org.htmlparser.lexer

Class PageAttribute

Implemented Interfaces:
Serializable

public class PageAttribute
extends Attribute

An attribute within a tag on a page. This attribute is similar to Attribute but 'lazy loaded' from the Page by providing the page and cursor offsets into the page for the name and value. This is done for speed, since if the name and value are not needed we can avoid the cost and memory overhead of creating the strings.

Thus the property getters, defer to the base class unless the property is null, in which case an attempt is made to read it from the underlying page. Optimizations in the predicates and length calculation defer the actual instantiation of strings until absolutely needed.

Field Summary

protected int
mNameEnd
The ending offset of the name within the page.
protected int
mNameStart
The starting offset of the name within the page.
protected Page
mPage
The page this attribute is extracted from.
protected int
mValueEnd
The ending offset of the name within the page.
protected int
mValueStart
The starting offset of the value within the page.

Fields inherited from class org.htmlparser.Attribute

mAssignment, mName, mQuote, mValue

Constructor Summary

PageAttribute()
Create an empty attribute.
PageAttribute(String value)
Create a whitespace attribute with the value given.
PageAttribute(String name, String value)
Create an attribute with the name and value given.
PageAttribute(String name, String assignment, String value)
Create an attribute with the name, assignment string and value given.
PageAttribute(String name, String assignment, String value, char quote)
Create an attribute with the name, assignment string, value and quote given.
PageAttribute(String name, String value, char quote)
Create an attribute with the name, value and quote given.
PageAttribute(Page page, int name_start, int name_end, int value_start, int value_end, char quote)
Create an attribute.

Method Summary

String
getAssignment()
Get the assignment string of this attribute.
void
getAssignment(StringBuffer buffer)
Get the assignment string of this attribute.
int
getLength()
Get the length of the string value of this attribute.
String
getName()
Get the name of this attribute.
void
getName(StringBuffer buffer)
Get the name of this attribute.
int
getNameEndPosition()
Get the ending position of the attribute name.
int
getNameStartPosition()
Get the starting position of the attribute name.
Page
getPage()
Get the page this attribute is anchored to, if any.
String
getRawValue()
Get the raw value of the attribute.
void
getRawValue(StringBuffer buffer)
Get the raw value of the attribute.
String
getValue()
Get the value of the attribute.
void
getValue(StringBuffer buffer)
Get the value of the attribute.
int
getValueEndPosition()
Get the ending position of the attribute value.
int
getValueStartPosition()
Get the starting position of the attribute value.
boolean
isEmpty()
Predicate to determine if this attribute has an equals sign but no value.
boolean
isStandAlone()
Predicate to determine if this attribute has no equals sign (or value).
boolean
isValued()
Predicate to determine if this attribute has a value.
boolean
isWhitespace()
Predicate to determine if this attribute is whitespace.
void
setNameEndPosition(int end)
Set the ending position of the attribute name.
void
setNameStartPosition(int start)
Set the starting position of the attribute name.
void
setPage(Page page)
Set the page this attribute is anchored to.
void
setValueEndPosition(int end)
Set the ending position of the attribute value.
void
setValueStartPosition(int start)
Set the starting position of the attribute value.

Methods inherited from class org.htmlparser.Attribute

getAssignment, getAssignment, getLength, getName, getName, getQuote, getQuote, getRawValue, getRawValue, getValue, getValue, isEmpty, isStandAlone, isValued, isWhitespace, setAssignment, setName, setQuote, setRawValue, setValue, toString, toString

Field Details

mNameEnd

protected int mNameEnd
The ending offset of the name within the page.

mNameStart

protected int mNameStart
The starting offset of the name within the page. If negative, the name is considered null.

mPage

protected Page mPage
The page this attribute is extracted from.

mValueEnd

protected int mValueEnd
The ending offset of the name within the page.

mValueStart

protected int mValueStart
The starting offset of the value within the page. If negative, the value is considered null.

Constructor Details

PageAttribute

public PageAttribute()

PageAttribute

public PageAttribute(String value)
            throws IllegalArgumentException
Create a whitespace attribute with the value given.
Parameters:
value - The value of this attribute.

PageAttribute

public PageAttribute(String name,
                     String value)
Create an attribute with the name and value given. Uses an equals sign as the assignment string if the value is not null, and calls PageAttribute to get the correct quoting.
Parameters:
name - The name of this attribute.
value - The value of this attribute.

PageAttribute

public PageAttribute(String name,
                     String assignment,
                     String value)
Create an attribute with the name, assignment string and value given. Calls PageAttribute to get the correct quoting.
Parameters:
name - The name of this attribute.
assignment - The assignment string of this attribute.
value - The value of this attribute.

PageAttribute

public PageAttribute(String name,
                     String assignment,
                     String value,
                     char quote)
Create an attribute with the name, assignment string, value and quote given. If the quote value is zero, assigns the value using PageAttribute which sets the quote character to a proper value if necessary.
Parameters:
name - The name of this attribute.
assignment - The assignment string of this attribute.
value - The value of this attribute.
quote - The quote around the value of this attribute.

PageAttribute

public PageAttribute(String name,
                     String value,
                     char quote)
Create an attribute with the name, value and quote given. Uses an equals sign as the assignment string if the value is not null, and calls PageAttribute to get the correct quoting if quote is zero.
Parameters:
name - The name of this attribute.
value - The value of this attribute.
quote - The quote around the value of this attribute.

