proposal for hamlet-like syntax that is more compatible with html
It is clear from my experience working with html that hamlet has the right idea. The one time I worked on a HAML (the original hamlet, for Ruby) project professionally it was wonderful. However, the actual hamlet syntax could be implemented more nicely and that there is an opportunity for the syntax to be more similar to html. In particular, I would much rather have white space (and quotes where needed) than exclamation marks. Here is one possible alternative: https://github.com/stonean/slim With this style you end up with something like this: form action=url = text #id.class But a more practical syntax could allow compatibility with existing html- this has always been the main weakness of these newer systems. As I said, I have only worked on 1 HAML project, but have used standard templates for everything else. Even after a proper converter is built, the different syntax is a point of pain. Compatibility would also help remove part of the criticism that Yesod is off in its own little world. Instead of '%body' why not '<body'. A closing angle bracket is required to begin text on the same line for the tag- '<body>text'. The alternative of just having a space '<body text' would be ambiguous with respect to attributes that have no value and be less html compatible. The 'attribute="name"' style would be kept although the quotes are optional- '<body class=page1', or '<body class="page1">' would also be acceptable for compatibility and closing over white space. Of course, the id and class shortcuts would be available- '<body.page1' If the previous tag has no inner text on its line and the next indented line does not start with a '#', '<', or '.' then it is the inner text of the previous tag. <body.page1 text #id.class And the advantage is that it looks much more similar to html, and has easier compatibility. Given <body class="page1"> text <div id="id" class="class" title="div">div text</div> </body> This could actually be parsed as valid if the indentation was consistent. However, at the point one is correcting indentation one might as well remove closing tags. The only thing that needs be done for the html to be parsed is consistent indentation and removal of closing tags. For the div above it might be possible to even keep the closing tag. If that were done it might be possible to allowing multiple tags on one line for the sake of easier html importing. <body class="page1"> text <div id="id" class="class" title="div"><h2>title</h2><p>div text</p></div> </body> But the general idea is that html can be copied into a Hamlet template and quickly converted into valid Hamlet. Then it is up to the developer whether to spend the time to compact things even more once the template can be parsed. <body.page1 text #id.class title=div <h2>title <p>div text That's not so scary, is it? One possible alternative syntax would be for a div with a class or id to still require the opening angle bracket- '<#id.class'. This might be more visually appealing when text is placed on the same line: '<#id.class title=div>text' instead of '#id.class title=div>text'. Perhaps both could be allowed. Michael Snoyman is "intrigued" by this proposal and pointed out that because '<' is not used in Hamlet it would be possible to maintain a backwards compatible mode. However, we both don't want to fracture the community- this is a proposal to permantenly improve things and then deprecate the previous syntax, providing a converter to upgrade. I would appreciate feedback from some haskellers. Are there any limitations are drawbacks to such a syntax, or is it just different? Does this appeal to you more hamlet? Will this make a convert out of anybody who runs away screaming when they see a hamlet template? Greg Weber
On Thu, Dec 9, 2010 at 9:20 PM, Greg Weber <greg@gregweber.info> wrote:
I would appreciate feedback from some haskellers. Are there any limitations are drawbacks to such a syntax, or is it just different? Does this appeal to you more hamlet? Will this make a convert out of anybody who runs away screaming when they see a hamlet template?
I took some time to "get" Hamlet's syntax. While Hamlet (and Yesod as a whole) is really great, I find those %s just plain ugly. Your proposal seems to be better and looks more like HTML without losing conciseness. Personally I would probably close all tags, including those that do not have text on the same line, but I don't want a bike shed around this point =). Cheers! -- Felipe.
I support this proposal's goal, and would be fine with rewriting my templates.
Alright, at this point I've only heard positive things about this syntax change. Does anyone want to volunteer to try and tackle this, or will this need to wait till I can get around to it? Fair warning: I'm likely to try to deal with the WAI + enumerator and xml-enumerator tasks first. If someone wants to take a crack at the Hamlet changes, I'll be happy to review things. Michael On Sat, Dec 11, 2010 at 2:38 AM, Simon Michael <simon@joyful.com> wrote:
I support this proposal's goal, and would be fine with rewriting my templates.
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My belated 2c (sorry, work has been keeping me away from things Yesod and Haskell): 1. The key reason I switched to Yesod was Hamlet. I'm very new to Haskell, and I wanted to try developing a webapp in it; when I looked at the various frameworks, my main question was "What will require me to learn the least new stuff, while still giving me a full Haskell-based development experience?" Yesod was the answer, because I was already familiar with Haml. So, it is one less thing a large swath of people need to learn when they decide to give Yesod a try. And at least in my case, it was a deciding factor. 2. I'm not convinced closeness to HTML is a design goal. My experience is again limited, but I wouldn't expect many people to switch existing projects to Yesod (or really, from any framework to any other); therefore, the idea that someone will have a bunch of HTML to be converted as simply as possible to whatever templating language we use seems remote. 3. Along the same lines, the reason for the existence of templating frameworks like Haml and Hamlet is precisely that people don't enjoy writing HTML: why would we constrain ourselves by similarity to something people have put large (and creative) amounts of effort into avoiding? I think it is unduly limiting. 4. I do believe there are some issues with Hamlet; in fact, the issues raised by Greg are exactly the issues I have. I don't see having a Yesod-specific templating language as the solution, unless this new syntax gives Yesod such a big productivity boost compared to using Hamlet that it's worth putting in the effort. In brief, I think Hamlet is 95% of the way there, and that Michael has done a great job with it. It seems easier to take it another 4% and get it to 99% than it would be to rewrite the syntax from scratch. I don't view HTML similarity as a bonus (or a malus, either way). Maintaining (and furthering) similarity with Haml seems worthier goal, given how many people use it, are familiar with it, and love it; it will ease adoption. I hope this all made sense, and that I didn't start an argument about bike shed colors... ;-) Alexandros On Sat, Dec 11, 2010 at 10:48 AM, Michael Snoyman <michael@snoyman.com>wrote:
Alright, at this point I've only heard positive things about this syntax change. Does anyone want to volunteer to try and tackle this, or will this need to wait till I can get around to it? Fair warning: I'm likely to try to deal with the WAI + enumerator and xml-enumerator tasks first. If someone wants to take a crack at the Hamlet changes, I'll be happy to review things.
Michael
On Sat, Dec 11, 2010 at 2:38 AM, Simon Michael <simon@joyful.com> wrote:
I support this proposal's goal, and would be fine with rewriting my templates.
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I would prefer that the bikeshed stay the color it already is. ;) The syntax is easier for me as it is different from HTML. The HTML-like syntax looks to me like invalid HTML and is more difficult to read. Alex On Sat, Dec 11, 2010 at 7:48 AM, Michael Snoyman <michael@snoyman.com> wrote:
Alright, at this point I've only heard positive things about this syntax change. Does anyone want to volunteer to try and tackle this, or will this need to wait till I can get around to it? Fair warning: I'm likely to try to deal with the WAI + enumerator and xml-enumerator tasks first. If someone wants to take a crack at the Hamlet changes, I'll be happy to review things.
Michael
On Sat, Dec 11, 2010 at 2:38 AM, Simon Michael <simon@joyful.com> wrote:
I support this proposal's goal, and would be fine with rewriting my templates.
_______________________________________________ web-devel mailing list web-devel@haskell.org http://www.haskell.org/mailman/listinfo/web-devel
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participants (6)
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Alexander Dunlap -
Alexandros Salazar -
Felipe Almeida Lessa -
Greg Weber -
Michael Snoyman -
Simon Michael