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Searching for News Headlines
7:11We'll use the Bing News Search API to get news headlines.
Now that we know how to use the web client
class to retrieve data from a web page,
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we can use the Bing search
API to retrieve data.
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We'll take our top ten players
of the MLS and then search for
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news headlines about each player.
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Earlier we use the web client
class with just a URL but
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this time we'll need to send
our API key with our request.
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We'll do that with headers.
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You might have learned about
headers with us before,
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they are extra pieces of
information about a web request or
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response that includes additional
information about the message.
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>> Let's take a look at
the Bing News Search API documentation.
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Here, we've got a little preview tool.
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We can click on one of these examples.
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And it looks like we've
got results to the right.
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Let's take a look at the JSON.
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We start out with a curly brace.
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That means that this entire
JSON response is one object.
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And looks like the results are in
this property named value.
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It's got an array,
I can tell because of this bracket.
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Name, it looks like that's a headline.
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And description, that's the summary.
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Let's go back up and
click on Documentation.
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Let's see, to get started read
our Getting Started guide
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which describes how you can obtain
your own subscription keys.
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I've already got my API key,
so if you haven't already and
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wanna follow along make sure
to pause the video now.
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Click on the Getting Started link right
here and follow the instructions.
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Use of these APIs are free under a certain
number of requests, so keep that in mind.
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For information that shows you how
to use the API, see News Guide.
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All right,
let's see we've got three URLs we can use.
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This second one here looks
like the one we should use for
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searching on soccer player names.
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Let's see if we can find an example.
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Getting news articles that
are relevant to a search query.
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All right.
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Get, here's what our URL should
look like when we make the request.
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And here's what our API
key header will look like.
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And we've got a sample of the response.
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I think this is all we
need to get started.
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We'll need a class first so
we can deserialize this data.
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We can copy this JSON response.
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And we'll use our paste JSON as
classes trick we did earlier.
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We'll reference this page later for
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the URL in our API key once
we get into using web client.
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Back in our code we'll click at class and
let's name a new search.
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Okay, we've got a response
in the clipboard.
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So I'll highlight this.
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Click Edit.
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Paste Special.
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Paste JSON as Classes.
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Back in the day, we used to have
to type all this out by hand.
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Let's rename RootObject to NewSearch.
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Now we can go back to
our program class and
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create a method to retrieve
our new search results.
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Down here at the bottom we can copy and
paste our Get Google home page method.
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We need to make a request for
each one of our players,
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so let's call it get news for player.
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GetNewsForPlayer, and
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it'll take a string
parameter called playerName.
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For now we'll focus on just getting
the string result before we deserialize.
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Let's change the variable name to,
searchResults.
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And change it down here, too.
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Now we need the URL,
we'll go copy it from the page.
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All right this, right here and
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We'll need to replace the search
parameter in the your URL, though.
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We can use a method on
the string class called format.
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It returns a string and
accepts additional parameters,
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that it inserts into
the string it returns.
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Let's see how it works.
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Place Google with string.format.
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The first parameter is the composite
string in which it will insert values.
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Which is our URL.
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Paste that there.
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Then we'll replace the text after Q
equals with an indexed placeholder.
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Which is specified by curly braces and
an index number.
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Curly brace zero, curly brace.
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Then we'll pass the player name
as the second parameter into
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the string.format method.
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PlayerName, then we enclose
the string.format method.
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The placeholder here is telling
string.format to insert the value
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of the playerName variable.
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There are lots of things you
can do with this method.
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It's especially useful for
formatting date time values and
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decimal numbers into culture
specific formatting.
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For more reading on this method,
check out the documentation and the notes.
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Next we need to get our
API key in the headers.
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You got your key ready?
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You won't be able to use the one I am
about to use, because it will be inactive.
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First, we'll need to add our header,
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webClient.Headers.Add.
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This add method has a few overloads.
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One of them uses an enum that has some
predefined headers that are often used.
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Except as a common one.
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It tells the endpoint what
type of data we want.
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So if the service we're requesting can
either send JSON or XML we'd specify JSON.
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In our case the default is JSON so
we won't need it.
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The header we need to use
though is a custom header and
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it won't be on this list.
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We need to use the last overload here
which just takes two strings one for
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name and one for value.
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We'll go back to the documentation and
grab the header name we need.
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All right, and we can paste that in here,
then I'm gonna paste in my API key.
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Okay, that should be all we
need to make this web request.
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Let's try it out in main.
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I'll replace this GetGoogleHomePage
with our new method.
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GetNewsForPlayer and
I'll pass it Diego Valari.
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And one more parenthesis.
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Okay, let's run with control F5.
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And we've got some data.
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Next step we'll need to deserialize
these results into our new search class.
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[BLANK-AUDIO]
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