简单 html parser （未完成）

lib/parser.js

@@ -0,0 +1,179 @@
+/**
+ * 简单 HTML Parser
+ *
+ * @author 老雷<leizongmin@gmail.com>
+ */
+
+
+/**
+ * 获取标签的名称
+ *
+ * @param {String} html 如：'<a hef="#">'
+ * @return {String}
+ */
+function getTagName (html) {
+  var i = html.indexOf(' ');
+  if (i === -1) {
+    var tagName = html.slice(1, -1);
+  } else {
+    var tagName = html.slice(1, i + 1);
+  }
+  tagName = tagName.trim().toLowerCase();
+  if (tagName[0] === '/') tagName = tagName.slice(1);
+  return tagName;
+}
+
+/**
+ * 是否为闭合标签
+ *
+ * @param {String} html 如：'<a hef="#">'
+ * @return {Boolean}
+ */
+function isClosing (html) {
+  return (html.slice(0, 2) === '</');
+}
+
+/**
+ * 分析HTML代码，调用相应的函数处理，返回处理后的HTML
+ *
+ * @param {String} html
+ * @param {Function} onTag 处理标签的函数
+ *   参数格式： function (originPosition, position, tag, html, isClosing)
+ * @param {Function} escapeHtml 对HTML进行转义的韩松
+ * @return {String}
+ */
+function parseTag (html, onTag, escapeHtml) {
+  'user strict';
+
+  var rethtml = '';        // 待返回的HTML
+  var lastPos = 0;         // 上一个标签结束位置
+  var tagStart = false;    // 当前标签开始位置
+  var quoteStart = false;  // 引号开始位置
+  var currentPos = 0;      // 当前位置
+  var len = html.length;   // HTML长度
+  var currentHtml = '';    // 当前标签的HTML代码
+  var currentTagName = ''; // 当前标签的名称
+
+  // 逐个分析字符
+  for (currentPos = 0; currentPos < len; currentPos++) {
+    var c = html.charAt(currentPos);
+    if (tagStart === false) {
+      if (c === '<') {
+        tagStart = currentPos;
+        continue;
+      }
+    } else {
+      if (quoteStart === false) {
+        if (c === '<') {
+          rethtml += escapeHtml(html.slice(lastPos, currentPos));
+          tagStart = currentPos;
+          lastPos = currentPos;
+          continue;
+        }
+        if (c === '>') {
+          rethtml += escapeHtml(html.slice(lastPos, tagStart));
+          currentHtml = html.slice(tagStart, currentPos + 1);
+          currentTagName = getTagName(currentHtml);
+          rethtml += onTag(currentPos,
+                           rethtml.length,
+                           currentTagName,
+                           currentHtml,
+                           isClosing(currentHtml));
+          lastPos = currentPos + 1;
+          tagStart = false;
+          continue;
+        }
+        if (c === '"' || c === "'") {
+          quoteStart = c;
+          continue;
+        }
+      } else {
+        if (c === quoteStart) {
+          quoteStart = false;
+          continue;
+        }
+      }
+    }
+  }
+  if (lastPos < html.length) {
+    rethtml += escapeHtml(html.substr(lastPos));
+  }
+
+  return rethtml;
+}
+
+// 不符合属性名称规则的正则表达式
+var REGEXP_ATTR_NAME = /[^a-zA-Z0-9_:\.\-]/img;
+
+/**
+ * 分析标签HTML代码，调用相应的函数处理，返回HTML
+ *
+ * @param {String} html 如标签'<a href="#" target="_blank">' 则为 'href="#" target="_blank"'
+ * @param {Function} onAttr 处理属性值的函数
+ *   函数格式： function (name, value)
+ * @return {String}
+ */
+function parseAttr (html, onAttr) {
+  'user strict';
+
+  var lastPos = 0;        // 当前位置
+  var retHtml = '';       // 待返回的HTML
+  var tmpName = false;    // 临时属性名称
+  var len = html.length;  // HTML代码长度
+
+  function addAttr (name, value) {
+    name =  name.trim();
+    name = name.replace(REGEXP_ATTR_NAME, '').toLowerCase();
+    if (name.length < 1) return;
+    retHtml += onAttr(name, value);
+  };
+
+  // 逐个分析字符
+  for (var i = 0; i < len; i++) {
+    var c = html.charAt(i),v;
+    if (tmpName === false && c === '=') {
+      tmpName = html.slice(lastPos, i);
+      lastPos = i + 1;
+      continue;
+    }
+    if (tmpName !== false) {
+      if (i === lastPos && (c === '"' || c === "'")) {
+        var j = html.indexOf(c, i + 1);
+        if (j === -1) {
+          break;
+        } else {
+          v = html.slice(lastPos + 1, j).trim();
+          addAttr(tmpName, v);
+          tmpName = false;
+          i = j;
+          lastPos = i + 1;
+          continue;
+        }
+      }
+    }
+    if (c === ' ') {
+      v = html.slice(lastPos, i).trim();
+      if (tmpName === false) {
+        addAttr(v);
+      } else {
+        addAttr(tmpName, v);
+      }
+      tmpName = false;
+      lastPos = i + 1;
+      continue;
+    }
+  }
+
+  if (lastPos < html.length) {
+    if (tmpName === false) {
+      addAttr(html.slice(lastPos));
+    } else {
+      addAttr(tmpName, html.slice(lastPos));
+    }
+  }
+
+  return retHtml.trim();
+}
+
+exports.parseTag = parseTag;
+exports.parseAttr = parseAttr;