class OvirtSDK4::XmlReader

Define the class:

Public Class Methods

new(p1) click to toggle source
static VALUE ov_xml_reader_initialize(VALUE self, VALUE io) {
    VALUE io_class;
    int rc = 0;
    ov_xml_reader_object* object = NULL;

    /* Get the pointer to the object: */
    Data_Get_Struct(self, ov_xml_reader_object, object);

    /* The parameter of the constructor can be a string or an IO object. If it is a string then we need to create aa
       IO object to read from it. */
    io_class = rb_class_of(io);
    if (io_class == rb_cString) {
        object->io = ov_xml_reader_create_string_io(io);
    }
    else if (io_class == rb_cIO) {
        object->io = io;
    }
    else {
        rb_raise(
            ov_error_class,
            "The type of the 'io' parameter must be 'String' or 'IO', but it is '%"PRIsVALUE"'",
            io_class
        );
    }

    /* Clear the closed flag: */
    object->closed = false;

    /* Create the libxml reader: */
    object->reader = xmlReaderForIO(ov_xml_reader_callback, NULL, object, NULL, NULL, 0);
    if (object->reader == NULL) {
        rb_raise(ov_error_class, "Can't create reader");
    }

    /* Move the cursor to the first node: */
    rc = xmlTextReaderRead(object->reader);
    if (rc == -1) {
        rb_raise(ov_error_class, "Can't read first node");
    }

    return self;
}

Public Instance Methods

close() click to toggle source
static VALUE ov_xml_reader_close(VALUE self) {
    ov_xml_reader_object* object = NULL;

    Data_Get_Struct(self, ov_xml_reader_object, object);
    ov_xml_reader_check_closed(object);
    xmlFreeTextReader(object->reader);
    object->reader = NULL;
    object->closed = true;
    return Qnil;
}
empty_element?() click to toggle source
static VALUE ov_xml_reader_empty_element(VALUE self) {
    ov_xml_reader_object* object = NULL;

    Data_Get_Struct(self, ov_xml_reader_object, object);
    ov_xml_reader_check_closed(object);
    return xmlTextReaderIsEmptyElement(object->reader)? Qtrue: Qfalse;
}
forward() click to toggle source
static VALUE ov_xml_reader_forward(VALUE self) {
    int c_type = 0;
    int rc = 0;
    ov_xml_reader_object *object = NULL;

    Data_Get_Struct(self, ov_xml_reader_object, object);
    ov_xml_reader_check_closed(object);

    for (;;) {
        c_type = xmlTextReaderNodeType(object->reader);
        if (c_type == -1) {
            rb_raise(ov_error_class, "Can't get current node type");
        }
        else if (c_type == XML_READER_TYPE_ELEMENT) {
            return Qtrue;
        }
        else if (c_type == XML_READER_TYPE_END_ELEMENT || c_type == XML_READER_TYPE_NONE) {
            return Qfalse;
        }
        else {
            rc = xmlTextReaderRead(object->reader);
            if (rc == -1) {
                rb_raise(ov_error_class, "Can't move to next node");
            }
        }
    }
}
get_attribute(p1) click to toggle source
static VALUE ov_xml_reader_get_attribute(VALUE self, VALUE name) {
    VALUE value;
    ov_xml_reader_object* object = NULL;
    xmlChar* c_name = NULL;
    xmlChar* c_value = NULL;

    Data_Get_Struct(self, ov_xml_reader_object, object);
    ov_xml_reader_check_closed(object);
    c_name = (xmlChar*) StringValueCStr(name);
    c_value = xmlTextReaderGetAttribute(object->reader, c_name);
    if (c_value == NULL) {
        return Qnil;
    }
    value = rb_str_new_cstr((char*) c_value);
    xmlFree(c_value);
    return value;
}
next_element() click to toggle source
static VALUE ov_xml_reader_next_element(VALUE self) {
    int rc = 0;
    ov_xml_reader_object* object = NULL;

