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  • EM12c Release 4: New Compliance features including DB STIG Standard

    - by DaveWolf
    Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Enterprise Manager’s compliance framework is a powerful and robust feature that provides users the ability to continuously validate their target configurations against a specified standard. Enterprise Manager’s compliance library is filled with a wide variety of standards based on Oracle’s recommendations, best practices and security guidelines. These standards can be easily associated to a target to generate a report showing its degree of conformance to that standard. ( To get an overview of  Database compliance management in Enterprise Manager see this screenwatch. ) Starting with release 12.1.0.4 of Enterprise Manager the compliance library will contain a new standard based on the US Defense Information Systems Agency (DISA) Security Technical Implementation Guide (STIG) for Oracle Database 11g. According to the DISA website, “The STIGs contain technical guidance to ‘lock down’ information systems/software that might otherwise be vulnerable to a malicious computer attack.” In essence, a STIG is a technical checklist an administrator can follow to secure a system or software. Many US government entities are required to follow these standards however many non-US government entities and commercial companies base their standards directly or partially on these STIGs. You can find more information about the Oracle Database and other STIGs on the DISA website. The Oracle Database 11g STIG consists of two categories of checks, installation and instance. Installation checks focus primarily on the security of the Oracle Home while the instance checks focus on the configuration of the running database instance itself. If you view the STIG compliance standard in Enterprise Manager, you will see the rules organized into folders corresponding to these categories. Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 -"/ /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} The rule names contain a rule ID ( DG0020 for example ) which directly map to the check name in the STIG checklist along with a helpful brief description. The actual description field contains the text from the STIG documentation to aid in understanding the purpose of the check. All of the rules have also been documented in the Oracle Database Compliance Standards reference documentation. In order to use this standard both the OMS and agent must be at version 12.1.0.4 as it takes advantage of several features new in this release including: Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Agent-Side Compliance Rules Manual Compliance Rules Violation Suppression Additional BI Publisher Compliance Reports /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Agent-Side Compliance Rules Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Agent-side compliance rules are essentially the result of a tighter integration between Configuration Extensions and Compliance Rules. If you ever created customer compliance content in past versions of Enterprise Manager, you likely used Configuration Extensions to collect additional information into the EM repository so it could be used in a Repository compliance rule. This process although powerful, could be confusing to correctly model the SQL in the rule creation wizard. With agent-side rules, the user only needs to choose the Configuration Extension/Alias combination and that’s it. Enterprise Manager will do the rest for you. This tighter integration also means their lifecycle is managed together. When you associate an agent-side compliance standard to a target, the required Configuration Extensions will be deployed automatically for you. The opposite is also true, when you unassociated the compliance standard, the Configuration Extensions will also be undeployed. The Oracle Database STIG compliance standard is implemented as an agent-side standard which is why you simply need to associate the standard to your database targets without previously deploying the associated Configuration Extensions. You can learn more about using Agent-Side compliance rules in the screenwatch Using Agent-Side Compliance Rules on Enterprise Manager's Lifecycle Management page on OTN. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Manual Compliance Rules Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} There are many checks in the Oracle Database STIG as well as other common standards which simply cannot be automated. This could be something as simple as “Ensure the datacenter entrance is secured.” or complex as Oracle Database STIG Rule DG0186 – “The database should not be directly accessible from public or unauthorized networks”. These checks require a human to perform and attest to its successful completion. Enterprise Manager now supports these types of checks in Manual rules. When first associated to a target, each manual rule will generate a single violation. These violations must be manually cleared by a user who is in essence attesting to its successful completion. The user is able to permanently clear the violation or give a future date on which the violation will be regenerated. Setting a future date is useful when policy dictates a periodic re-validation of conformance wherein the user will have to reperform the check. The optional reason field gives the user an opportunity to provide details of the check results. Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Violation Suppression There are situations that require the need to permanently or temporarily suppress a legitimate violation or finding. These include approved exceptions and grace periods. Enterprise Manager now supports the ability to temporarily or permanently suppress a violation. Unlike when you clear a manual rule violation, suppression simply removes the violation from the compliance results UI and in turn its negative impact on the score. The violation still remains in the EM repository and can be accounted for in compliance reports. Temporarily suppressing a violation can give users a grace period in which to address an issue. If the issue is not addressed within the specified period, the violation will reappear in the results automatically. Again the user may enter a reason for the suppression which will be permanently saved with the event along with the suppressing user ID. Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Additional BI Publisher compliance reports As I am sure you have learned by now, BI Publisher now ships and is integrated with Enterprise Manager 12.1.0.4. This means users can take full advantage of the powerful reporting engine by using the Oracle provided reports or building their own. There are many new compliance related reports available in 12.1.0.4 covering all aspects including the association status, library as well as summary and detailed results reports.  10 New Compliance Reports Compliance Summary Report Example showing STIG results Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Conclusion Together with the Oracle Database 11g STIG compliance standard these features provide a complete solution for easily auditing and reporting the security posture of your Oracle Databases against this well known benchmark. You can view an overview presentation and demo in the screenwatch Using the STIG Compliance Standard on Enterprise Manager's Lifecycle Management page on OTN. Additional EM12c Compliance Management Information Compliance Management - Overview ( Presentation ) Compliance Management - Custom Compliance on Default Data (How To) Compliance Management - Custom Compliance using SQL Configuration Extension (How To) Compliance Management - Customer Compliance using Command Configuration Extension (How To)

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  • Metro Walkthrough: Creating a Task List with a ListView and IndexedDB

