Registering script for event validation from within the JS file - javascript

Just a quick question here. I am trying to register a js file for script validation using
if (!Page.ClientScript.IsClientScriptBlockRegistered("strIncludeJSFile")) Page.ClientScript.RegisterClientScriptBlock(strIncludeJSFile.GetType(), "strIncludeJSFile", strIncludeJSFile);
code in C# and it works well for the js files. But, some js files are used in multiple pages, so I am unsure if the above code will be a good idea. As such, I want to do the same thing in the js file itself, instead of using the code behind. Is there any possibility to do that? Or is this thing specific to C#?

of course you can register a js file (or script block) from html by using a script tag. However, the main reason RegisterClientScriptBlock exists is because developers might need to generate (or modify) a script block dynamically from code behind or conditionally register a script file dynamically.
If you need any of the above...generate a script block dynamically, then you "might" be better off registering it from code behind, I mean, it depends on the whole solution itself, it's hard to recommend an approach without having some context. Either way, some options are:
register the script blocks from code behind if you need to generate based on some conditions that can only be evaluated from server side code
use a master page for better and register the script block from the master page. This will make it easier to maintain if you keep the logic in one place
similar to the option above, you can use a base page class if using a master page is not possible
use an html script element if what you need is to reference a static js file
use place holders such as js variables and fetch dynamic data from the server using ajax
use unobtrusive javascript, custom data attributes and ajax
Whatever the suitable option(s) is depends on too many factor that you have to assess

Related

Is it possible to load external js files/libraries into Acumatica?

I'm working on a new Acumatica screen for our company that will require some javascript code to retrieve and display a map object (from ESRI).
This code requires an external .js file that is included to the HTML by the javascript code itself. Everything works fine if I use a blank HTML page to test this.
The problem I have is that when I try using the same code from inside the Acumatica screen, it doesn't load this required external file, and therefore the code does not work properly.
I attempted to load the full .js file code along with my code, but it returned the following error:
error CS8095: Length of String constant exceeds current memory limit. Try splitting the string into multiple constants.
I haven't tried splitting this file into multiple strings (as the error message suggests), because I want to make sure there isn't a cleaner and more professional, direct/right way to do this.
Is it possible to manually import this external .js file into our Acumatica instance, so I can point to it instead? (in case it makes a difference if it's hosted in the same environment)
or, is there any way to make Acumatica able to load external files so we can keep using our current approach? (any setting that may be preventing external files from loading?)
I'm not sure i fully understand the question. What comes to mind however is you may be looking to use the PXJavaScript control. I used this link to help get my head wrapped around how to use the control. We had a need to trigger something off with Java Script and the PXJavaScript control got us to the end result we needed. Let me know if this gets you in the right direction?
Dynamically Change Button Color

Loading JavaScript files selectively in Django

I have Post model for a blog app in Django. It has a field named body. In posts, I may use Latex so I need to use MathJax.js. In some posts, I add code snippet, so I use highlight.js. In some I use both, in some I use none of them.
I want to load the relevant javascript depending on the body field of the Post model (similar to THIS). How can I make the relevant .js file(s) to load automatically?
I know that I can add an indicator field like hasLatex (True, False) or hasCode (True, False). But I'm lazy, I want Post.body to be automatically scanned and only relevant js files loaded.
Set something in your context or use a template context processor. For example I load code that handles forms if there is a form key is my context. For something I want on almost every page I put a no_something in my context to disable it. This is done by putting a conditional around the tag in your base template. If the variable is not there or is false it won't show.
What I also do is put my static files in lists inside of my context. JavaScript is in context['js'] and css in context['css']. Those are looped through in my header. I can implement get_context_data in a base class, and all the views that extend from that will have the javascript and css files.

Using Struts tags in Javascript

We have some widgets developed using Dojo and Javascript. The dojo code invokes some application services using io script mechanism to overcome cross browser issues. Currently the action for the io script is hard coded as follows.
var host="myhost.com";
var url = "http://"+host+"/context/service";
Every time we need to create WAR, we have to change host details. Is there a way in JS we can configure this ie., some thing like reading it from properties.
I found this s:url struts tag. I assume we can use this tag inside javascript code in a JSP. Can i use it in plain JS out side of JSP?
Sure, if you have your container set up to process *.js files as JSP files.
IMO this is a bit brittle.
You can also do things like hide data in the DOM via hidden elements or <script> tags with reasonable type attributes (e.g., not "text/javascript", the default).
You can also put the data into JavaScript variables in the JSP and access them from external JS files.

