Tuesday, December 6, 2011

Creating a Flex AIR text editor: Part 57

In this tutorial we will add the Save features for editing categories' names and snippets' names and text values.

Set the snippet's save button's click event handler to saveSnippet() function:

<s:Button id="bSaveSnippet" label="Save changes" enabled="false" click="saveSnippet();"/>

And the category's save button's click event handler to saveCategory():

<s:Button id="bSaveCategory" label="Save changes" enabled="false" click="saveCategory();" />

We'll do the category function first, because it is more simple. All we need to do is first get the ID value of the current category. Then we use this id to update the needed item in categories database. After that we update the item in the xml and call updateCategoryCombo().

private function saveCategory():void {
var currentID:int = snippetManageTree.selectedItem.@id;

var stat:SQLStatement = new SQLStatement();
stat.sqlConnection = categoryConnection;
stat.text = "UPDATE categories SET categoryName=@categoryName WHERE id=" + currentID;
stat.parameters["@categoryName"] = newCategoryInput.text;
stat.execute();

treeData.category[snippetManageTree.selectedItem.@categoryPosition].@label = newCategoryInput.text;
updateCategoryCombo();
}

Next, the saveSnippet() function. Here things will be a little bit more complex. First we do the same procedure to update the SQL database (except that we pass 2 values - the name and the text). After that, we need to determine if the snippet is located in a category or in the root tags.

Declare 3 variables, currentPos, currentCategoryID and currentCategoryPos in the function:

var currentPos:int = snippetManageTree.selectedItem.@snippetPosition;
var currentCategoryID:int = snippetManageTree.selectedItem.@categoryID;
var currentCategoryPos:int;

Now we do the check for currentCategoryID and use the needed path:

if (currentCategoryID != -1) {
currentCategoryPos = treeData.category.(@id == currentCategoryID).@categoryPosition;
treeData.category[currentCategoryPos].snippet[currentPos].@label = newNameInput.text;
}else {
treeData.snippet[currentPos].@label = newNameInput.text;
}

And the function becomes like this:

private function saveSnippet():void {
var currentID:int = snippetManageTree.selectedItem.@id;

var stat:SQLStatement = new SQLStatement();
stat.sqlConnection = snippetConnection;
stat.text = "UPDATE snippets SET snippetName=@snippetName, snippetText=@snippetText WHERE id=" + currentID;
stat.parameters["@snippetName"] = newNameInput.text;
stat.parameters["@snippetText"] = newTextInput.text;
stat.execute();

var currentPos:int = snippetManageTree.selectedItem.@snippetPosition;
var currentCategoryID:int = snippetManageTree.selectedItem.@categoryID;
var currentCategoryPos:int;

if (currentCategoryID != -1) {
currentCategoryPos = treeData.category.(@id == currentCategoryID).@categoryPosition;
treeData.category[currentCategoryPos].snippet[currentPos].@label = newNameInput.text;
}else {
treeData.snippet[currentPos].@label = newNameInput.text;
}

}

Full SnippetWindow.mxml code:

<?xml version="1.0" encoding="utf-8"?>
<mx:Window xmlns:fx="http://ns.adobe.com/mxml/2009" 
xmlns:s="library://ns.adobe.com/flex/spark" 
xmlns:mx="library://ns.adobe.com/flex/mx"
xmlns:custom="*"
title="Snippet management" type="utility" width="500" height="730"
creationComplete="init();" showStatusBar="false" alwaysInFront="true" resizable="false" backgroundColor="#dddddd">

<fx:Script>
<![CDATA[
import flash.data.SQLConnection;
import flash.data.SQLResult;
import flash.data.SQLStatement;
import flash.events.Event;
import flash.net.Responder;
import mx.controls.Alert;

[Bindable]
public var treeData:XMLList;
private var snippetConnection:SQLConnection;
private var categoryConnection:SQLConnection;
[Bindable]
private var categories:Array = [];

private function init():void{
this.addEventListener(Event.CLOSING, onClose);
}

private function onClose(evt:Event):void {
this.visible = false;
evt.preventDefault();
}

public function setValues(xmlData:XMLList, conn1:SQLConnection, conn2:SQLConnection, createNewOnStart:Boolean = false, newText:String = ""):void {
snippetConnection = conn1;
categoryConnection = conn2;
treeData = xmlData;
newTextInput.text = newText;
newNameInput.text = "New snippet name here";
if (newText=="") {
newTextInput.text = "New snippet text here";
}
updateCategoryCombo();
}