    Data_Get_Struct(self, ov_xml_reader_object, object);
    ov_xml_reader_check_closed(object);
    rc = xmlTextReaderNext(object->reader);
    if (rc == 0) {
        return Qfalse;
    }
    if (rc == 1) {
        return Qtrue;
    }
    rb_raise(ov_error_class, "Can't move to next element");
}
node_name() click to toggle source
static VALUE ov_xml_reader_node_name(VALUE self) {
    VALUE name;
    const xmlChar* c_name = NULL;
    ov_xml_reader_object* object = NULL;

    Data_Get_Struct(self, ov_xml_reader_object, object);
    ov_xml_reader_check_closed(object);
    c_name = xmlTextReaderConstName(object->reader);
    if (c_name == NULL) {
        return Qnil;
    }
    name = rb_str_new_cstr((char*) c_name);
    return name;
}
read() click to toggle source
static VALUE ov_xml_reader_read(VALUE self) {
    int rc = 0;
    ov_xml_reader_object* object = NULL;

    Data_Get_Struct(self, ov_xml_reader_object, object);
    ov_xml_reader_check_closed(object);
    rc = xmlTextReaderRead(object->reader);
    if (rc == 0) {
        return Qfalse;
    }
    if (rc == 1) {
        return Qtrue;
    }
    rb_raise(ov_error_class, "Can't move to next node");
    return Qnil;
}
read_element() click to toggle source
static VALUE ov_xml_reader_read_element(VALUE self) {
    VALUE value;
    int c_empty = 0;
    int c_type = 0;
    int rc = 0;
    ov_xml_reader_object *object = NULL;
    xmlChar *c_value = NULL;

    Data_Get_Struct(self, ov_xml_reader_object, object);
    ov_xml_reader_check_closed(object);

    /* Check the type of the current node: */
    c_type = xmlTextReaderNodeType(object->reader);
    if (c_type == -1) {
        rb_raise(ov_error_class, "Can't get current node type");
    }
    if (c_type != XML_READER_TYPE_ELEMENT) {
        rb_raise(ov_error_class, "Current node isn't the start of an element");
    }

    /* Check if the current node is empty: */
    c_empty = xmlTextReaderIsEmptyElement(object->reader);
    if (c_empty == -1) {
        rb_raise(ov_error_class, "Can't check if current element is empty");
    }

    /* For empty values elements there is no need to read the value. For non empty values we need to read the value, and
       check if it is NULL, as that means that the value is an empty string. */
    if (c_empty) {
        c_value = NULL;
    }
    else {
        c_value = xmlTextReaderReadString(object->reader);
        if (c_value == NULL) {
            c_value = xmlCharStrdup("");
            if (c_value == NULL) {
                rb_raise(ov_error_class, "Can't allocate XML string");
            }
        }
    }

    /* Move to the next element: */
    rc = xmlTextReaderNext(object->reader);
    if (rc == -1) {
        if (c_value != NULL) {
            xmlFree(c_value);
        }
        rb_raise(ov_error_class, "Can't move to the next element");
    }

    /* Return the result: */
    if (c_value == NULL) {
       return Qnil;
    }
    value = rb_str_new_cstr((char*) c_value);
    xmlFree(c_value);
    return value;
}
read_elements() click to toggle source
static VALUE ov_xml_reader_read_elements(VALUE self) {
    VALUE element;
    VALUE list;
    int c_type = 0;
    int rc = 0;
    ov_xml_reader_object* object = NULL;

    Data_Get_Struct(self, ov_xml_reader_object, object);
    ov_xml_reader_check_closed(object);
    list = rb_ary_new();
    for (;;) {
        c_type = xmlTextReaderNodeType(object->reader);
        if (c_type == -1) {
            rb_raise(ov_error_class, "Can't get current node type");
        }
        else if (c_type == XML_READER_TYPE_ELEMENT) {
            element = ov_xml_reader_read_element(self);
            rb_ary_push(list, element);
        }
        else if (c_type == XML_READER_TYPE_END_ELEMENT || c_type == XML_READER_TYPE_NONE) {
            break;
        }
        else {
            rc = xmlTextReaderNext(object->reader);
            if (rc == -1) {
                rb_raise(ov_error_class, "Can't move to the next element");
            }
        }
    }
    return list;
}