Preprocessor CSS: txheej txheem cej luam, xaiv, daim ntawv thov

Kiag li tag nrho cov kev paub cov web designers siv lub preprocessor. Muaj tsis muaj kev zam. Yog hais tias koj xav mus kawm tau ntawv zoo nyob rau hauv qhov kev ua, tsis txhob hnov qab txog cov kev pab cuam. Thaum xub thawj siab ib muag, lawv yuav ua rau ib tug novice nyob ntsiag to ntshai heev - nws yog ib yam nkaus thiab zoo ib yam li cov programming! Nyob rau hauv qhov tseeb, koj yuav hais rau tag nrho cov nta ntawm CSS preprocessor rau txog ib hnub twg, thiab yog hais tias koj sim, ces ib tug ob peb teev. Nyob rau hauv lub neej yav tom ntej, lawv yuav ho piv koj lub neej.

Yuav ua li cas puas tau CSS preprocessor

Yuav kom to taub zoo dua cov yam ntxwv ntawm no technology, luv luv delve rau hauv lub keeb kwm ntawm lub nrig txog kev pom kev nthuav qhia ntawm nplooj ntawv Web site.

Thaum tsuas nyuam qhuav pib lub loj heev siv cov Internet, tsis muaj style los xij tsis ua ib ke. Tiav ntawm cov ntaub ntawv depended nkaus rau lub browser. Txhua yam ntawm lawv muaj lawv tus kheej yeej, uas tau siv rau cov kev kho mob ntawm tej yam cim npe. Raws li, qhov nplooj ntawv zoo sib txawv nyob ntawm seb qhov kev txiav txim nyob rau hauv uas lub browser koj qhib lawv. Cov - lub chaos, tsis meej pem, muaj teeb meem rau developers.

Nyob rau hauv 1994, Norwegian paub txog Håkon dag tsim ib tug style daim ntawv uas yuav siv tau rau cov tsos ntawm cov nplooj ntawv nyias los ntawm lub HTML-daim ntawv. Lub tswv yim priglanulas mej zeej ntawm lub W3C, uas tam sim ntawd teem tawm mus ua kom tiav. Ib tug ob peb xyoos tom qab ntawd nws luam tawm ib tug thawj version ntawm lub CSS specification. Ces nws twb lossi zoo, raug finalized ... Tab sis lub tswv yim tseem nyob rau tag nrho cov tib: txhua style teem tej zog.

Siv CSS ntxhuav yeej ib txwm tau problematic. Piv txwv li, web designers feem ntau muaj teeb meem nrog sorting thiab grouping nta, thiab qub txeeg qub teg yog tsis yog li ntawd yooj yim.

Thiab ces tuaj lub ob thousandth. Cim yog nce pib mus koom nyob rau hauv kev pem hauv ntej-end developers, uas yog ib qho tseem ceeb yuav tsum tau saj zawg zog thiab dynamic ua hauj lwm yeej. Muaj nyob rau ntawm lub sij hawm uas cog noob CSS tsiaj ntawv ua pib kev tso kawm thiab nrhiav kev pab txhawb nqa lub tshiab peevxwm ntawm qhov browser. Ces, los ntawm JavaScript, thiab Ruby cov kws txawj tau txais cia rau ua lag ua luam, tsim ib preprocessor - superstructure rau CSS, tshiab nta no ntxiv rau nws.

CSS rau Beginners: preprocessor nta

Lawv muaj ob peb zog:

• koom ua ib lub browser tsiaj ntawv ua pib thiab khaki;

• piv syntax;

• muab lub sij hawm mus ua hauj lwm nrog nested selectors tsis muaj uas tsis;

• txhim kho logic styling.

Nyob rau hauv luv luv: lub preprocessor ntxiv CSS programming logic tuition. Tam sim no, styling yog tsis tau nyob rau hauv lub li ib txwm qhia yeej thiab nrog ib tug ob peb yam yooj yim cov hom kev kawm thiab le caag: qhob, zog, hagfish, mus tej yam kev mob. Nyob rau hauv tas li ntawd, muaj peev xwm siv kev ua lej.