private function addSnippet(name:String, text:String):void{
if (name != "" && text != "") {
var stat:SQLStatement = new SQLStatement();
stat.sqlConnection = snippetConnection;
stat.text = "INSERT INTO snippets (snippetName, snippetText, categoryID, snippetPosition) VALUES (@snippetName, @snippetText, @categoryID, @snippetPosition);"
stat.parameters["@snippetName"] = name;
stat.parameters["@snippetText"] = text;
stat.parameters["@categoryID"] = categoryCombo.selectedItem.ind;
stat.parameters["@snippetPosition"] = totalItemsIn(categoryCombo.selectedItem.ind);
stat.execute(-1, new Responder(addSnippetXML));
}else {
Alert.show("The name and text of the snippet must not be blank!","Oops!");
}
}

private function addSnippetXML(evt:SQLResult):void {
if (treeData.category.length() == 0 && treeData..snippet.length() == 0) {
treeData = new XMLList(<root></root>);
}
var aSnippet:XML = <snippet/>;
aSnippet.@id = evt.lastInsertRowID;
aSnippet.@label = newNameInput.text;
aSnippet.@categoryID = categoryCombo.selectedItem.ind;
aSnippet.@snippetPosition = totalItemsIn(categoryCombo.selectedItem.ind);
aSnippet.@isBranch = false;
if(aSnippet.@categoryID!=-1){
treeData.category.(@id == categoryCombo.selectedItem.ind).appendChild(aSnippet);
}else {
treeData[0].appendChild(aSnippet);
}
}

private function addCategory(name:String):void {
if (name != "") {
var stat:SQLStatement = new SQLStatement();
stat.sqlConnection = categoryConnection;
stat.text = "INSERT INTO categories (categoryName, categoryPosition) VALUES (@categoryName, @categoryPosition);"
stat.parameters["@categoryName"] = name;
stat.parameters["@categoryPosition"] = treeData.category.length();
stat.execute(-1, new Responder(addCategoryXML));
}else {
Alert.show("The name of the category must not be blank!","Oops!");
}
}

private function addCategoryXML(evt:SQLResult):void {
if (treeData.category.length() == 0 && treeData..snippet.length() == 0) {
treeData = new XMLList(<root></root>);
}
var aCategory:XML = <category/>;
aCategory.@id = evt.lastInsertRowID;
aCategory.@label = newCategoryInput.text;
aCategory.@categoryPosition = treeData.category.length();
aCategory.@isBranch = true;
if(treeData.category.length()>0){
var prevLastCategory:XML = treeData.category[treeData.category.length()-1];
treeData[0].insertChildAfter(prevLastCategory, aCategory);
} else
if(treeData[0].snippet.length()>0){
var firstSnippet:XML = treeData[0].snippet[0];
treeData[0].insertChildBefore(firstSnippet, aCategory);
} else {
treeData[0].appendChild(aCategory);
}
snippetManageTree.selectedItem = aCategory;
selectTree();
updateCategoryCombo();
}

private function updateCategoryCombo():void{
categories = [];
categories.push( { label:"No category", ind: -1 } );
for each (var cat:XML in treeData.category) {
categories.push({label:cat.@label, ind:cat.@id});
}
categoryCombo.selectedIndex = 0;
}

private function totalItemsIn(id:int):int {
var toRet:int;
if(id>=0){
toRet = treeData.category.(@id == id).children().length();
}
if (id == -1) {
toRet = treeData.snippet.length();
}
return toRet;
}

private function selectTree():void {
bSaveSnippet.enabled = false;
bDeleteSnippet.enabled = false;
bSaveCategory.enabled = false;
bDeleteCategory.enabled = false;
upCategory.enabled = false;
downCategory.enabled = false;
upSnippet.enabled = false;
downSnippet.enabled = false;

if (snippetManageTree.selectedItem.@isBranch == true) {
bSaveCategory.enabled = true;
bDeleteCategory.enabled = true;
upCategory.enabled = canCategoryUp();
downCategory.enabled = canCategoryDown();
newCategoryInput.text = snippetManageTree.selectedItem.@label;
} else {
bSaveSnippet.enabled = true;
bDeleteSnippet.enabled = true;
upSnippet.enabled = canSnippetUp();
downSnippet.enabled = canSnippetDown();
categoryCombo.selectedIndex = treeData.category.(@id == snippetManageTree.selectedItem.@categoryID).@categoryPosition + 1;
if (snippetManageTree.selectedItem.@categoryID == -1) {
categoryCombo.selectedIndex = 0;
}
var stat:SQLStatement = new SQLStatement();
stat.sqlConnection = snippetConnection;
stat.text = "SELECT snippetText FROM snippets WHERE id=" + snippetManageTree.selectedItem.@id;
stat.execute( -1, new Responder(loadSnippetText));
}
}

