8 Scriptiong with diputab

8.1 It's a programming language

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 diputab applet for example is a component.

The objects of the script are dynamically typed and they don’t need to be declared, this results in easier and shorter code.

8.2 Web scripting

Today there are two standards for scripting in a web document, Javascript and Vbscript.
diputab is accessible from both languages.

Reflection

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.

8.3 diputab's methods

public methods of diputab

paramter and return types

With these methods you can add/replace/remove records in the following tables:

diputab is thread safe, so multiple concurrent accesses to diputab are allowed.

8.3.1 Adding or replacing records

With the addRecords(tablename,records) method you can add record(s) to diputab 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="#C0C0C0">
<applet CODE="diputab.class" NAME="diputab" WIDTH="400" HEIGHT="40">
</applet>
<form>
<input TYPE="BUTTON" VALUE="Add tab nr. 1"
onClick="
diputab.addRecords('entries','^a|tab nr. 1');">

<input TYPE="BUTTON" VALUE="Add tab nr. 2"
onClick="
diputab.addRecords('entries','^b|tab nr. 2');">

<input TYPE="BUTTON" VALUE="Add tab nr. 3"
onClick="
diputab.addRecords('entries','^c|tab nr. 3');">
</form>
</body>
</html>


after loading the page

after pressing the "Add tab nr. 1" button

after pressing the "Add tab nr. 2" button

after pressing the "Add tab nr. 3" button

 

 

 

8.3.2 Removind records

With the removeRecords(tablename,records) method you can remove record(s) from diputab in the specified table. With diputab version 2 you can only remove records from the entries and images tables.

Example

<html>
<body bgcolor="#C0C0C0">
<applet CODE="diputab.class" NAME="diputab" WIDTH="400" HEIGHT="40">
<param name="entries" value="
^a|tab nr. 1
^b|tab nr. 2
^c|tab nr. 3
">
</applet>

<form>
<input TYPE="BUTTON" VALUE="remove tab nr. 2"
onClick="
diputab.removeRecords('entries','^b');"></p>
</form>

</body>
</html>

after loading the page

after pressing the "remove tab nr. 2" button

 

 

8.3.3 Getting the key's from a table

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.

Example

<html>
<body bgcolor="#C0C0C0">
<applet CODE="diputab.class" NAME="diputab" WIDTH="400" HEIGHT="40">
<param name="entries" value="
^a|tab nr. 1
^b|tab nr. 2
^c|tab nr. 3
">
</applet>

<form name="main">
<BR>keys: <input type="text" name="keys" size="40">
<BR><input TYPE="BUTTON" VALUE="print keys"
onClick="
main.keys.value = diputab.getKeys('entries',',');">
</form>
</body>
</html>

after loading the page

after pressing the "print keys" button

8.3.4 Getting and setting the selected tab

With the getSelected() method you can query diputab for the selected tab. With the setSelected (key) you can programmatically set the selected tab.

Example

<html>
<body bgcolor="#C0C0C0">
<applet CODE="diputab.class" NAME="diputab" 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 = diputab.getSelected();">
<input type="text" name="getselected" size="10"></p>

<p><input TYPE="BUTTON" VALUE="set selected"
onClick="
diputab.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

 

8.3.5 Getting and setting individual fields in a record

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 diputab is customizable.

Example

<html>
<body bgcolor="#C0C0C0">
<applet CODE="diputab.class" NAME="diputab" 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="
diputab.setField('options','foregroundcolor',1,main.fgcolor.value);">
<input type="text" name="fgcolor" size="10"></p>

<p><input TYPE="BUTTON" VALUE="set font"
onClick="
diputab.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 E0E0E0 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