Interested in building list boxes that can automatically adapt the height of each row to its content so that the full text or picture can be displayed? What about using object arrays in columns (this allows entering and displaying various types of values in the rows of a single list box’s column).
These are very cool features, right? Previously, you needed to have a valid 4D View Pro license in order to use them. Well, not anymore!
4D v18 R4 lets you access these features for FREE! No additional licensing is required, they’re now included in the standard product.
List boxes are powerful form objects. They’re easily created and manipulated, and most importantly, they can handle any kind of data. Additionally, they can be fully set up by programming … everything from inserting or deleting rows and columns, to defining or modifying tons of properties using the 4D language. With 4D v18 R4, another important property has been added to the list. Can you guess which one? Hint: read the title again.
To display a list of records, an entity selection list box is the most suitable when using ORDA technology. 4D v18 R2 simplifies your life with a new tool to easily build entity selection list boxes: List box builder. What is it? It’s a simple dialog where you can set up your list box in a few quick steps (select the table and fields to display, enter column titles, and define the column order).
by guest author Chris Belanger, a 4D developer from Canada
List box typeahead (a method for progressively searching) is not a native feature of list boxes. However, you can easily implement this feature with some creative coding. In this blog post, I’ll demonstrate the technique along with a database example and an exhaustive document explaining the details step by step.
The final result is summarized in the GIF below, It illustrates two “searches”. One for E-L-L-I-O-T, then another (after a column sort) for H-A-N-N-A-H:
Using ORDA to access large tables (especially those with relations) in Client/Server mode has been greatly enhanced. With 4D v17 R5, you’ll see 2-3xs improved LAN performance and up to 30xs faster WAN performance. And best of all – there’s no need to change anything in your code, it’s all automatic. Interesting, isn’t it? Well, let’s delve into the details.
Starting with 4D v17, the content of a multilevel collection can easily be displayed in different list boxes. Meaning that you can bind several list boxes to display nested details … without a single line of code! This can be achieved by simply using an object or a collection as the data source for another list box!
With the new list box collection type, the “Current item” and “Selected items” properties have been added. Keep in mind that the “Current item” property allows you to get an object, while the “Selected item” property returns a collection.
4D v17 introduces a new concept: ORDA. If you’re not familiar with ORDA yet, we’ve created a series of blog posts to explain how to use and take advantage of ORDA. When working with ORDA, you’re going to use entity selections, which are basically objects containing references to entities belonging to the same dataclass (i.e. table). One of the main benefits of ORDA, is the very simple and powerful ability of binding with forms.
In this blog post, you’ll learn how to display an entity selection in a list box. In fact, it’s very simple.
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