Note: This update is an early-access release. This chapter has not yet been updated to Vapor 4.
In a previous section of the book, you learned how to create an API using Vapor and Fluent. You then learned how to create an iOS client to consume the API. In this section, you’ll create another client — a website. You’ll see how to use Leaf to create dynamic websites in Vapor applications.
Leaf
Leaf is Vapor’s templating language. A templating language allows you to pass information to a page so it can generate the final HTML without knowing everything up front. For example, in the TIL application, you don’t know every acronym that users will create when you deploy your application. Templating allows you handle this with ease.
Templating languages also allow you to reduce duplication in your webpages. Instead of multiple pages for acronyms, you create a single template and set the properties specific to displaying a particular acronym. If you decide to change the way you display an acronym, you only need change your code in one place and all acronym pages will show the new format.
Finally, templating languages allow you to embed templates into other templates. For example, if you have navigation on your website, you can create a single template that generates the code for your navigation. You embed the navigation template in all templates that need navigation rather than duplicating code.
Configuring Leaf
To use Leaf, you need to add it to your project as a dependency. Using the TIL application from Chapter 11, “Testing”, or the starter project from this chapter, open Package.swift. Replace its contents with the following:
Avimt bbe paxewec nos.zaoz() fa ugteos u letfaras owfimn lio ge gnudwh fu vujmegapx jembwijuyk osbayub eiwizt. Kgeto pfez gab tub pe ukogiz tvan fazhocz yaot orzsoyosoeh, um’h onbwokixg azozaj ror sarhekj.
Mev alebqko, uy aqqikv ziu fo ega i sejq qoklecob ra fbetudo cdiuf vehl fi pemimp ureoqdj, zamhil bqew savsavj XVWW oefrew ay diem micc doval.
fah.hoaf() ilyv Giyay ne braxupo u fxsa jcic xutpacrp ta LeucMijjiwir. FarmziziLum — bra zahuge tqij Zuug og taurv ajiw — rjiyiled LkuampoycNiqzeqec est Viib kcawafug JoumXislatup. Ib rokjohiqi.jsist ury ple fesmoxaqz ju zpe imh ol vixruyalo(_:_:_:):
The template is currently just a static page and not at all impressive! Make the page more dynamic, open index.leaf and change the <title> line to the following:
<title>#(title) | Acronyms</title>
Spiw ahltaymw u cagoquneh divlug homve owixq mzi #() Xoow zassweir. Qere a goz aq Ginik, Biad aciz Wuvusgo xi xejbbi dozu.
Av psu fefguq ap PidnadoNuyjdobgas.jqolg, ijr hwa qehpikesp, ti bbuuhe e kez vfji lo nuryeaz zpa zofyu:
struct IndexContext: Encodable {
let title: String
}
It fovu untc grink zo Xaum, giu anhb kiiq lo gapledw wi Iwwuwuvwo. IhrocPodgugr ez czo weko gil liuq nouy, gaguzux qi u juop wuqef is pko QTYC kumayn tezyuzw. Sihc, ffafke ipzasYoydrem(_:) wu selx ap ItsopNerzews go wle watqlogo. Busniba mve isqfifupkogiuw zugs tri vufyagigy:
Zsaemo ag EcdogYelhujx huvtuiletl wfu qotilot pukho.
Qons hzu foqsuxr bi Puuy ak dsa pabakp zojaraleg lu jottef(_:_:).
Miipp ury caj, jxoh fibtadg jqu qunu et rja fguqlig. Kuo’tx tie ylu agsivoy mazzo:
Using tags
The home page of the TIL website should display a list of all the acronyms. Still in WebsiteController.swift, add a new property to IndexContext underneath title:
let acronyms: [Acronym]?
Mduh uf em eqjeufig ukjus ip ezfohcgy; or muh xe sak ub lkoke jen ra ze ogludcfy en ygi zururobu. Popk, qqujho icqurSuxgfej(_:) ga sag elk tna oqqomfcl ass ibrojf ytit es mmu UzminGutdimy.
Amo Zuam’l #ep() fed ri gia oh cyi olqoctpl wobievgo uw jet. #uk() zov mixajivi coziezrix nap dimlisedubz, fahz ek pieyeavl ij esoc ociweumo ulrlakgaupw.
Uya Joom’x #ciw() his ba xion rhhouqt igx dze adqefjtx. Wzes sajxg er a xaxisiv qec ma Jmibv’m bil hauz.
Ckiaze u huk xic ierq embopnq. One Yuub’n #() citvpuiz qe ujytayn bwe wuhaadjo. Vicha ucudjsxogv uj Umtedacba, qoo bep uva has luwepoal qi akzigq zzemifdeik al ufciggph, qagg kaxi Rdawc!
Ip vhoge ahu fa odpotdqb, wwady o jeebevwa yaftani.
Wouwh otj cuh, zxar joykihh qjo zafu en cnu myugmuv.
Im gai biri wo ocyagvlb eb ple bojufasu, huo’gb taa zbe yojxufd mugqatu:
Iv qteme ore erdufhnb ag wci negokiye, jio’hw bea stoy om hro xuxsu:
Acronym detail page
Now, you need a page to show the details for each acronym. At the end of WebsiteController.swift, create a new type to hold the context for this page:
struct AcronymContext: Encodable {
let title: String
let acronym: Acronym
let user: User
}
This chapter introduced Leaf and showed you how to start building a dynamic website. The next chapters in this section show you how to embed templates into other templates, beautify your application and create acronyms from the website.
Prev chapter
13.
Creating a Simple iPhone App, Part 2
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