Palm WebOS应用并不是常规的"网站程序"

寂夜清风

中文翻译见4楼

Monday, January 12, 2009

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Palm webOS applications are not "web apps"
4 g, O8 B( d5 B: U+ G$ A# YI've been seeing a number of folks describing applications for the just-announced Palm webOS as "web apps." It's understandable given the name and some of the technologies mentioned at CES, but it's quite misleading. I posted an explanation of this on PalmInfocenter and figured I would post it here as well (with a few edits) since what Palm has really done is create an interesting new fusion between web and locally installed applications.

First of all, a web application runs in a browser, which is a piece of software that's optimized first and foremost for making requests to a server on the Internet and rendering the responses as a web page. Browsers have gradually been twisted or tortured with plugins to playback media, use cookies as local databases, and integrate with other apps on the machine, but to operate reliably and safely on the Internet they're necessarily somewhat crippled in using features of the system or hardware. Just because Palm said that webOS apps can be written with HTML, CSS and JavaScript doesn't mean they run in a browser or have the limitations of a web browser. Those are technologies for rendering a GUI that can--and have been--used outside the confines of the browser, and Palm is doing just that.

Secondly, people should understand that HTML 5 goes well beyond what we're accustomed to thinking of as HTML. It includes APIs for immediate-mode 2D drawing, video playback, offline databases, drag-and-drop--pretty cutting edge stuff. Palm is certainly the first company to release a mobile product based on HTML 5, and even modern desktop browsers only implement parts of the spec, often through optionally installed plugins like Google Gears.

As for JavaScript, it's a general programming language that is separate from the HTML document object model that it's most commonly associated with. Palm has already stated that they have extended that model to enable access to local databases on the phone and handling of notifications of system events, and there's no reason they couldn't expose much of the system API that way if they chose to. Sure, you're not going to be able to write hardware drivers in JavaScript but while some developers have good reasons for wanting to do such things a little sandboxing can a good thing on a device connected to the wild, wild Internet. A developer who partnered with Palm told the press at CES that "everything he did before in Visual Studio he could do in Javascript on the Pre." If he was much of a Visual Studio developer at all that means there's a lot more than the HTML DOM being scripted there.
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Next, there's the complaint that JavaScript and HTML are interpreted and therefore slow. But remember, webOS applications aren't running in a browser, so there's nothing that says any of this need be interpreted. Palm knows all about compiling HTML applications into native code: they developed tools and APIs for doing this on the Palm VII back in 1999 and presumably own patents on it. They called these "web clipping" applications, and they displayed in the launcher and ran as first-class native applications on Palm devices, not as interpreted scripts in an HTML browser.
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Now JavaScript may not be a lot of fun to code and debug, compared to a statically compiled language like Java or even C/C++. But let's remember that we don't have an SDK yet. Until we do we have no idea if JavaScript is the only API or if there are other ways to access more of the system APIs. Obviously there are other ways to access system APIs, which developers will discover on their own if Palm doesn't document them, but for now it's too early to say. I have a suspicion that a Java runtime is lurking in there somewhere and Palm didn't want to mention it yet for fear of comments about Palm being "late to the mobile Java party." J2ME, Danger, RIM, Android, JavaFX, Sprint Titan... the advance of mobile Java may be exciting for mobile Java developers but to everyone else a new Java SDK sounds warmed over, and Palm's had enough of that kind of talk.
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If you watched any of the announcement you know that webOS is also intended for delivering a cutting edge web app experience, but that has to do with the browser they developed. It should also be clear that applications originally written for the web using JS/HTML/CSS (like GMail, BaseCamp, Facebook, etc.) should be easy to port to webOS and be enhanced to run in offline mode, due to webOS's HTML 5 support for offline databases.

All this starts to blur the distinction between "web apps" and "local apps," and that's where I think we're going with the mobile web. My friend Enrique Ortiz seems to agree. Nice to see good old Palm pushing out the frontier once again.

寂夜清风

http://www.pikesoft.com/blog/index.php?itemid=204

ursace

说实话一直搞不清web OS是啥意思，web只是一个名字和网络无关？

lila55

I've been seeing a number of folks describing applications for the just-announced Palm webOS as "web apps." It's understandable given the name and some of the technologies mentioned at CES, but it's quite misleading. I posted an explanation of this on PalmInfocenter and figured I would post it here as well (with a few edits) since what Palm has really done is create an interesting new fusion between web and locally installed applications.

