A.4.1.1 Evaluate any attribute of any tag

###
A.4.1.1 Evaluate any attribute of any tag

Arbitrary HTML tags can now access the templating engine by prefixing the tag with "al-". Attributes of the tag can then be selectively evaluated to derive their value. Appending "expr" to the attribute name causes the result of evaluating the expression to be substituted for the value of the attribute. Appending "bool" results in the attribute value being evaluated in a boolean context, and if true, a boolean HTML attribute is emitted. For example:

    <al-td colspanexpr="i.span()">

could produce

    <td colspan="3">

and:

    <al-input name="abc.value" disabledbool="abc.isdisabled()">

could produce

    <input name="abc.value" disabled>