diff options
Diffstat (limited to 'book/src/main/scalatex/book/handson/WebPage.scalatex')
| -rw-r--r-- | book/src/main/scalatex/book/handson/WebPage.scalatex | 26 |
1 files changed, 13 insertions, 13 deletions
diff --git a/book/src/main/scalatex/book/handson/WebPage.scalatex b/book/src/main/scalatex/book/handson/WebPage.scalatex index 1078d7d..03ed452 100644 --- a/book/src/main/scalatex/book/handson/WebPage.scalatex +++ b/book/src/main/scalatex/book/handson/WebPage.scalatex @@ -18,10 +18,10 @@ @hl.ref(webpage/"HelloWorld0.scala") @less - @BookData.example(div, "HelloWorld0().main") + @BookData.example(div, "webpage.HelloWorld0().main") @p - Remember that we're now requiring a @hl.scala{dom.HTMLDivElement} instead of a @hl.scala{dom.HTMLCanvsElement} to be passed in when the Javascript calls @hl.javascript{HelloWorld0().main(...)}. If you're coming to this point from the previous chapter, you'll need to update the on-page Javascript's @hl.javascript{document.getElementById} to pick a @hl.html{<div>} rather than the @hl.html{<canvas>} we were using in the previous chapter. + Remember that we're now requiring a @hl.scala{dom.HTMLDivElement} instead of a @hl.scala{dom.HTMLCanvasElement} to be passed in when the Javascript calls @hl.javascript{webpage.HelloWorld0().main(...)}. If you're coming to this point from the previous chapter, you'll need to update the on-page Javascript's @hl.javascript{document.getElementById} to pick a @hl.html{<div>} rather than the @hl.html{<canvas>} we were using in the previous chapter. @p This approach works, as the above example shows, but has a couple of disadvantages: @@ -39,7 +39,7 @@ @p @lnk("Scalatags", "https://github.com/lihaoyi/scalatags") is a cross-platform Scala.js/Scala-JVM library that is designed to generate HTML. To use Scalatags, you need to add it as a dependency to your Scala.js SBT project, in the @code{build.sbt} file: - @hl.ref(wd/'examples/'demos/"build.sbt", "com.scalatags", "") + @hl.ref(wd/'examples/'demos/"build.sbt", "scalatags", "") @p With that, the above snippet of code re-written using Scalatags looks as follows: @@ -49,7 +49,7 @@ @hl.ref(webpage/"HelloWorld1.scala") @less - @BookData.example(div, "HelloWorld1().main") + @BookData.example(div, "webpage.HelloWorld1().main") @p Scalatags has some nice advantages over plain HTML: it's type-safe, so typos like @hl.scala{dvi} get caught at compile-time. It's also secure, such that you don't need to worry about script-tags in strings or similar. The @lnk("Scalatags Readme", "https://github.com/lihaoyi/scalatags#scalatags") elaborates on these points and other advantages. As you can see, it takes just 1 import at the top of the file to bring it in scope, and then you can use all of Scalatags' functionality. @@ -63,7 +63,7 @@ @hl.ref(webpage/"Inputs.scala", "val box") @less - @BookData.example(div(height:="150px"), "Inputs().main") + @BookData.example(div(height:="150px"), "webpage.Inputs().main") @p In Scalatags, you build up fragments of type @hl.scala{Frag} using functions like @hl.scala{div}, @hl.scala{h1}, etc., and call @hl.scala{.render} on it to turn it into a real @lnk.dom.Element. Different fragments render to different things: e.g. @hl.scala{input.render} gives you a @lnk.dom.HTMLInputElement, @hl.scala{span.render} gives you a @lnk.dom.HTMLSpanElement. You can then access the properties of these elements: adding callbacks, checking their value, anything you want. @@ -96,17 +96,17 @@ @hl.ref(webpage/"Search0.scala", "val output") @less - @BookData.example(div, "Search0().main") + @BookData.example(div, "webpage.Search0().main") @p - And there you have it! A working search box. This is a relatively self-contained example: all the items its searching are available locally, no Ajax calls, and there's no fancy handling of the searched items. If we want to, for example, highlght the matched section of each fruit's name, we can modify the @hl.scala{def renderListings} call to do so: + And there you have it! A