Is it possible to create javascript elements like OpenStreetMap or jQuery inside a vaadin application?
Because vaadin websites are created by programming in java and letting the compiler autocreate the DOM and JavaScript out of it?
So, is it possible at all?
You can create such an integration with AbstractJavaScriptComponent
The basic idea here is to subclass this class, annotate with #JavaScript to pull in the needed JS libs. Then write at least a global function, that sets up your lib in the DOM (you will have a <div> at your disposal). Your component can hold state, the server side can call defined functions on the client (while sending e.g. state) and the client can call server functions (params passed as JSON).
The Wiki has an example how to include such a component
There are some easy and cheap solutions which are not the best in the long term, but they may be enough:
1)
If you just want to render some html you cant insert it as the value of a label and change its Content Mode to html.
https://vaadin.com/book/-/page/components.label.html
2)
If you just want to execute some javascript code after a ui event you can call Javascript.getCurrent().execute(javascriptCode).
https://vaadin.com/book/vaadin7/-/page/advanced.javascript.html
Notice that if you are trying to do some re-usable components, this is not the right answer
I am currently using FormFactory (http://formfactory.apphb.com/) to dynamically generate forms for me. This generally works well except for when rending my custom field types which require certain JavaScript files.
What I would like to do is dynamically add JavaScript references to the page depending on what Editor templates have been rendered by FormFactory.
At the moment I am having to reference all JavaScript libraries regardless of whether they are being used. Is there a better way of doing this to ensure that I don't reference libraries which aren't being used?
Edit: Yes, I could add the reference into the EditorFor template, however this would duplicate references if the same template is used more than once.
Thanks
After I realized this also applies to Partial views it was easy to find an answer.
Using sections in Editor/Display templates
I have a very simple scenario where I want to have a textbox where you can enter a number, and a button next to it which when pressed will call a javascript method and send it the integer value in the textbox as a parameter.
I am just learning MVC and have been very spoiled by WebForms so forgive me for the silly question, but why doesn't this work?
Enter Value 1-4<textarea id="param"></textarea>
<br />
<button id="btnTest" onclick="WCFJSONp(" + param.value + ")">Test Service</button>
I tried adding a # sign in front of 'param.value' hoping Razor might see what I'm trying to do, but that didn't work either? And can anyone recommend any links to 'crash courses' in Javascript/HTML for MVC newbs spoiled by WebForms?
As you state the question this has very little to do with MVC -- this is only javascript. Typically you would use jQuery with javascript when running the MVC platform, in which case something like this would work.
onclick="WCFJSONp($('#param').val());"
vs onclick="WCFJSONp(document.getElementById('param').value)"
When using getElementById you are not using the jQuery library but instead just base JavaScript.
There are advantages and disadvantages to using one over the other.
Using base JavaScript is faster, you don't have to load the jQuery library.
jQuery can make your scripts more portable (probably not an issue in this case), because it defines an exact interface to the DOM and takes care of any browser specific issues (this is the BIG one for me.)
jQuery is easier to use and understand. (some might argue if they are use to base javascript)
jQuery has lots of examples of advanced use (also not an issue here).
There are probably more but these are the ones that come right to mind.
This should be:
onclick="WCFJSONp(document.getElementById('param').value)"
Update: after another day of digging
into this issue, I have found that the
current jQuery template lib provides
no way to do this. this article
describes a good approach.
I would still like to hear of any
additional thoughts on doing this. The
article linked above requires that the
returned string of templates be
inserted into the DOM. Seems as though
leaving the DOM out of this would be
ideal, and less overhead on the
browser. Imagine a large page, with
multiple composite templates that may
not get used. Although, maybe because
the templates are wrapped in a script
tag, there is only a single DOM item per template? Come on, let's
hear some thoughts...
Using jQuery template libs, what's the best way to combine multiple, related, relatively small templates together? Do you need a single <script> tag for each individual template? What about in the case of dynamically pulling these templates via AJAX? Can I combine these templates somehow?
Consider the following:
<script id="movieTemplate" type="text/x-jquery-tmpl">
{{tmpl "#titleTemplate"}}
<tr class="detail"><td>Director: ${Director}</td></tr>
</script>
<script id="titleTemplate" type="text/x-jquery-tmpl">
<tr class="title"><td>${Name}</td></tr>
</script>
Now because these two templates are very closely related (and one depends on the other) it would make sense to consolidate these into a single AJAX call, and get them both at once. I have a few ideas, but I'd like to know if there is common/best way to do this? Currently I pull in a chunk of HTML, and then do a .find() to get the specific peice of HTML for a template... e.g.:
var templatePackage = fancyAjaxCalltoGetTemplates();
"templatePackage" might then look like this:
<div id="templatePkg">
<div id="movieTemplate">
{{tmpl "#titleTemplate"}}
<tr class="detail"><td>Director: ${Director}</td></tr>
</div>
<div id="titleTemplate">
<tr class="title"><td>${Name}</td></tr>
</div>
</div>
I could then do:
var titleTemplate = jQuery.template('titleTemplate', $(templatePackage).find('#titleTemplate') );
and
var movieTemplate = jQuery.template('movieTemplate', $(templatePackage).find('#movieTemplate') );
...let me know what you think... what would you do?
