Wednesday, May 16, 2012

KirSQLite - Flex AIR Database Manager: Part 15

In this tutorial we'll add the ability to add a new record to a table.

Find the HBox containing the "Delete selected" and "Save changes" buttons and add a new button next to them, called "Add a record". Set its click event handler to "newRecord()" and enabled property boudn to isTableSelected.

<mx:HBox width="100%" height="30" paddingLeft="8" paddingTop="6">
<mx:CheckBox label="Select all" change="selectAllChange(event);" />
<s:Button label="Delete selected" enabled="{isTableSelected}" click="deleteSelected();" />
<s:Button id="saveTableButton" label="Save changes" click="saveTable();" enabled="{isTableSelected}"/>
<s:Button id="newRecordButton" label="Add a record" click="newRecord();" enabled="{isTableSelected}"/>
</mx:HBox>

Now we'll create the newRecord() function.

All we really need to do is insert a new row into the SQL using an SQLStatement and then reload the data to update the array and the data grid.

The trick is that when we INSERT a record, we have to set a value under at least one column, or else we'll get an error. This can be done by adding "DEFAULT VALUES" to the SQL query instead of specifying values. Add a Responder object for the statement.

var stat:SQLStatement = new SQLStatement();
stat.sqlConnection = connection;
stat.text = "INSERT INTO " + selectedDatabase + "." + tableTree.selectedItem.@label + " DEFAULT VALUES;";
stat.execute( -1, new Responder(newSuccess, newError));

On success, update the data. On error, display the error:

function newSuccess(evt:SQLResult):void {
tableSelect();
tableGrid.invalidateDisplayList();
tableGrid.invalidateList();
}
function newError(evt:SQLError):void {
Alert.show("ERROR: " + evt.details, "Error");
}

Full function:

private function newRecord():void {
var stat:SQLStatement = new SQLStatement();
stat.sqlConnection = connection;
stat.text = "INSERT INTO " + selectedDatabase + "." + tableTree.selectedItem.@label + " DEFAULT VALUES;";
stat.execute( -1, new Responder(newSuccess, newError));

function newSuccess(evt:SQLResult):void {
tableSelect();
tableGrid.invalidateDisplayList();
tableGrid.invalidateList();
}
function newError(evt:SQLError):void {
Alert.show("ERROR: " + evt.details, "Error");
}
}

Full code:

<?xml version="1.0" encoding="utf-8"?>
<s:WindowedApplication xmlns:fx="http://ns.adobe.com/mxml/2009"
                       xmlns:s="library://ns.adobe.com/flex/spark"
                       xmlns:mx="library://ns.adobe.com/flex/mx" showStatusBar="false">
   
<s:menu>
<mx:FlexNativeMenu dataProvider="{windowMenu}" showRoot="false" labelField="@label" keyEquivalentField="@key" itemClick="menuSelect(event);" />
</s:menu>

<fx:Declarations>
<fx:XML id="windowMenu">
<root>
<menuitem label="Database">
<menuitem id="newdb" label="New" key="n" controlKey="true" />
<menuitem id="opendb" label="Open" key="o" controlKey="true" />
<menuitem id="savedb" label="Save a copy" key="s" controlKey="true" enabled="{tableTree.selectedItems.length>0}"/>
</menuitem>
<menuitem label="Table">
<menuitem id="newtable" label="Add table" key="t" controlKey="true" enabled="{tableTree.selectedItems.length>0}"/>
<menuitem id="droptable" label="Drop table" key="d" controlKey="true" enabled="{isTableSelected}"/>
</menuitem>
</root>
</fx:XML>
<fx:XMLList id="dbData">
</fx:XMLList>
<mx:ArrayCollection id="tableData">
</mx:ArrayCollection>
<mx:AdvancedDataGridColumn id="checkboxColumn" headerText=" " width="30" sortable="false" draggable="false" resizable="false" editable="false">
<mx:itemRenderer>
<fx:Component>
<mx:Box width="30" horizontalAlign="center">
<mx:CheckBox selected="@{data.sel}" />
</mx:Box>
</fx:Component>
</mx:itemRenderer>
</mx:AdvancedDataGridColumn>
<mx:TitleWindow id="newTableWindow" title="Create new table" close="closeNewTableWindow();" showCloseButton="true">
<s:VGroup>
<s:HGroup width="100%" verticalAlign="middle">
<s:Label>Table name: </s:Label>
<s:TextInput id="newTableName" />
</s:HGroup>
<s:Button click="createNewTable();" label="Create" width="100%" />
</s:VGroup>
</mx:TitleWindow>
<mx:TitleWindow id="historyWindow" title="SQL History" close="closeHistoryWindow();" showCloseButton="true">
<mx:Box width="100%" height="100%" paddingLeft="10" paddingRight="10" paddingTop="10" paddingBottom="10">
<s:TextArea id="historyText" width="100%" height="100%" editable="false" />
</mx:Box>
</mx:TitleWindow>
</fx:Declarations>

