Logical operations on entity selections
The ORDA series continues! In this blog post we’ll see how to use logical operators on entity selections!
These operations allow you to get intersections, unions, or differences between two entity selections like you can with classic 4D sets.
Handle entities in an entity selection
FIRST RECORD, LAST RECORD, NEXT RECORD, PREVIOUS RECORD; does that ring any bells? I bet it does. You’ve already been using them to handle selections! ORDA provides useful and familiar methods to navigate through entities in an entity selection – and obviously, some perks!
For starters, you can handle several entity selections at the same time and navigate through them independently, whereas normally you can only manage a single ‘current selection’ per table. That’s precisely what we’re going to see in this blog post.
Get the position of any part of a 4D Write Pro document
4D Write Pro is continuously evolving; thanks to the new features and functionalities we’re shipping with every R-release. A world of possibilities is wide open! Today, thanks to a new command, you can get a set of information about the location of any element within your documents.
Working with ORDA optimistic locking
4D v17 introduces ORDA, a major evolution in 4D which is opening a world of new possibilities for 4D developers. One of the benefits of using ORDA is related to record locking, because ORDA offers a choice between optimistic and pessimistic locking. After having introduced the ORDA locking mechanisms, we continue the ORDA series so you can discover how to work efficiently with optimistic locking with ORDA.
Use table ranges in 4D Write Pro
Since 4D v16 R4, it’s been possible to create tables by programming in your 4D Write Pro documents. Styling the whole table or just certain cells could be done during the creation of the document, but maybe you also want to manage your tables afterwards. Now, it’s easy to manipulate tables in an existing document, to change the border style or color, to change the font size or make it bold, etc.
4D Write Pro programming is highly based on “ranges“. After paragraph ranges and picture ranges, 4D v17 introduces a new type of range: table ranges, returned by a new command: WP Create table range. Styling tables is now simple with this new command and new type of range!
Programmatically access elements in 4D Write Pro
4D Write Pro keeps offering more and more programming capabilities! Let’s say you want to programmatically change the style of a table, paragraph, or image in an existing 4D Write Pro document. With 4D v17, it’s possible! Now you can access any element or part of a document, by programming. These parts, called elements, will be returned either as a collection thanks to the WP Get elements function, or as a single element with WP Get element by ID function.
Locking entities with ORDA
The ORDA series continues! In this blog post, we’ll look at how you can use locks in your databases with ORDA concepts! It’s not uncommon to need to manage conflicts that might occur when several users or processes load and/or attempt to modify the same records at the same time. Record locking is a methodology used in relational databases to avoid inconsistent updates to data.
ORDA provides an optimistic locking mode in addition to the one you already know (pessimistic locking).
Loops, loops and … more loops!
Like many other programming languages, 4D provides the ability to iterate over numbers with a For(…) / End for statement, or over a condition thanks to the While(…)/End while and Repeat/Until(…) keywords. These iterations (or loops) are very useful, but not the most appropriate way to iterate over advanced data types such as collections and entity selections. That’s why the new For each(…)/End for each iterator has been created, to help ease your coding!
How to create a dynamic form from a table in 3 steps!
4D v17 includes dynamic forms, initially introduced in 4D v16 R6, a powerful and flexible way to dynamically build forms fully adapted to your end users’ needs. The possibilities of dynamic forms are tremendous. In this post, we’ll see a concrete example of what you can do with these new forms.
ORDA: work with objects and collections
In this latest addition to the ORDA series, we’ll look at how the new ORDA concepts can interact with existing objects and collections. In fact, it’s possible to turn entities and entity selections into objects and collections, as well as build entities and entity selections from objects and collections. By doing so, you can easily integrate ORDA code within your existing code. You can take full advantage of ORDA without needing to rewrite your code!
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