I like the referenced article in your update, except the assumption that you can't cache templates unless you insert them into the DOM. From the jQuery.tmpl documentation,
"To cache the template when using markup that is obtained from a string (rather than from inline markup in the page), use $.template( name, markup ) to create a named template for reuse. See jQuery.template()."
Using this, we can build a javascript template management system that allows us to load as many templates at a time as we need while keeping the DOM clean. On the client, keep a hash of template objects by name. You can use your favorite object based javascript pattern here, but I would think the structure could be like this:
templates[templateName] = {
templateMarkup: markupFromServer,
loadedAt: Date.now(),
compiledTemplateFunction: jQuery.template( templateName, markupFromServer )
}
Then use the templates to generate HTML like this:
templates['unique-name'].compiledTemplateFunction(inputData)
Then, build an unload mechanism to free up memory:
function unload(templateName) {
delete templates[templateName];
delete jquery.template[templateName];
}
Most importantly, you now have a method of storing multiple templates so you can make requests like: $.get('/TemplateManagement/Render', arrayOfTemplateNamesToLoad, loadManyTemplatesSuccess) to load multiple templates at a time. The only thing we need is a controller TemplateManagement that will take an array of template names as an input and return JSON that pairs a template name with its markup. There are a few ways to do this but it seems to me the most convenient is to define partial views for each template. In ASP.NET MVC 3, you can use this technique and RenderPartial to emit each template's markup into a JSON response. You can either name the partial views the same as the templates or map the names in some custom way.
OK, I read the article you reference in this post. As I see it, his way is probably one of the best ways to load up the template page(s). The only thing I don't like is the asynchronous problems that could crop up, esp. if you need to immediately do some templating before the async get returns... plus any binding issues that could happen before it returns something. In several projects I have done I use his "ancient" SSI (server side includes), but I just use something even easier like:
<% Response.WriteFile("this_page_template_file.html"); %>
You could put it anywhere where you'd place a tag. Like he says, just put in only the templates you need, or maybe include two templates: one is a "base" template with commonly-used items and the second one would have the page-specific ones with template references {{tmpl}}.
Is this even close to an answer? ;-)
[First off, great question. I love this topic]
I have no experience with the plugin "jquery-template-libs", but there is a particular lightweight javascript template plugins that are becoming almost a standard and plays very nicely with jQuery, which is probably better suited for the task than JTL, Mustache:
https://github.com/janl/mustache.js
It's got something that's called a "partial" which is essentially a way to include smaller templates within another one. Which sounds like it will help you out a lot.
On top of that there is a library called ICanHaz.js:
http://icanhazjs.com/
ICanHaz essentially extends Mustache to include built in functionality for templates and works incredibly well.
Mustache/ICanHaz allow you to add templates by variable, by a json call or by using tags. The choice is yours.
I know this is an old question but you might want to take a look at Closure-Templates. They provide the kind of functionality you're after with the added advantage of being compiled into JavaScript at compile-time instead of at run-time in each user's browser.
If you do decide to look into using them then I'd suggest using plovr for building them.
I currently am working on a little app that requests user info from my server and displays them using a special template.
At first, I just hardcoded the little snippet in jQuery:
$("<li><div class='outer'><table><tr><td rowspan=2 class='imgcontainer'><img class='thumb'/></td><td><span class='username'/></td></tr><tr><td><span class='name'/></td></tr></table></div></li>")
I clone it several times.
It's ugly and I want it to have syntax highlighting and whatnot, so it would be better for me to have it in the HTML file itself.
Also, it will make merges easier so somebody can just change a line or two.
Is there a pattern for this? Am I OK putting it in the HTML file that I include this JS in (there's only one), and making it hidden using CSS.
The third option I thought of is just creating a separate HTML file and having jQuery request that from the server to keep it separate. Is this technique used much?
Also, is there any term I can use to describe what I'm doing? (It's harder to ask a question for a concept I don't know the name for)
I gave a similar answer on SO earlier today. What you are looking for is called micro-templates. John Resig posted this on his blog. Essentially you can get a json dataset and apply a template to the data to create html and update the DOM.