<fx:Script>
<![CDATA[
import flash.data.SQLConnection;
import flash.data.SQLResult;
import flash.data.SQLSchema;
import flash.data.SQLSchemaResult;
import flash.data.SQLStatement;
import flash.errors.SQLError;
import flash.events.Event;
import flash.events.MouseEvent;
import flash.events.SQLEvent;
import flash.filesystem.File;
import flash.net.FileFilter;
import flash.net.FileReference;
import flash.net.Responder;
import flash.ui.ContextMenu;
import flash.ui.ContextMenuItem;
import mx.collections.ArrayCollection;
import mx.controls.advancedDataGridClasses.AdvancedDataGridColumn;
import mx.controls.Alert;
import mx.events.CloseEvent;
import mx.events.FlexNativeMenuEvent;
import mx.managers.PopUpManager;

private var connection:SQLConnection = new SQLConnection();
private var selectedDatabase:String = "";
[Bindable]
private var isTableSelected:Boolean = false;
private var sqlHistory:Array = [];

private function selectAllChange(evt:Event):void {
var i:int;
if (evt.currentTarget.selected) {
for (i = 0; i < tableData.length; i++) {
tableData[i].sel = true;
}
} else
if (!evt.currentTarget.selected) {
for (i = 0; i < tableData.length; i++) {
tableData[i].sel = false;
}
}
tableGrid.invalidateDisplayList();
tableGrid.invalidateList();
}

private function menuSelect(evt:FlexNativeMenuEvent):void {
(evt.item.@id == "newdb")?(newDatabase()):(void);
(evt.item.@id == "opendb")?(openDatabase()):(void);
(evt.item.@id == "newtable")?(newTable()):(void);
(evt.item.@id == "droptable")?(dropTable()):(void);
(evt.item.@id == "savedb")?(saveCopy()):(void);
}

private function newDatabase():void {
var file:File = File.desktopDirectory.resolvePath("Untitled");
file.addEventListener(Event.SELECT, newSelect);
file.browseForSave("Choose where to save the database");
var newDB:XML;
var statement:SQLStatement = new SQLStatement();
function newSelect(evt:Event):void {
if (file.exists) {
Alert.show("File already exists, cannot overwrite.", "Nope");
return;
}
file.nativePath += ".db";
var n:String = parseDatabase(file);
loadDataSchema(n);
}
}

private function openDatabase():void {
var file:File = new File();
file.browseForOpen("Open database", [new FileFilter("Databases", "*.db"), new FileFilter("All files", "*")]);
file.addEventListener(Event.SELECT, openSelect);

function openSelect(evt:Event):void {
var n:String = parseDatabase(file, true);
loadDataSchema(n);
}
}

private function saveCopy():void {
var databasePath:String;
if (selectedDatabase == "main") databasePath = dbData.db[0].@path;
if (selectedDatabase != "main") {
var newNum:int = Number(selectedDatabase.replace("db", ""));
var newInd:int;
for (var i:int = 0; i < dbData.db.length(); i++) {
if (dbData.db[i].@numid == newNum) {
newInd = i;
break;
}
}
databasePath = dbData.db[newInd].@path;
}
var file:File = new File(databasePath);
file.browseForSave("Save copy of database");
file.addEventListener(Event.SELECT, onCopySelect);
function onCopySelect(evt:Event):void {
if(notAlreadyOpen(file)){
var initFile:File = new File(databasePath);
initFile.copyTo(file, true);
}else {
Alert.show("Cannot overwrite a file that is currently open.", "Nope");
}
}
}

