Is there a way to disable the caching of html pages in the browser with GWT ?
I'd rather avoid using inserting META HTTP-EQUIV="EXPIRES" CONTENT=... in the header of my html pages, and do it programmatically instead - if possible.
I'd be surprised, if this is possible (and has any effect) with GWT/JavaScript, because it would mean, that the question if and how long the page will be cached can change dynamically while the user views the page.
But even if it is, it won't work with proxies, because they don't evaluate JavaScript... The same is true for your web server, which should serve the page with that HTTP header.
So if you want to make your caching http-equiv meta tags dynamic, you should probably do that on the application server: Use a Servlet or any dynamic page (could even be PHP, if you want) to generate the HTML page. You could even set the real HTTP header there (e.g. in a Servlet by using HttpServletResponse.setHeader(String name, String value))
i would say you can't.
however, you can use tricks to always refresh your application by adding parameters on links, for example the URL to your app. a changed parameter is considered as a not-yet-fetched page
so try something like that:
<script type="text/javascript">
document.write("<"+"script src='client/client.nocache.js?today=" + getTime() + "'><"+"/script>");
</script>
Related
I'm working on a URL preview widget, so I'd like to extract the meta tags from the HTML of a given URL.
However, the problem is that websites like Twitter don't return the entire HTML when they detect there's no JavaScript engine enabled (i.e. doing a GET request from the http package).
So, I'd like to know if there's any workaround for these cases, for example, using some kind of headless browser to get the entire HTML.
Thanks!
General Scala-JS page building advice needed. Most of the examples seem to be of the pattern where the main into which your single page application will go is between the tags in a landing page html file. How do you handle the need to insert something in the meta area of the dom? Do I need to render my landing page dynamically from the server to accomplish this? My specific need is to inject a script tag into the meta area of an already defined static html page. I'm using scalajs-react.
Generally you will want a server-rendered "root page" for the SPA. This allows you to dynamically compute proper cache busting file names for your script and stylesheet tags and to easily manage the cache expiration of the root page. Also, for proper html5 push state support you'll want to serve that page at every URL, which is easily done with a server side route.
As per the GWT docs, there are two ways two internationalize my GWT app. One is, declare the language in the HTML itself (hardcoding) through meta tags, another is to use a query param in the URL (like &locale=de).
My webapp is dynamic,different users from different locales will be using it, so the first option is not viable. The 2nd option is fine, but somehow, appending query params to a URL is my pet peeve. I tried to make it dynamic by doing something like $("head).append("<meta name='gwt:property' content='locale=de'>"); first thing on onModuleLoad, it doesn't work.
My app will actually be a redirection, some other web-page will contain a redirection like foo.com&locale=de. Based on that, it will load the required locale fine. But after that, I want to reload it again without showing the query param in the URL, taking the locale information from cookies which can be set in the first load. Is it possible to do so?
There is a third option using cookie.
Reference - GWT Internationalization for dynamically generated content
Ensure you set locale value to the cookie or have a default value for your cookie before user chooses his locale. In our case user chooses a language before login ( where i set the cookie locale value for the user) and read this into the gwt application on load.
Adding the parameter to a model (in a Controller) and picking it up on the client (in a *.jsp) will work for you?
<meta name="gwt:property" content="locale=${locale}">
Then you just need to refresh the page and reset the locale value in a controller. Add the meta-tag code in your html/jsp page, it should be there prior to page loading.
onModuleLoad works with code already loaded to the browser window, so appending meta after loading will not work.
Let's say that I have a link to a webpage that contains some text. What's the easiest way to grab this text to process?
Thanks.
Long story short, I don't think it's possible to make a request from the client js to grab the text from a url with a different domain.
It is possible to make requests to load json. This link describes how.
Basically, the steps are:
Embed a tag in the GWT page
after GWT page is initialized, update
the script tag's src to load remote
url
remote url returns some json data
padded inside a callback javascript
function such as:
callback({blah:foo})
So, you're only option may be writing a method on the server side that loads the url, gets the text. You could then call this method from gwt client using normal rpc technique.
Assuming same origin: use the "RequestBuilder" class.
If you are trying to grab a webpage from a different origin, then it obviously won't work.
I'm trying to cache the mobile Gmail webpage because UIWebView does not cache the content itself (mobile safari does, but not UIWebView).
I tried the methods listed here Reading HTML content from a UIWebView basically saving the html either directly from URLRequest or from UIWebView itself. When I try to put the html saved back into UIWebView it is not the same page!
This is the page that I want to save
alt text http://img39.imageshack.us/img39/5679/screenshot20090830at123.png
This is the page that the html saved will display
alt text http://img39.imageshack.us/img39/8734/screenshot20090830at122.png
If you're loading using loadData:MIMEType:textEncodingName:baseURL: make sure you're setting baseURL correctly - that way, the WebView will know where to look for relative stylesheets and so on.
Edit: For example, if I was saving this page, I'd set the base URL to Just can't seem to fetch the mobile Gmail html, what is wrong?.
That looks like the same page to me, but with different stylesheets attached. If you're just re-displaying identical HTML from your local server, the relative stylesheet paths in Google's HTML would no longer be correct. Also, any AJAX requests meant to run after the page loads would no longer work (both because the relative paths to the scripts would be wrong, and also because Cross-Site Scripting restrictions would prevent them from contacting Google).
Attempting to scrape content from an AJAX-enabled application is no small undertaking. You'd have to replicate a lot of GMail's functionality to truly reproduce the exact page Google presents.