Is it possible to write the below line in js file
var lst = #Html.Raw(Json.Encode(ViewBag.List));
You cannot use server side code in static js files. You could declare this global variable in the view and then use from separate javascript files.
You can made you js file dynamic, such as any other asp.net file by renaming it in
filename.aspx for example. Then your modded 'js' file will be something like:
<%# Page Title="" Language="C#" %>
<%
Response.ContentType = "application/x-javascript";
%>
function foo() {
var a = "<%= myVar %>";
}
you can include in your page with the standard way:
<script type="text/javascript" src="filename.aspx"></script>
Html Helpers can be used only in Views and not in the JavaScript files.
To make things work, you need to write your input variables to View and rest of the code in JavaScript files. So, your code should be like :
View:
<script>
var lst = #Html.Raw(Json.Encode(ViewBag.List));
</script>
and rest of the code to access "lst" will reside in javaScript file:
JS File:
$(document).ready(function(){
// access lst here, rest of the code goes here
});
Note: Do not forget to include JS file to View.
my fav solution is to give arguments as parameters:
function foo(parameter) {
var lst = parameter;
...
}
and in the View:
<input type='button' onclick="foo('#Html.Raw(Json.Encode(ViewBag.List))');" />
You may as well use an object to store every server side property and the pass it to your js as a global. Do it in the $(document).ready();. There's already a good question on SO, with more insights ont this. Will edit later with the link.
Regards,
EDIT: give a read to this SO question you'll find some more insights.
Related
I'm working on a Node.js app (it's a game). In this case, I have some code set up such that when a person visits the index and chooses a room, he gets redirected to the proper room.
Right now, it's being done like this with Express v2.5.8:
server.get("/room/:name/:roomId, function (req, res) {
game = ~databaseLookup~
res.render("board", { gameState : game.gameState });
}
Over in board.ejs I can access the gameState manner with code like this:
<% if (gameState) { %>
<h2>I have a game state!</h2>
<% } %>
Is there a way for me to import this into my JavaScript logic? I want to be able to do something like var gs = ~import ejs gameState~ and then be able to do whatever I want with it--access its variables, print it out to console for verification. Eventually, what I want to do with this gameState is to display the board properly, and to do that I'll need to do things like access the positions of the pieces and then display them properly on the screen.
Thanks!
You could directly inject the gameState variable into javascript on the page.
<% if (gameState) { %>
<h2>I have a game state!</h2>
<script>
var clientGameState = <%= gameState %>
</script>
<% } %>
Another option might be to make an AJAX call back to the server once the page has already loaded, return the gameState JSON, and set clientGameState to the JSON response.
You may also be interested in this: How can I share code between Node.js and the browser?
I had the same problem. I needed to use the data not for just rendering the page, but in my js script. Because the page is just string when rendered, you have to turn the data in a string, then parse it again in js. In my case my data was a JSON array, so:
<script>
var test = '<%- JSON.stringify(sampleJsonData) %>'; // test is now a valid js object
</script>
Single quotes are there to not be mixed with double-quotes of stringify. Also from ejs docs:
"<%- Outputs the unescaped value into the template"
The same can be done for arrays. Just concat the array then split again.
I feel that the below logic is better and it worked for me.
Assume the variable passed to the ejs page is uid, you can have the contents of the div tag or a h tag with the variable passed. You can access the contents of the div or h tag in the script and assign it to a variable.
code sample below : (in ejs)
<script type="text/javascript">
$(document).ready(function() {
var x = $("#uid").html();
alert(x); // now JS variable 'x' has the uid that's passed from the node backend.
});
</script>
<h2 style="display:none;" id="uid"><%=uid %></h2>
In the EJS template:
ex:- testing.ejs
<html>
<!-- content -->
<script>
// stringify the data passed from router to ejs (within the EJS template only)
var parsed_data = <%- JSON.stringify(data) %>
</script>
</html>
In the Server side script:
ex: Router.js
res.render('/testing', {
data: data // any data to be passed to ejs template
});
In the linked js (or jquery) script file:
ex:- script.js
In JavaScript:
console.log(parsed_data)
In JQuery:
$(document).ready(function(){
console.log(parsed_data)
});
Note:
1. user - instead of = in <% %> tag
2. you can't declare or use data passed from router to view directly into the linked javascript or jquery script file directly.