private function loadDataSchema(name:String):void {
if (name != "") {
connection.loadSchema(null, null, name, true, new Responder(schemaSuccess, schemaError));
function schemaSuccess(evt:SQLSchemaResult):void {
// Schema found! Now parsing:
var result:SQLSchemaResult = evt;
// Adding tables:
var nid:Number = (name=="main")?(1):(Number(name.replace("db", "")));
var dataNode:XMLList = dbData.db.(@numid == nid);
dataNode.setChildren(<placeholder/>);
delete dataNode.placeholder;
for (var i:int = 0; i < result.tables.length; i++) {
var newTable:XML = new XML(<tb/>);
newTable.@label = result.tables[i].name;
newTable.@isBranch = false;
newTable.@databaseName = name;
dataNode.appendChild(newTable);
}
}
function schemaError(evt:SQLError):void {
// Alert.show("Database is empty");
}
isTableSelected = false;
}
}

private function parseDatabase(file:File, needCheck:Boolean = false):String {
var ret:String = "";
if (!needCheck || file.exists) {
if(!needCheck || notAlreadyOpen(file)){
var newDB:XML;
if (dbData.db.length() == 0) {
connection.open(file);
dbData = new XMLList(<root></root>);
newDB = <db/>
newDB.@label = file.name;
newDB.@numid = 1;
newDB.@isBranch = true;
newDB.@path = file.nativePath;
dbData[0].appendChild(newDB);
ret = "main";
}else
if (dbData.db.length() > 0) {
var newnum:int = dbData.db.length() + 1;
connection.attach("db"+newnum.toString(), file);
newDB = <db/>
newDB.@label = file.name;
newDB.@numid = newnum.toString();
newDB.@isBranch = true;
newDB.@path = file.nativePath;
dbData[0].appendChild(newDB);
ret = "db" + newnum.toString();
}}else {
Alert.show("Database already opened.", "Error");
}
}else {
Alert.show("File not found.", "Error");
}
return ret;
}

private function notAlreadyOpen(file:File):Boolean{
var r:Boolean = true;
for (var i:int = 0; i < dbData.db.length(); i++) {
if (file.nativePath == dbData.db[i].@path) {
r = false;
}
}
return r;
}

private function tableSelect():void {
saveTableButton.emphasized = false;
if (tableTree.selectedItem.@isBranch) {
isTableSelected = false;
var dataname:String;
if (tableTree.selectedItem.@numid == 1) dataname = "main";
if (tableTree.selectedItem.@numid > 1) dataname = "db" + tableTree.selectedItem.@numid;
selectedDatabase = dataname;
}
if (tableTree.selectedItem.@isBranch == false) {
isTableSelected = true;
selectedDatabase = tableTree.selectedItem.@databaseName;
tableData = new ArrayCollection([]);
var newColumns:Array = [checkboxColumn];
connection.loadSchema(SQLTableSchema, tableTree.selectedItem.@label, tableTree.selectedItem.@databaseName);
var schema:SQLSchemaResult = connection.getSchemaResult();
for (var i:int = 0; i < schema.tables[0].columns.length; i++) {
var aColumn:AdvancedDataGridColumn = new AdvancedDataGridColumn();
aColumn.headerText = schema.tables[0].columns[i].name;
aColumn.dataField = "db_" + schema.tables[0].columns[i].name;
if (schema.tables[0].columns[i].autoIncrement) aColumn.editable = false;
if (schema.tables[0].columns[i].primaryKey) tableTree.selectedItem.@primaryKeyColumn = schema.tables[0].columns[i].name;
newColumns.push(aColumn);
}
tableGrid.columns = newColumns;
var stat:SQLStatement = new SQLStatement();
stat.sqlConnection = connection;
stat.text = "SELECT * FROM " + tableTree.selectedItem.@databaseName + "." + tableTree.selectedItem.@label;
lastStatement(stat.text);
stat.execute(-1, new Responder(tableSuccess, tableError));
}
function tableSuccess(evt:SQLResult):void {
if (evt.data != null) {
for (var item:Object in evt.data) {
var obj:Object = new Object();
for (var value:Object in evt.data[item]) {
obj["db_"+value] = evt.data[item][value];
}
tableData.addItem(obj);
}
}
}
function tableError(evt:SQLError):void {
Alert.show("Unable to read table data.", "Error");
}
}

