HTMLHelper (Communote 3.5 API)

java.lang.Object
- com.communote.common.util.HTMLHelper

```
public final class HTMLHelper
extends Object
```
Helper class for HTML processing.

Author:

Communote GmbH - http://www.communote.com/

Field Summary

Fields
Modifier and Type	Field and Description
`static String`	`LINE_TERMINATORS_REGEX_CLASS` Regex class of line terminators.
`static Set<String>`	`NODES_TO_REMOVE_WHEN_EMPTY` Names of HTML tags whose nodes should be removed when they do not have a body.

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static String`	`closeBrTags(String htmlContent)` Converts br tags to the XHTML compatible form.
`static boolean`	`containsNonEmptyTextNodes(String htmlContent)` Tests whether the provided HTML contains non-empty text nodes.
`static String`	`convertHTMLListToText(String htmlContent)` Converts HTML lists to readable plain text representations.
`static String`	`convertXmlSerializedHtmlToLegalHtml(String xmlSerializedHtml)` Does some cleanup to convert HTML generated by serializing an HTML DOM with an XML processor to legal HTML.
`static String`	`encapsulateAttributesInQuotes(String htmlContent)` Some tools (e.g.
`static String`	`htmlToPlaintext(String htmlContent)` A simple helper which converts HTML to plain text which works similarly to `StringEscapeHelper.removeHtmlMarkup(String)`, but tries to preserve linebreaks by replacing closing paragraphs and br elements with newlines.
`static String`	`htmlToPlaintextExt(String htmlContent, boolean convertLists)` Helper method similar to `htmlToPlaintext(String)` with the difference that it uses a more advanced approach to replace HTML lists (namely by invoking `convertHTMLListToText(String)`).
`static String`	`plaintextToHTML(String plainText)` A simple helper which converts a plain text string to HTML by encapsulating all lines with paragraphs and escapes characters reserved in XML.
`static String`	`removeComments(String htmlContent)` Removes all HTML comments.
`static String`	`removeHeadElement(String htmlContent)` Strips the head element with all children from an HTML string.
`static String`	`removeNamespaces(String htmlContent)` Removes all namespace definitions and the nodes using these namespaces.
`static String`	`removeUnclosedMetaElements(String htmlContent)` Remove open meta elements.
`static String`	`stripLinebreaks(String htmlContent)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - NODES_TO_REMOVE_WHEN_EMPTY
```
public static final Set<String> NODES_TO_REMOVE_WHEN_EMPTY
```
    Names of HTML tags whose nodes should be removed when they do not have a body.
  - LINE_TERMINATORS_REGEX_CLASS
```
public static final String LINE_TERMINATORS_REGEX_CLASS
```
    Regex class of line terminators. Note: using this class for line break removal/replacement is not save because of '\r\n' combination which must be checked separately.
    
    See Also:
    
    Constant Field Values
- Method Detail
  - closeBrTags
```
public static String closeBrTags(String htmlContent)
```
    Converts br tags to the XHTML compatible form.
    
    Parameters:
    
    htmlContent - the content to process
    
    Returns:
    
    the processed content
  - containsNonEmptyTextNodes
```
public static boolean containsNonEmptyTextNodes(String htmlContent)
```
    Tests whether the provided HTML contains non-empty text nodes.
    
    Parameters:
    
    htmlContent - the HTML to test
    
    Returns:
    
    false if htmlContent is null or contains only whitespace (including Unicode codepoint 160) as text, true otherwise
  - convertHTMLListToText
```
public static String convertHTMLListToText(String htmlContent)
```
    Converts HTML lists to readable plain text representations. The lists can be nested ol or ul elements.
    
    Parameters:
    
    htmlContent - the HTML content to parse for lists
    
    Returns:
    
    the converted content
  - convertXmlSerializedHtmlToLegalHtml
```
public static String convertXmlSerializedHtmlToLegalHtml(String xmlSerializedHtml)
```
    Does some cleanup to convert HTML generated by serializing an HTML DOM with an XML processor to legal HTML.
    
    Parameters:
    
    xmlSerializedHtml - the HTML that was serialized by an XML processor
    
    Returns:
    
    the cleaned HTML
  - encapsulateAttributesInQuotes
```
public static String encapsulateAttributesInQuotes(String htmlContent)
```
    Some tools (e.g. M$-Outlook) create HTML where single-word attribute values are not encapsulated in quotes. Although this is legal HTML, it is not parsable by an XML parser. This method adds the quotes (double quotes).
    
    Parameters:
    
    htmlContent - The content as HTML.
    
    Returns:
    
    the repaired content
  - htmlToPlaintext
```
public static String htmlToPlaintext(String htmlContent)
```
    A simple helper which converts HTML to plain text which works similarly to StringEscapeHelper.removeHtmlMarkup(String), but tries to preserve linebreaks by replacing closing paragraphs and br elements with newlines. More over list items are surrounded by minus and newline character.
    
    Parameters:
    
    htmlContent - the HTML content
    
    Returns:
    
    the plain text version
  - htmlToPlaintextExt
```
public static String htmlToPlaintextExt(String htmlContent,
                                        boolean convertLists)
```
    Helper method similar to htmlToPlaintext(String) with the difference that it uses a more advanced approach to replace HTML lists (namely by invoking convertHTMLListToText(String)). This method also converts hyperlinks into text representation using UrlHelper.convertAnchorsToString(String).
    
    Parameters:
    
    htmlContent - the HTML content
    
    convertLists - whether to convert HTML lists. If true lists will be converted by invoking convertHTMLListToText(String). If false, list entries will only be separated by line breaks.
    
    Returns:
    
    the plain text version
  - plaintextToHTML
```
public static String plaintextToHTML(String plainText)
```
    A simple helper which converts a plain text string to HTML by encapsulating all lines with paragraphs and escapes characters reserved in XML.
    
    Parameters:
    
    plainText - the plain text
    
    Returns:
    
    the converted string
  - removeComments
```
public static String removeComments(String htmlContent)
```
    Removes all HTML comments.
    
    Parameters:
    
    htmlContent - the HTML content
    
    Returns:
    
    the content without comments
  - removeHeadElement
```
public static String removeHeadElement(String htmlContent)
```
    Strips the head element with all children from an HTML string.
    
    Parameters:
    
    htmlContent - the content to process
    
    Returns:
    
    the htmlContent without meta tags
  - removeNamespaces
```
public static String removeNamespaces(String htmlContent)
```
    Removes all namespace definitions and the nodes using these namespaces. The body of the nodes will be kept.
    
    Parameters:
    
    htmlContent - the content to process
    
    Returns:
    
    the cleaned content
  - removeUnclosedMetaElements
```
public static String removeUnclosedMetaElements(String htmlContent)
```
    Remove open meta elements.
    
    Parameters:
    
    htmlContent - the HTML content
    
    Returns:
    
    the cleaned content
  - stripLinebreaks
```
public static String stripLinebreaks(String htmlContent)
```

Class HTMLHelper

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

NODES_TO_REMOVE_WHEN_EMPTY

LINE_TERMINATORS_REGEX_CLASS

Method Detail

closeBrTags

containsNonEmptyTextNodes

convertHTMLListToText

convertXmlSerializedHtmlToLegalHtml

encapsulateAttributesInQuotes

htmlToPlaintext

htmlToPlaintextExt

plaintextToHTML

removeComments

removeHeadElement

removeNamespaces

removeUnclosedMetaElements

stripLinebreaks