I've been writing a source-to-display converter for a small project. Basically, it takes an input and transforms the input into an output that is displayable by the browser (think Wikipedia-like).
The idea is there, but it isn't like the MediaWiki style, nor is like the MarkDown style. It has a few innovations by itself. For example, when the user types in a chain of spaces, I would presume he wants the spaces preserved. Since html ignores spaces by default, I was thinking of converting these chain of spaces into respective s (for example 3 spaces in a row converted to 1 )
So what happens is that I can foresee a possibility of a ton of tags per post (and a single page may have multiple posts).
I've been hearing alot of anti- s in the web, but most of it boils down to readability headaches (in this case, the input is supplied by the user. if he decides to make his post unreadable he can do so with any of the other formatting actions supplied) or maintenance headaches (which in this case is not, since it's a converted output).
I'm wondering what are the disadvantages of having tons of tags on a webpage?
You are rendering every space as ?
Besides wasting so much bandwidth, this will not allow dynamic line breaking as "nbsp" means "*n*on *b*reaking *sp*ace". This will most probably cause much trouble.
If it's just being dumped to a client, it's just a matter of size, and if it's gzipped, it barely matters in terms of network traffic.
It'll slow down rendering, I'm sure, and take up DOM space, but whether or not that matters depends on stuff I don't know about your use case(s). You might be able to achieve the same result in other ways, too; not sure.
s aren't tags, but are character entities like ©, <, >, etc.
I'd say that the disadvantages would be readability. When I see a word, I expect the spacing to be constant (unless it is in a block of justified text).
Can you show me a case where you'd need s?
Have you considered trying to figure out what the user, by inserting those spaces, is really trying to achieve? Rather than the how (they want to insert the spaces), the what (if the spaces are at the beginning of a line, they want to indent the text in question).
An example of this is many programming sites convert 4 spaces at the start of a line to a pre+code block.
For your purposes, maybe it should be a <block> block.
The end goal being that of converting the spaces not to what the user (with their limited resources) intended to show up there but, rather, what they meant to convey with it.
Related
What kinds of challenges are there facing automatic hyphenation? It seems that you could just draw word by word, breaking when the length of the line exceeds the length of the viewport (or whatever we're wrapping our text in), placing hyphens after as many characters as can fit (provided at least two characters fit and the word is at least four characters), skipping words that already contain a hyphen (there's no requirement that words have to be hyphenated).
But I note how Firefox and IE need a dictionary to be able to hyphenate with CSS's hyphens. This seems to imply that there are further issues regarding where we can place hyphens.
What kinds of issues are these? Do any exist in the English language or do they only exist in other languages?
You have these issues in all languages. You can only place a hyphen where meaningful tokens result from the split, as has already been pointed out. You don't want to, for example, split a word like "wr-ong".
This may or may not be a syllable, while in most languages (including English) it is. But the main point is that you cannot pin it down as easily just with some simple rules. You would need to consider a lot of phonology to get a highly accurate result, and these rules vary from language to language.
With this background, I can see why one would take a dictionary instead, and frankly, being a computational linguist myself, this is also what I would probably opt for.
If you DO want to go for an automatic solution, I would recommend doing some research in English phonology of syllables, or the so-called syllabification. You might want to start with this article on Wikipedia:
Wikipedia - Syllabification
I know the percent symbol has to be URL-encoded when being passed around, but when I display it in the browser, is it also necessary to escape it like so: %?
In URLs, the percent sign (%) has a special meaning, so it should be escaped. In HTML, it does not, so it is not necessary to escape it.
I agree with the chosen answer, but would like to qualify the statement “it is not necessary to escape it.”
If you have a need (or desire) to escape a percentage sign in HTML code, (and there are good reasons to do this with any potentially ambiguous character or symbol) then I would highly recommend using the percentage entity code % as opposed to any numeric code. (those I use when there is no entity name you could use)
That was the answer I was looking for when I found this page, because I forgot it looses the final "e".
We should probably all be using at least the entities kindly listed here. (whoever Webmasterish is; thank you)
Reasoning: Numeric codes (and particularly byte codes from unencoded characters) change with code–pages, on systems using different default languages, and / or different operating systems. (Windows and Mac using slightly different code sets for “English” being the classic, which still plagues plain–text eMail sent between Apple Mail and Outlook) This is slowing down, and should stop with UTF, but I'm still seeing it pop up.
If you're converting HTML to some other mark–up, (note, I used "–" not a "-", or even "−" for the same reason) such as LaTeX, DVI, PostScript or even MarkDown, then it's useful to completely squash any ambiguity… And those processes tend to happen on the information you least expect to be used in such a way when you initially write it. So just get used to doing it everywhere and be grateful to your former self for having had the foresight to do so. Probably years down the line, when you're looking to update formulae to be more readable by utilising MathJax or such, and keep picking up hyphenated words. <swearmarks>
I'd like to add this - if you use javascript in href, you are in troubles too. Check this example:
http://jsfiddle.net/cs4MZ/
One of the workarounds might be using onclick instead of href.