private function loadSnippetText(evt:SQLResult):void{
newNameInput.text = snippetManageTree.selectedItem.@label;
newTextInput.text = evt.data[0].snippetText;
}

private function canCategoryUp():Boolean {
var toRet:Boolean = true;
if (snippetManageTree.selectedItem.@categoryPosition == 0) {
toRet = false;
}
return toRet;
}

private function canCategoryDown():Boolean {
var toRet:Boolean = true;
if (snippetManageTree.selectedItem.@categoryPosition == (treeData.category.length()-1)) {
toRet = false;
}
return toRet;
}

private function canSnippetUp():Boolean {
var toRet:Boolean = true;
if (snippetManageTree.selectedItem.@snippetPosition == 0) {
toRet = false;
}
return toRet;
}

private function canSnippetDown():Boolean {
var toRet:Boolean = true;
if (snippetManageTree.selectedItem.@categoryID != -1 && snippetManageTree.selectedItem.@snippetPosition == (treeData.category.(@id == snippetManageTree.selectedItem.@categoryID).children().length()-1)) {
toRet = false;
}
if (snippetManageTree.selectedItem.@snippetPosition == (treeData.snippet.length()-1)) {
toRet = false;
}
return toRet;
}

private function categoryMove(dir:String):void{
var currentPos:int = snippetManageTree.selectedItem.@categoryPosition;
var currentId:int = snippetManageTree.selectedItem.@id;
var newPos:int = (dir=="up")?(currentPos - 1):(currentPos + 1);

// Databases:

// Set the above category's position to current one
var stat:SQLStatement = new SQLStatement();
stat.sqlConnection = categoryConnection;
stat.text = "UPDATE categories SET categoryPosition=@currentPos WHERE categoryPosition=@newPos"
stat.parameters["@newPos"] = newPos;
stat.parameters["@currentPos"] = currentPos;
stat.execute();

// Set the current category's position to the one above
var stat2:SQLStatement = new SQLStatement();
stat2.sqlConnection = categoryConnection;
stat2.text = "UPDATE categories SET categoryPosition=@newPos WHERE id=@currentId"
stat2.parameters["@newPos"] = newPos;
stat2.parameters["@currentId"] = currentId;
stat2.execute();

// XML:

var copy:XML = treeData.category[currentPos].copy();
delete treeData.category[currentPos];
if(dir=="up"){
treeData.insertChildBefore(treeData.category[newPos], copy);
}else {
treeData.insertChildAfter(treeData.category[currentPos], copy);
}
copy.@categoryPosition = newPos;
treeData.category[currentPos].@categoryPosition = currentPos;
snippetManageTree.selectedItem = copy;
selectTree();
}

private function snippetMove(dir:String):void{
var currentPos:int = snippetManageTree.selectedItem.@snippetPosition;
var currentId:int = snippetManageTree.selectedItem.@id;
var newPos:int = (dir == "up")?(currentPos - 1):(currentPos + 1);
var currentCategoryID:int = snippetManageTree.selectedItem.@categoryID;
var currentCategoryPos:int = NaN;

if (currentCategoryID != -1) {
currentCategoryPos = treeData.category.(@id == currentCategoryID).@categoryPosition;
}

// Databases:

// Set the above category's position to current one
var stat:SQLStatement = new SQLStatement();
stat.sqlConnection = snippetConnection;
stat.text = "UPDATE snippets SET snippetPosition=@currentPos WHERE snippetPosition=@newPos"
stat.parameters["@newPos"] = newPos;
stat.parameters["@currentPos"] = currentPos;
stat.execute();

// Set the current category's position to the one above
var stat2:SQLStatement = new SQLStatement();
stat2.sqlConnection = snippetConnection;
stat2.text = "UPDATE snippets SET snippetPosition=@newPos WHERE id=@currentId"
stat2.parameters["@newPos"] = newPos;
stat2.parameters["@currentId"] = currentId;
stat2.execute();