Pom qhov chaw ntawm no add-ins, lub W3C tau pib maj mam ntxiv tau ntawm lawv nyob rau hauv lub CSS code. Piv txwv li, nyob rau hauv lub specification thiaj li muaj calc () muaj nuj nqi, uas yog kev txhawb los ntawm ntau browsers. Nws yuav tsum hais tias tsis ntev nws yuav tau teem ntau yam thiab tsim tau ib hagfish. Txawm li cas los, qhov no yuav tshwm sim nyob rau hauv lub deb yav tom ntej, thiab preprocessors twb nyob ntawm no thiab twb ua hauj lwm zoo.

Nrov preprocessors CSS. sass

Tsim nyob rau hauv 2007. Keeb xeeb ib feem Haml - ib tug template HTML. Tshiab nta rau CSS ntsiab tswj relished developers rau lub Ruby nyob ntsia, uas pib rau kis nws qhov txhia chaw. Lub sass ib tug lossis loj tus naj npawb ntawm cov nta uas tam sim no muaj nyob rau hauv tej preprocessor: qhob, embedding ntawm selectors, hagfish (ces, li cas los xij, cov lus sib cav tsis muaj peev xwm yuav muab ntxiv).

Kev tshaj tawm ntau yam nyob rau hauv sass

Zog tshaj tawm hais tias nrog lub $ kos npe rau. Lawv muaj peev xwm tswj tau lawv lub zog thiab poob lawm, piv txwv li: "$ borderSolid: 1px khoom liab;". Nyob rau hauv qhov kev piv txwv, peb tshaj tawm hais tias ib tug nce mus nce los hu ua borderSolid thiab rua nws nqi 1px khoom liab. Tam sim no, Yog hais tias nyob rau hauv lub CSS peb yuav tsum tau tsim ib tug liab ciam teb dav ntawm 1px, tsuas qhia tau hais tias nce mus nce los tom qab cov cuab yeej lub npe. Tom qab cov ntawv tshaj tawm ntawm lub zog yuav hloov tsis tau. Muaj ntau ntau ua-nyob rau hauv kev khiav dej num. Piv txwv li, hais ib tug nce mus nce los nrog ib tug nqi ntawm $ redcolor # FF5050. Tam sim no, nyob rau hauv lub CSS code nyob rau hauv lub thaj chaw ntawm tej lub caij, siv nws los teev cov font xim: p {xim: $ redColor; }. Koj puas xav kom xyaum ua tej yam nrog rau xim? Siv kev ua tsaus ntuj los yog qee kom sib. Qhov no yog ua li ntawd: p {xim: tsaus ntuj ($ redColor, 20%); }. Raws li ib tug tshwm sim, cov xim redColor yuav yuav 20% sib zog.

Lub sass ntau ua-nyob rau hauv kev khiav dej num. Tsim tsawg kawg nyeem lawv, tab sis zoo dua - mus kawm.

zes

Yav tas los, yuav qhia ua zes yuav tsum tau siv ib tug ntev thiab seeb tsim. Xav txog tej yam uas peb muaj ib tug div, uas yog p, thiab nyob rau hauv nws, nyob rau hauv lem, muab luv. Rau cov div, peb yuav tsum tau teev cov font xim liab, rau p - daj, rau lub luv - liab. Nyob rau hauv ib tug raug CSS nws yuav ua tau raws li nram no:

div {

xim: liab;

}

div p {

xim: daj;

}

div p ncua {

xim: liab;

}

Nrog CSS preprocessor tag nrho yuav yooj yim dua thiab ntau compact:

div {

xim: liab;

p {

xim: daj;

.span {

xim: liab;

}

}

}

Hais cia "ua lag luam" ib leeg.

preprocessor coj

Siv @import coj yuav import cov ntaub ntawv. Piv txwv li, peb muaj fonts.sass cov ntaub ntawv uas hais tias yeej rau fonts. Txuas nws mus rau lub ntsiab ntaub ntawv style.sass: @import 'fonts'. Ua li cas! Es tsis txhob ib tug loj cov ntaub ntawv nrog lub yeej peb muaj ib tug ob peb uas muaj peev xwm yuav siv tau txoj kev sai thiab yooj yim nkag tau mus rau qhov yuav tsum tau cov khoom.

hagfish

Ib qho ntawm feem nthuav tswv yim. Nws tso cai rau ib tug kab mus nug ib tug txheej ntawm cov khoom. Khiav lag luam raws li nram no:

@mixin largeFont {

font-tsev neeg: 'Times Tshiab Roman';

font-size: 64px;

kab-qhov siab: 80px;

font-ceeb thawj: bold;

