feat(uniqueHeaderId): add unique id prefix and suffix to headers

If two headers have similar texts, the generated id could be equal. In order to prevent id clash: - A unique suffix is added if a header id already exists - Option to add a prefix to header id - Update of correspondent tests - (credits to nicovalencia) Closes #81, closes #82
showdownjs · Jan 18, 2015 · c367a4b · c367a4b
1 parent c9de4b6
commit c367a4b
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Showing 8 changed files with 81 additions and 13 deletions.
diff --git a/dist/showdown.js b/dist/showdown.js
diff --git a/dist/showdown.js.map b/dist/showdown.js.map
diff --git a/dist/showdown.min.js b/dist/showdown.min.js
diff --git a/dist/showdown.min.js.map b/dist/showdown.min.js.map
diff --git a/src/showdown.js b/src/showdown.js
@@ -6,7 +6,8 @@
 var showdown = {},
     parsers = {},
     globalOptions = {
-        omitExtraWLInCodeBlocks: false
+        omitExtraWLInCodeBlocks: false,
+        prefixHeaderId: false
     };
 
 ///////////////////////////////////////////////////////////////////////////
@@ -29,10 +30,17 @@ showdown.extensions = {};
 //Public methods
 showdown.setOption = function (key, value) {
     globalOptions[key] = value;
-
     return this;
 };
 
+showdown.getOption = function (key) {
+    return globalOptions[key];
+};
+
+showdown.getOptions = function () {
+    return globalOptions;
+};
+
 /**
  * Static Method
  *
@@ -97,7 +105,8 @@ showdown.Converter = function (converterOptions) {
             gHtmlBlocks: [],
             gUrls: {},
             gTitles: {},
-            gListLevel: 0
+            gListLevel: 0,
+            hashLinkCounts: {}
         };
 
         // attacklab: Replace ~ with ~T

diff --git a/src/subParsers/headers.js b/src/subParsers/headers.js
@@ -5,6 +5,8 @@
 showdown.subParser('headers', function (text, options, globals) {
     'use strict';
 
+    var prefixHeader = options.prefixHeaderId;
+
     // Set text-style headers:
     //	Header 1
     //	========
@@ -52,7 +54,25 @@ showdown.subParser('headers', function (text, options, globals) {
         });
 
     function headerId(m) {
-        return m.replace(/[^\w]/g, '').toLowerCase();
+        var title,
+            escapedId = m.replace(/[^\w]/g, '').toLowerCase();
+
+        if (globals.hashLinkCounts[escapedId]) {
+            title = escapedId + '-' + (globals.hashLinkCounts[escapedId]++);
+        } else {
+            title = escapedId;
+            globals.hashLinkCounts[escapedId] = 1;
+        }
+
+        // Prefix id to prevent causing inadvertent pre-existing style matches.
+        if (prefixHeader === true) {
+            prefixHeader = 'section';
+        }
+
+        if (showdown.helper.isString(prefixHeader)) {
+            return prefixHeader + title;
+        }
+        return title;
     }
 
     return text;

diff --git a/test/cases/repeated-headers.html b/test/cases/repeated-headers.html
@@ -0,0 +1,5 @@
+<h1 id="sametitle">Same Title</h1>
+
+<p>some text</p>
+
+<h1 id="sametitle-1">Same Title</h1>
diff --git a/test/cases/repeated-headers.md b/test/cases/repeated-headers.md
@@ -0,0 +1,5 @@
+# Same Title
+
+some text
+
+# Same Title