// XML:

var copy:XML = new XML();

if(currentCategoryID != -1){
copy = treeData.category[currentCategoryPos].snippet[currentPos].copy();
delete treeData.category[currentCategoryPos].snippet[currentPos];
if(dir=="up"){
treeData.category[currentCategoryPos].insertChildBefore(treeData.category[currentCategoryPos].snippet[newPos], copy);
}else {
treeData.category[currentCategoryPos].insertChildAfter(treeData.category[currentCategoryPos].snippet[currentPos], copy);
}
copy.@snippetPosition = newPos;
treeData.category[currentCategoryPos].snippet[currentPos].@snippetPosition = currentPos;
}

if(currentCategoryID == -1){
copy = treeData.snippet[currentPos].copy();
delete treeData.snippet[currentPos];
if(dir=="up"){
treeData.insertChildBefore(treeData.snippet[newPos], copy);
}else {
treeData.insertChildAfter(treeData.snippet[currentPos], copy);
}
copy.@snippetPosition = newPos;
treeData.snippet[currentPos].@snippetPosition = currentPos;
}

snippetManageTree.selectedItem = copy;
selectTree();
}

private function saveCategory():void {
var currentID:int = snippetManageTree.selectedItem.@id;

var stat:SQLStatement = new SQLStatement();
stat.sqlConnection = categoryConnection;
stat.text = "UPDATE categories SET categoryName=@categoryName WHERE id=" + currentID;
stat.parameters["@categoryName"] = newCategoryInput.text;
stat.execute();

treeData.category[snippetManageTree.selectedItem.@categoryPosition].@label = newCategoryInput.text;
updateCategoryCombo();
}

private function saveSnippet():void {
var currentID:int = snippetManageTree.selectedItem.@id;

var stat:SQLStatement = new SQLStatement();
stat.sqlConnection = snippetConnection;
stat.text = "UPDATE snippets SET snippetName=@snippetName, snippetText=@snippetText WHERE id=" + currentID;
stat.parameters["@snippetName"] = newNameInput.text;
stat.parameters["@snippetText"] = newTextInput.text;
stat.execute();

var currentPos:int = snippetManageTree.selectedItem.@snippetPosition;
var currentCategoryID:int = snippetManageTree.selectedItem.@categoryID;
var currentCategoryPos:int;

if (currentCategoryID != -1) {
currentCategoryPos = treeData.category.(@id == currentCategoryID).@categoryPosition;
treeData.category[currentCategoryPos].snippet[currentPos].@label = newNameInput.text;
}else {
treeData.snippet[currentPos].@label = newNameInput.text;
}

}
]]>
</fx:Script>

<s:VGroup paddingLeft="5" paddingRight="5" paddingTop="5" paddingBottom="5">
<s:Label text="Snippet creation and management: " />
<s:HGroup>
<s:TextInput id="newNameInput" text="New snippet name" width="240" />
<mx:ComboBox id="categoryCombo" width="240" dataProvider="{categories}" />
</s:HGroup>
<s:TextArea id="newTextInput" width="490" height="200" text="Snippet text" />
<s:HGroup>
<s:Button id="bAddSnippet" label="Add snippet" click="addSnippet(newNameInput.text, newTextInput.text);" />
<s:Button id="bSaveSnippet" label="Save changes" enabled="false" click="saveSnippet();"/>
<s:Button id="bDeleteSnippet" label="Delete snippet"  enabled="false" />
<custom:IconButton id="upSnippet" icon="@Embed('../lib/arrow_up.png')" toolTip="Move up" enabled="false" click="snippetMove('up');" />
<custom:IconButton id="downSnippet" icon="@Embed('../lib/arrow_down.png')" toolTip="Move down" enabled="false" click="snippetMove('down');" />
</s:HGroup>

<s:Label text="" />

<s:Label text="Category creation and management: " />
<s:TextInput id="newCategoryInput" text="New category name" width="490" />
<s:HGroup>
<s:Button id="bAddCategory" label="Add category" click="addCategory(newCategoryInput.text);"/>
<s:Button id="bSaveCategory" label="Save changes" enabled="false" click="saveCategory();" />
<s:Button id="bDeleteCategory" label="Delete category with its contents" enabled="false"/>
<custom:IconButton id="upCategory" icon="@Embed('../lib/arrow_up.png')" toolTip="Move up" enabled="false" click="categoryMove('up');" />
<custom:IconButton id="downCategory" icon="@Embed('../lib/arrow_down.png')" toolTip="Move down" enabled="false" click="categoryMove('down');" />
</s:HGroup>

<s:Label text="" />

<mx:Tree id="snippetManageTree" dataProvider="{treeData}" width="490" height="300" showRoot="false" labelField="@label" itemClick="selectTree();" />
</s:VGroup>

</mx:Window>

Thanks for reading!

2 comments:

a13 said...

Отличный пошаговый пример! Единственно пожелание, вы бы не могли выкладывать после каждого урока архив с проектом, потому как если начинать не сначала, то потом трудно врубиться где какие компоненты нужны(кастомные), так было бы здорово целиком импортировать проект и разбираться. Спасибо)

Kirill Poletaev said...

После каждого урока уже навряд ли буду давать архивы, но в последней части выложу обязательно!

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