3. declare the <% %> in the EJS template only and use it any linked script file.
I'm not sure but I've found it to be the best practice to use passed data from router to view in a script file or script tag.
This works for me.
// bar chart data
var label = '<%- JSON.stringify(bowlers) %>';
var dataset = '<%- JSON.stringify(data) %>';
var barData = {
labels: JSON.parse(label),
datasets: JSON.parse(dataset)
}
You can assign backend js to front end ejs by making the backend js as a string.
<script>
var testVar = '<%= backEnd_Var%>';
</script>
This should work
res.render("board", { gameState : game.gameState });
in frontend js
const gameState = '<%- JSON.stringify(gameState) %>'
Well, in this case you can simply use input text to get data. It is easy and tested when you use it in firebase.
<input type="text" id="getID" style="display: none" value="<%=id%>">
I know this was answered a long time ago but thought I would add to it since I ran into a similar issue that required a different solution.
Essentially I was trying to access an EJS variable that was an array of JSON objects through javascript logic like so:
<script>
// obj is the ejs variable that contains JSON objects from the backend
var data = '<%= obj %>';
</script>
When I would then try and use forEach() on data I would get errors, which was because '<%= obj %>' provides a string, not an object.
To solve this:
<script>
var data = <%- obj %>;
</script>
After removing the string wrapping and changing to <%- (so as to not escape html going to the buffer) I could access the object and loop through it using forEach()
Suppose you are sending user data from the node server.
app.get("/home",isLoggedIn,(req,res)=>{
res.locals.pageTitle="Home"
res.locals.user=req.user
res.render("home.ejs");
})
And now you can use the 'user' variable in the ejs template. But to use the same value using client-side javascipt. You will have to pass the data to a variable in the tag.
Passing ejs variable to client-side variable:
<script>
let user= '<%- JSON.stringify(user) %>';
</script>
<script>home.js</script>
Now you can access the user variable at home.js
I'm try to add a value to my vb variable in my js code, this is my example
<script>
'<%Dim Myvariable As Integer%>' = 201278
</script>
but this doesn't work.
Is there a way to do this?
Declare variable either protected or public:
Protected test As Integer = 201278;
And in .aspx file:
<script>
<%=test.toString()%>
</script>
edit.
that comment doesn't make any sense #JoséGregorioCalderón the example shows that it IS in script tags. If you mean the file is an external JS file, that is a different problem.
You could solve this in two ways.
1) You serve the JS file as an ASPX file to generate parts of it that are dynamic. you'll need to take care of the headers to serve it is text/javascript
2) You write the variable to your HTML as a data attribute and read it into your JS directly.
i.e.
or...very quick pseudo code.
<body id="myBody" data-variable="<%=MyVariable%>">
var bodyElement = document.getElementById('myBody')
alert(bodyElement.dataset.variable);
I use this for different languages on our site:
Locale locale2 = (Locale)session.getAttribute("org.apache.struts.action.LOCALE");
ResourceBundle bundle = ResourceBundle.getBundle("content.test.Language", locale2);
I can easy access the string values of the ResourceBundle in HTML to include it on the site via:
<%= bundle.getString("line1") %>
But in some cases I need to access the string values out of javascript.
I have not found a way to do this so far.
I only found a ugly workaround to get the string values.
On the HTML part I include:
<input type="hidden" name="hiddenLine2" id="hiddenLine2" value=<%= bundle.getString("line2") %>>
I do this for all strings I could possibly need.
To access one of them out of javascript I do this:
var line2 = document.getElementById("hiddenLine2").value;
This is working so far, but I don´t like it.
I am sure there could be a better solution.
Some of the possible solutions.
