package com.jclark.xsl.tr;

import com.jclark.xsl.om.*;
import com.jclark.xsl.expr.VariantExpr;
import com.jclark.xsl.expr.Variant;

class BindLocalParamAction implements Action {
  private final Name name;
  private final VariantExpr expr;

  BindLocalParamAction(Name name, VariantExpr expr) {
    this.name = name;
    this.expr = expr;
  }

  public void invoke(ProcessContext context, Node sourceNode, Result result) throws XSLException {
    Variant value = context.getParam(name);
    if (value == null)
      value = expr.eval(sourceNode, context);
    context.bindLocalVariable(name, value);
  }
}