XML Authoring and Validation

1
XML Authoring and Validation

• - Nupura Neurgaonkar

2
Agenda

• Introduction
• Design and Framework
• Features
• Demo
• Challenges
• Conclusion

3
Goals of the Project

• Develop a WYSIWYG, cross-platform XML editor
  using JEditorKit Framework .
• Study existing XML Editors.
• Provide intuitive context-sensitive editing for
  XML Elements and Entities.
• Provide DTD Validation.
• Provide Pluggable rendering of Elements.

4
Related Work and Background

• Extension of existing JEditorKit Framework .
• Supported basic Views and simple Document
  structure.
• More MathML specific.
• No DTD Validation.
• No support for editing.

5
Comparison of Existing XML Editors
6
Building Blocks of XML Editor
7
Features

• Task (Insertion Deletion of text)
• Implemented insertString(int offset, String text,
  AttributeSet set) method of DefaultStyledDocument
  to insert text with predefined attributes.
• Problem faced Undesired behavior in following
  cases
• inserting text at beginning of a Branch Element
• inserting text that contains newline.
• inserting text with a different AttributeSet than
  those of leaf element under the insertion
  offset.
• If a character is inserted at offset 10, it
  becomes part of Elem2 and not Elem1. This
  disturbs the whole document structure and Views
  cannot render the Elements.

8
Features

• Task Insertion Deletion of text (Contd)
• Solved this problem using ElementBuffer, an inner
  class of DefaultStyledDocument.
• Element elem getCharacterElement(offset)
• AttributeSet att elem.getAttributes()
• ElementSpec e new ElementSpec2
• char data new char1
• data str.toCharArray()
• e0 new ElementSpec(null,ElementSpec.EndTagT
  ype)
• e1 new ElementSpec(att,ElementSpec.ContentT
  ype,data,0,1)
• e1.setDirection(ElementSpec.JoinNextDirection
  )
• myWriteLock()
• this.insert(offset,e)
• myWriteUnlock()

9
Features

• Task(Custom rendering of Bold and Italic tags)
• The task was to achieve MVC effect by segregating
  Style attributes from Document attributes to gain
  a better control on how the Document should be
  rendered by storing the Style attributes in a
  View and not in the Document.
• Implement two different views where one View
  would render Bold and Italic tags using the
  styles defined in a Stylesheet while the other
  View (Simple View) would render these tags as
  simple text.
• Problem faced When a Stylesheet is loaded by
  EditorKit, it is attached to the Document. So,
  all the styles defined in the stylesheet become
  part of Document AttributeSet and hence Views no
  longer have control on how to render these
  styles. As a result, a bold tag will be rendered
  as bold in both the Views.

10
Features

• Task(Custom rendering of Bold and Italic tags)
• This problem was solved by overriding
  paintChild(Graphics g, Rectangle r, int n)
  method of ParagraphView.
• fontSize elem.getAttributes().getAttribute("Sty
  lefont-size")
• fontFamily elem.getAttributes().getAttribute("Sty
  lefont-family")
• fontWeight elem.getAttributes().getAttribute("S
  tylefont-style")
• color elem.getAttributes().getAttribute("Stylec
  olor")
• g.setColor(getColor(color))
• g.setFont(Font.decode(fontFamily"-"fontWeight"
  -"fontSize)) g.drawString(data, X, Y)

11
Features

• Task(DTD Validation)

12
Features

• Task(Attribute Views Inline and Popup)

13
Features

• Task(Context Sensitive Editing)

14
Challenges

15
Conclusion