PageAttribute

public PageAttribute(Page page,
                     int name_start,
                     int name_end,
                     int value_start,
                     int value_end,
                     char quote)
Create an attribute.
Parameters:
page - The page containing the attribute.
name_start - The starting offset of the name within the page. If this is negative, the name is considered null.
name_end - The ending offset of the name within the page.
value_start - he starting offset of the value within the page. If this is negative, the value is considered null.
value_end - The ending offset of the value within the page.
quote - The quote, if any, surrounding the value of the attribute, (i.e. ' or "), or zero if none.

Method Details

getAssignment

public String getAssignment()
Get the assignment string of this attribute. This is usually just an equals sign, but in poorly formed attributes it can include whitespace on either or both sides of an equals sign.
Overrides:
getAssignment in interface Attribute
Returns:
The assignment string.

getAssignment

public void getAssignment(StringBuffer buffer)
Get the assignment string of this attribute.
Overrides:
getAssignment in interface Attribute
Parameters:
buffer - The buffer to place the assignment string in.

getLength

public int getLength()
Get the length of the string value of this attribute.
Overrides:
getLength in interface Attribute
Returns:
The number of characters required to express this attribute.

getName

public String getName()
Get the name of this attribute. The part before the equals sign, or the contents of the stand-alone attribute.
Overrides:
getName in interface Attribute
Returns:
The name, or null if it's just a whitepace 'attribute'.

getName

public void getName(StringBuffer buffer)
Get the name of this attribute.
Overrides:
getName in interface Attribute
Parameters:
buffer - The buffer to place the name in.
See Also:
getName()

getNameEndPosition

public int getNameEndPosition()
Get the ending position of the attribute name.
Returns:
The offset into the page at which the name ends.

getNameStartPosition

public int getNameStartPosition()
Get the starting position of the attribute name.
Returns:
The offset into the page at which the name begins.

getPage

public Page getPage()
Get the page this attribute is anchored to, if any.
Returns:
The page used to construct this attribute, or null if this is just a regular attribute.

getRawValue

public String getRawValue()
Get the raw value of the attribute. The part after the equals sign, or the text if it's just a whitepace 'attribute'. This includes the quotes around the value if any.
Overrides:
getRawValue in interface Attribute
Returns:
The value, or null if it's a stand-alone attribute, or the text if it's just a whitepace 'attribute'.

getRawValue

public void getRawValue(StringBuffer buffer)
Get the raw value of the attribute. The part after the equals sign, or the text if it's just a whitepace 'attribute'. This includes the quotes around the value if any.
Overrides:
getRawValue in interface Attribute
Parameters:
buffer - The string buffer to append the attribute value to.
See Also:
getRawValue()

getValue

public String getValue()
Get the value of the attribute. The part after the equals sign, or the text if it's just a whitepace 'attribute'. NOTE: This does not include any quotes that may have enclosed the value when it was read. To get the un-stripped value use getRawValue.
Overrides:
getValue in interface Attribute
Returns:
The value, or null if it's a stand-alone or empty attribute, or the text if it's just a whitepace 'attribute'.

getValue

public void getValue(StringBuffer buffer)
Get the value of the attribute.
Overrides:
getValue in interface Attribute
Parameters:
buffer - The buffer to place the value in.
See Also:
getValue()

getValueEndPosition

public int getValueEndPosition()
Get the ending position of the attribute value.
Returns:
The offset into the page at which the value ends.

getValueStartPosition

public int getValueStartPosition()
Get the starting position of the attribute value.
Returns:
The offset into the page at which the value begins.

isEmpty

public boolean isEmpty()
Predicate to determine if this attribute has an equals sign but no value.
Overrides:
isEmpty in interface Attribute
Returns:
true if this attribute is an empty attribute. false if has an equals sign and a value.

isStandAlone

public boolean isStandAlone()
Predicate to determine if this attribute has no equals sign (or value).
Overrides:
isStandAlone in interface Attribute
Returns:
true if this attribute is a standalone attribute. false if has an equals sign.

isValued

public boolean isValued()
Predicate to determine if this attribute has a value.
Overrides:
isValued in interface Attribute
Returns:
true if this attribute has a value. false if it is empty or standalone.

isWhitespace

public boolean isWhitespace()
Predicate to determine if this attribute is whitespace.
Overrides:
isWhitespace in interface Attribute
Returns:
true if this attribute is whitespace, false if it is a real attribute.

setNameEndPosition

public void setNameEndPosition(int end)
Set the ending position of the attribute name.
Parameters:
end - The new offset into the page at which the name ends.

setNameStartPosition

public void setNameStartPosition(int start)
Set the starting position of the attribute name.
Parameters:
start - The new offset into the page at which the name begins.

setPage

public void setPage(Page page)
Set the page this attribute is anchored to.
Parameters:
page - The page to be used to construct this attribute. Note: If you set this you probably also want to uncache the property values by setting them to null.

setValueEndPosition

public void setValueEndPosition(int end)
Set the ending position of the attribute value.
Parameters:
end - The new offset into the page at which the value ends.

setValueStartPosition

public void setValueStartPosition(int start)
Set the starting position of the attribute value.
Parameters:
start - The new offset into the page at which the value begins.

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