/**
* Sets scope for this expression so it knows its
* source table.
*
* @param $stmt FQLStatement that this expression was contained in
*/
public function set_scope($stmt)
{
$this->right->set_scope($stmt);
parent::set_scope($stmt);
}
/**
* Sets the scope for this field expression. Performs validity
* check on the field name by checking if the field name is
* contained in the source table. Initializes the appropriate
* field object for the field name for this table.
*
* @param $scope FQLStatement that this expression is
* contained in
*
* Throws UnknownFieldException if this field name is not
* a valid field in the source table.
*/
public function set_scope($scope)
{
$fields = $scope->from_table->get_fields();
if (isset($fields[$this->field_name])) {
$this->field = new $fields[$this->field_name]($scope->user, $scope->app_id, $scope->from_table, $this->field_name);
} else {
throw new UnknownFieldException($this->field_name, $scope->from, 'table');
}
parent::set_scope($scope);
}
/**
* Gets the list of query expressions that matches the constraints
* expressed in the IN expression.
*
* Queries are only generated when the expression is of the form
* uid IN (1, 2, 3,...) where uid is a field name and the list
* contains only constants, or 90210 IN (hometown_location, current_location)
* where the initial expression is a constant and the list
* contains only field names. In all other cases, this function
* will just return the generic ':' wildcard query, which matches all
* ids.
*
* @return associative array of queries where the keys are the queries,
* all mapping to 1
*/
public function get_queries()
{
if ($this->expression instanceof FQLFieldExpression) {
// like (uid IN (1,3,5))
$queries = array();
$all_consts = array();
foreach ($this->list as $const) {
if (!$const instanceof FQLConstantExpression) {
return parent::get_queries();
}
$val = $const->evaluate(null);
$all_consts[$val] = 1;
$query = $this->expression->field->get_query($val, '=');
if ($query) {
$queries[$query] = 1;
}
}
// save the list of constants so it doesn't need to be reevaluated each time
$this->const_list = $all_consts;
return $queries;
} else {
if ($this->expression instanceof FQLConstantExpression) {
// like (90210 IN (hometown_location, current_location))
$queries = array();
$val = $this->expression->evaluate(null);
foreach ($this->list as $field) {
if (!$field instanceof FQLFieldExpression) {
return parent::get_queries();
}
$query = $field->field->get_query($val, '=');
if ($query) {
$queries[$query] = 1;
}
}
return $queries;
}
}
return parent::get_queries();
}