I'd like to display XML pulled from a database on a website. I'd like to be able to style how it is displayed (such as different colors for string value, attributes, elements,..).
How would you do this? Can you use CSS? Thanks!
EDIT: I mean display the XML as XML editor would, sorry for the confusion!
Have a look at XSL/XSLT.
(I'm interpreting your question to be about displaying the XML content as XML, but with pretty syntax highlighting, as you would get with an XML editor for example.)
I'd recommend xmlverbatim via an XSLT transform (either server-side or via JavaScript). You can change its indent-elements parameter to control whether you want it to indent the XML.
For the XSLT transform on the client side, xslt.js (possibly in conjunction with jQuery) should help.
Related
I'm having trouble wrapping my head around using XML as complement to HTML. I know what they are used for but I don't quite understand how to use them together.
I know that you can use JavaScript to convert an XML file to HTML, but I don't get how that's going to do the trick. How would I be able to style this HTML-file?
I have a template form, which I want to be accessible on a server and for which I want to enable edits. Once edited I want to save the edits on a separate file, so that the template is still available.(Just so you guys have a little bit of background regarding what I need this for).
After a lot of research I came to the conclusion that I would need to use XML, as I will have to store and transport data.
Could anyone explain in more detail how exactly XML can be used as a complement to HTML?
If you need more details or information please let me know. I did do a lot of research and I read the other posts regarding how to convert XML to HTML with JavaScript, but that doesn't answer my question about how EXACTLY they complement each other.
I guess my problem here is that I have yet to manage to wrap my head around the concept.
XML is related to HTML, as it uses the same magic characters for its markup and the same logic where to put the data.
The characters <> are used to separate the markups from the content.
The character & together with an entity code like < is used to encode characters, which would lead to troubles otherwise
elements can contain attributes like <someElement someAttribute="attr value">
elements can contain text or sub elements
The big difference is, that XML is absolutely free how you name your elements and attributes, while HTML relys on dedicated names (like <body>), whereas XML is absolutely strict in structure while HTML allows a lot (like unclosed tags).
As a thing in the middle there is XHTML, which is as strict as XML but sticks to the rules of HTML.
It is almost impossible to read HTML as XML, but you can easily create XML which is taken by any browser as a valid web page.
Your issue cries for XSLT. This is a method to transform a given XML into a new format. This allows for example, to export your data as XML and create a nice web page from it. Different XSLT will present the same data in different ways.
There are several online tools to test this feature. you might have a look here.
Your statement After a lot of research I came to the conclusion that I would need to use XML, as I will have to store and transport data is not all clear... How you send data (to a web application), and the way you send the (manipulated) data back, is not bound to XML. This is very often done with JSON, using Java Script to read, edit and send it back.
XML -> XSLT - HTML is often seen to create (rather static) reports for a web viewer
I am using HTML to make a websites. I know an alternative languages to markup a website: XHTML, WML. Is there any more markup languages? Can I make a website only with XML or SGML?
Thank you for responses.
There aren't many.
To have a browser make your website viewable, you must provide your website in some language your browser can understand. Just plaintext and HTML work universally, there is quite some SVG and PDF support these days, but the only language you can use that can do all the things most people want a website to be able to do, you will have to use HTML or XHTML in some way. Either through JS or by some templating system, but you'll have to use it to generate what's commonly accepted as being a webpage as far as I'm aware.
That being said, there are some languages like Haml, which can be 'compiled' to HTML so you could use that instead. There are also converters for other XML-based languages and such.
If you want to deliver XML from your server, you can convert it to HTML in the browser using either
(a) XSLT 1.0: nearly all browsers have built in support for XSLT 1.0, which can be invoked using the xml-stylesheet processing instruction embedded in the XML
(b) XSLT 3.0: supported using Saxon-JS, which can be invoked using a small Javascript call in a skeletal HTML page.
(c) CSS: if the XML is reasonably close in structure to what you want to present to the user, you can attach styling properties to the XML elements using CSS.
You can also of course maintain your content in XML and convert it to rendered HTML using XSLT either at publishing time, or when each page is requested using code on the server to do the conversion on demand.
Many scientific journals use XML (actually JATS XML) for publishing scientific articles. XML in this case is transforming to HTML either on server or on client side by javascript. As example you can look here, where taking place client-side transformation. But Google will not index such XML.
I'm generating a XML documentation using Doxygen. I'm formatting my descriptions with Markdown and I'm perplexed that the tags that are in between the "detaileddescription" tag are not HTML tags. For example.
<heading level="1">Example</heading>
I checked the configuration file of Oxygen to see if it possible to force it to generate HTML tags instead of the custom ones. I also Googled to see if someone had the same problem, but nothing.
Do you see a solution to this problem I should i just write a converter by myself?
While (in theory) doxygen could have produced XHTML for the documentation blocks inside the XML output, it does not do so.
So yes it is a different format and if you need HTML you will need to translate it.
Reasons behind this.
Flexibility: If someone wants to produce another output format, starting from XHTML would be more difficult than using the same internal representation that doxygen itself uses to produce all output formats.