    - by Stephen.Walther
    The goal of this blog entry is to describe how you can work with data in a Metro style application written with JavaScript. In particular, we create a super simple Task List application which enables you to create and delete tasks. Here’s a video which demonstrates how the Task List application works: In order to build this application, I had to take advantage of several features of the WinJS library and technologies including: IndexedDB – The Task List application stores data in an IndexedDB database. HTML5 Form Validation – The Task List application uses HTML5 validation to ensure that a required field has a value. ListView Control – The Task List application displays the tasks retrieved from the IndexedDB database in a WinJS ListView control. Creating the IndexedDB Database The Task List application stores all of its data in an IndexedDB database named TasksDB. This database is opened/created with the following code: var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; The msIndexedDB.open() method accepts two parameters: the name of the database to open and the version of the database to open. If a database with a matching version already exists, then calling the msIndexedDB.open() method opens a connection to the existing database. If the database does not exist then the upgradeneeded event is raised. You handle the upgradeneeded event to create a new database. In the code above, the upgradeneeded event handler creates an object store named “tasks” (An object store roughly corresponds to a database table). When you add items to the tasks object store then each item gets an id property with an auto-incremented value automatically. The code above also includes an error event handler. If the IndexedDB database cannot be opened or created, for whatever reason, then an error message is written to the Visual Studio JavaScript Console window. Displaying a List of Tasks The TaskList application retrieves its list of tasks from the tasks object store, which we created above, and displays the list of tasks in a ListView control. Here is how the ListView control is declared: <div id="tasksListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: TaskList.tasks.dataSource, itemTemplate: select('#taskTemplate'), tapBehavior: 'toggleSelect', selectionMode: 'multi', layout: { type: WinJS.UI.ListLayout } }"> </div> The ListView control is bound to the TaskList.tasks.dataSource data source. The TaskList.tasks.dataSource is created with the following code: // Create the data source var tasks = new WinJS.Binding.List(); // Open the database var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; // Load the data source with data from the database req.onsuccess = function () { db = req.result; var tran = db.transaction("tasks"); tran.objectStore("tasks").openCursor().onsuccess = function(event) { var cursor = event.target.result; if (cursor) { tasks.dataSource.insertAtEnd(null, cursor.value); cursor.continue(); }; }; }; // Expose the data source and functions WinJS.Namespace.define("TaskList", { tasks: tasks }); Notice the success event handler. This handler is called when a database is successfully opened/created. In the code above, all of the items from the tasks object store are retrieved into a cursor and added to a WinJS.Binding.List object named tasks. Because the ListView control is bound to the WinJS.Binding.List object, copying the tasks from the object store into the WinJS.Binding.List object causes the tasks to appear in the ListView: Adding a New Task You add a new task in the Task List application by entering the title of a new task into an HTML form and clicking the Add button. Here’s the markup for creating the form: <form id="addTaskForm"> <input id="newTaskTitle" title="New Task" required /> <button>Add</button> </form> Notice that the INPUT element includes a required attribute. In a Metro application, you can take advantage of HTML5 Validation to validate form fields. If you don’t enter a value for the newTaskTitle field then the following validation error message is displayed: For a brief introduction to HTML5 validation, see my previous blog entry: http://stephenwalther.com/blog/archive/2012/03/13/html5-form-validation.aspx When you click the Add button, the form is submitted and the form submit event is raised. The following code is executed in the default.js file: // Handle Add Task document.getElementById("addTaskForm").addEventListener("submit", function (evt) { evt.preventDefault(); var newTaskTitle = document.getElementById("newTaskTitle"); TaskList.addTask({ title: newTaskTitle.value }); newTaskTitle.value = ""; }); The code above retrieves the title of the new task and calls the addTask() method in the tasks.js file. Here’s the code for the addTask() method which is responsible for actually adding the new task to the IndexedDB database: // Add a new task function addTask(taskToAdd) { var transaction = db.transaction("tasks", "readwrite"); var addRequest = transaction.objectStore("tasks").add(taskToAdd); addRequest.onsuccess = function (evt) { taskToAdd.id = evt.target.result; tasks.dataSource.insertAtEnd(null, taskToAdd); } } The code above does two things. First, it adds the new task to the tasks object store in the IndexedDB database. Second, it adds the new task to the data source bound to the ListView. The dataSource.insertAtEnd() method is called to add the new task to the data source so the new task will appear in the ListView (with a nice little animation). Deleting Existing Tasks The Task List application enables you to select one or more tasks by clicking or tapping on one or more tasks in the ListView. When you click the Delete button, the selected tasks are removed from both the IndexedDB database and the ListView. For example, in the following screenshot, two tasks are selected. The selected tasks appear with a teal background and a checkmark: When you click the Delete button, the following code in the default.js file is executed: // Handle Delete Tasks document.getElementById("btnDeleteTasks").addEventListener("click", function (evt) { tasksListView.winControl.selection.getItems().then(function(items) { items.forEach(function (item) { TaskList.deleteTask(item); }); }); }); The selected tasks are retrieved with the TaskList selection.getItem() method. In the code above, the deleteTask() method is called for each of the selected tasks. Here’s the code for the deleteTask() method: // Delete an existing task function deleteTask(listViewItem) { // Database key != ListView key var dbKey = listViewItem.data.id; var listViewKey = listViewItem.key; // Remove item from db and, if success, remove item from ListView var transaction = db.transaction("tasks", “readwrite”); var deleteRequest = transaction.objectStore("tasks").delete(dbKey); deleteRequest.onsuccess = function () { tasks.dataSource.remove(listViewKey); } } This code does two things: it deletes the existing task from the database and removes the existing task from the ListView. In both cases, the right task is removed by using the key associated with the task. However, the task key is different in the case of the database and in the case of the ListView. In the case of the database, the task key is the value of the task id property. In the case of the ListView, on the other hand, the task key is auto-generated by the ListView. When the task is removed from the ListView, an animation is used to collapse the tasks which appear above and below the task which was removed. The Complete Code Above, I did a lot of jumping around between different files in the application and I left out sections of code. For the sake of completeness, I want to include the entire code here: the default.html, default.js, and tasks.js files. Here are the contents of the default.html file. This file contains the UI for the Task List application: <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>Task List</title> <!-- WinJS references --> <link href="//Microsoft.WinJS.0.6/css/ui-dark.css" rel="stylesheet"> <script src="//Microsoft.WinJS.0.6/js/base.js"></script> <script src="//Microsoft.WinJS.0.6/js/ui.js"></script> <!-- TaskList references --> <link href="/css/default.css" rel="stylesheet"> <script src="/js/default.js"></script> <script type="text/javascript" src="js/tasks.js"></script> <style type="text/css"> body { font-size: x-large; } form { display: inline; } #appContainer { margin: 20px; width: 600px; } .win-container { padding: 10px; } </style> </head> <body> <div> <!-- Templates --> <div id="taskTemplate" data-win-control="WinJS.Binding.Template"> <div> <span data-win-bind="innerText:title"></span> </div> </div> <h1>Super Task List</h1> <div id="appContainer"> <form id="addTaskForm"> <input id="newTaskTitle" title="New Task" required /> <button>Add</button> </form> <button id="btnDeleteTasks">Delete</button> <div id="tasksListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: TaskList.tasks.dataSource, itemTemplate: select('#taskTemplate'), tapBehavior: 'toggleSelect', selectionMode: 'multi', layout: { type: WinJS.UI.ListLayout } }"> </div> </div> </div> </body> </html> Here is the code for the default.js file. This code wires up the Add Task form and Delete button: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { WinJS.UI.processAll().then(function () { // Get reference to Tasks ListView var tasksListView = document.getElementById("tasksListView"); // Handle Add Task document.getElementById("addTaskForm").addEventListener("submit", function (evt) { evt.preventDefault(); var newTaskTitle = document.getElementById("newTaskTitle"); TaskList.addTask({ title: newTaskTitle.value }); newTaskTitle.value = ""; }); // Handle Delete Tasks document.getElementById("btnDeleteTasks").addEventListener("click", function (evt) { tasksListView.winControl.selection.getItems().then(function(items) { items.forEach(function (item) { TaskList.deleteTask(item); }); }); }); }); } }; app.start(); })(); Finally, here is the tasks.js file. This file contains all of the code for opening, creating, and interacting with IndexedDB: (function () { "use strict"; // Create the data source var tasks = new WinJS.Binding.List(); // Open the database var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; // Load the data source with data from the database req.onsuccess = function () { db = req.result; var tran = db.transaction("tasks"); tran.objectStore("tasks").openCursor().onsuccess = function(event) { var cursor = event.target.result; if (cursor) { tasks.dataSource.insertAtEnd(null, cursor.value); cursor.continue(); }; }; }; // Add a new task function addTask(taskToAdd) { var transaction = db.transaction("tasks", "readwrite"); var addRequest = transaction.objectStore("tasks").add(taskToAdd); addRequest.onsuccess = function (evt) { taskToAdd.id = evt.target.result; tasks.dataSource.insertAtEnd(null, taskToAdd); } } // Delete an existing task function deleteTask(listViewItem) { // Database key != ListView key var dbKey = listViewItem.data.id; var listViewKey = listViewItem.key; // Remove item from db and, if success, remove item from ListView var transaction = db.transaction("tasks", "readwrite"); var deleteRequest = transaction.objectStore("tasks").delete(dbKey); deleteRequest.onsuccess = function () { tasks.dataSource.remove(listViewKey); } } // Expose the data source and functions WinJS.Namespace.define("TaskList", { tasks: tasks, addTask: addTask, deleteTask: deleteTask }); })(); Summary I wrote this blog entry because I wanted to create a walkthrough of building a simple database-driven application. In particular, I wanted to demonstrate how you can use a ListView control with an IndexedDB database to store and retrieve database data.

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  • Metro Walkthrough: Creating a Task List with a ListView and IndexedDB

