Scripting is a type of programming. A program contains actions (code) and the objects on which the actions are performed (data).
Because scripting is aimed at a big audience the syntax is kept as simple as possible.
Some refer to scripting as the glue that connects different components together. A component is a collection of code and data that represents a higher level of functionality. The diputree applet for example is a component.
The objects of the script are dynamically typed and they dont need to be declared, this results in easier and shorter code.
Today there are two standards for scripting in a web
document, Javascript and Vbscript.
diputree is accessible from both languages.
If you load a web document in your browser, all the elements contained in your document are reflected in the scripting environment. This means that all elements (such as all html tags) that are contained in your document are mapped to objects in your scripting environment.
This is also the case for applets. In Netscape navigator 3 or greater and in Microsoft Internet Explorer 4 or greater you can simply use the public methods of an applet.
In the following examples we will use javascript because both browsers support it.
With these methods you can add/replace/remove records in the following tables:
diputree is thread safe, so multiple concurrent accesses to diputree are allowed.
With the addRecords(tablename,records) method you can add record(s) to diputree in the specified table. If there is already a record with the specified key, then the new record will replace the old record.
Example<html>
<body BGCOLOR="#FFFFFF">
<applet CODE="diputree.class" NAME="diputree" WIDTH="300" HEIGHT="100">
</applet>
<form>
<input TYPE="BUTTON" VALUE="Add root entry" onClick="diputree.addRecords(entries,^root|javascripting with
diputree|-start-|c|o);">
<input TYPE="BUTTON" VALUE="Add an entry" onClick="diputree.addRecords(entries,^one|an entry|root)">
<input TYPE="BUTTON" VALUE="Add another entry" onClick="diputree.addRecords(entries,^two|another
entry|root)">
</form>
</body>
</html>
after loading the page
after pressing the "Add root entry" button
after pressing the "Add an entry" button
after pressing the "Add another entry"
button
With the removeRecords(tablename,records) method you can remove record(s) from diputree in the specified table. With diputree version 2 you can only remove records from the entries and images tables.
If you remove an entry, you automatically remove all
entries that are descendants of this entry.
So if you delete the root entry you effectively remove all entries from diputree.
<html>
<body BGCOLOR="#FFFFFF">
<applet CODE="diputree.class" NAME="diputree" WIDTH="300" HEIGHT="100">
<param name="entries" value="
^root|this is the root|-start-|c|o
^child|Im a child|root|c|o
^grandchild|Im a grandchild|child
">
</applet>
<form>
<input TYPE="BUTTON" VALUE="Remove children" onClick="diputree.removeRecords(entries,^child);">
<input TYPE="BUTTON" VALUE="Remove all" onClick="diputree.removeRecords(entries,^root);">
</form>
</body>
</html>
after loading the page
after pressing the "Remove children" button
after pressing the "Remove all" button
With the getKeys(tablename, separator) method you can retrieve all the keys who are present in a table.
Array String.split (separator)The javascript function split operates on a String value, takes a separator as an argument and returns an Array. This gives you an easy way to convert the result string from the getKeys function to an Array.
<html>
<body BGCOLOR="#FFFFFF">
<applet CODE="diputree.class" NAME="diputree" WIDTH="400" HEIGHT="100">
<param name="entries"
value="
^root|this is the root|-start-|c|o
^child|I'm a child|root|c|o
^grandchild|I'm a grandchild|child
">
</applet>
<form name="main">
<p>keys: <input type="text" name="keys" size="40"> <input TYPE="BUTTON" VALUE="print keys"
onClick="main.keys.value =
diputree.getKeys('entries',',');"> </p>
</form>
</body>
</html>
after loading the page
after pressing the "print keys" button
With the getSelected() method you can query diputree for the selected entry. With the setSelected (key) you can programmatically set the selected entry.
<html>
<body bgcolor="#C0C0C0">
<applet CODE="diputree.class" NAME="diputree" WIDTH="400" HEIGHT="40">
<param name="entries"
value="
^a|tab nr. 1 (key = a)
^b|tab nr. 2 (key = b)
^c|tab nr. 3 (key = c)
">
</applet>
<form name="main">
<p><input TYPE="BUTTON" VALUE="get selected"
onClick="main.getselected.value =
diputree.getSelected();">
<input type="text" name="getselected" size="10"></p>
<p><input TYPE="BUTTON" VALUE="set selected"
onClick="diputree.setSelected(main.setselected.value);">
<input type="text" name="setselected" size="10"></p>
</form>
</body>
</html>
after loading the page
after filling in c in the text field
and pressing the "set selected" button
after pressing the "get selected" button
With the getField(tablename, key, column index) method you can fetch any field value from a record. With the setField (tablename, key, column index, value) method you can set any field value in a record
Now every property of diputree is customizable.
<html>
<body bgcolor="#C0C0C0">
<applet CODE="diputree.class" NAME="diputree" WIDTH="400" HEIGHT="40">
<param name="entries" value="
^a|tab nr. 1
^b|tab nr. 2
^c|tab nr. 3
">
</applet>
<form name="main">
<p><input TYPE="BUTTON" VALUE="set foreground color"
onClick="diputree.setField('options','foregroundcolor',1,main.fgcolor.value);">
<input type="text" name="fgcolor" size="10"></p>
<p><input TYPE="BUTTON" VALUE="set font"
onClick="diputree.setField('fonts','defaultfont',1,main.font.value);">
<input type="text" name="font" size="20"></p>
</form>
</body>
</html>
after loading the page
after filling in C0C0C0 in the text field
and pressing the "set foreground color" button
after filling in Monospaced in the text field
and pressing the "set font" button