Your IBM i HTTP Server powered by Apache is a powerful web-serving system akin to a bank staffed with multiple fast-working tellers. The AJAX requests coming in from your front-end apps are like customers entering the bank to perform transactions. Each "customer" queues up in an orderly line on a first-in/first-out basis, and is serviced by the next available "teller" as soon as they're finished dealing with the prior customer.

Nitro Query apps containing charts or graphs can make conveying your company's business trends or performance metrics much more effective than showing raw numbers alone.  It's particularly common (and easy) to create a dashboard app that includes a grid of monthly sales details supplemented by a chart showing month-to-month performance.  This adds some great context to the lists of numbers.

Just about every business has a situation where users need to perform a single process against multiple items in one pass.  For example, you might have a list of open invoices that you'd like to flag as ready for payment, or a group of inventory items that you would like to transfer out of a special holding area.

Older Valence file maintenance apps created through Nitro AutoCode can sometimes exhibit a display problem upon migration to Valence 5.1.  This can also be true for AutoCode-based file maintenance apps created in 5.1 builds prior to 5.1.20171202.0.  The most common symptom is that a portion of the edit/add window displays outside of the portal boundary, as shown here.

Wrapping up 2017 with a simple but powerful tip for Nitro Query grid apps... Very often lists of business data include columns that can be classified as boolean, with text representing values of yes/no, true/false, 1/0, etc.  When you're creating a Nitro Query grid app that includes such columns, you can make "truthy" values stand out much more clearly by replacing the column text with a visual checkmark. 

Power Servers running IBM i are remarkably stable systems, to such a degree that it's easy to overlook those rare occasions when something on the system has gone awry and requires operator attention. When an exception does occur, many IBM i sites have third party monitoring tools or home-grown software in place to notify system administrators that an issue has occurred that may require some kind of action. 

Whether you're a seasoned SQL pro or just learning the ropes of SQL syntax on IBM i, the SQL parser built into Nitro Query App Builder is an invaluable tool you can leverage to quickly generate a web-based report for your users, or even a file maintenance application containing multiple joined files. SQL-based data sources were introduced in Valence 5.1 back in May 2017, and the feature was formally removed from Beta status this month.

We're long past the days where a single on-site server could handle all the IT needs of a typical business.  

One of the most common requirements in a modern business application is the need to present users with easily digested summaries of data in list form.  The ability for inquiring minds to quickly and easily drill down into that summarized data to glean specific details where needed is an added bonus.

The tried and true IBM i Query Utility (as accessed via STRQRY or WRKQRY) is mainstay in many IBM i shops.  But it goes without saying that the user interface associated with the configuration and the output of an IBM i Query leaves a bit to be desired. This is particularly true when users must navigate through the query's definition to change selection or sort criteria.

As we prepare for next month's release of Valence 5.1, we thought it'd be both interesting and useful to summarize some of the blog post contents in a single, categorized list.  From customizing the look and feel of the Valence Portal to tips on back-end and front-end development, there's likely to be at least one or two blog posts to pique your interest. Without further ado, here's a categorized breakdown of the more useful blog posts from the past few years: 

With every user action in the browser that results in a call to a Valence instance running on your IBM i Power Server, a wealth of data about the user's session is sent to the integrated Apache Server.  This information can be accessed by your back-end RPG programs to potentially alter how they respond to the front-end. Want to know what URL is on the user's browser page?  Or what type of browser is being used?

The Nitro Query app included with Valence is designed to quickly take large volumes of IBM i data and make it easily accessible to your users in the form of a dashboard or query.

The latest version of Valence 5 (5.0.20170120.0 as of this writing) makes it significantly easier and more convenient to develop Valence apps using Sencha Architect.  Specifically you can now:

In a typical Valence app you have a myriad of front-end UI logic working in tandem with back-end RPG programs that process AJAX calls and perform functions to retrieve or update IBM i data.  Whenever something goes wrong on the front-end, you can typically zero in on the issue by peering into the browser's console.

By far the most popular UI component in the Valence modernization framework is the subfile-on-steroids known as the Ext JS grid.

Sometimes the best way to get a business point across to someone, or get them to look at something at all, is to make it insanely easy for them to get where they need to go with a single click. The Valence 5 portal makes it possible to do this with just about any app or Nitro Query you've got set up. Simply construct a special URL and email it!

AutoCode apps generated with Valence 4.2 use Ext JS 4.2 -- the fact that these are the same version numbers iwherever possible it is recommended that you just regenerate the app using the new autocode that comes with valence 5.  However, if you've made enhancements to AutoCode apps generated in Valence 4.2 then regeneration from scratch isn't a very viable option.  

One of the most powerful widgets available in Nitro Query is the Edit Grid.  Traditionally queries are read-only, but with an Edit Grid you can actually allow users to update records in a single-file data source — right from within the query itself!  In some cases you may find you can simply create a query for data entry in lieu of coding an actual app, saving yourself a ton of time and effort.

In order to provide data to more intricate UI elements in Ext JS such as trees or collapsible grids with nested lists, you will often find it necessary for your RPG programs to create JSON strings containing arrays within arrays.