}

Hagfish thov kom lub caij rau cov nplooj ntawv, siv lub qhia @include. Piv txwv li, peb xav thov nws mus rau lub H1 header. Peb muaj cov nram qab no qauv: H1 {@include: largeFont; }

Tag nrho cov thaj chaw ntawm hagfish raug ib tug H1 caij.

preprocessor Tsawg

Syntax sass txiav ntaqwm programming. Yog hais tias koj tab tom nrhiav rau ib qho kev xaiv uas yog tsim rau beginners kawm CSS, saib rau Tsawg. Nws yog tsim nyob rau hauv 2009. Lub ntsiab feature - them nyiaj yug rau CSS haiv neeg syntax, yog li txawv nrog rau programming Imposer nws yuav yooj yim rau kev kawm.

Cov tsiaj ntawv yog hais tias siv cov @ cim. Piv txwv li: @fontSize: 14px;. Zes tej hauj lwm rau cov ntsiab cai raws li nyob rau hauv sass. Hagfish yog tshaj tawm raws li nram no: .largeFont () {font-tsev neeg: 'Times Tshiab Roman'; font-size: 64px; kab-qhov siab: 80px; font-ceeb thawj: bold; }. Mus cuag nws yog tsis tsim nyog los siv preprocessor coj - cia li ntxiv tus tshiab khiv tsim hagfish nyob rau hauv lub zog ntawm cov xaiv caij. Piv txwv li: H1 {.largeFont; }.

stylus

Lwm preprocessor. Tsim nyob rau hauv 2011 los ntawm cov tib neeg sau, uas tau muab lub ntiaj teb no lub Jade, Express thiab lwm yam khoom uas pab.

Ntau yam yuav tau tshaj tawm hais tias nyob rau hauv ob txoj kev - yog ntsees los implicitly. Piv txwv li: koos pis = 'Times Tshiab Roman'; - ib tug implicit kev xaiv. Tab sis $ font = 'Times Tshiab Roman' - ntshiab. Hagfish yog tshaj tawm hais tias thiab implicitly kev cob cog rua. Cov syntax yog raws li nram no: redColor () xim liab. Tam sim no peb muaj peev xwm ntxiv yam khoom, piv txwv li: H1 redColor ();.

Stylus nyob rau thawj nuam tej zaum nws yuav zoo li to taub tsis tau. Qhov twg yog qhov "haiv neeg" nkhaus thiab semicolons? Tab sis nws yog tsim nyog los plunge rau hauv nws, tag nrho cov ua ntau dlaim phaj. Nco ntsoov tias, txawm li cas los, hais tias ntev-lub sij hawm kev loj hlob ntawm no preprocessor yuav "wean" koj siv cov classic CSS syntax. Qhov no tej zaum kuj ua rau cov teeb meem thaum muaj mus ua hauj lwm nrog ib tug "dawb huv" style.

Yuav ua li cas preprocessor xaiv?

Nyob rau hauv qhov tseeb, nws yog ... nws tsis muaj nqi. Tag nrho versions muaj txog cov yam ntxwv tib cia li lub syntax ntawm txhua sib txawv. Peb pom zoo kom mus raws li nram no:

• Yog hais tias koj - programmer thiab xav mus ua hauj lwm nrog yeej ob leeg nyob rau hauv code, siv lub sass;
• Yog hais tias koj - ib tug coder thiab xav mus ua hauj lwm nrog yeej raws li nrog cov pa layout, them mloog mus rau lub Tsawg;
• Yog hais tias koj nyiam minimalism, siv lub Stylus.

Rau tag nrho variants ntawm ib qho kev txom xov tooj uas interesting cov tsev qiv ntawv uas muaj peev xwm txawm ntxiv piv txoj kev loj hlob. Cov neeg siv sass pom zoo them sai sai mus rau lub Compass - ib tug haib cuab tam nrog ntau ua-nyob rau hauv cov yam ntxwv. Piv txwv li, tom qab koj nruab nws koj yuav tsis muaj kev txhawj txog tus neeg muag khoom version prefix. Simplifies ua hauj lwm nrog sob. Muaj cov cuab yeej rau ua hauj lwm nrog paj, sprites. Ib tug ntau twb tshaj tawm hagfish. Muab qhov cuab tam ib tug ob peb hnub - yog li koj yuav cawm tau ib tug ntau ntawm cov sij hawm thiab kev rau siab nyob rau hauv lub neej yav tom ntej.