    - by Stephen.Walther
    The goal of this blog entry is to describe how you can work with data in a Metro style application written with JavaScript. In particular, we create a super simple Task List application which enables you to create and delete tasks. Here’s a video which demonstrates how the Task List application works: In order to build this application, I had to take advantage of several features of the WinJS library and technologies including: IndexedDB – The Task List application stores data in an IndexedDB database. HTML5 Form Validation – The Task List application uses HTML5 validation to ensure that a required field has a value. ListView Control – The Task List application displays the tasks retrieved from the IndexedDB database in a WinJS ListView control. Creating the IndexedDB Database The Task List application stores all of its data in an IndexedDB database named TasksDB. This database is opened/created with the following code: var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; The msIndexedDB.open() method accepts two parameters: the name of the database to open and the version of the database to open. If a database with a matching version already exists, then calling the msIndexedDB.open() method opens a connection to the existing database. If the database does not exist then the upgradeneeded event is raised. You handle the upgradeneeded event to create a new database. In the code above, the upgradeneeded event handler creates an object store named “tasks” (An object store roughly corresponds to a database table). When you add items to the tasks object store then each item gets an id property with an auto-incremented value automatically. The code above also includes an error event handler. If the IndexedDB database cannot be opened or created, for whatever reason, then an error message is written to the Visual Studio JavaScript Console window. Displaying a List of Tasks The TaskList application retrieves its list of tasks from the tasks object store, which we created above, and displays the list of tasks in a ListView control. Here is how the ListView control is declared: <div id="tasksListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: TaskList.tasks.dataSource, itemTemplate: select('#taskTemplate'), tapBehavior: 'toggleSelect', selectionMode: 'multi', layout: { type: WinJS.UI.ListLayout } }"> </div> The ListView control is bound to the TaskList.tasks.dataSource data source. The TaskList.tasks.dataSource is created with the following code: // Create the data source var tasks = new WinJS.Binding.List(); // Open the database var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; // Load the data source with data from the database req.onsuccess = function () { db = req.result; var tran = db.transaction("tasks"); tran.objectStore("tasks").openCursor().onsuccess = function(event) { var cursor = event.target.result; tasks.dataSource.beginEdits(); if (cursor) { tasks.dataSource.insertAtEnd(null, cursor.value); cursor.continue(); } else { tasks.dataSource.endEdits(); }; }; }; // Expose the data source and functions WinJS.Namespace.define("TaskList", { tasks: tasks }); Notice the success event handler. This handler is called when a database is successfully opened/created. In the code above, all of the items from the tasks object store are retrieved into a cursor and added to a WinJS.Binding.List object named tasks. Because the ListView control is bound to the WinJS.Binding.List object, copying the tasks from the object store into the WinJS.Binding.List object causes the tasks to appear in the ListView: Adding a New Task You add a new task in the Task List application by entering the title of a new task into an HTML form and clicking the Add button. Here’s the markup for creating the form: <form id="addTaskForm"> <input id="newTaskTitle" title="New Task" required /> <button>Add</button> </form> Notice that the INPUT element includes a required attribute. In a Metro application, you can take advantage of HTML5 Validation to validate form fields. If you don’t enter a value for the newTaskTitle field then the following validation error message is displayed: For a brief introduction to HTML5 validation, see my previous blog entry: http://stephenwalther.com/blog/archive/2012/03/13/html5-form-validation.aspx When you click the Add button, the form is submitted and the form submit event is raised. The following code is executed in the default.js file: // Handle Add Task document.getElementById("addTaskForm").addEventListener("submit", function (evt) { evt.preventDefault(); var newTaskTitle = document.getElementById("newTaskTitle"); TaskList.addTask({ title: newTaskTitle.value }); newTaskTitle.value = ""; }); The code above retrieves the title of the new task and calls the addTask() method in the tasks.js file. Here’s the code for the addTask() method which is responsible for actually adding the new task to the IndexedDB database: // Add a new task function addTask(taskToAdd) { var transaction = db.transaction("tasks", IDBTransaction.READ_WRITE); var addRequest = transaction.objectStore("tasks").add(taskToAdd); addRequest.onsuccess = function (evt) { taskToAdd.id = evt.target.result; tasks.dataSource.insertAtEnd(null, taskToAdd); } } The code above does two things. First, it adds the new task to the tasks object store in the IndexedDB database. Second, it adds the new task to the data source bound to the ListView. The dataSource.insertAtEnd() method is called to add the new task to the data source so the new task will appear in the ListView (with a nice little animation). Deleting Existing Tasks The Task List application enables you to select one or more tasks by clicking or tapping on one or more tasks in the ListView. When you click the Delete button, the selected tasks are removed from both the IndexedDB database and the ListView. For example, in the following screenshot, two tasks are selected. The selected tasks appear with a teal background and a checkmark: When you click the Delete button, the following code in the default.js file is executed: // Handle Delete Tasks document.getElementById("btnDeleteTasks").addEventListener("click", function (evt) { tasksListView.winControl.selection.getItems().then(function(items) { items.forEach(function (item) { TaskList.deleteTask(item); }); }); }); The selected tasks are retrieved with the TaskList selection.getItem() method. In the code above, the deleteTask() method is called for each of the selected tasks. Here’s the code for the deleteTask() method: // Delete an existing task function deleteTask(listViewItem) { // Database key != ListView key var dbKey = listViewItem.data.id; var listViewKey = listViewItem.key; // Remove item from db and, if success, remove item from ListView var transaction = db.transaction("tasks", IDBTransaction.READ_WRITE); var deleteRequest = transaction.objectStore("tasks").delete(dbKey); deleteRequest.onsuccess = function () { tasks.dataSource.remove(listViewKey); } } This code does two things: it deletes the existing task from the database and removes the existing task from the ListView. In both cases, the right task is removed by using the key associated with the task. However, the task key is different in the case of the database and in the case of the ListView. In the case of the database, the task key is the value of the task id property. In the case of the ListView, on the other hand, the task key is auto-generated by the ListView. When the task is removed from the ListView, an animation is used to collapse the tasks which appear above and below the task which was removed. The Complete Code Above, I did a lot of jumping around between different files in the application and I left out sections of code. For the sake of completeness, I want to include the entire code here: the default.html, default.js, and tasks.js files. Here are the contents of the default.html file. This file contains the UI for the Task List application: <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>Task List</title> <!-- WinJS references --> <link href="//Microsoft.WinJS.0.6/css/ui-dark.css" rel="stylesheet"> <script src="//Microsoft.WinJS.0.6/js/base.js"></script> <script src="//Microsoft.WinJS.0.6/js/ui.js"></script> <!-- TaskList references --> <link href="/css/default.css" rel="stylesheet"> <script src="/js/default.js"></script> <script type="text/javascript" src="js/tasks.js"></script> <style type="text/css"> body { font-size: x-large; } form { display: inline; } #appContainer { margin: 20px; width: 600px; } .win-container { padding: 10px; } </style> </head> <body> <div> <!-- Templates --> <div id="taskTemplate" data-win-control="WinJS.Binding.Template"> <div> <span data-win-bind="innerText:title"></span> </div> </div> <h1>Super Task List</h1> <div id="appContainer"> <form id="addTaskForm"> <input id="newTaskTitle" title="New Task" required /> <button>Add</button> </form> <button id="btnDeleteTasks">Delete</button> <div id="tasksListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: TaskList.tasks.dataSource, itemTemplate: select('#taskTemplate'), tapBehavior: 'toggleSelect', selectionMode: 'multi', layout: { type: WinJS.UI.ListLayout } }"> </div> </div> </div> </body> </html> Here is the code for the default.js file. This code wires up the Add Task form and Delete button: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { WinJS.UI.processAll().then(function () { // Get reference to Tasks ListView var tasksListView = document.getElementById("tasksListView"); // Handle Add Task document.getElementById("addTaskForm").addEventListener("submit", function (evt) { evt.preventDefault(); var newTaskTitle = document.getElementById("newTaskTitle"); TaskList.addTask({ title: newTaskTitle.value }); newTaskTitle.value = ""; }); // Handle Delete Tasks document.getElementById("btnDeleteTasks").addEventListener("click", function (evt) { tasksListView.winControl.selection.getItems().then(function(items) { items.forEach(function (item) { TaskList.deleteTask(item); }); }); }); }); } }; app.start(); })(); Finally, here is the tasks.js file. This file contains all of the code for opening, creating, and interacting with IndexedDB: (function () { "use strict"; // Create the data source var tasks = new WinJS.Binding.List(); // Open the database var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; // Load the data source with data from the database req.onsuccess = function () { db = req.result; var tran = db.transaction("tasks"); tran.objectStore("tasks").openCursor().onsuccess = function(event) { var cursor = event.target.result; tasks.dataSource.beginEdits(); if (cursor) { tasks.dataSource.insertAtEnd(null, cursor.value); cursor.continue(); } else { tasks.dataSource.endEdits(); }; }; }; // Add a new task function addTask(taskToAdd) { var transaction = db.transaction("tasks", IDBTransaction.READ_WRITE); var addRequest = transaction.objectStore("tasks").add(taskToAdd); addRequest.onsuccess = function (evt) { taskToAdd.id = evt.target.result; tasks.dataSource.insertAtEnd(null, taskToAdd); } } // Delete an existing task function deleteTask(listViewItem) { // Database key != ListView key var dbKey = listViewItem.data.id; var listViewKey = listViewItem.key; // Remove item from db and, if success, remove item from ListView var transaction = db.transaction("tasks", IDBTransaction.READ_WRITE); var deleteRequest = transaction.objectStore("tasks").delete(dbKey); deleteRequest.onsuccess = function () { tasks.dataSource.remove(listViewKey); } } // Expose the data source and functions WinJS.Namespace.define("TaskList", { tasks: tasks, addTask: addTask, deleteTask: deleteTask }); })(); Summary I wrote this blog entry because I wanted to create a walkthrough of building a simple database-driven application. In particular, I wanted to demonstrate how you can use a ListView control with an IndexedDB database to store and retrieve database data.

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  • DevConnections Session Slides, Samples and Links