private function newTable():void {
PopUpManager.addPopUp(newTableWindow, this);
PopUpManager.centerPopUp(newTableWindow);
newTableWindow.title = "Create new table";
focusManager.setFocus(newTableName);
}

private function dropTable():void {
Alert.show("Are you sure you want to completely delete this table?", "Drop table?", Alert.YES | Alert.NO, null, dropConfirm);
function dropConfirm(evt:CloseEvent):void {
if (evt.detail == Alert.YES) {
var stat:SQLStatement = new SQLStatement();
stat.sqlConnection = connection;
stat.text = "DROP TABLE " + selectedDatabase + "." + tableTree.selectedItem.@label;
lastStatement(stat.text);
stat.execute( -1, new Responder(dropTableSuccess, dropTableError));
}
}
function dropTableSuccess(evt:SQLResult):void {
loadDataSchema(selectedDatabase);
}
function dropTableError(evt:SQLError):void {
Alert.show("ERROR:" + evt.details, "Error");
}
}

private function closeNewTableWindow():void{
PopUpManager.removePopUp(newTableWindow);
}

private function createNewTable():void {
var stat:SQLStatement = new SQLStatement();
stat.sqlConnection = connection;
stat.text = "CREATE TABLE IF NOT EXISTS " + selectedDatabase + "." + newTableName.text + "(id INTEGER PRIMARY KEY AUTOINCREMENT, blankColumn TEXT)";
lastStatement(stat.text);
stat.execute( -1, new Responder(newTableSuccess, newTableError));
function newTableSuccess(evt:SQLResult):void {
closeNewTableWindow();
loadDataSchema(selectedDatabase);
}
function newTableError(evt:SQLError):void {
Alert.show("ERROR:" + evt.details, "Error");
}
}

private function lastStatement(text:String):void {
statementText.text = text;
sqlHistory.push(text);
}

private function openHistory():void {
PopUpManager.addPopUp(historyWindow, this);
historyWindow.width = width - 100;
historyWindow.height = height - 100;
PopUpManager.centerPopUp(historyWindow);
historyText.text = "";
for (var i:int = sqlHistory.length - 1; i >= 0; i--) {
historyText.appendText(sqlHistory[i] + "\n");
}
}

private function closeHistoryWindow():void {
PopUpManager.removePopUp(historyWindow);
}

private function saveTable():void {
var keyColumnName:String = tableTree.selectedItem.@primaryKeyColumn;
// clear all "sel" and store them in a temp array
var tempSel:Array = [];
for (var s:int = 0; s < tableData.length; s++) {
if (tableData[s].sel) {
tempSel.push(true);
tableData[s].sel = false;
}else
if (!tableData[s].sel) {
tempSel.push(false);
}
}
// update each row
for (var i:int = 0; i < tableData.length; i++) {
var stat:SQLStatement = new SQLStatement();
var sqlStat:String = "UPDATE " + selectedDatabase + "." + tableTree.selectedItem.@label + " SET";
// add each attribute as parameter
for (var attribute:String in tableData[i]) {
// if column is not our CheckBox column or the key column
if (attribute != "mx_internal_uid" && attribute!=keyColumnName && attribute!="sel") {
// add value as parameter
stat.parameters["@" + attribute.substr(3)] = tableData[i][attribute];
sqlStat += " " + attribute.substr(3) + "=@" + attribute.substr(3) + ",";
}
}
// remove the last comma
sqlStat = sqlStat.substr(0, sqlStat.length - 1);
sqlStat += " WHERE " + keyColumnName + "=" + tableData[i]["db_"+keyColumnName];
stat.sqlConnection = connection;
stat.text = sqlStat;
stat.execute( -1, new Responder(saveSuccess, saveError));
}

function saveSuccess(evt:SQLResult):void {
}

function saveError(evt:SQLError):void {
Alert.show("ERROR: " + evt.details, "Error");
}