有很多兄弟把刚刚发布的用于webOS平台上的程序当作了“web apps（网络程序？）”。考虑到在CES大会上提到的那些技术和名称，把webOS程序误当作 web apps是难免的，但却会带来一些误解。我在palminfocenter上发了这个帖子，在这儿也发了一份儿（有修改）。实际上palm所作的，是在web和本地程序之间创造出了一个全新的、并且很有趣的中间件（不知道这个fusion这么翻译对不对，请指正）
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: U- S/ O" i- |. X1 g) ?First of all, a web application runs in a browser, which is a piece of software that's optimized first and foremost for making requests to a server on the Internet and rendering the responses as a web page. Browsers have gradually been twisted or tortured with plugins to playback media, use cookies as local databases, and integrate with other apps on the machine, but to operate reliably and safely on the Internet they're necessarily somewhat crippled in using features of the system or hardware. Just because Palm said that webOS apps can be written with HTML, CSS and JavaScript doesn't mean they run in a browser or have the limitations of a web browser. Those are technologies for rendering a GUI that can--and have been--used outside the confines of the browser, and Palm is doing just that.
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第一，web app是运行在浏览器里的。web app主要是用来向internet网上的服务器发出请求，然后把回应转换成页面形式呈现出来。如此一来，因为乱七八糟的插件（比如播放音乐的、用cookies追踪信息的、还有其他一些和机器上应用程序关联的插件），浏览器变得越来越慢。但是为了能安全快速浏览，这些插件的功能往往都不完整，不能完全发挥硬件或者是系统的能力。尽管palm说用html、CSS和Jscript就能写webOS程序，但是这并不意味着这些程序是在浏览器里面运行的，也不会有任何浏览器的限制。这些技术（html、CSS和Jscript）是用来渲染用户界面（GUI）的，它们不受浏览器的限制。palm做的就是这件事儿而已。
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Secondly, people should understand that HTML 5 goes well beyond what we're accustomed to thinking of as HTML. It includes APIs for immediate-mode 2D drawing, video playback, offline databases, drag-and-drop--pretty cutting edge stuff. Palm is certainly the first company to release a mobile product based on HTML 5, and even modern desktop browsers only implement parts of the spec, often through optionally installed plugins like Google Gears.

- b/ |3 K6 w& x4 E# W" f第二，大家应该明白，html 5已经不是我们日常见到的html那么简单了。html 5内含了一些API，支持快速2D渲染、视频播放、离线数据库、拖放等等功能，这些都是很前沿的技术。palm肯定是头一个在移动设备里用到html 5的公司。就算是桌面浏览器，也仅仅支持部分html 5标准，而且还要安装插件（比如google gears）才能实现。

/ z( M9 i0 ~. A6 ?7 G' G* CAs for JavaScript, it's a general programming language that is separate from the HTML document object model that it's most commonly associated with. Palm has already stated that they have extended that model to enable access to local databases on the phone and handling of notifications of system events, and there's no reason they couldn't expose much of the system API that way if they chose to. Sure, you're not going to be able to write hardware drivers in JavaScript but while some developers have good reasons for wanting to do such things a little sandboxing can a good thing on a device connected to the wild, wild Internet. A developer who partnered with Palm told the press at CES that "everything he did before in Visual Studio he could do in Javascript on the Pre." If he was much of a Visual Studio developer at all that means there's a lot more than the HTML DOM being scripted there.
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至于JScript，它仅仅是个普通的编程语言，是从html对象模型里分离出来的，它和html对象模型联系比较紧密。palm已经表明，他们已经将这个模型进行了扩展，以便于访问电话上的本地数据库，而且能够处理系统事件。而且，没理由认为他们会隐藏太多系统api。当然了，用Jscript写驱动不大可能。但是开发人员要是想这么做的话，试试也未尝不可，尤其是在这个能够和无所不能的互联网连接的机器上。一位和palm合作的开发人员在CES上说，他以前在Visual Studio上做的东西现在都能用JScript移植到“胖皮儿”上。如果他真的是个VS开发人员，那就证明，HTML DOM能做的事情就不止编脚本那么简单。
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' Y  [( u4 v8 `2 q8 ]0 |Next, there's the complaint that JavaScript and HTML are interpreted and therefore slow. But remember, webOS applications aren't running in a browser, so there's nothing that says any of this need be interpreted. Palm knows all about compiling HTML applications into native code: they developed tools and APIs for doing this on the Palm VII back in 1999 and presumably own patents on it. They called these "web clipping" applications, and they displayed in the launcher and ran as first-class native applications on Palm devices, not as interpreted scripts in an HTML browser.