    - by Rick Strahl
    Finally coming up for air this week, after catching up with being on the road for the better part of three weeks. Here are my slides, samples and links for my four DevConnections Session two weeks ago in Vegas. I ended up doing one extra un-prepared for session on WebAPI and AJAX, as some of the speakers were either delayed or unable to make it at all to Vegas due to Sandy's mayhem. It was pretty hectic in the speaker room as Erik (our event coordinator extrodinaire) was scrambling to fill session slots with speakers :-). Surprisingly it didn't feel like the storm affected attendance drastically though, but I guess it's hard to tell without actual numbers. The conference was a lot of fun - it's been a while since I've been speaking at one of these larger conferences. I'd been taking a hiatus, and I forgot how much I enjoy actually giving talks. Preparing - well not  quite so much, especially since I ended up essentially preparing or completely rewriting for all three of these talks and I was stressing out a bit as I was sick the week before the conference and didn't get as much time to prepare as I wanted to. But - as always seems to be the case - it all worked out, but I guess those that attended have to be the judge of that… It was great to catch up with my speaker friends as well - man I feel out of touch. I got to spend a bunch of time with Dan Wahlin, Ward Bell, Julie Lerman and for about 10 minutes even got to catch up with the ever so busy Michele Bustamante. Lots of great technical discussions including a fun and heated REST controversy with Ward and Howard Dierking. There were also a number of great discussions with attendees, describing how they're using the technologies touched in my talks in live applications. I got some great ideas from some of these and I wish there would have been more opportunities for these kinds of discussions. One thing I miss at these Vegas events though is some sort of coherent event where attendees and speakers get to mingle. These Vegas conferences are just like "go to sessions, then go out and PARTY on the town" - it's Vegas after all! But I think that it's always nice to have at least one evening event where everybody gets to hang out together and trade stories and geek talk. Overall there didn't seem to be much opportunity for that beyond lunch or the small and short exhibit hall events which it seemed not many people actually went to. Anyways, a good time was had. I hope those of you that came to my sessions learned something useful. There were lots of great questions and discussions after the sessions - always appreciate hearing the real life scenarios that people deal with in relation to the abstracted scenarios in sessions. Here are the Session abstracts, a few comments and the links for downloading slides and  samples. It's not quite like being there, but I hope this stuff turns out to be useful to some of you. I'll be following up a couple of these sessions with white papers in the following weeks. Enjoy. ASP.NET Architecture: How ASP.NET Works at the Low Level Abstract:Interested in how ASP.NET works at a low level? ASP.NET is extremely powerful and flexible technology, but it's easy to forget about the core framework that underlies the higher level technologies like ASP.NET MVC, WebForms, WebPages, Web Services that we deal with on a day to day basis. The ASP.NET core drives all the higher level handlers and frameworks layered on top of it and with the core power comes some complexity in the form of a very rich object model that controls the flow of a request through the ASP.NET pipeline from Windows HTTP services down to the application level. To take full advantage of it, it helps to understand the underlying architecture and model. This session discusses the architecture of ASP.NET along with a number of useful tidbits that you can use for building and debugging your ASP.NET applications more efficiently. We look at overall architecture, how requests flow from the IIS (7 and later) Web Server to the ASP.NET runtime into HTTP handlers, modules and filters and finally into high-level handlers like MVC, Web Forms or Web API. Focus of this session is on the low-level aspects on the ASP.NET runtime, with examples that demonstrate the bootstrapping of ASP.NET, threading models, how Application Domains are used, startup bootstrapping, how configuration files are applied and how all of this relates to the applications you write either using low-level tools like HTTP handlers and modules or high-level pages or services sitting at the top of the ASP.NET runtime processing chain. Comments:I was surprised to see so many people show up for this session - especially since it was the last session on the last day and a short 1 hour session to boot. The room was packed and it was to see so many people interested the abstracts of architecture of ASP.NET beyond the immediate high level application needs. Lots of great questions in this talk as well - I only wish this session would have been the full hour 15 minutes as we just a little short of getting through the main material (didn't make it to Filters and Error handling). I haven't done this session in a long time and I had to pretty much re-figure all the system internals having to do with the ASP.NET bootstrapping in light for the changes that came with IIS 7 and later. The last time I did this talk was with IIS6, I guess it's been a while. I love doing this session, mainly because in my mind the core of ASP.NET overall is so cleanly designed to provide maximum flexibility without compromising performance that has clearly stood the test of time in the 10 years or so that .NET has been around. While there are a lot of moving parts, the technology is easy to manage once you understand the core components and the core model hasn't changed much even while the underlying architecture that drives has been almost completely revamped especially with the introduction of IIS 7 and later. Download Samples and Slides   Introduction to using jQuery with ASP.NET Abstract:In this session you'll learn how to take advantage of jQuery in your ASP.NET applications. Starting with an overview of jQuery client features via many short and fun examples, you'll find out about core features like the power of selectors for document element selection, manipulating these elements with jQuery's wrapped set methods in a browser independent way, how to hook up and handle events easily and generally apply concepts of unobtrusive JavaScript principles to client scripting. The second half of the session then delves into jQuery's AJAX features and several different ways how you can interact with ASP.NET on the server. You'll see examples of using ASP.NET MVC for serving HTML and JSON AJAX content, as well as using the new ASP.NET Web API to serve JSON and hypermedia content. You'll also see examples of client side templating/databinding with Handlebars and Knockout. Comments:This session was in a monster of a room and to my surprise it was nearly packed, given that this was a 100 level session. I can see that it's a good idea to continue to do intro sessions to jQuery as there appeared to be quite a number of folks who had not worked much with jQuery yet and who most likely could greatly benefit from using it. Seemed seemed to me the session got more than a few people excited to going if they hadn't yet :-).  Anyway I just love doing this session because it's mostly live coding and highly interactive - not many sessions that I can build things up from scratch and iterate on in an hour. jQuery makes that easy though. Resources: Slides and Code Samples Introduction to jQuery White Paper Introduction to ASP.NET Web API   Hosting the Razor Scripting Engine in Your Own Applications Abstract:The Razor Engine used in ASP.NET MVC and ASP.NET Web Pages is a free-standing scripting engine that can be disassociated from these Web-specific implementations and can be used in your own applications. Razor allows for a powerful mix of code and text rendering that makes it a wonderful tool for any sort of text generation, from creating HTML output in non-Web applications, to rendering mail merge-like functionality, to code generation for developer tools and even as a plug-in scripting engine. In this session, we'll look at the components that make up the Razor engine and how you can bootstrap it in your own applications to hook up templating. You'll find out how to create custom templates and manage Razor requests that can be pre-compiled, detecting page changes and act in ways similar to a full runtime. We look at ways that you can pass data into the engine and retrieve both the rendered output as well as result values in a package that makes it easy to plug Razor into your own applications. Comments:That this session was picked was a bit of a surprise to me, since it's a bit of a niche topic. Even more of a surprise was that during the session quite a few people who attended had actually used Razor externally and were there to find out more about how the process works and how to extend it. In the session I talk a bit about a custom Razor hosting implementation (Westwind.RazorHosting) and drilled into the various components required to build a custom Razor Hosting engine and a runtime around it. This sessions was a bit of a chore to prepare for as there are lots of technical implementation details that needed to be dealt with and squeezing that into an hour 15 is a bit tight (and that aren't addressed even by some of the wrapper libraries that exist). Found out though that there's quite a bit of interest in using a templating engine outside of web applications, or often side by side with the HTML output generated by frameworks like MVC or WebForms. An extra fun part of this session was that this was my first session and when I went to set up I realized I forgot my mini-DVI to VGA adapter cable to plug into the projector in my room - 6 minutes before the session was about to start. So I ended up sprinting the half a mile + back to my room - and back at a full sprint. I managed to be back only a couple of minutes late, but when I started I was out of breath for the first 10 minutes or so, while trying to talk. Musta sounded a bit funny as I was trying to not gasp too much :-) Resources: Slides and Code Samples Westwind.RazorHosting GitHub Project Original RazorHosting Blog Post   Introduction to ASP.NET Web API for AJAX Applications Abstract:WebAPI provides a new framework for creating REST based APIs, but it can also act as a backend to typical AJAX operations. This session covers the core features of Web API as it relates to typical AJAX application development. We’ll cover content-negotiation, routing and a variety of output generation options as well as managing data updates from the client in the context of a small Single Page Application style Web app. Finally we’ll look at some of the extensibility features in WebAPI to customize and extend Web API in a number and useful useful ways. Comments:This session was a fill in for session slots not filled due MIA speakers stranded by Sandy. I had samples from my previous Web API article so decided to go ahead and put together a session from it. Given that I spent only a couple of hours preparing and putting slides together I was glad it turned out as it did - kind of just ran itself by way of the examples I guess as well as nice audience interactions and questions. Lots of interest - and also some confusion about when Web API makes sense. Both this session and the jQuery session ended up getting a ton of questions about when to use Web API vs. MVC, whether it would make sense to switch to Web API for all AJAX backend work etc. In my opinion there's no need to jump to Web API for existing applications that already have a good AJAX foundation. Web API is awesome for real externally consumed APIs and clearly defined application AJAX APIs. For typical application level AJAX calls, it's still a good idea, but ASP.NET MVC can serve most if not all of that functionality just as well. There's no need to abandon MVC (or even ASP.NET AJAX or third party AJAX backends) just to move to Web API. For new projects Web API probably makes good sense for isolation of AJAX calls, but it really depends on how the application is set up. In some cases sharing business logic between the HTML and AJAX interfaces with a single MVC API can be cleaner than creating two completely separate code paths to serve essentially the same business logic. Resources: Slides and Code Samples Sample Code on GitHub Introduction to ASP.NET Web API White Paper© Rick Strahl, West Wind Technologies, 2005-2012Posted in Conferences  ASP.NET   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • 64-bit Archives Needed

