Formulated in kind of a raw way, Power BI splits its coding part in terms on languages into frontend with DAX and
backend with M. The M query language is needed to prepare various incoming data sources. All preprocessing steps
are coded sequentually. DAX is then used to adapt to circumstances that cannot be done beforehand
with M. Stuff that either has to adapt to the user or time for example.
Something that falls into that category is the adoption of titles of elements
in the frontend to the current year.
The easiest way to get the current year can be fetched through DAX internal functions.
With this function, a measure called currentYear is calculated dynamically with the
YEAR function.
This function expects as input a value of type date. A way to obtain both, a value
of type date and dynamically an actual value would be with the DAX internal function
TODAY. Another alternative would
be through the NOW, which adapts
even to time. In this case, that information is not needed and TODAY corresponds to the actual use case.
currentYear = YEAR(TODAY())
With M, the default use case is to create tables that are then displayed in the PowerBI frontend
through various kinds of charts. DAX on the other hand calculates among other things so called measures.
This dynamically calculated measure currentYear can then be used further to create a text measure.
A measure in DAX is created in kind of a clicky way by mouse. By right click on the
corresponding table the measure can be added a line on the top of the front end arises.
There the DAX formula has to be written. In this case here, a goLives variable of type text
is dynamically written and can be further used by a frontend element in its title as the third step
in this process then.
goLives = "Go-lives" & xxx[lastYear] & " vs. " & xxx[currentYear]
An important fact here is to convert the variable to a specific type in PowerBI, which
again is a clicky task. The problem is described in this thread
thread.
The created text measurement has to be of type text. Otherwise it can not selected by the element later on
as the last step of that process. Here it has to be changed from decimal to text type.
Through kind of a clicky procedure described in figure 2, the title of a visual element
can be described dynamically through a measure in a table.
To finally create the dynamic title, an element has to be selected first by through
clicking on it. The properties section on the right hand side offers an option called Visualizations and Titel.
By using the fx option, the a measure from the table can be selected as shown in figure 3.
As a result of all of those settings, the title of the visual element is adapting dynamically to date,
in this case to year, as the measure is a dynamically calculated by refreshing the page. Finally an example
of this title is shown in figure 4.
