dom as a rendering engine vs being the dom

《dom as a rendering engine vs being the dom》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。

1、DOMasarenderingengineVSBeingtheDOMStatus: DraftAuthor: igor@angularjs.orgtldr;Angularv1,Knockout,Ember,….istheformer,solutionsthatutilizeWebComponentsattheircore,likePolymerandX-Tags,arethelatter.Whileit’scommontoseeWebComponentsasastandardforjustdefiningvisualcomponents(widgets),itispo

2、ssibletousethisparadigmforconstructionofthewholewebappratherthanonlyitsindividualcomponents.WeneedtodecidewhichparadigmAngularv2shouldusebecauseit'samajordesignchoicewithmanyprosandconstoconsider.BeingDOMBeingDOMmeansthatthecorebuildingblockoftheframeworkisacustomelementthatisregistered

3、withthebrowser.It'sthebrowserthatinstantiatesandwiresupallofthecomponents.Nothingcanhappenwithoutacustomelement(Polymer’spolymer-ajax,polymer-jsonandpolymer-datastoragecustomelementsaregoodexamplesofthisapproach).Therearetypicallymanysmallelementsthatarecomposedtobuildthefinalapp.Everyc

4、omponentisisolatedfromothersandtheycancommunicateonlyviaDOMAPIs.Pros/Cons:[+]forpurposesofstylingandDOMmanipulation,there’snoneedtotreatcustomelementsasspecialbecausetheybehaveandcanbetreatedlikenativeelement[+]instantiatingacomponentiseasybutwithhiddencost(seedisadvantagesbelow)andusua

5、llydonebythebrowserautomaticallywhichcanpotentiallybefasterbutsincecomponentsstillneedtowaitfortheirdependenciestogetinstantiatedthedifferencemightnotbebigorvisibleatally[+]canleverageexistingandupcomingtoolingforDOMandwebcomponents[-]thepresentationandbusinesslogicishardnottomixbecause

6、amodelformaintainingaseparationofconcernsismissingwhichmakesitdifficulttobuildmaintainableandtestableapplications[-]instantiationofnon-trivialelementshastorelyonglobalstatetogetwireupnon-DOMdependencies,whichbreaksencapsulationofcomponents,resultinginhardreuseandtesting[?]insteadof"fixi

7、ngup"nativeelementsviadecoration,itispreferabletocreateacustomcomponentthatreplacesthem.Forsmalltweaksthisisacumbersomeapproachbecauseitisatonofworkandlooksweirdforoneofftweaks.Howeveritisabetteroptionifdoneaspartofawellalignsuiteofcomponents–e.g.customreplacementforallformelem