org.onosproject.ui.table.TableRequestHandler Maven / Gradle / Ivy
/*
* Copyright 2015-present Open Networking Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.onosproject.ui.table;
import com.fasterxml.jackson.databind.node.ObjectNode;
import org.onosproject.ui.JsonUtils;
import org.onosproject.ui.RequestHandler;
import static org.onosproject.ui.table.TableModel.sortDir;
/**
* Message handler specifically for table views.
*/
public abstract class TableRequestHandler extends RequestHandler {
private static final String FIRST_COL = "firstCol";
private static final String FIRST_DIR = "firstDir";
private static final String SECOND_COL = "secondCol";
private static final String SECOND_DIR = "secondDir";
private static final String ASC = "asc";
private static final String ANNOTS = "annots";
private static final String NO_ROWS_MSG_KEY = "no_rows_msg";
private final String respType;
private final String nodeName;
/**
* Constructs a table request handler for a specific table view. When
* table requests come in, the handler will generate the appropriate
* table rows, sort them according the the request sort parameters, and
* send back the response to the client.
*
* @param reqType type of the request event
* @param respType type of the response event
* @param nodeName name of JSON node holding row data
*/
public TableRequestHandler(String reqType, String respType, String nodeName) {
super(reqType);
this.respType = respType;
this.nodeName = nodeName;
}
@Override
public void process(ObjectNode payload) {
TableModel tm = createTableModel();
populateTable(tm, payload);
String firstCol = JsonUtils.string(payload, FIRST_COL, defaultColumnId());
String firstDir = JsonUtils.string(payload, FIRST_DIR, ASC);
String secondCol = JsonUtils.string(payload, SECOND_COL, null);
String secondDir = JsonUtils.string(payload, SECOND_DIR, null);
tm.sort(firstCol, sortDir(firstDir), secondCol, sortDir(secondDir));
addTableConfigAnnotations(tm, payload);
ObjectNode rootNode = MAPPER.createObjectNode();
rootNode.set(nodeName, TableUtils.generateRowArrayNode(tm));
rootNode.set(ANNOTS, TableUtils.generateAnnotObjectNode(tm));
sendMessage(respType, rootNode);
}
/**
* Creates the table model (devoid of data) using {@link #getColumnIds()}
* to initialize it, ready to be populated.
*
* This default implementation returns a table model with default
* formatters and comparators for all columns.
*
* @return an empty table model
*/
protected TableModel createTableModel() {
return new TableModel(getColumnIds());
}
/**
* Adds table configuration specific annotations to table model.
*
* @param tm a table model
* @param payload the event payload from the client
*/
protected void addTableConfigAnnotations(TableModel tm, ObjectNode payload) {
tm.addAnnotation(NO_ROWS_MSG_KEY, noRowsMessage(payload));
}
/**
* Returns the default column ID to be used when one is not supplied in
* the payload as the column on which to sort.
*
* This default implementation returns "id".
*
* @return default sort column identifier
*/
protected String defaultColumnId() {
return "id";
}
/**
* Subclasses should return the array of column IDs with which
* to initialize their table model.
*
* @return the column IDs
*/
protected abstract String[] getColumnIds();
/**
* Subclasses should return the message to display in the table when there
* are no rows to display. For example, a host table might return
* "No hosts found".
*
* @param payload request payload
* @return the message
*/
protected abstract String noRowsMessage(ObjectNode payload);
/**
* Subclasses should populate the table model by adding
* {@link TableModel.Row rows}.
*
* tm.addRow()
* .cell(COL_ONE, ...)
* .cell(COL_TWO, ...)
* ... ;
*
* The request payload is provided in case there are request filtering
* parameters (other than sort column and sort direction) that are required
* to generate the appropriate data.
*
* @param tm the table model
* @param payload request payload
*/
protected abstract void populateTable(TableModel tm, ObjectNode payload);
}