Use an ajax method to get your resource by passing a key.
Use Hidden input fields and load values.
Use a dedicated jsp page to declare js variables or even a js function to get values according to key.
like this.
<script type="text/javascript">
var messageOne = '<%=bundle.getString("line1") %>';
var messageTwo = '<%=bundle.getString("line2") %>';
</script>
It is normally bad practice to use scriplets <% %> inside your jsp files.
You can use the fmt tag from the jstl core library to fetch information from your resource bundles.
<fmt:bundle basename="bundle">
<fmt:message var="variableName" key="bundleKey" />
</fmt:bundle>
<input type="hidden" name="hiddenLine2" id="hiddenLine2" value="${variableName}">
should work
infact, i think you can also directly embed it into the javascript with EL aswell
var line2 = ${variableName}; //instead of getting it from document.getElement(...)
Based on what I have tried, you can use jstl library to print the translated messages directly into JavaScript like:
alert("<fmt:message key='line1'/>");
And if you are using struts2 for handling the locales you can easily define you Bundles getting either the struts2 locale, saved by the i18nInterceptor present on the default stack, or the user request locale (the clients' browser one)
<!-- //Import the requierd libraries -->
<%#taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>
<%#taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!-- //Take the Locale from struts if it's present and from the user request if not -->
<c:set var="locale" value="${not empty sessionScope.WW_TRANS_I18N_LOCALE
? sessionScope.WW_TRANS_I18N_LOCALE : pageContext.request.locale}"/>
<!-- //Get the bundle based on the Locale -->
<fmt:setLocale value="${locale}"/>
<fmt:setBundle basename="content.test.Language"/>
But if you want to be able to extract that JavaScript code into an external .js file on the future I recommend you to use some of the internalionalization libraries available for JavaScript, like Globalize (It's the only one I have used, but there are plenty on the net).
The downside of using an external JavaScript library for internationalization is that you will have to define the tranlation resources directly on .js files, it's impossible to access to your .properties on the server from a client-based language like JavaScript.
Here is a different solution.
Load bundle like OP did, with the method getBundle().
Using the third option on Arun's answer, create a separate JSP file to create a custom JavaScript object.
This is the content of said JSP:
<%#page import="com.tenea.intranet.conf.Conf" %>
<%#page import="java.util.ResourceBundle,
java.util.Enumeration" %>
<script type="text/javascript">
var _get = function(ID){
if (this.hasOwnProperty(ID)) return this[ID];
else {
console.warn("[Resources] Error al obtener clave <"+ ID +">");
return "[ERROR]";
}
};
var _search = function(text){
var elems = { }
Object.keys(this).map(e => {
if (typeof (this[e]) !== "function" && this[e].includes(text)) { elems[e] = this[e]; }
});
return elems;
};
var Resources = {
<%
ResourceBundle labels = ResourceBundle.getBundle("content.test.Language", locale2);
Enumeration<String> e = labels.getKeys();
while (e.hasMoreElements()) {
String param = e.nextElement();
out.print(param +":\""+ labels.getString(param) +"\"");
if (e.hasMoreElements()) out.println(",");
}
%>
};
Resources._get = _get;
Resources._search = _search;
</script>
What this JSP does is:
Creates object Resources
Using some snippets (sorry Martin :p), and iterating on the list of keys from the resourceBundle, for each key I print a line like "key: value" with out.println().
The resulting object is something like this:
Resources {
abrilAbrText: "Apr"
abrilText: "April"
...
}
To make some extra functionality, I also added 2 functions inside Resources.
_get() returns the text related to the key passed as parameter. If said key doesn't exist, return the text '[ERROR]'.
_search() is a function I added for development purposes. It searches and returns a custom object with every key whose corresponding text contains the text passed as parameter. NOTE: since it uses "e => {}", it won't work on IE or Safari, so it's best to comment it once the development phase has ended.
Once you have this JSP created, to use it you just have to import it to any JSP you want with this:
<%#include file="[relative_path]" %>
Hope it helps! :)
I am working on a legacy application and I want to move some JS code onto a separate JS file.