If you're talking about in HTML text, visible to the reader, no. It can't do anything harmful, there.
...if you're talking about inside of HTML attributes, then yes, that would be good to consider.
URLs and HTML are different languages, as weird as that might seem, so they have different weaknesses.
Sometimes when I look at style sheets of big websites (even this one) the css code is completely formated (or however you call it), like this: http://cdn.sstatic.net/stackoverflow/all.css
Is this just the result of a style sheet beeing generated by a CMS ?
I call it "minified", and I think that's the general term. But the reason is to reduce loading times. All those useless spaces and comments still count as bytes, and sometimes you can have more spaces and comments than actual effective characters! (It also obfuscates the stylesheets, although that's really pointless as spaces can easily be restored with whatever formatting you need.)
It's probably generated on the fly from a more scriptable/dynamic/dry layout language, and there is simply no reason to add the whitespaces since non-one should be reading them, and it would only add to the file-size.
It can be generated by CMS or manually. Removing all the tabs and spaces reduces the size of the file, thereby loading it faster an inturn can make a site faster.
EDIT: Rephrased question.
Other than being bad practice, what other reasons are there against empty paragraphs in HTML?
ORIGINAL:
Background
Currently to add a nicely space paragraph in our CMS you press Enter key twice. I don't like empty paragraphs because they seem unnecessary to me. If you want a new paragraph, just press Enter and space it with CSS. If you want to write just below some text (e.g. to display code), then do a line break with Shift+Enter.
Question
Is there any very good reason in not allowing empty paragraphs? Is there a standard here? Seems like I just have a philosophical issue right now -- i.e. using empty paragraphs probably won't make page viewing faster or save that much space.
One thing I've learnt the heard way is that any time you have a WYSIWYG editor for a web page, you stand a risk of ending up with poor quality HTML.
It doesn't matter how good the editor is, or how well trained your people are to use it, you will end up with bad code.
They'll click the 'bold' button instead of selecting your sub-title class. They'll create spurious paragraph tags rather than line breaks. And I've had to explain to one person several times why it's a bad idea to use multiple spaces to indent stuff.
Even when people are very good at using the editor and understand the implications, you'll still get things like stray markup setting styles and then unsetting them without any content, because if you (for example) make a word bold and then delete it, it generally doesn't delete the bold tags, and no-one thinks to switch to the HTML view to check.
The basic problem is that when you make it easy to use like a word processor, people will treat it like a word processor, and the underlying code becomes completely irrelevant to them. Their job is to produce content that looks good, and as long as they can achieve that, they don't generally care for how the code looks.
The good thing is that there is a solution. In general, the people generating the content are the same people who care the most about SEO. If you emphasise that there might be SEO consequences to poor quality HTML, I find that they suddenly care a lot more about the code they're generating. They still don't generally have the skills to fix it when they've broken it, but it does seem to make people take more care to follow the rules.
To directly answer your question, I don't think it's a disaster to have empty paragraph tags like that. It's preferable not to though, and you need to consider how the content would look semantically to a search engine - it may cause the search engine to see the two paragraphs of content as being less connected to each other than they should be. This may affect how it weights the content of each paragraph when it comes to deciding its page rank. In truth, it's unlikely to be a huge difference; in fact, I'd say it's probably very tiny, but in a competitive world, it could be enough to push you down a few places. There are probably other more important SEO issues for you to deal with, but as they say, every little helps.
There are times when you have a CSS styling a particular element in your case a paragraph. IF you will use empty paragraph they will unneccesarily pick up that styling which might not be needed.
By styling paragraphs with CSS, you can change the way paragraphs are styled easily in future.
For example, you might want to style differently if the user is browsing on a mobile device, or you might just decide that you want to add more or less space between paragraphs (using attributes like margin-top and margin-bottom on the p tag I guess) because it just looks better that way. If the spacing is done with extra p tags it'd be a lot harder to change.
I expect that things like screen readers for the visually impaired would deal with CSS-styled paragraphs better than if the structure of the page is changed by adding empty paragraphs.
What work, if any, has been done to automatically determine the most important data within an html document? As an example, think of your standard news/blog/magazine-style website, containing navigation (with submenu's possibly), ads, comments, and the prize - our article/blog/news-body.
How would you determine what information on a news/blog/magazine is the primary data in an automated fashion?
Note: Ideally, the method would work with well-formed markup, and terrible markup. Whether somebody uses paragraph tags to make paragraphs, or a series of breaks.
Readability does a decent job of exactly this.
It's open source and posted on Google Code.