    - by user9154181
    A little over a year ago, we received a question from someone who was trying to build software on Solaris. He was getting errors from the ar command when creating an archive. At that time, the ar command on Solaris was a 32-bit command. There was more than 2GB of data, and the ar command was hitting the file size limit for a 32-bit process that doesn't use the largefile APIs. Even in 2011, 2GB is a very large amount of code, so we had not heard this one before. Most of our toolchain was extended to handle 64-bit sized data back in the 1990's, but archives were not changed, presumably because there was no perceived need for it. Since then of course, programs have continued to get larger, and in 2010, the time had finally come to investigate the issue and find a way to provide for larger archives. As part of that process, I had to do a deep dive into the archive format, and also do some Unix archeology. I'm going to record what I learned here, to document what Solaris does, and in the hope that it might help someone else trying to solve the same problem for their platform. Archive Format Details Archives are hardly cutting edge technology. They are still used of course, but their basic form hasn't changed in decades. Other than to fix a bug, which is rare, we don't tend to touch that code much. The archive file format is described in /usr/include/ar.h, and I won't repeat the details here. Instead, here is a rough overview of the archive file format, implemented by System V Release 4 (SVR4) Unix systems such as Solaris: Every archive starts with a "magic number". This is a sequence of 8 characters: "!<arch>\n". The magic number is followed by 1 or more members. A member starts with a fixed header, defined by the ar_hdr structure in/usr/include/ar.h. Immediately following the header comes the data for the member. Members must be padded at the end with newline characters so that they have even length. The requirement to pad members to an even length is a dead giveaway as to the age of the archive format. It tells you that this format dates from the 1970's, and more specifically from the era of 16-bit systems such as the PDP-11 that Unix was originally developed on. A 32-bit system would have required 4 bytes, and 64-bit systems such as we use today would probably have required 8 bytes. 2 byte alignment is a poor choice for ELF object archive members. 32-bit objects require 4 byte alignment, and 64-bit objects require 64-bit alignment. The link-editor uses mmap() to process archives, and if the members have the wrong alignment, we have to slide (copy) them to the correct alignment before we can access the ELF data structures inside. The archive format requires 2 byte padding, but it doesn't prohibit more. The Solaris ar command takes advantage of this, and pads ELF object members to 8 byte boundaries. Anything else is padded to 2 as required by the format. The archive header (ar_hdr) represents all numeric values using an ASCII text representation rather than as binary integers. This means that an archive that contains only text members can be viewed using tools such as cat, more, or a text editor. The original designers of this format clearly thought that archives would be used for many file types, and not just for objects. Things didn't turn out that way of course — nearly all archives contain relocatable objects for a single operating system and machine, and are used primarily as input to the link-editor (ld). Archives can have special members that are created by the ar command rather than being supplied by the user. These special members are all distinguished by having a name that starts with the slash (/) character. This is an unambiguous marker that says that the user could not have supplied it. The reason for this is that regular archive members are given the plain name of the file that was inserted to create them, and any path components are stripped off. Slash is the delimiter character used by Unix to separate path components, and as such cannot occur within a plain file name. The ar command hides the special members from you when you list the contents of an archive, so most users don't know that they exist. There are only two possible special members: A symbol table that maps ELF symbols to the object archive member that provides it, and a string table used to hold member names that exceed 15 characters. The '/' convention for tagging special members provides room for adding more such members should the need arise. As I will discuss below, we took advantage of this fact to add an alternate 64-bit symbol table special member which is used in archives that are larger than 4GB. When an archive contains ELF object members, the ar command builds a special archive member known as the symbol table that maps all ELF symbols in the object to the archive member that provides it. The link-editor uses this symbol table to determine which symbols are provided by the objects in that archive. If an archive has a symbol table, it will always be the first member in the archive, immediately following the magic number. Unlike member headers, symbol tables do use binary integers to represent offsets. These integers are always stored in big-endian format, even on a little endian host such as x86. The archive header (ar_hdr) provides 15 characters for representing the member name. If any member has a name that is longer than this, then the real name is written into a special archive member called the string table, and the member's name field instead contains a slash (/) character followed by a decimal representation of the offset of the real name within the string table. The string table is required to precede all normal archive members, so it will be the second member if the archive contains a symbol table, and the first member otherwise. The archive format is not designed to make finding a given member easy. Such operations move through the archive from front to back examining each member in turn, and run in O(n) time. This would be bad if archives were commonly used in that manner, but in general, they are not. Typically, the ar command is used to build an new archive from scratch, inserting all the objects in one operation, and then the link-editor accesses the members in the archive in constant time by using the offsets provided by the symbol table. Both of these operations are reasonably efficient. However, listing the contents of a large archive with the ar command can be rather slow. Factors That Limit Solaris Archive Size As is often the case, there was more than one limiting factor preventing Solaris archives from growing beyond the 32-bit limits of 2GB (32-bit signed) and 4GB (32-bit unsigned). These limits are listed in the order they are hit as archive size grows, so the earlier ones mask those that follow. The original Solaris archive file format can handle sizes up to 4GB without issue. However, the ar command was delivered as a 32-bit executable that did not use the largefile APIs. As such, the ar command itself could not create a file larger than 2GB. One can solve this by building ar with the largefile APIs which would allow it to reach 4GB, but a simpler and better answer is to deliver a 64-bit ar, which has the ability to scale well past 4GB. Symbol table offsets are stored as 32-bit big-endian binary integers, which limits the maximum archive size to 4GB. To get around this limit requires a different symbol table format, or an extension mechanism to the current one, similar in nature to the way member names longer than 15 characters are handled in member headers. The size field in the archive member header (ar_hdr) is an ASCII string capable of representing a 32-bit unsigned value. This places a 4GB size limit on the size of any individual member in an archive. In considering format extensions to get past these limits, it is important to remember that very few archives will require the ability to scale past 4GB for many years. The old format, while no beauty, continues to be sufficient for its purpose. This argues for a backward compatible fix that allows newer versions of Solaris to produce archives that are compatible with older versions of the system unless the size of the archive exceeds 4GB. Archive Format Differences Among Unix Variants While considering how to extend Solaris archives to scale to 64-bits, I wanted to know how similar archives from other Unix systems are to those produced by Solaris, and whether they had already solved the 64-bit issue. I've successfully moved archives between different Unix systems before with good luck, so I knew that there was some commonality. If it turned out that there was already a viable defacto standard for 64-bit archives, it would obviously be better to adopt that rather than invent something new. The archive file format is not formally standardized. However, the ar command and archive format were part of the original Unix from Bell Labs. Other systems started with that format, extending it in various often incompatible ways, but usually with the same common shared core. Most of these systems use the same magic number to identify their archives, despite the fact that their archives are not always fully compatible with each other. It is often true that archives can be copied between different Unix variants, and if the member names are short enough, the ar command from one system can often read archives produced on another. In practice, it is rare to find an archive containing anything other than objects for a single operating system and machine type. Such an archive is only of use on the type of system that created it, and is only used on that system. This is probably why cross platform compatibility of archives between Unix variants has never been an issue. Otherwise, the use of the same magic number in archives with incompatible formats would be a problem. I was able to find information for a number of Unix variants, described below. These can be divided roughly into three tribes, SVR4 Unix, BSD Unix, and IBM AIX. Solaris is a SVR4 Unix, and its archives are completely compatible with those from the other members of that group (GNU/Linux, HP-UX, and SGI IRIX). AIX AIX is an exception to rule that Unix archive formats are all based on the original Bell labs Unix format. It appears that AIX supports 2 formats (small and big), both of which differ in fundamental ways from other Unix systems: These formats use a different magic number than the standard one used by Solaris and other Unix variants. They include support for removing archive members from a file without reallocating the file, marking dead areas as unused, and reusing them when new archive items are inserted. They have a special table of contents member (File Member Header) which lets you find out everything that's in the archive without having to actually traverse the entire file. Their symbol table members are quite similar to those from other systems though. Their member headers are doubly linked, containing offsets to both the previous and next members. Of the Unix systems described here, AIX has the only format I saw that will have reasonable insert/delete performance for really large archives. Everyone else has O(n) performance, and are going to be slow to use with large archives. BSD BSD has gone through 4 versions of archive format, which are described in their manpage. They use the same member header as SVR4, but their symbol table format is different, and their scheme for long member names puts the name directly after the member header rather than into a string table. GNU/Linux The GNU toolchain uses the SVR4 format, and is compatible with Solaris. HP-UX HP-UX seems to follow the SVR4 model, and is compatible with Solaris. IRIX IRIX has 32 and 64-bit archives. The 32-bit format is the standard SVR4 format, and is compatible with Solaris. The 64-bit format is the same, except that the symbol table uses 64-bit integers. IRIX assumes that an archive contains objects of a single ELFCLASS/MACHINE, and any archive containing ELFCLASS64 objects receives a 64-bit symbol table. Although they only use it for 64-bit objects, nothing in the archive format limits it to ELFCLASS64. It would be perfectly valid to produce a 64-bit symbol table in an archive containing 32-bit objects, text files, or anything else. Tru64 Unix (Digital/Compaq/HP) Tru64 Unix uses a format much like ours, but their symbol table is a hash table, making specific symbol lookup much faster. The Solaris link-editor uses archives by examining the entire symbol table looking for unsatisfied symbols for the link, and not by looking up individual symbols, so there would be no benefit to Solaris from such a hash table. The Tru64 ld must use a different approach in which the hash table pays off for them. Widening the existing SVR4 archive symbol tables rather than inventing something new is the simplest path forward. There is ample precedent for this approach in the ELF world. When ELF was extended to support 64-bit objects, the approach was largely to take the existing data structures, and define 64-bit versions of them. We called the old set ELF32, and the new set ELF64. My guess is that there was no need to widen the archive format at that time, but had there been, it seems obvious that this is how it would have been done. The Implementation of 64-bit Solaris Archives As mentioned earlier, there was no desire to improve the fundamental nature of archives. They have always had O(n) insert/delete behavior, and for the most part it hasn't mattered. AIX made efforts to improve this, but those efforts did not find widespread adoption. For the purposes of link-editing, which is essentially the only thing that archives are used for, the existing format is adequate, and issues of backward compatibility trump the desire to do something technically better. Widening the existing symbol table format to 64-bits is therefore the obvious way to proceed. For Solaris 11, I implemented that, and I also updated the ar command so that a 64-bit version is run by default. This eliminates the 2 most significant limits to archive size, leaving only the limit on an individual archive member. We only generate a 64-bit symbol table if the archive exceeds 4GB, or when the new -S option to the ar command is used. This maximizes backward compatibility, as an archive produced by Solaris 11 is highly likely to be less than 4GB in size, and will therefore employ the same format understood by older versions of the system. The main reason for the existence of the -S option is to allow us to test the 64-bit format without having to construct huge archives to do so. I don't believe it will find much use outside of that. Other than the new ability to create and use extremely large archives, this change is largely invisible to the end user. When reading an archive, the ar command will transparently accept either form of symbol table. Similarly, the ELF library (libelf) has been updated to understand either format. Users of libelf (such as the link-editor ld) do not need to be modified to use the new format, because these changes are encapsulated behind the existing functions provided by libelf. As mentioned above, this work did not lift the limit on the maximum size of an individual archive member. That limit remains fixed at 4GB for now. This is not because we think objects will never get that large, for the history of computing says otherwise. Rather, this is based on an estimation that single relocatable objects of that size will not appear for a decade or two. A lot can change in that time, and it is better not to overengineer things by writing code that will sit and rot for years without being used. It is not too soon however to have a plan for that eventuality. When the time comes when this limit needs to be lifted, I believe that there is a simple solution that is consistent with the existing format. The archive member header size field is an ASCII string, like the name, and as such, the overflow scheme used for long names can also be used to handle the size. The size string would be placed into the archive string table, and its offset in the string table would then be written into the archive header size field using the same format "/ddd" used for overflowed names.