有人抱怨说JScript和html需要经过解释，因此运行起来很慢。但是请记住，webOS的程序不是在浏览器里运行的。所以就没有“解释”这个过程了，那么，运行缓慢这个问题也就不存在了。palm很明白如何把html程序编译成本地代码：早在1999年，palm VII上就出现了能够完成这项功能的工具和api了（而且palm应该还有这方面的专利）。palm把这些工具和api称作“web clipping”程序。在palm VII上，这些东西显示在launcher里，而且是作为一级本地代码运行的，不需要在任何html浏览器里进行“解释”。

- [2 V1 C* |: ^' \Now JavaScript may not be a lot of fun to code and debug, compared to a statically compiled language like Java or even C/C++. But let's remember that we don't have an SDK yet. Until we do we have no idea if JavaScript is the only API or if there are other ways to access more of the system APIs. Obviously there are other ways to access system APIs, which developers will discover on their own if Palm doesn't document them, but for now it's too early to say. I have a suspicion that a Java runtime is lurking in there somewhere and Palm didn't want to mention it yet for fear of comments about Palm being "late to the mobile Java party." J2ME, Danger, RIM, Android, JavaFX, Sprint Titan... the advance of mobile Java may be exciting for mobile Java developers but to everyone else a new Java SDK sounds warmed over, and Palm's had enough of that kind of talk.

不得不承认，和java或者c/c++比起来，编写和调试JScript没那么多挑战和乐趣。但是，要知道我们现在还没看到相应的sdk呢。除非拿到sdk，否则我们没法知道JScript是否是唯一的API，或者还有没有其他能够访问系统api的方法。就算palm不愿意公开，有理由相信开发人员仍然能够自己找到其他访问系统api的方式。但是目前这么说，有点早了。我推测，肯定在系统里面有个java的run time。只不过palm不愿意公开罢了，因为如果palm承认这点，也许会有人批评说“palm在移动java领域里姗姗来迟”。J2ME, Danger, RIM, Android, JavaFX, Sprint Titan... 这些技术对移动java开发人员来说也许很有趣。一个新的sdk听起来的确有些炒冷饭的意思。palm老是这么做。

9 [( i$ H$ M* n/ R+ C5 KIf you watched any of the announcement you know that webOS is also intended for delivering a cutting edge web app experience, but that has to do with the browser they developed. It should also be clear that applications originally written for the web using JS/HTML/CSS (like GMail, BaseCamp, Facebook, etc.) should be easy to port to webOS and be enhanced to run in offline mode, due to webOS's HTML 5 support for offline databases.
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5 O2 V5 {, S& B- @8 @+ ~2 F如果你观看了发布会，你就会知道，webOS也打算给用户带来一些很前沿的web app体验。但是，这需要palm开发的浏览器才行。而且，那些最初用JS/HTML/CSS 写的web应用（比如like GMail, BaseCamp, Facebook等）应该能够很容易地移植到webOS上，而且能够被改写为，以便于离线使用，因为webOS使用的html 5支持离线数据库。
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% r8 D( k- j" v0 eAll this starts to blur the distinction between "web apps" and "local apps," and that's where I think we're going with the mobile web. My friend Enrique Ortiz seems to agree. Nice to see good old Palm pushing out the frontier once again.

所有我说的这些都让web app和本地程序之间的区别变得模糊。但正是从这一点考虑，我觉得我们就要迎来移动web时代了。我的朋友E.O.和我意见一致。

真的很高兴，老palm又能和以前一样带来全新的变革。

& C+ u+ e4 q+ O& g, d8 ?" z8 I[ 本帖最后由 lila55 于 2009-1-19 18:12 编辑 ]

2b6c3d729918489

原帖由 lila55 于 2009-1-19 18:10 发表
4 {% m7 @$ C: p6 S2 m* z) H' @I've been seeing a number of folks describing applications f

非常感谢lila55的翻译。
. }8 U; z2 {: ~这个文章对于大家正确理解webos上的应用很有帮助

hellojp

顶啊顶，期待更多的软件出现

opportunist

最终用户对中间的技术，其实没兴趣。