package com.brainysoftware;

import javax.servlet.jsp.*;
import javax.servlet.jsp.tagext.*;

public class EncoderTag implements BodyTag {

  PageContext pageContext;
  BodyContent bodyContent;

  /**
   * Encode an HTML tag so it will be displayed
   * as it is on the browser.
   * Particularly, this method searches the
   * passed in String and replace every occurrence
   * of the following character:
   * '<' with "&lt;"
   * '>' with "&gt;"
   * '&' with "&amp;"
   * //'"' with "&quot;"
   * ' ' with "&nbsp;"
   */
  private String encodeHtmlTag(String tag) {
    if (tag==null)
      return null;
    int length = tag.length();
    StringBuffer encodedTag = new StringBuffer(2 * length);
    for (int i=0; i<length; i++) {
      char c = tag.charAt(i);
      if (c=='<')
        encodedTag.append("&lt;");
      else if (c=='>')
        encodedTag.append("&gt;");
      else if (c=='&')
        encodedTag.append("&amp;");
      else if (c=='"')
        encodedTag.append("&quot;");  
        //when trying to output text as tag's value as in
        // values="???".
      else if (c==' ')
        encodedTag.append("&nbsp;");
      else
        encodedTag.append(c);

    }
    return encodedTag.toString();
  }

  public void setParent(Tag t) {
  }

  public void setPageContext(PageContext p) {
    pageContext = p;
  }

  public void release() {
  }

  public Tag getParent() {
    return null;
  }

  public int doStartTag() {
    return EVAL_BODY_BUFFERED;
  }

  public void setBodyContent(BodyContent bodyContent) {
    this.bodyContent = bodyContent;
  }

  public void doInitBody() {

  }
  public int doAfterBody() {
    String content = bodyContent.getString();
    try{
      JspWriter out = bodyContent.getEnclosingWriter();
      out.print(encodeHtmlTag(content));
    }
    catch(Exception e) {}

    return SKIP_BODY;
  }

  public int doEndTag() throws JspException {
    return EVAL_PAGE;
  }
}