Referencing ASPX controls from an External JS file

I have a question. I have a aspx control (for e.g textbox). I reference it using document.getElementById('<%=textbox.ClientID%>').value. When I have the code in the same aspx file it works. But as soon reference it from an external file (example MyJSFunctions.js), I cannnot. I get an error saying "the object does not exist or it is null"
I have included the name of the js file like
I did this because I like having all my js functions in a seperate file nad doing this also reduces the load overhead.
Why is this happening? Can I accomplish the same using jquery?
You will need to parametise your Javascript to accept the desired argument, then pass the inline ASP.NET script within the server-side page or control as the value of such. This will allow the engine to render the inline code appropriately.
It happens because the server renders your pages (not in the sense of a browser rendering HTML, but rather the ASP.NET engine making transformations to turn your .NETified web mark-up into standard web mark-up) prior to pushing them down to the client - this will only happen for "registered" types, and that doesn't (and shouldn't) include Javascript files (although you can technically register items to handle, unless you have a bespoke module to handle compilation of inline scripting among Javascript, then it would err anyway.)
jQuery essentially being something of a Javascript framework, you're in the same boat with that, so to speak.
As an example, consider the following...
Your script file:
function doSomethingJavascripty(withThisClientID) {
//do something with...
document.getElementById(withThisClientID).value;
}
Your ASPX page:
<script type="text/javascript" src="/path/to/script.js"><script>
<script type="text/javascript">
//call your function when appropriate...
doSomethingJavascripty('<%=textbox.ClientID%>');
</script>
One thing you could do is have the following Javascript code in your ASPX page:
var myTextbox = '<%=textbox.ClientID%>';
Then, in your external JS file (make sure this is after the above line), have:
document.getElementById(myTextbox).value
Another alternative is just hardcode in the ClientID into your code, but note you'll break it if you change the ID or parent container of that textbox control in the future.

Executing groovy statements in JavaScript sources in Grails

There are essentially 2 places to define JavaScript functions in Grails, directly in a element on the GSP, and within a separate javascript source file under /web-app/js (for example, application.js). We have defined a commonly reused javascript function within application.js, but we also need to be able to generate parts of the function dynamically using groovy code. Unfortunately, ${some groovy code} does not appear to be processed within separate javascript source files.
Is the only way to do this by defining the javascript function within a script tag on a GSP page, or is there a more general solution? Obviously we could define the javascript function in a script tag within a template GSP file which would be reused, but there is a lot of push to keep our javascript functions defined all together in one place (i.e. the external javascript source file). This has performance benefits as well (the javascript source files are usually just downloaded once by each client's browser, instead of reloading the same javascript functions within the source of every html page they visit). I have toyed around with the idea of breaking the function up into static and dynamic pieces, putting the static ones in the external source and putting the dynamic ones in the template GSP, then gluing them together, but this seems like an unnecessary hack.
Any ideas?
(edit: It may sound like the idea of dynamically generating parts of a JavaScript function, which is then downloaded once and used over and over again by the client, would be a bad idea. However, the piece which is "dynamic" only changes perhaps once a week or month, and then only very slightly. Mostly we just want this piece generated off the database, even if only once, instead of hard coded.)
An easy solution to keep your JavaScript unobtrusive is to create a JavaScriptController and map its actions "/js/*" by adding this to your UrlMappings.groovy file:
"/js/$action"{
controller = "javascript"
}
then just create an action for each dynamic JS file you want, include in in your layout <HEAD>, and presto, you've got a JS file that you can insert Grails snippets into! :)
Note: I've found that there's currently a bug in Grails that doesn't map file extensions to content-types properly, so you'll need to include <%# page contentType="text/javascript; UTF-8" %> at the top of your view files.
This is a great solution. I would like to offer a suggestion to use somthing other then a mapping of "/js/$action" because this is no longer going to allow you to access you javascript files in /web-app/js/. All your javascript files would have to be moved to a the directory your controller would point to.
I would use something like
"/dynjs/$action"
This way you still can point to files in the /web-app/js/ files with out conflict and enjoy the benifits of gsp tags in javascript files
Please correct me if I'm wrong.
Or this... have a tag/service/dynamic method that lets tags write out their JS+CSS+whatever else, to a "cache" which is used to build the JS+CSS resources by a different controller.
Full concept here: [http://www.anyware.co.uk/2005/2009/01/19/an-idea-to-give-grails-tags-esp/][1]
If you want to use models created by the controller (that rendered HTML page which reference the Javascript in which you intend to use groovy code) in the Javascript code, then you can use this technique:
This technique does not need to change URL mappings and does not require you to create extra controller.
In your view GSP add javascript as follows:
<script type="text/javascript">
<g:render template="/javascript/yourJavascriptFile"/>
</script>
In views folder create a "javascript" folder. And create a file named:
_yourJavascriptFile.gsp
You can not only use all the GSP code in your _yourJavascriptFile.gsp file, but you can also use all the models created in your controller (that is rendering the view).
NOTE: There is nothing special about javascript folder. You can name it anything you want OR use an existing view folder. This is just a matter of organizing and identifying your HTML spitting GSP from Javascript spitting GSPs. Alternatively, you can use some naming conventions like: _something.js.gsp etc.
Name your scripts like this
/wherever/the/js/files/are/thescript.js.gsp
The gsp code inside will be rendered correctly by grails. This works, but I have no idea if it's considered a Good Idea or not.
There is another way - pass in the generated code into a function that expects closures. Those closures is generated by the program of course. The generated code is of course inlined/script-tagged in the gsp page.
it may or may not work depending on the nature of the code being generated. But i suspect it will work, and if it doesnt, minor tweaking to the coding style of your javascript will definitely make it work. Though, if these 'generated' code doesnt change much, this quite overkill imo.

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