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  • How to safely reboot via First Boot script

    - by unixman
    With the cost and performance benefits of the SPARC T4 and SPARC T5 systems undeniably validated, the banking sector is actively moving to Solaris 11.  I was recently asked to help a banking customer of ours look at migrating some of their Solaris 10 logic over to Solaris 11.  While we've introduced a number of holistic improvements in Solaris 11, in terms of how we ease long-term software lifecycle management, it is important to appreciate that customers may not be able to move all of their Solaris 10 scripts and procedures at once; there are years of scripts that reflect fine-tuned requirements of proprietary banking software that gets layered on top of the operating system. One of these requirements is to go through a cycle of reboots, after the system is installed, in order to ensure appropriate software dependencies and various configuration files are in-place. While Solaris 10 introduced a facility that aids here, namely SMF, many of our customers simply haven't yet taken the time to take advantage of this - proceeding with logic that, while functional, without further analysis has an appearance of not being optimal in terms of taking advantage of all the niceties bundled in Solaris 11 at no extra cost. When looking at Solaris 11, we recognize that one of the vehicles that bridges the gap between getting the operating system image payload delivered, and the customized banking software installed, is a notion of a First Boot script.  I had a working example of this at one of the Oracle OpenWorld sessions a few years ago - we've since improved our documentation and have introduced sections where this is described in better detail.   If you're looking at this for the first time and you've not worked with IPS and SMF previously, you might get the sense that the tasks are daunting.   There is a set of technologies involved that are jointly engineered in order to make the process reliable, predictable and extensible. As you go down the path of writing your first boot script, you'll be faced with a need to wrap it into a SMF service and then packaged into a IPS package. The IPS package would then need to be placed onto your IPS repository, in order to subsequently be made available to all of your AI (Automated Install) clients (i.e. the systems that you're installing Solaris and your software onto).     With this blog post, I wanted to create a single place that outlines the entire process (simplistically), and provide a hint of how a good old "at" command may make the requirement of forcing an initial reboot handy. The syntax and references to commands here is based on running this on a version of Solaris 11 that has been updated since its initial release in 2011 (i.e. I am writing this on Solaris 11.1) Assuming you've built an AI server (see this How To article for an example), you might be asking yourself: "Ok, I've got some logic that I need executed AFTER Solaris is deployed and I need my own little script that would make that happen. How do I go about hooking that script into the Solaris 11 AI framework?"  You might start here, in Chapter 13 of the "Installing Oracle Solaris 11.1 Systems" guide, which talks about "Running a Custom Script During First Boot".  And as you do, you'll be confronted with command that might be unfamiliar to you if you're new to Solaris 11, like our dear new friend: svcbundle svcbundle is an aide to creating manifests and profiles.  It is awesome, but don't let its awesomeness overwhelm you. (See this How To article by my colleague Glynn Foster for a nice working example).  In order to get your script's logic integrated into the Solaris 11 deployment process, you need to wrap your (shell) script into 2 manifests -  a SMF service manifest and a IPS package manifest.  ....and if you're new to XML, well then -- buckle up We have some examples of small first boot scripts shown here, as templates to build upon. Necessary structure of the script, particularly in leveraging SMF interfaces, is key. I won't go into that here as that is covered nicely in the doc link above.    Let's say your script ends up looking like this (btw: if things appear to be cut-off in your browser, just select them, copy and paste into your editor and it'll be grabbed - the source gets captured eventhough the browser may not render it "correctly" - ah, computers). #!/bin/sh # Load SMF shell support definitions . /lib/svc/share/smf_include.sh # If nothing to do, exit with temporary disable completed=`svcprop -p config/completed site/first-boot-script-svc:default` [ "${completed}" = "true" ] && \ smf_method_exit $SMF_EXIT_TEMP_DISABLE completed "Configuration completed" # Obtain the active BE name from beadm: The active BE on reboot has an R in # the third column of 'beadm list' output. Its name is in column one. bename=`beadm list -Hd|nawk -F ';' '$3 ~ /R/ {print $1}'` beadm create ${bename}.orig echo "Original boot environment saved as ${bename}.orig" # ---- Place your one-time configuration tasks here ---- # For example, if you have to pull some files from your own pre-existing system: /usr/bin/wget -P /var/tmp/ $PULL_DOWN_ADDITIONAL_SCRIPTS_FROM_A_CORPORATE_SYSTEM /usr/bin/chmod 755 /var/tmp/$SCRIPTS_THAT_GOT_PULLED_DOWN_IN_STEP_ABOVE # Clearly the above 2 lines represent some logic that you'd have to customize to fit your needs. # # Perhaps additional things you may want to do here might be of use, like # (gasp!) configuring ssh server for root login and X11 forwarding (for testing), and the like... # # Oh and by the way, after we're done executing all of our proprietary scripts we need to reboot # the system in accordance with our operational software requirements to ensure all layered bits # get initialized properly and pull-in their own modules and components in the right sequence, # subsequently. # We need to set a "time bomb" reboot, that would take place upon completion of this script. # We already know that *this* script depends on multi-user-server SMF milestone, so it should be # safe for us to schedule a reboot for 5 minutes from now. The "at" job get scheduled in the queue # while our little script continues thru the rest of the logic. /usr/bin/at now + 5 minutes <<REBOOT /usr/bin/sync /usr/sbin/reboot REBOOT # ---- End of your customizations ---- # Record that this script's work is done svccfg -s site/first-boot-script-svc:default setprop config/completed = true svcadm refresh site/first-boot-script-svc:default smf_method_exit $SMF_EXIT_TEMP_DISABLE method_completed "Configuration completed"  ...and you're happy with it and are ready to move on. Where do you go and what do you do? The next step is creating the IPS package for your script. Since running the logic of your script constitutes a service, you need to create a service manifest. This is described here, in the middle of Chapter 13 of "Creating an IPS package for the script and service".  Assuming the name of your shell script is first-boot-script.sh, you could end up doing the following: $ cd some_working_directory_for_this_project$ mkdir -p proto/lib/svc/manifest/site$ mkdir -p proto/opt/site $ cp first-boot-script.sh proto/opt/site  Then you would create the service manifest  file like so: $ svcbundle -s service-name=site/first-boot-script-svc \ -s start-method=/opt/site/first-boot-script.sh \ -s instance-property=config:completed:boolean:false -o \ first-boot-script-svc-manifest.xml   ...as described here, and place it into the directory hierarchy above. But before you place it into the directory, make sure to inspect the manifest and adjust the appropriate service dependencies.  That is to say, you want to properly specify what milestone should be reached before your service runs.  There's a <dependency> section that looks like this, before you modify it: <dependency restart_on="none" type="service" name="multi_user_dependency" grouping="require_all"> <service_fmri value="svc:/milestone/multi-user"/>  </dependency>  So if you'd like to have your service run AFTER the multi-user-server milestone has been reached (i.e. later, as multi-user-server has more dependencies then multi-user and our intent to reboot the system may have significant ramifications if done prematurely), you would modify that section to read:  <dependency restart_on="none" type="service" name="multi_user_server_dependency" grouping="require_all"> <service_fmri value="svc:/milestone/multi-user-server"/>  </dependency> Save the file and validate it: $ svccfg validate first-boot-script-svc-manifest.xml Assuming there are no errors returned, copy the file over into the directory hierarchy: $ cp first-boot-script-svc-manifest.xml proto/lib/svc/manifest/site Now that we've created the service manifest (.xml), create the package manifest (.p5m) file named: first-boot-script.p5m.  Populate it as follows: set name=pkg.fmri value=first-boot-script-AT-1-DOT-0,5.11-0 set name=pkg.summary value="AI first-boot script" set name=pkg.description value="Script that runs at first boot after AI installation" set name=info.classification value=\ "org.opensolaris.category.2008:System/Administration and Configuration" file lib/svc/manifest/site/first-boot-script-svc-manifest.xml \ path=lib/svc/manifest/site/first-boot-script-svc-manifest.xml owner=root \ group=sys mode=0444 dir path=opt/site owner=root group=sys mode=0755 file opt/site/first-boot-script.sh path=opt/site/first-boot-script.sh \ owner=root group=sys mode=0555 Now we are going to publish this package into a IPS repository. If you don't have one yet, don't worry. You have 2 choices: You can either  publish this package into your mirror of the Oracle Solaris IPS repo or create your own customized repo.  The best practice is to create your own customized repo, leaving your mirror of the Oracle Solaris IPS repo untouched.  From this point, you have 2 choices as well - you can either create a repo that will be accessible by your clients via HTTP or via NFS.  Since HTTP is how the default Solaris repo is accessed, we'll go with HTTP for your own IPS repo.   This nice and comprehensive How To by Albert White describes how to create multiple internal IPS repos for Solaris 11. We'll zero in on the basic elements for our needs here: We'll create the IPS repo directory structure hanging off a separate ZFS file system, and we'll tie it into an instance of pkg.depotd. We do this because we want our IPS repo to be accessible to our AI clients through HTTP, and the pkg.depotd SMF service bundled in Solaris 11 can help us do this. We proceed as follows: # zfs create rpool/export/MyIPSrepo # pkgrepo create /export/MyIPSrepo # svccfg -s pkg/server add MyIPSrepo # svccfg -s pkg/server:MyIPSrepo addpg pkg application # svccfg -s pkg/server:MyIPSrepo setprop pkg/port=10081 # svccfg -s pkg/server:MyIPSrepo setprop pkg/inst_root=/export/MyIPSrepo # svccfg -s pkg/server:MyIPSrepo addpg general framework # svccfg -s pkg/server:MyIPSrepo addpropvalue general/complete astring: MyIPSrepo # svccfg -s pkg/server:MyIPSrepo addpropvalue general/enabled boolean: true # svccfg -s pkg/server:MyIPSrepo setprop pkg/readonly=true # svccfg -s pkg/server:MyIPSrepo setprop pkg/proxy_base = astring: http://your_internal_websrvr/MyIPSrepo # svccfg -s pkg/server:MyIPSrepo setprop pkg/threads = 200 # svcadm refresh application/pkg/server:MyIPSrepo # svcadm enable application/pkg/server:MyIPSrepo Now that the IPS repo is created, we need to publish our package into it: # pkgsend publish -d ./proto -s /export/MyIPSrepo first-boot-script.p5m If you find yourself making changes to your script, remember to up-rev the version in the .p5m file (which is your IPS package manifest), and re-publish the IPS package. Next, you need to go to your AI install server (which might be the same machine) and modify the AI manifest to include a reference to your newly created package.  We do that by listing an additional publisher, which would look like this (replacing the IP address and port with your own, from the "svccfg" commands up above): <publisher name="firstboot"> <origin name="http://192.168.1.222:10081"/> </publisher>  Further down, in the  <software_data action="install">  section add: <name>pkg:/first-boot-script</name> Make sure to update your Automated Install service with the new AI manifest via installadm update-manifest command.  Don't forget to boot your client from the network to watch the entire process unfold and your script get tested.  Once the system makes the initial reboot, the first boot script will be executed and whatever logic you've specified in it should be executed, too, followed by a nice reboot. When the system comes up, your service should stay in a disabled state, as specified by the tailing lines of your SMF script - this is normal and should be left as is as it helps provide an auditing trail for you.   Because the reboot is quite a significant action for the system, you may want to add additional logic to the script that actually places and then checks for presence of certain lock files in order to avoid doing a reboot unnecessarily. You may also want to, alternatively, remove the SMF service entirely - if you're unsure of the potential for someone to try and accidentally enable that service -- eventhough its role in life is to only run once upon the system's first boot. That is how I spent a good chunk of my pre-Halloween time this week, hope yours was just as SPARCkly^H^H^H^H fun!    

