Inset data into sequence

This section explains how to inset your data instead of part of HTML page in PageMixer framework. Explanation uses the filter which insets user-name string between "<span>" and corresponding "</span>" in HTML page.

<span class="Auth-UserName"></span>

<span class="Auth-UserName">foozy</span>

Overview

Class diagram

Class diagram in this section is shown below:

Class diagram (click for large figure)

Classes which you must define are colored, and other are already defined.

Object diagram

Object diagram in this section is shown below:

Object diagram (click for large figure)

Sequence diagram

Sequence diagram in this section is shown below:

Sequence diagram (click for large figure)

Class names

In this tutorial, abbreviated class names are used. Complete names are shown below.

Classes of PageMixer framework

Tutorial specific classes

Create SequenceWatcher

As described above, this section let the filter inset user-name string between "<span>" and corresponding "</span>" in HTML page. But, it is not good idea to inset it into all parts between them in given HTML page.

Then, condition of target sub-sequence are:

• between start and stop tag named as "span"
• start tag has "class" attribute, and
• its value is "Auth-UserName"

In this case, "SequenceWatcher.NameAttr" is used as "SequenceWatcher". It is "Sequence Watcher watching at Name and Attribute of first token".

new SequenceWatcher.NameAttr(HTMLSymbolSet.SET.SPAN,
                             HTMLSymbolSet.SET.CLASS,
                             "Auth-UserName")

Concretize SequenceDataInsetFilter

PageMixer framework provides the utility classes which provide the template to inset data instead of sub-sequence found by SequenceWatcher given on construction, and these are SequenceDataInsetFilter and its derived classes.

In the situation of this section, you must inset data as "HTML-Safe" TextToken, because:

• data may contain HTML special characters(e.g.: '<', '>'...), or
• some scripts for dynamic contents, and
• those scripts may causes Cross Site Scripting(XSS) problem

and, "SequenceDataInsetFilter.HTMLSafeTextInside" is good for this purpose.

public class UsernameTextInsetFilter
    extends SequenceDataInsetFilter.HTMLSafeTextInside
{
    final static
    private HTMLSymbolSet SET = HTMLSymbolSet.SET;

    final static
    private String ATTR_VALUE = "Auth-UserName";

    ////////////////////////////////////////

    public UsernameTextInsetFilter(Object key){
        super(new SequenceWatcher.NameAttr(SET.SPAN,
                                           SET.CLASS,
                                           ATTR_VALUE),
              key);
    }

    /////////////////////////////////////////////
    // Concretization of class HTMLSafeTextInside

    protected String getText(Object data){
        return (null != data ? data.toString() : "");
    }
}

Differences between samples of "Inset data into token" and this section are:

• TokenDataInsetFilter or SequenceDataInsetFilter
• TokenWatcher or SequenceWatcher
• needs name of inset target attribute, or not

Connect and mix

Now, everything needed are ready to use. Execution code is as below (see UsernameTextInsetFilter for detail).

try{
    // key to set/get user name
    final Object key = "Auth.Login";
    // user name
    final String name = "foozy";

    Bootstrap bootstrap =
    new Bootstrap.Default(filename)
    {
        protected void prepare(ConsumerContext context)
        {
            // put user name into context
            context.setValue(key, name);
        }
    };

    // apply the filter
    bootstrap.execute(new UsernameTextInsetFilter(key));
}
catch(Exception e){
    e.printStackTrace(System.err);
}

Sample HTML file as input is "auth.en.html" (or "index.en.html") under "src/demo/servlet/war/WEB-INF/page/demosite" in distribution.