tableSelect();
for (var t:int = 0; t < tableData.length; t++) {
if (tempSel[t]) tableData[t].sel=true;
}
tableGrid.invalidateDisplayList();
tableGrid.invalidateList();
}

private function deleteSelected():void {
var keyColumnName:String = tableTree.selectedItem.@primaryKeyColumn;
for (var i:int = 0; i < tableData.length; i++) {
if (tableData[i].sel) {
var stat:SQLStatement = new SQLStatement();
stat.sqlConnection = connection;
stat.text = "DELETE FROM " + selectedDatabase + "." + tableTree.selectedItem.@label + " WHERE " + keyColumnName + "=" + tableData[i]["db_" + keyColumnName];
stat.execute( -1, new Responder(deleteSuccess, deleteError));
}
}
tableSelect();
tableGrid.invalidateDisplayList();
tableGrid.invalidateList();

function deleteSuccess(evt:SQLResult):void {
}
function deleteError(evt:SQLError):void {
Alert.show("ERROR: " + evt.details, "Error");
}
}

private function newRecord():void {
var stat:SQLStatement = new SQLStatement();
stat.sqlConnection = connection;
stat.text = "INSERT INTO " + selectedDatabase + "." + tableTree.selectedItem.@label + " DEFAULT VALUES;";
stat.execute( -1, new Responder(newSuccess, newError));

function newSuccess(evt:SQLResult):void {
tableSelect();
tableGrid.invalidateDisplayList();
tableGrid.invalidateList();
}
function newError(evt:SQLError):void {
Alert.show("ERROR: " + evt.details, "Error");
}
}
]]>
</fx:Script>

<s:HGroup gap="0" width="100%" height="100%">
<s:VGroup width="200" height="100%" gap="0">
<s:HGroup>
<s:Button label="New table" click="newTable();" enabled="{tableTree.selectedItems.length>0}"/>
<s:Button label="Drop table" click="dropTable();" enabled="{isTableSelected}" />
</s:HGroup>
<mx:Tree id="tableTree" width="100%" height="100%" dataProvider="{dbData}" showRoot="false" labelField="@label" itemClick="tableSelect();"/>
</s:VGroup>
<s:VGroup width="100%" height="100%" gap="0">
<mx:Box height="80" width="100%">
<s:VGroup paddingTop="10" paddingLeft="10" paddingRight="10" paddingBottom="10" width="100%" height="100%">
<s:HGroup width="100%" verticalAlign="middle">
<s:Label width="100%">Latest SQL statement:</s:Label>
<s:Button width="100" label="View history" click="openHistory();" />
</s:HGroup>
<s:TextArea id="statementText" editable="false" width="100%" height="30"/>
</s:VGroup>
</mx:Box>
<mx:TabNavigator width="100%" height="100%" paddingTop="0">
<s:NavigatorContent label="Table contents">
<s:VGroup width="100%" height="100%" gap="0">
<mx:HBox width="100%" height="30" paddingLeft="8" paddingTop="6">
<mx:CheckBox label="Select all" change="selectAllChange(event);" />
<s:Button label="Delete selected" enabled="{isTableSelected}" click="deleteSelected();" />
<s:Button id="saveTableButton" label="Save changes" click="saveTable();" enabled="{isTableSelected}"/>
<s:Button id="newRecordButton" label="Add a record" click="newRecord();" enabled="{isTableSelected}"/>
</mx:HBox>
<mx:AdvancedDataGrid id="tableGrid" width="100%" height="100%" dataProvider="{tableData}" editable="true" itemEditBegin="saveTableButton.emphasized=true;">
<mx:columns>
<mx:AdvancedDataGridColumn dataField="" headerText="Data" editable="false" />
</mx:columns>
</mx:AdvancedDataGrid>
</s:VGroup>
</s:NavigatorContent>
<s:NavigatorContent label="Edit columns">

</s:NavigatorContent>
<s:NavigatorContent label="Query">

</s:NavigatorContent>
</mx:TabNavigator>
</s:VGroup>
</s:HGroup>

</s:WindowedApplication>

Thanks for reading!

No comments:

Post a Comment