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  • RIA Services vs ADO.NET Data Services

    - by Cody C
    I'm currently in the process of creating a Silverlight 3 data driven application. To access the database, 2 common approaches are used: RIA Services and ADO.NET Data Services. Does anyone have any guidance on when/why to choose each approach? Here is what I've gathered from my research / experience. Any thoughts? ADO.NET seems to be only useful for strictly database calls. If you need to expose the data services to other applications (ignoring Silverlight 3's domain restriction), this is a good approach. Also, if the URL/Query syntax can be useful in your application, this is another advantage RIA Services seem to be a more flexible, accepted framework. It seems to give you more than strictly database access. It does have a limitation of only being used for the Silverlight / Web application as it is not exposed via a service. Thoughts? Ideas? Comments?

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  • QListView/QListWidget with custom items

    - by Daniel
    I'm writing my first Qt application with PyQt and am having some trouble creating a custom list view. I'd like the list to contain arbitrary widgets (one custom widget in particular). How would I go about this? It seems that the alternative would be to create a table or grid view wrapped in a scrollbar. However, I'd like to be able to take advantage of the model/view approach as well as the nesting (tree-view) support the built-ins handle. EDIT: To clarify, this widget is interactive (contains buttons), so the solution requires more than painting a widget.

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  • Java 2D Game Frameworks

    - by Software Monkey
    I have been looking at frameworks for writing 2D games in Java - part of a growing desire to rediscover my roots in writing those simple but addictive video games. I have googled and found some possibilities, but it's hard to judge which is best without investing significant time in each. Does anyone out there have any recommendations from experience, preferably with a list of pro's and con's for the framework. NOTE: I am not looking so much for comparisons between frameworks but, rather, feedback on any given framework from actually having used it firsthand, or knowing someone who has. The other possibility I am considering is rolling my own, but would rather not. EDIT: I am targeting Java on the Desktop, and expect capable machines, though not state of the art. Some of the 2D engines I have found: Free PulpCore (License: BSD) Slick2D (License: BSD) GTGE - Golden T Game Engine JGame GAGE - Genuine Advantage Gaming Engine GameFrame for Java Basilisk (2D and 3D) Free for non-commercial use Genuts EasyWay - a high-level 2D engine

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  • Getting ANT to scp only new/changed files

    - by Artem
    I would like to optimize my scp deployment which currently copies all files to only copy files that have changed since the last build. I believe it should be possible with the current setup somehow, but I don't know how to do this. I have the following: Project/src/blah/blah/ <---- files I am editing (mostly PHP in this case, some static assets) Project/build <------- I have a local build step that I use to copy the files to here I have an scp task right now that copies all of Project/build out to a remote server when I need it. Is it possible to somehow take advantage of this extra "build" directory to accomplish what I want -- meaning I only want to upload the "diff" between src/** and build/**. Is it possible to somehow retrieve this as a fileset in ANT and then scp that? I do realize that what it means is that if I somehow delete/mess around with files on the server in between, the ANT script would not notice, but for me this is okay.

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  • Horizontal UITableView

    - by imran
    I want implement a layout in my ipad application that has a uitable view that scrolls left and right rather then up and down : So rather than row 1 row 2 row 3 ( scrolling vertically ) It would be : row 1, row2, row 3 (scrolling horizontally ) I've seen that UItableView is designed to only do vertical scrolling so doing a transform does not give the desired effect. Is there a standard way to do this taking advantage of a datasource provider like uitableview provides? I basically want to do somthing similar to what the BBC News reader app ( http://itunes.apple.com/us/app/bbc-news/id364147881?mt=8 ) on the Ipad does with the list of stories to select from. Thanks

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  • Multi-statement Table Valued Function vs Inline Table Valued Function

    - by AndyC
    ie: CREATE FUNCTION MyNS.GetUnshippedOrders() RETURNS TABLE AS RETURN SELECT a.SaleId, a.CustomerID, b.Qty FROM Sales.Sales a INNER JOIN Sales.SaleDetail b ON a.SaleId = b.SaleId INNER JOIN Production.Product c ON b.ProductID = c.ProductID WHERE a.ShipDate IS NULL GO versus: CREATE FUNCTION MyNS.GetLastShipped(@CustomerID INT) RETURNS @CustomerOrder TABLE (SaleOrderID INT NOT NULL, CustomerID INT NOT NULL, OrderDate DATETIME NOT NULL, OrderQty INT NOT NULL) AS BEGIN DECLARE @MaxDate DATETIME SELECT @MaxDate = MAX(OrderDate) FROM Sales.SalesOrderHeader WHERE CustomerID = @CustomerID INSERT @CustomerOrder SELECT a.SalesOrderID, a.CustomerID, a.OrderDate, b.OrderQty FROM Sales.SalesOrderHeader a INNER JOIN Sales.SalesOrderHeader b ON a.SalesOrderID = b.SalesOrderID INNER JOIN Production.Product c ON b.ProductID = c.ProductID WHERE a.OrderDate = @MaxDate AND a.CustomerID = @CustomerID RETURN END GO Is there an advantage to using one over the other? Is there certain scenarios when one is better than the other or are the differences purely syntactical? I realise the 2 example queries are doing different things but is there a reason I would write them in that way? Reading about them and the advantages/differences haven't really been explained. Thanks

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  • Win32: Is there a replacement GDI32.dll that uses hardware acceleration?

