrl) {
+  let ext = path.extname(baseUrl);
+
+  if (!ext && baseUrl[baseUrl.length - 1] !== "/") {
+    baseUrl = baseUrl + "/";
+  }
+
+  return baseUrl;
+}
 
 module.exports = function(acetate) {
   /**
@@ -211,4 +236,84 @@ module.exports = function(acetate) {
       : [];
     return `npm install ${package.name} ${peers.join(" ")}`;
   });
+
+  acetate.helper(
+    "link",
+    function(context, destinationUrl, text) {
+      const currentUrl = context.options.currentUrl || context.page.url;
+      const options = context.options;
+      let finalUrl;
+      let isActive = false;
+
+      if (
+        PROTOCOL_REGEX.test(destinationUrl) ||
+        HASH_REGEX.test(destinationUrl)
+      ) {
+        finalUrl = destinationUrl;
+      } else {
+        finalUrl = url.resolve(currentUrl, destinationUrl);
+
+        // strip all leading and trailing slashes
+        finalUrl = stripSlashes(finalUrl);
+
+        // ensure we have leading slash unless this starts with a protocol
+        if (!PROTOCOL_REGEX.test(finalUrl) && finalUrl[0] !== "/") {
+          finalUrl = `/${finalUrl}`;
+        }
+
+        // ensure there is a trailing slash unless there is a extension
+        // and remove index.html
+        let parsedUrl = url.parse(finalUrl);
+        parsedUrl.pathname = ensureTrailingSlash(parsedUrl.pathname).replace(
+          "index.html",
+          ""
+        );
+
+        finalUrl = url.format(parsedUrl);
+      }
+
+      const hrefAttr = `href="${finalUrl}"`;
+      const idAttr = options.id ? `id="${options.id}"` : "";
+      if (`${BASE_URL}${currentUrl}` === finalUrl) {
+        isActive = true;
+      } else if (PROTOCOL_REGEX.test(destinationUrl)) {
+        isActive = false;
+      } else if (HASH_REGEX.test(destinationUrl)) {
+        isActive = true;
+      } else if (options.requireExactMatch) {
+        isActive = `${BASE_URL}${currentUrl}` === finalUrl;
+      } else {
+        let parsedUrl = url.parse(finalUrl);
+
+        isActive = `${BASE_URL}${currentUrl}`.match(parsedUrl.pathname) && finalUrl !== "/";
+      }
+
+      const classes = isActive
+        ? _([options.activeClass, options.class])
+            .compact()
+            .join(" ")
+        : options.class;
+      const classAttr = classes && classes.length ? `class="${classes}"` : "";
+
+      delete options.id;
+      delete options.activeClass;
+      delete options.class;
+      delete options.requireExactMatch;
+      delete options.currentUrl;
+
+      const attrs = _(options)
+        .map((value, key) => `${key}="${value}"`)
+        .reverse()
+        .concat([classAttr, idAttr, hrefAttr])
+        .reverse()
+        .compact()
+        .join(" ");
+
+      return `<a ${attrs}>${text}</a>`;
+    },
+    {
+      activeClass: "is-active",
+      requireExactMatch: false
+    }
+  );
 };