HtmlTagDesc (JHOVE - JSTOR/Harvard Object Validation Environment 1.16.0 API)

java.lang.Object
- edu.harvard.hul.ois.jhove.module.html.HtmlTagDesc

Direct Known Subclasses:

HtmlTempTagDesc
```
public class HtmlTagDesc
extends Object
```
This class defines the permitted behavior of a particular HTML tag. The full descriptive power of a DTD description isn't implemented here, but content types and sequences of content are implemented.

Author:

Gary McGath

Field Summary

Fields
Modifier and Type	Field and Description
`protected int[]`	`_sequence` Array controlling the number of times each element of _contentArray may be used.
`static int`	`SEQ0_1` Value in _sequence indicating an element may be used 0 or 1 times.
`static int`	`SEQ0_MANY` Value in _sequence indicating an element may be used 0 or more times.
`static int`	`SEQ1` Value in _sequence indicating an element must be used exactly once.
`static int`	`SEQ1_MANY` Value in _sequence indicating an element may be used 1 or more times.

Constructor Summary

Constructors
Constructor and Description
`HtmlTagDesc(String name, boolean openTagRequired, boolean closeTagRequired, int[] sequence, List[] contentArray, List attributes)` Constructor for sequenced case.
`HtmlTagDesc(String name, boolean openTagRequired, boolean closeTagRequired, List content, List attributes)` Constructor for simple case.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addImplicitContainer(HtmlTagDesc container)` Provides the object with an array of element tags in which this element can be nested.
`protected boolean`	`allowsPCData()`
`protected boolean`	`allowsTag(String tag, HtmlDocDesc doc)` Reports whether this element allows a given tag name in its content.
`protected boolean`	`allowsTag(String tag, int index, HtmlDocDesc doc)` Reports whether this element allows a given tag name in its content, at the specified index.
`protected boolean`	`canAdvanceFrom(int index, int elemCount)` Reports whether it's legal to advance to the next content index.
`protected boolean`	`canGetMoreAt(int index, int elemCount)` Reports whether additional elements can be matched at the specified content index.
`boolean`	`excludesTag(String tag)` Returns `true` if a given tag is excluded within this element.
`protected List`	`implicitContainers(String tag)` Reports whether this element can be implicitly nested in an element with a given tag.
`protected boolean`	`isCloseTagRequired()` Returns true if the closing tag is required
`protected boolean`	`isContentEmpty()` Returns true if this element has empty content
`boolean`	`isTemp()` Reports whether this is a temporary tag descriptor.
`boolean`	`matches(String name)`
`protected List`	`missingRequiredAttributes(List names)` Accepts a list of attribute names, and returns a List of required attribute names which are not present in the parameter list.
`protected HtmlAttributeDesc`	`namedAttDesc(String name)` Returns the attribute with a given name, or null if no such attribute is defined for the element
`void`	`setAttributes(String[] attributeArray)` Alternative way of setting the attribute names.
`void`	`setExcludedContent(String[] content)` Specifies tags which may not be included in this element or in any element nested at any depth within it.

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

- Field Detail
  - _sequence
```
protected int[] _sequence
```
    Array controlling the number of times each element of _contentArray may be used.
  - SEQ0_1
```
public static final int SEQ0_1
```
    Value in _sequence indicating an element may be used 0 or 1 times.
    
    See Also:
    
    Constant Field Values
  - SEQ1
```
public static final int SEQ1
```
    Value in _sequence indicating an element must be used exactly once.
    
    See Also:
    
    Constant Field Values
  - SEQ1_MANY
```
public static final int SEQ1_MANY
```
    Value in _sequence indicating an element may be used 1 or more times.
    
    See Also:
    
    Constant Field Values
  - SEQ0_MANY
```
public static final int SEQ0_MANY
```
    Value in _sequence indicating an element may be used 0 or more times.
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - HtmlTagDesc
```
public HtmlTagDesc(String name,
                   boolean openTagRequired,
                   boolean closeTagRequired,
                   List content,
                   List attributes)
```
    Constructor for simple case.
    