UPDATE: I see (via HN) that someone has used Readability to mangle RSS feeds into a more useful format, automagically.
think of your standard news/blog/magazine-style website, containing navigation (with submenu's possibly), ads, comments, and the prize - our article/blog/news-body.
How would you determine what information on a news/blog/magazine is the primary data in an automated fashion?
I would probably try something like this:
open URL
read in all links to same website from that page
follow all links and build a DOM tree for each URL (HTML file)
this should help you come up with redundant contents (included templates and such)
compare DOM trees for all documents on same site (tree walking)
strip all redundant nodes (i.e. repeated, navigational markup, ads and such things)
try to identify similar nodes and strip if possible
find largest unique text blocks that are not to be found in other DOMs on that website (i.e. unique content)
add as candidate for further processing
This approach of doing it seems pretty promising because it would be fairly simple to do, but still have good potential to be adaptive, even to complex Web 2.0 pages that make excessive use of templates, because it would identify similiar HTML nodes in between all pages on the same website.
This could probably be further improved by simpling using a scoring system to keep track of DOM nodes that were previously identified to contain unique contents, so that these nodes are prioritized for other pages.
Sometimes there's a CSS Media section defined as 'Print.' It's intended use is for 'Click here to print this page' links. Usually people use it to strip a lot of the fluff and leave only the meat of the information.
http://www.w3.org/TR/CSS2/media.html
I would try to read this style, and then scrape whatever is left visible.
You can use support vector machines to do text classification. One idea is to break pages into different sections (say consider each structural element like a div is a document) and gather some properties of it and convert it to a vector. (As other people suggested this could be number of words, number of links, number of images more the better.)
First start with a large set of documents (100-1000) that you already choose which part is the main part. Then use this set to train your SVM.
And for each new document you just need to convert it to vector and pass it to SVM.
This vector model actually quite useful in text classification, and you do not need to use an SVM necessarily. You can use a simpler Bayesian model as well.
And if you are interested, you can find more details in Introduction to Information Retrieval. (Freely available online)
I think the most straightforward way would be to look for the largest block of text without markup. Then, once it's found, figure out the bounds of it and extract it. You'd probably want to exclude certain tags from "not markup" like links and images, depending on what you're targeting. If this will have an interface, maybe include a checkbox list of tags to exclude from the search.
You might also look for the lowest level in the DOM tree and figure out which of those elements is the largest, but that wouldn't work well on poorly written pages, as the dom tree is often broken on such pages. If you end up using this, I'd come up with some way to see if the browser has entered quirks mode before trying it.
You might also try using several of these checks, then coming up with a metric for deciding which is best. For example, still try to use my second option above, but give it's result a lower "rating" if the browser would enter quirks mode normally. Going with this would obviously impact performance.
I think a very effective algorithm for this might be, "Which DIV has the most text in it that contains few links?"
Seldom do ads have more than two or three sentences of text. Look at the right side of this page, for example.
The content area is almost always the area with the greatest width on the page.
I would probably start with Title and anything else in a Head tag, then filter down through heading tags in order (ie h1, h2, h3, etc.)... beyond that, I guess I would go in order, from top to bottom. Depending on how it's styled, it may be a safe bet to assume a page title would have an ID or a unique class.
I would look for sentences with punctuation. Menus, headers, footers etc. usually contains seperate words, but not sentences ending containing commas and ending in period or equivalent punctuation.
You could look for the first and last element containing sentences with punctuation, and take everything in between. Headers are a special case since they usually dont have punctuation either, but you can typically recognize them as Hn elements immediately before sentences.
While this is obviously not the answer, I would assume that the important content is located near the center of the styled page and usually consists of several blocks interrupted by headlines and such. The structure itself may be a give-away in the markup, too.
A diff between articles / posts / threads would be a good filter to find out what content distinguishes a particular page (obviously this would have to be augmented to filter out random crap like ads, "quote of the day"s or banners). The structure of the content may be very similar for multiple pages, so don't rely on structural differences too much.
Instapaper does a good job with this. You might want to check Marco Arment's blog for hints about how he did it.
Today most of the news/blogs websites are using a blogging platform.
So i would create a set of rules by which i would search for content.
By example two of the most popular blogging platforms are wordpress and Google Blogspot.
Wordpress posts are marked by:
<div class="entry">
...
</div>
Blogspot posts are marked by:
<div class="post-body">
...
</div>
If the search by css classes fails you could turn to the other solutions, identifying the biggest chunk of text and so on.
As Readability is not available anymore:
If you're only interested in the outcome, you use Readability's successor Mercury, a web service.
If you're interested in some code how this can be done and prefer JavaScript, then there is Mozilla's Readability.js, which is used for Firefox's Reader View.
If you prefer Java, you can take a look at Crux, which does also pretty good job.
Or if Kotlin is more your language, then you can take a look at Readability4J, a port of above's Readability.js.