    - by Ian Boyd
    Has anyone out there created a version of GDI32.dll that takes advantage of hardware acceleration available on the machine? gdiplus.dll? Starting with Windows Vista, GDI is no longer hardware accelerated. (GDI+ was never hardware accelerated). Without Microsoft fixing GDI (and GDI+) to be able to run well on the computer: native applications (C++ MFC, Delphi, etc), and managed WinForms applications, will continue to run poorly forever. While i could use Direct2D for business applications, i cannot control the fact that the development environment still creates controls, with decades of library support code, that assumes the presence of GDI.

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  • Windows Mobile Silverlight?

    - by eidylon
    Is it possible to develop Silverlight apps to run on WinMo devices? I see all around searching on the web - in articles from 2008 and 2009 - that they were adding Silverlight support in WinMo 6.1, for example: Internet Explorer Mobile The new version of Internet Explorer Mobile adds the ability to easily view full-screen Web pages and multimedia on the Web with a smartphone. Microsoft's press release states the new version takes advantage of "Internet Explorer 6 technologies" and supports industry standards such as H.264, Adobe Flash and Microsoft Silverlight. The update will be available to mobile phone partners in the third quarter of 2008, with the first Windows Mobile phones using the new version expected to be available by the end of 2008. But I have found an SL app supposedly geared for mobile devices (as much as I hate weatherbug), but when i try going there in PIE on my WinMo 6.1 device, it shows me the little "get silverlight" image button, but clicking it doesn't do anything. So, what is the story? Is SL/WinMo development possible, or ?

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  • Storing user info in Session using an Object vs. normal variables

    - by justinl
    I'm in the process of implementing a user authentication system for my website. I'm using an open source library that maintains user information by creating a User object and storing that object inside my php SESSION variable. Is this the best way to store and access that information? I find it a bit of a hassle to access the user variables because I have to create an object to access them first: $userObj = $_SESSION['userObject']; $userObj->userId; instead of just accessing the user id like this how I would usually store the user ID: $_SESSION['userId']; Is there an advantage to storing a bunch of user data as an object instead of just storing them as individual SESSION variables? ps - The library also seems to store a handful of variables inside the user object (id, username, date joined, email, last user db query) but I really don't care to have all that information stored in my session. I only really want to keep the user id and username.

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  • Difference between Singleton implemention using pointer and using static object

    - by Anon
    EDIT: Sorry my question was not clear, why do books/articles prefer implementation#1 over implementation#2? What is the actual advantage of using pointer in implementation of Singleton class vs using a static object? Why do most books prefer this class Singleton { private: static Singleton *p_inst; Singleton(); public: static Singleton * instance() { if (!p_inst) { p_inst = new Singleton(); } return p_inst; } }; over this class Singleton { public: static Singleton& Instance() { static Singleton inst; return inst; } protected: Singleton(); // Prevent construction Singleton(const Singleton&); // Prevent construction by copying Singleton& operator=(const Singleton&); // Prevent assignment ~Singleton(); // Prevent unwanted destruction };

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  • Cross Platform Tips, Tricks & Gotchas

    - by codeelegance
    If you've worked on a cross platform development project: What did you learn from the experience? What worked? What didn't? What problems did you run into and how did you solve them? Did you aim for consistent appearance and functionality across all platforms or try to take advantage of each platform's strengths? What language and cross platform libraries did you use and did they live up to their claims? Was it a desktop application or web-based?

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  • Server Security

    - by mahatmanich
    I want to run my own root server (directly accessible from the web without a hardware firewall) with debian lenny, apache2, php5, mysql, postfix MTA, sftp (based on ssh) and maybe dns server. What measures/software would you recomend, and why, to secure this server down and minimalize the attack vector? Webapplications aside ... This is what I have so far: iptables (for gen. packet filtering) fail2ban (brute force attack defense) ssh (chang default, port disable root access) modsecurity - is really clumsy and a pain (any alternative here?) ?Sudo why should I use it? what is the advantage to normal user handling thinking about greensql for mysql www.greensql.net is tripwire worth looking at? snort? What am I missing? What is hot and what is not? Best practices? I like "KISS" - Keep it simple secure, I know it would be nice! Thanks in advance ...

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  • What does using RESTful URLs buy me?

    - by Spike Williams
    I've been reading up on REST, and I'm trying to figure out what the advantages to using it are. Specifically, what is the advantage to REST-style URLs that make them worth implementing over a more typical GET request with a query string? Why is this URL: http://www.parts-depot.com/parts/getPart?id=00345 Considered inferior to this? http://www.parts-depot.com/parts/00345 In the above examples (taken from here) the second URL is indeed more elegant looking and concise. But it comes at a cost... the first URL is pretty easy to implement in any web language, out of the box. The second requires additional code and/or server configuration to parse out values, as well as additional documentation and time spent explaining the system to junior programmers and justifying it to peers. So, my question is, aside from the pleasure of having URLs that look cool, what advantages do RESTful URLs gain for me that would make using them worth the cost of implementation?

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  • Why is the unit test useful when the view is not unit testable in MVVM?

    - by BigTiger
    Why is the unit test useful when the view is not unit testable in MVVM? In MVVM, we have the models, view-models, and views. The claimed advantage is that MVVM can make the models and view=models unit testable. But all the three parties belong to the same application. If the views are not unit testable, why test the other two? Will unit testing the other two and leave one not tested improve the quality? Removing all the code-behind from the views sounds weird to me. How about the code-behind only handles the pure UI operations?

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  • Where/what is the specification for odata.service meta tag?

    - by Sam Saffron
    I would like to add some tags to our web app to enable auto-discovery of our odata feeds. So for example Nerd Dinner has the following tag: <link rel="odata.service" title="NerdDinner.com OData Service" href="/Services/OData.svc" /><link rel="odata.feed" title="NerdDinner.com OData Service - Dinners" href="/Services/OData.svc/Dinners" /> The trouble is that I have 4 different feeds and am unclear if I am allowed to add multiple link rel="odata.service" to the document. Where is the specification for this meta tag? (follow on question, are there any apps that take advantage of this tag that I can use to test out behavior)

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  • Thrift and .NET - Is this is right combination?

    - by Vadi
    I've been evaluating various technologies for a Social Networking project. The Thrift kind of interested me to evaluate. The advantage I see using Thrift is I can even come with C++ services when the computation in any such business is huge and may not fits with .NET etc., Please suggest your comments. My Questions: Is the open-sourced one is production-ready? Is it the right stack for services layer to choose when the application (GUI) is primarily gets developed in ASP.NET and DB is SQL Server? Is there any other caveats

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  • iPhone Foundation - performance implications of mutable and xxxWithCapacity:0

    - by Adam Eberbach
    All of the collection classes have two versions - mutable and immutable, such as NSArray and NSMutableArray. Is the distinction merely to promote careful programming by providing a const collection or is there some performance hit when using a mutable object as opposed to immutable? Similarly each of the collection classes has a method xxxxWithCapacity, like [NSMutableArray arrayWithCapacity:0]. I often use zero as the argument because it seems a better choice than guessing wrongly how many objects might be added. Is there some performance advantage to creating a collection with capacity for enough objects in advance? If not why isn't the function something like + (id)emptyArray?

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  • which ASP.NET hosting site allows listening on different ports than 80 and uses .NET 4?

    - by ijjo
    I'm trying to take advantage of HTML 5 web sockets in .NET and the easiest way appears to be something like what this guy does. I've already tested this myself and it works great, but there are a few problems if I try to deploy this to my hosting site (discountasp.net). Basically, I am not allowed to open up a port on 8080 and listen on it. I then tried to figure out a way to listen on port 80 with IIS as well, but using the HTTPListener, I run into sercurity issues as well. This doesn't seem like it will help since I can't mess with this stuff on the hosting site server either. So to make my life easier, I think I need to find a hosting site that simply allows me to open up a socket on port 8080 and listen on it. Anyone know of one? Or does anyone know of a workaround (besides sniffing all the traffic on port 80)?

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  • which asp net hosting site allows to listen on differnt port than 80 and uses .net 4?

    - by ijjo
    i'm trying to take advantage of html 5 web sockets in .NET and the easiest way appears to do something like this guy does: http://www.codeproject.com/KB/webservices/c_sharp_web_socket_server.aspx?msg=3485900#xx3485900xx i've already tested this myself and it works great, but there are a few problems if i try to deploy this to my hosting site (discountasp.net). basically i am not allowed to open up a port on 8080 and listen on it. i then tried to figure out a way to listen non port 80 with IIS as well, but using the HTTPListener runs into sercurity issues as well that doesn't seem like will help since i can't mess with this stuff on the hosting site server either: http://stackoverflow.com/questions/169904/can-i-listen-on-a-port-using-httplistener-or-other-net-code-on-vista-without-r so to make my life easier, i think i need to find a hosting site that simply allows me to open up a socket on port 8080 and listen on it. anyone know of one? or anyone know of a workaround (besides sniffing ALL the traffic on port 80)?

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