    Parameters:
    
    name - Name of the element
    
    openTagRequired - true if an opening tag is required
    
    closeTagRequired - true if a closing tag is required
    
    content - List of permitted tags. But what do I do when a particular order is required? Null if element is defined at EMPTY.
    
    attributes - List of HtmlAttributeDesc elements enumerating the permitted attributes. May be null, in which case _attributes will be stored as an empty list.
  - HtmlTagDesc
```
public HtmlTagDesc(String name,
                   boolean openTagRequired,
                   boolean closeTagRequired,
                   int[] sequence,
                   List[] contentArray,
                   List attributes)
```
    Constructor for sequenced case.
    
    Parameters:
    
    name - Name of the element
    
    openTagRequired - true if an opening tag is required
    
    closeTagRequired - true if a closing tag is required
    
    sequence - Array indicating the sequencing of elements in content. Must have the same length as sequence.
    attributes - List of HtmlAttributeDesc elements enumerating the permitted attributes. May be null, in which case _attributes will be stored as an empty list.
Method Detail setExcludedContent public void setExcludedContent(String[] content) Specifies tags which may not be included in this element or in any element nested at any depth within it. Corresponds to the -(content) feature of the DTD. excludesTag public boolean excludesTag(String tag) Returns true if a given tag is excluded within this element. It is necessary to call this method for each element on the stack to determine if it is excluded. setAttributes public void setAttributes(String[] attributeArray) Alternative way of setting the attribute names. This can be used where all the attributes are unrestricted. This will replace any previously set attributes. addImplicitContainer public void addImplicitContainer(HtmlTagDesc container) Provides the object with an array of element tags in which this element can be nested. Only tags for elements with optional opening tags may be listed here. matches public boolean matches(String name) isTemp public boolean isTemp() Reports whether this is a temporary tag descriptor. Returns false unless overridden. allowsTag protected boolean allowsTag(String tag, int index, HtmlDocDesc doc) Reports whether this element allows a given tag name in its content, at the specified index. implicitContainers protected List implicitContainers(String tag) Reports whether this element can be implicitly nested in an element with a given tag. There may be more than one implicit container for a tag; if the DTD is unambiguous, there should be only one which is permissible in any given context. canGetMoreAt protected boolean canGetMoreAt(int index, int elemCount) Reports whether additional elements can be matched at the specified content index. The index is assumed to be legal. canAdvanceFrom protected boolean canAdvanceFrom(int index, int elemCount) Reports whether it's legal to advance to the next content index. The index is assumed to be legal, but the one to which it's trying to advance may not be. allowsTag protected boolean allowsTag(String tag, HtmlDocDesc doc) Reports whether this element allows a given tag name in its content. This version should be used only with element descriptors that aren't associated with tags, for determining if a hypothetical implied element could contain the given tag. allowsPCData protected boolean allowsPCData() namedAttDesc protected HtmlAttributeDesc namedAttDesc(String name) Returns the attribute with a given name, or null if no such attribute is defined for the element missingRequiredAttributes protected List missingRequiredAttributes(List names) Accepts a list of attribute names, and returns a List of required attribute names which are not present in the parameter list. Returns an empty List if all required attributes are present. isCloseTagRequired protected boolean isCloseTagRequired() Returns true if the closing tag is required isContentEmpty protected boolean isContentEmpty() Returns true if this element has empty content

Class HtmlTagDesc

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

_sequence

SEQ0_1

SEQ1

SEQ1_MANY

SEQ0_MANY

Constructor Detail

HtmlTagDesc

HtmlTagDesc

Method Detail

setExcludedContent

excludesTag

setAttributes

addImplicitContainer

matches

isTemp

allowsTag

implicitContainers

canGetMoreAt

canAdvanceFrom

allowsTag

allowsPCData

namedAttDesc

missingRequiredAttributes

isCloseTagRequired

isContentEmpty