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Plugging in the Data
10:11It's time to do more than just write our weather data to the log. Let's use all the views we've added to display real weather data.
Our next step is to update our data model.
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In current weather, we need to create two
different constructors for our class.
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Fortunately, Android Studio
can generate those for us.
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Go to Code > Generate > Constructor.
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As I mentioned, we need two
different constructors in our class.
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So we'll generate the first one
that will accept no arguments.
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We just need to click on Select None.
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Give some space.
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We'll generate our second one.
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Instructor, this one,
we'll select all the variables.
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And let's clean this up a little bit.
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The basic constructor is
used in main activity
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in our get current details method.
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The second constructor will be
used when we bind our data.
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And these dual constructors
are a great example
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of constructor overloading in Java.
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For more information about this,
check the teachers notes.
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Alright, with our model updated,
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let's take another look at
the data binding documentation.
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If we look here at Binding Data,
we see that the easiest means for
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creating the bindings is
to do it while inflating.
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I'm all about doing things
the easiest way possible.
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So let's follow this example.
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So we need to go back into onCreate and
adjust our set content view statement.
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Back into MainActivity, so
here we're at SetContentView.
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ActivityMainBinding, Binding,
do our imports.
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It's gonna be a DataBindingUtil,
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convert context, MainActivity.this.
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Let's drop that down to a new line.
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The documentation says that we need to
bind our data to our new binding variable.
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Well, we don't have any data
at this point in onCreate.
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We do, however,
have it down in onResponse,
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where we're making a call
to getCurrentDetails.
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So let's bind our data at that point.
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So down here in onResponse, We'll
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make a new CurrentWeather, Object,
we'll call it displayWeather.
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Will be new CurrentWeather.
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Here's where we'll use
our new constructor.
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We'll pass in the information from our
CurrentWeather variable as called for
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in the constructor.
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GetIcon.
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GetTime.
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GetTemperature.
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GetHumidity.
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GetPrecipChance.
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Get our summary.
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And get our time zone.
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Fantastic, now we need to use this
new displayWeather with our binding
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variable to bind our data.
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We can do binding.setWeather,
and we'll pass in displayWeather.
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Since we're using binding
from within an inter class,
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we need to make sure
that it's declared final.
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And it is, thank you Android Studio.
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Since we already have one data point,
our summary, set up in our layout,
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let's run this and
make sure our data is coming through.
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And it's changed in our app, and
if we look in Logcat and our JSON data.
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It's the same there.
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That's awesome.
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Let's head over to our activity main XML
file and update the rest of our fields.
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Before we get started on this process,
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let's think a little bit about
what our text field is wanting.
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It's expecting string values, so
we're going to have to make a decision.
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Do we want to alter our model and
store data as strings?
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Or do we want to convert them
to strings here in the XML?
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I think it makes more sense to keep our
data in its native state in our model.
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With that in mind,
let's look at our temperature value here.
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We want to update this static
value to our data value.
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We'll do @ with our curly braces.
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We wanna convert it to a string and
get the value of,
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weather.tempeture.
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Next up is our time value.
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Here we want to use our formatted time and
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add it into the middle of our statement
of at such and such a time it will be.
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To concatenate text inside
an Android text value,
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we need to use the grave accent
character instead of quotes.
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That character is found above
the Tab key on most keyboards.
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Inside our time value then,
our string will look like this.
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Grave accent At space and
we'll concatenate,
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String.valueOf.
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Weather.formattedTime, and
then the rest of our string characters.
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It will be and another grave accent.
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Let's go down to humidity.
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Humidity value, String,
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value of, weather.humidity.
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And for precipitation,
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we need to concatenate that
percent sign in there as well.
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Add in a grave accent with a percent.
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Let's run it again and see how that looks.
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Well, there's our data, but our
temperature has a decimal point in there,
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and our precipitation value is a decimal.
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I think just having the whole
number is better, and
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it fits with our design markups also.
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Again, it's decision time for
how we handle that.
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We can do it in our model or in our XML.
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We can certainly handle it in either place
but changing it in the XML allows for
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more flexibility if we decide to
expand our app to another activity and
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need to use the data elsewhere.
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Therefore, let's update the temperature
and precipitation values in there.
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We can use the round method from
Java's Math class to round our values.
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For temperature, then,
we can go back up here to temperature.
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We'll do Math.round, weather.Temperature.
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And for precipitation,
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we want to multiply it by 100 to make
the decimal into a percentage as well.
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Math.round.
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Let's run it again.
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Very nice, our text data is coming
through and updating our view.
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This is looking great.
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We lost all of our default text though,
in this process,
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making it a bit of a challenge
in our design pane.
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Let's add the default values back in, not
only for ourselves during the development
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process, but also so our users don't
have to stare at a blank screen.
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So we'll come here, Default, 50%.
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For humidity, Default,
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0.88.
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Default here will be at 5 o'clock PM,
it will be.
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For temperature, we'll do a default, 100.
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And we'll add one for the summary as well.
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Default is stormy with
a chance of meatballs.
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Remember to use the grave accent character
there to be able to have spaces in our
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strings.
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This is looking nice, but
what about that weather icon?
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Let's see about updating that next.
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