I will have to refractor some of the code to do this. I can put #Url.Content statements into data attributes in the HTML.
But how would I replace this line of code?
var array = #Html.Raw(Json.Encode(ViewBag.JobList));
A separate JS file will not know what #Html.Raw means.
Server side code like that cannot run in a seperate javascript file. My solution for such problems is having a short javascript part in the head that runs on the onload event. There you can set variables that you can use in a seperate javascript file:
in the head:
array = #Html.Raw(Json.Encode(ViewBag.JobList));
in the seperate javascript file:
var array;
Then, in the seperate javascript file you can do with your array whatever is necessary.
The ViewBag.JobList data is only known at HTML page generation time. To include it in an external JavaScript file, you have to have another ASP.NET resource that recalculated ViewBag.JobList and then served as part of a dynamic JavaScript file. This is pretty inefficient.
Instead, do what you're doing with the URLs: pass the data through the DOM. If you're writing into normal DOM instead of a script block, you don't need the raw-output any more (*), normal HTML escaping is fine:
<script
id="do_stuff_script" src="do_stuff.js"
data-array="#Json.Encode(ViewBag.JobList)"
></script>
...
var array = $('#do_stuff_script').data('array');
// jQuery hack - equivalent to JSON.parse($('#do_stuff_script').attr('data-array'));
(Actually, the raw-output might have been a security bug, depending on what JSON encoder you're using and whether it chooses to escape </script to \u003C/script. Writing to HTML, with well-understood HTML-encoding requirements, is a good idea as it avoids problems like this too.)
I think you need to create action with JavaScriptResult
public ActionResult Test()
{
string script = "var textboxvalue=$('#name').val();";
return JavaScript(script);
}
But, before proceeding please go through following links
Beware of ASP.NET MVC JavaScriptResult
Working example for JavaScriptResult in asp.net mvc
I would also follow MelanciaUK's suggestion :
In your javascript file, put your code inside a function :
function MyViewRefactored( array ){
... your code ...
}
In your view, leave a minimal javascript bloc :
<script>
var array = #Html.Raw(Json.Encode(ViewBag.JobList));
MyViewRefactored( array );
</script>
I am working on an MVC application and all the JavaScript for the pages is in their own JavaScript files, so there are no Script tags on the pages. Now, there is a Messages class that contains Errors, Information and Confirmation classes with Static strings. The error messages and information messages are being returned from the server, which is fine. But the confirmation messages (eg. Do you wish to Save (OK/Cancel), which is the confirm function in JavaScript) are hard coded in each JavaScript file. I now want the JavaScript to use the confirmation messages from the Messages.Confirmation class.
Currently, to solve this I do something like this in my page,
<%# Import Namespace="Business.Common" %>
.....
<script type="text/javascript">
confirmSaveQuestion= '<%= Messages.Confirmations.CONFIRM_SAVE %>';
</script>
and my .js file looks like this
var confirmSaveQuestion;
function ConfirmSave() {
var result = window.confirm(confirmSaveQuestion);
if (result)
return true;
else
return false;
}
and this works fine.
Is it possible to import the namespace Business.Common into the .js file, so that I don't have to set the value for confirmSaveQuestion in my page?
Your .js files are static, so there is no way for them to interact with server code. I'd recommend one of two things:
1) Use an ASHX handler to dynamically build javascript files - this will return your javascript dynamically, so that you can inject it with server stuff. Instead of referencing a .js file in your markup, you would reference your .ashx file.
2) Put the <%= %> tags into your master page - still shows up on the page, but at least you only have to deal with them once.
As I can't import namespace to my .js file, I went with a different solution. I removed the script tags from my page and instead added the following line of code. I guess it probably ends up doing a similar sort of thing, but it looks a bit cleaner.
<% Html.Telerik().ScriptRegistrar().OnDocumentReady("confirmSaveQuestion = '" + Messages.Confirmations.CONFIRM_SAVE + "'"); %>