Is it possible to call a custom tag from another custom tag? If so how?

You can have nested tags and the value of a tag attribute also may be evaluated by JSP engine. Please see bodycontent and rtexprvalue element in the following example of a tld file.

<tag>
<name>..</name>
<tagclass>...</tagclass>
<bodycontent>JSP</bodycontent>
<attribute>
<name>name</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
</attribute>
...
...
</tag>