working search box. This is a relatively self-contained example: all the items its searching are available locally, no Ajax calls, and there's no fancy handling of the searched items. If we want to, for example, highlight the matched section of each fruit's name, we can modify the @hl.scala{def renderListings} call to do so: @split @more @hl.ref(webpage/"Search1.scala", "def renderListings", "lazy val") @less - @BookData.example(div, "Search1().main") + @BookData.example(div, "webpage.Search1().main") @p Here, instead of sticking the name of the matched fruits directly into the @hl.scala{li}, we instead first split off the part which matches the query, and then highlght the first section yellow. Easy! @@ -138,7 +138,7 @@ @hl.ref(webpage/"Weather0.scala", "val xhr") @less - @BookData.example(div(height:="400px"), "Weather0().main") + @BookData.example(div(height:="400px"), "webpage.Weather0().main") @p The above snippet of code uses the raw Javascript Ajax API in order to make a request to @lnk("openweathermap.org", "http://openweathermap.org/"), to get the weather data for the city of Singapore as a JSON blob. The part of the API that we'll be using is documented @lnk("here", "http://openweathermap.org/current"), and if you're interested you can read all about the various options that they provide. For now, we're unceremoniously dumping it in a @hl.scala{pre} so you can see the raw response data. @@ -186,7 +186,7 @@ @hl.ref(webpage/"Weather1.scala", "val url") @less - @BookData.example(div(height:="400px", overflow:="scroll"), "Weather1().main") + @BookData.example(div(height:="400px", overflow:="scroll"), "webpage.Weather1().main") @p A single call to @hl.scala{Ajax.get(...)}, with the URL, and we receive a @hl.scala{scala.concurrent.Future} that we can use to get access to the result when ready. Here we're just using it's @hl.scala{onSuccess}, but we could use it in a for-comprehension, with @lnk("Scala Async", "https://github.com/scala/async"), or however else we can use normal @hl.scala{Future}s @@ -203,7 +203,7 @@ @hl.ref(webpage/"Weather2.scala", "Ajax.get") @less - @BookData.example(div(height:="400px"), "Weather2().main") + @BookData.example(div(height:="400px"), "webpage.Weather2().main") @p We do this by taking @hl.scala{xhr.responseText} and putting it through both @hl.scala{JSON.parse} and @hl.scala{JSON.stringify}, passing in a @hl.scala{space} argument to tell @hl.scala{JSON.stringify} to spread it out nicely. @@ -216,7 +216,7 @@ @hl.ref(webpage/"Weather3.scala", "Ajax.get") @less - @BookData.example(div(height:="400px", overflow:="scroll"), "Weather3().main") + @BookData.example(div(height:="400px", overflow:="scroll"), "webpage.Weather3().main") @p First we parse the incoming response, extract a bunch of values from it, and then stick it in a Scalatags fragment for us to see. Note how we can use the names of the attributes e.g. @hl.scala{json.name} even though @hl.scala{name} is a dynamic property which you can't be sure exists: this is because @hl.scala{json} is of type @hl.scala{js.Dynamic}, which allows us to refer to arbitrary parameters and methods on the underlying object without type-checking. @@ -246,7 +246,7 @@ @p Here is the meat and potatoes of this program: every time it gets called with an array of weather-data, we iterate over the cities in that array. It then does a similar sort of data-extraction that we did earlier, putting the results into the @hl.scala{output} div we defined above, including highlighting. - @BookData.example(div, "WeatherSearch().main") + @BookData.example(div, "webpage.WeatherSearch().main") @p And that's the working example! Try searching for cities like "Singapore" or "New York" or "San Francisco" and watch as the search narrows as you enter more characters into the text box. Note that the OpenWeatherMap API limits ambiguous searches to about a dozen results, so if a city doesn't turn up in a partial-search, try entering more characters to narrow it down. |