com.viaoa.jfc.editor.html.OAHTMLParser Maven / Gradle / Ivy

Go to download
/*  Copyright 1999-2015 Vince Via [email protected]
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
*/
package com.viaoa.jfc.editor.html;

/** 
    Parse and "clean up" HTML code.
    Currently used by Editor to convert pasted code from Microsoft Word.
    This needs to be set up to convert styles to HTML tags.
*/
public class OAHTMLParser {
    HTMLTokenManager tokenManager;
    HTMLToken token;

    public static final int EOF = 1;
    public static final int VARIABLE = 2;
    public static final int GT = 3;
    public static final int LT = 4;
    public static final int EQUAL = 5;
    public static final int STRING = 6;
    public static final int SQ = 7; // single quote
    public static final int DQ = 8; // double quote
    public static final int SLASH = 9; // "/>"
    public static final int COMMENT = 10; 


    public OAHTMLParser() {
        tokenManager = new HTMLTokenManager();
    }

    public boolean isMicrosoft(String code) {
        return (code != null && code.toLowerCase().indexOf("urn:schemas-microsoft-com") >= 0);
    }

    /**
        Removes all code outside and including html body tags, and leading white space and leading paragraphs
    */
    public static String removeBody(String code) {
        if (code == null) return null;

        String lcode = code.toLowerCase();
        
        int beginPos = 0;
        int endPos = code.length();
        
        String tag = "body";
        beginPos = lcode.indexOf("<"+tag);
        if (beginPos < 0) {
            tag = "html";
            beginPos = lcode.indexOf("<"+tag);
        }
        if (beginPos >= 0) {
            beginPos = code.indexOf(">", beginPos);
            if (beginPos > 0) {
                beginPos++;
                endPos = lcode.indexOf(" .. 
            endPos = lcode.indexOf("= 0) {
                code = code.substring(0, endPos);
                lcode = lcode.substring(0, endPos);
            }
            else {
                return code;
            }
        }
        

        // skip all whitespace and leading 
        boolean bRemovedP = false;
        for ( ;; ) {
            for ( ; beginPos < endPos; beginPos++) {
                if (!Character.isWhitespace(code.charAt(beginPos))) break;
            }
         
            String s = "";
            if (lcode.startsWith(s, beginPos)) {
                beginPos += s.length();
                bRemovedP = false;
            }
            else {
                s = "", beginPos);
                if (pos < 0) break;
                if (pos - beginPos > 5) {
                    if (!lcode.startsWith("", beginPos)) break; // 
 has attribute data
                }
                if (pos >= 0) {
                    beginPos = pos+1;
                    bRemovedP = true;
                }
            }
        }            
        if (beginPos > 0) {
            // remove ending whitespace
            for (;;) {
                for ( ; endPos > beginPos; endPos--) {
                    if (!Character.isWhitespace(code.charAt(endPos-1))) break;
                }
                
                if (!bRemovedP) break;
                bRemovedP = false;
                // remove last 
                String s = "";
                int pos = lcode.indexOf(s, endPos-s.length());
                if (pos > 0) endPos = pos;
            }   
            if (endPos >= beginPos) {
                code = code.substring(beginPos, endPos);
            }
        }
        
        return code;
    }


    public String convert(String code) {
        return convert(code, true);
    }

    /** convert HTML to safe HTML 
        Strips all span tags, style attributes, 
        makes sure that all attribute values are in quotes
        ignores bogus attribute names
    */
    public String convert(String code, boolean bStrict) {
        code = convertBadChars(code, bStrict);
        // 20120505 added bStrict
        StringBuffer sb = new StringBuffer(code.length());
        tokenManager.setCode(code);

        for (;;) {
            if (token != null && token.type == EOF) break;
            nextToken();
            if (token.type == EOF) break;

            if (token.whitespace != null) sb.append(token.whitespace);
            
            if (token.type != LT) {
                if (token.type == COMMENT) continue;
                if (token.type == SQ) sb.append("'");
                else if (token.type == DQ) sb.append("\"");
                sb.append(token.value);
                if (token.type == SQ) sb.append("'");
                else if (token.type == DQ) sb.append("\"");
                continue;
            }
            
            // process begin tag "<"
            nextToken();
            boolean bSlash = false;
            if (token.type == SLASH) {
                bSlash = true;
                nextToken();
            }
            
            if (bStrict) {
            if (token.type != VARIABLE || (token.value != null && token.value.equalsIgnoreCase("SPAN"))) {
                // bad tag name - find ending GT
                for (;;) {
                    nextToken();
                    if (token == null) break;
                    if (token.type == GT) break;
                    if (token.type == EOF) break;
                }
                continue;
            }
            }
            sb.append("<");
            if (bSlash) sb.append("/");
            sb.append(token.value.toLowerCase()); // TAG Name
            nextToken();
            
            // get attribute name=value pairs
            for (;;) { 
                if (token.type == SLASH) break;
                if (token.type == GT) break;
                if (token.type == EOF) break;

                if (bStrict) {
                // need to strip/ignore all "styles"
                if (token.value != null) {
                    if (token.value.equalsIgnoreCase("style")) {
                        token.type = STRING; 
                    }
                    else if (token.value.equalsIgnoreCase("class")) token.type = STRING; 
                    else if (token.value.equalsIgnoreCase("id")) token.type = STRING; 
                }
                }
                
                if (token.type != VARIABLE) {
                    // bad attribute name - find next attribute or ending GT
                    for (;;) {
                        nextToken();
                        if (token.type == SLASH) break;
                        if (token.type == GT) break;
                        if (token.type == EOF) break;
                        if (token.type == EQUAL) {
                            nextToken(); // skip value
                            if (token.type != EOF) nextToken();
                            break;
                        }
                    }
                    continue;
                }
                
