History of MQL5.community development

In order to obtain values of a built-in or custom indicator in an Expert Advisor, first its handle should be created using the corresponding function. Examples in the article show how to use this or that technical indicator while creating your own programs. The article describes indicators that are built n the MQL5 language. It is intended for those who don't have much experience in the development of trading strategies and offers simple and clear ways of working with indicators using the offered library of functions.

Suppose that simple MA (Moving Average) indicator with period 13 is applied to a chart. And we want to change the period to 20, but we do not want to go to indicator properties dialog box and edit the number 13 to 20: simply tired of these tedious actions with mouse and keyboard. And especially we don't want to open indicator code and modify it. We want to do all this with a single press of a button - "up arrows" next to the numeric keypad. In this article I'll describe how to do it.

With new version of MQL programming language available not only the approach of dealing with indicators have changed, but there are also new ways of how to create indicators. Furthermore, you have additional flexibility working with indicator's buffers - now you can specify the desired direction of indexing and get exactly as many indicator's values as you want. This article explains the basic methods of calling indicators and retrieving data from the indicator's buffers.

Any new subject seems complicated and hard-to-learn for a newbie. Subjects that we know seem very simple and clear to us. But we simply do not remember, that everyone has to study something from scratch, and even our native language. The same is with the MQL5 programming language that offers wide possibilities of developing one's own trading strategies - you can start learning it from basic notions and simplest examples. Interaction of a technical indicator with the MetaTrader 5 client terminal is consider in this article on the example of the simple custom indicator SMA.

Every object, whether it is a custom object, a dynamic array or an array of objects, is created and deleted in MQL5-program in its particular way. Often, some objects are part of other objects, and the order of object deleting at deinitialization becomes especially important. This article provides some examples that cover the mechanisms of working with objects.