Legacy: Doxygen already produced XML before there was a XML compliant standard for HTML (i.e. XHTML)
I have a situation where the underlying application provides a UI layer and this in turn has to be rendered as a portlet. However, I do not want all parts of the UI originally presented to be rendered in Portlet.
Proposed solution: Using Datapower for parsing an XML being a norm, I am wondering if it is possible to parse a HTML. I understand HTML may not be always well formed. But if there are very few HTML pages in underlying application, then a contract can be enforced..
Also, if one manages to parse and extract data out of HTML using DP, then the resultant (perhaps and XML) can be used to produce HTML5 with all its goodies.
So question: Is it advisable to use Datapower to parse an HTML page to extract an XML out of it? Prerequisite: number of HTML pages per application could vary in data but not with many pages.
I suspect you will be unable to parse HTML using DataPower. DataPower can parse well-formed XML, but HTML - unless it is explicitly designed as xHTML - is likely to be full of tags that break well-formedness.
Many web pages are full of tags like <br> or <ul><li>Item1<li>Item2<li>Item3</ul>, all of which will cause the parsing to fail.
If you really want to follow your suggested approach, you'll probably need to do something on a more flexible platform such as WAS where you can build (or reuse) a parser that takes care of all of that for you.
If you think about it, this is what your web browser does - it has all the complex rules that turn badly-formed XML tags (i.e. HTML) into a valid DOM structure. It sounds like you may be better off doing manipulation at the level of the DOM rather than the HTML, as that way you can leverage existing, well-tested parsing solutions and focus on the structure of the data. You could do this client-side using JavaScript or you could look at a server-side JavaScript option such as Rhino or PhantomJS.
All of this might be doing things the hard way, though. Have you confirmed whether or not the underlying application has any APIs or web services that IT uses to render the pages, allowing you to get to the data without the existing presentation layer getting in the way?
Cheers,
Chris
Question of parsing and HTML page originates when you want to do some processing over it. If this is the case you can face problems because datapower by default will not allow hyperlinks inside the well formed XML or HTML document [It is considered to be a security risk], however this can be overcome with appropriate settings in XML manager present.
As far as question of HTML page parsing is concerned, Datapower being and ESB layer is expected to provide message format translation and that it indeed does. So design wise it is a good place to do message format translation. Practically however you will face above mentioned problem when you try to parse HTML as XML document.
The parsing can produce any message format model you wish [theoretically] hence you can use the XSLT to achieve what you wish.
Ajitabh
From time to time, I see web pages whose content is solely written in XML (not HTML or XHTML). These pages usually have some style sheets (either XSLT or CSS) attached to them which makes them look like any other ordinary web page.
My question is, what are the advantages of such an approach (if any), and why would anyone choose to work this way?
EDIT: If this is a good thing, why is it not widespread?
EDIT 2: Thanks everyone for the great responses. They really enlightened me. I also found this question whose content is also related.
It's easier to generate it programmatically and reuse it for other purposes than displaying as webpage.
Update:
EDIT: If this is a good thing, why is it not widespread?
Not everyone needs to generate it programmatically or reuse it for other purposes than displaying as webpage. It's then easier to use plain HTML.
One possible advantage would be for use of the data of the page in something other than a web browser; that would (presumably) be easier to do if a page's content were well-formed XML. Of course in theory a well-formed, semantic XHTML page should be nearly as able to be parsed, as well.
It can also be easier to generate XML instead of XHTML, depending on the data source.
When you are getting XML data in to your system, and you are supposed to present this XML data then it is much easier to write some XSLT for that XML instead of parsing it using some sort of parser and then presenting the data.
That can be a valid point for using XML instead of XHTML or HTML
Update
To answer your question on why this is not widespread, is because XSTL is tedious and hard to work with. Specifically XPath, which can be for some people quite difficult to use.
Those pages use XSLT to get rendered on the client side. Not every browser (especially older ones) supports rendering XML + XSLT. XML can however be used server-side as template and get transformed to HTML by the application running on the server. I personally don't see any advantages to this approach.
There are a lot more web pages that are written solely in XML than you know. You're only seeing the ones that do the XSLT transformation on the client side. Server-side transformation of XML is not at all unusual, because there's a plethora of things that produce data in XML, and transforming XML to HTML in XSLT is straightforward. You'll never know this is happening if you just look at the HTML, which bears no signs of having been generated via XSLT.
Personally, I don't understand it either though one of the biggest problems is support in IE. I created a skeleton ecommerce site serving XML, transformed by XSLT and styled using CSS. I sorely missed the ability to use XLink and other wonderful XML features. It's also nice to be able to tag the data for what it is. I used a 'menu' tag for the restaurant menus. 'price' tags for prices and so on. If a user clicked on a link to change menus, all I had to do was send the name of the item, the price and the description instead of the complete page. iirc, a 4K or more HTML menu page was only 200 bytes of sent data.
As far as the "one error makes everything crash in XML" type comments, the same is true of any programming language so proper coding should be no bother for programmers and careful HTML/CSS types.
Before anyone says that what I did was actually XHTML...no. I served XML. I did call up XHTML namespaces when needed for links, images and HTML type things but only when necessary.