                String s = token.value;
                nextToken();
                if (token.type == EQUAL) {
                    sb.append(' ' + s + " = ");
                    nextToken();
                    if (token.type == VARIABLE) sb.append("'" + token.value + "'");
                    else if (token.type == SQ) sb.append("'" + token.value + "'");
                    else if (token.type == DQ) sb.append("\"" + token.value + "\"");
                    else if (token.type == STRING) sb.append("\'" + token.value + "\'");
                    nextToken();
                }
            }     
            if (token.type == SLASH) {
                sb.append("/");
                nextToken();
            }
                
            sb.append(">");
        }
        return new String(sb);
    }

    protected String convertBadChars(String code, boolean bStrict) {
        int len = code.length();
        StringBuilder sb = new StringBuilder(len);
        for (int i=0; i 8000) {
                if (ch == 8216) ch = '\'';
                else if (ch == 8217) ch = '\'';
                else if (ch == 8220) ch = '"';
                else if (ch == 8221) ch = '"';
                else if (ch == 8211) ch = '-';
                else if (!bStrict && ch == 8482) {
                    // trademark
                    sb.append("™"); 
                    ch = ';'; 
                }
                else  {
                    if (bStrict) continue;
                    
                    sb.append("&#"+((int)ch)); 
                    ch = ';'; 
                }
            }
            else if (ch == 25) ch = '\'';
            else if (ch > 127 || (ch < 32 && (ch < 9 || ch > 12)) ) {
                ch = ' ';
            }
            sb.append(ch);
        }
        return new String(sb);
    }


    protected void nextToken() {
        token = tokenManager.getNext();
        // System.out.println("TOKEN"+token.type+": "+token.value);
    }

}


class HTMLToken {
    public int type;
    public String value;
    public String whitespace;
}


class HTMLTokenManager {
    String code;
    int len;
    int pos = 0;
    StringBuilder sb;


    public void setCode(String code) {
        this.code = code;
        len = code.length();
        sb = new StringBuilder(len);
    }

    public HTMLToken getNext() {
        HTMLToken token = new HTMLToken();
        char chQuote = 0;
        sb.delete(0, len-1);
        boolean bReturn = false;
        char ch=0;

        int dashCount = 0;
        int commentCount = 0;
        boolean bCodeComment = false;
        for ( ; !bReturn && pos' && bCodeComment) {
                    pos++;
                    break; // end of code
                }
                if (ch == '>' && dashCount >= 2) {
                    if (--commentCount == 0) {
                        pos++;
                        break;
                    }
                }
                if (ch == '-') dashCount++;
                else dashCount = 0;
                continue;
            }

            // convert MS Word smart quotes
            if (ch > 8000) {
                if (ch == 8216) ch = '\'';
                else if (ch == 8217) ch = '\'';
                else if (ch == 8220) ch = '"';
                else if (ch == 8221) ch = '"';
                else if (ch == 8211) ch = '-';
                else if (ch == 8482) {
                    sb.append("™"); // trademark
                    ch = ';';
                }
            }
            if (ch > 127) ch = ' ';
            if (ch < 32 && (ch < 9 || ch > 12)) {
                ch = ' ';
            }
            
            if (chQuote != 0) {
                if (ch == chQuote) {
                    bReturn = true;
                    continue;
                }
                sb.append(ch);
                continue;
            }

            if (ch == ' ' || ch == '\t' || ch == '\f' || ch == '\n' || ch == '\r') {
                if (token.type != 0) break;
                else {
                    if (token.whitespace == null) token.whitespace = "";
                    token.whitespace += ""+ch;
                }
                continue;
            }

            if (ch == '\'' || ch == '\"') {
                if (token.type == 0) {
                    chQuote = ch;
                    if (ch == '\'') token.type = OAHTMLParser.SQ;
                    else token.type = OAHTMLParser.DQ;
                    continue;
                }
            }
            else if (ch == '/' && token.type == 0) {
                if (token.type != 0) {
                    if (chNext == '>') break;
                    else token.type = OAHTMLParser.STRING;
                }
                else {
                    token.type = OAHTMLParser.SLASH;
                    bReturn = true;
                }
            }
            else if (ch == '>') {
                if (token.type != 0) break;
                else {
                    token.type = OAHTMLParser.GT;
                    bReturn = true;
                }
            }
            else if (ch == '<') {
                if (token.type != 0) break;
                else {
                    token.type = OAHTMLParser.LT;
                }
            }
            else if (ch == '=') {
                if (token.type != 0) break;
                else {
                    token.type = OAHTMLParser.EQUAL;
                    bReturn = true;
                }
            }
            else if ( (token.type == 0 || token.type == OAHTMLParser.VARIABLE) && ( (ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z') || ch == '_') ) {
                token.type = OAHTMLParser.VARIABLE;
            }
            else {
                if (token.type != OAHTMLParser.SQ && token.type != OAHTMLParser.DQ) token.type = OAHTMLParser.STRING;
            }
            
            sb.append(ch);
        }

        token.value = new String(sb);

        if (token.type == 0) token.type = OAHTMLParser.EOF;
        return token;
    }
}