How to pass or use variable from GSP in Javascript - javascript

I have below line in my grails gsp file.
<div class="pagination">
<g:paginate total="${lotCount ?: 0}" />
</div>
I want to pass lotCount value to one of my javascript named area-switcher.js file to further use it. How can I do this?
I tried to refer one suggestion from How to pass a value directly from a controller to a javascript file in Grails
where I do below in my gsp
<g:javascript> var theId = ${lotCount} </g:javascript>
and try below in my js file for testing
alert(theId);
but it doesn't work.
Got error like ReferenceError: theId is not defined.
Please help.

Use a hiddenField:
<g:hiddenField name="lotCount" value="${lotCount}" />
<div class="pagination">
<g:paginate total="${lotCount ?: 0}" />
</div>

Your solution should work.
Just ensure that in source of generated html page line
<g:javascript> var theId = ${lotCount} </g:javascript>
is placed before line which includes area-switcher.js
<script type="text/javascript" src="area-switcher.js">
Besides that, there are two more options to pass some value from .gsp to javascript file (examples use jQuery):
By using of data attribute. For example,
gsp (here div, span, input, other tags could be used):
<div id="countElem" data-count="${count}">
js(jQuery used here):
var count = $("#countElem").data('count');
As was mentioned in another comments, by using of hidden field:
gsp:
<g:hiddenField name="countElem" data-count="${count}"/>
js(jQuery used here):
// hidden field will have name and id equals to countElem
var count = $("#countElem").val();

Related

Dropdown change will populate the two textbox values in javascript? [duplicate]

Problem: Sometimes you will want to access a component from javascript with
getElementById, but id's are generated dynamically in JSF, so you
need a method of getting an objects id. I answer below on how you can do this.
Original Question:
I want to use some code like below. How can I reference the inputText JSF component in my Javascript?
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core">
<head>
<title>Input Name Page</title>
<script type="javascript" >
function myFunc() {
// how can I get the contents of the inputText component below
alert("Your email address is: " + document.getElementById("emailAddress").value);
}
</script>
</head>
<h:body>
<f:view>
<h:form>
Please enter your email address:<br/>
<h:inputText id="emailAddresses" value="#{emailAddresses.emailAddressesStr}"/>
<h:commandButton onclick="myFunc()" action="results" value="Next"/>
</h:form>
</f:view>
</h:body>
</html>
Update: this post Client Identifiers in JSF2.0 discusses using a technique like:
<script type="javascript" >
function myFunc() {
alert("Your email address is: " + document.getElementById("#{myInptTxtId.clientId}").value);
}
</script>
<h:inputText id="myInptTxtId" value="backingBean.emailAddress"/>
<h:commandButton onclick="myFunc()" action="results" value="Next"/>
Suggesting that the attribute id on the inputText component
creates an object that can be accessed with EL using #{myInptTxtId},
in the above example. The article goes on to state that JSF 2.0 adds
the zero-argument getClientId() method to the UIComponent class.
Thereby allowing the #{myInptTxtId.clientId} construct suggested
above to get the actual generated id of the component.
Though in my tests this doesn't work. Can anyone else confirm/deny.
The answers suggested below suffer from drawback that the above
technique doesn't. So it would be good to know if the above technique
actually works.
You need to use exactly the ID as JSF has assigned in the generated HTML output. Rightclick the page in your webbrowser and choose View Source. That's exactly the HTML code which JS sees (you know, JS runs in webbrowser and intercepts on HTML DOM tree).
Given a
<h:form>
<h:inputText id="emailAddresses" ... />
It'll look something like this:
<form id="j_id0">
<input type="text" id="j_id0:emailAddress" ... />
Where j_id0 is the generated ID of the generated HTML <form> element.
You'd rather give all JSF NamingContainer components a fixed id so that JSF don't autogenerate them. The <h:form> is one of them.
<h:form id="formId">
<h:inputText id="emailAddresses" value="#{emailAddresses.emailAddressesStr}"/>
This way the form won't get an autogenerated ID like j_id0 and the input field will get a fixed ID of formId:emailAddress. You can then just reference it as such in JS.
var input = document.getElementById('formId:emailAddress');
From that point on you can continue using JS code as usual. E.g. getting value via input.value.
See also:
How to select JSF components using jQuery?
Update as per your update: you misunderstood the blog article. The special #{component} reference refers to the current component where the EL expression is been evaluated and this works only inside any of the attributes of the component itself. Whatever you want can also be achieved as follows:
var input = document.getElementById('#{emailAddress.clientId}');
with (note the binding to the view, you should absolutely not bind it to a bean)
<h:inputText binding="#{emailAddress}" />
but that's plain ugly. Better use the following approach wherein you pass the generated HTML DOM element as JavaScript this reference to the function
<h:inputText onclick="show(this)" />
with
function show(input) {
alert(input.value);
}
If you're using jQuery, you can even go a step further by abstracting them using a style class as marker interface
<h:inputText styleClass="someMarkerClass" />
with
$(document).on("click", ".someMarkerClass", function() {
var $input = $(this);
alert($input.val());
});
Answer: So this is the technique I'm happiest with. Doesn't require doing too much weird stuff to figure out the id of a component. Remember the whole point of this is so you can know the id of a component from anywhere on your page, not just from the actual component itself. This is key. I press a button, launch javascript function, and it should be able to access any other component, not just the one that launched it.
This solution doesn't require any 'right-click' and see what the id is. That type of solution is brittle, as the id is dynamically generated and if I change the page I'll have to go through that nonsense each time.
Bind the component to a backing bean.
Reference the bound component wherever you want.
So here is a sample of how that can be done.
Assumptions: I have an *.xhtml page (could be *.jsp) and I have defined a backing bean. I'm also using JSF 2.0.
*.xhtml page
<script>
function myFunc() {
var inputText = document.getElementById("#{backBean.emailAddyInputText.clientId}")
alert("The email address is: " + inputText.value );
}
</script>
<h:inputText binding="#{backBean.emailAddyInputText}"/>
<h:commandButton onclick="myFunc()" action="results" value="Next"/>
BackBean.java
UIInput emailAddyInputText;
Make sure to create your getter/setter for this property too.
Id is dynamically generated, so you should define names for all parent elements to avoid j_id123-like ids.
Note that if you use jQuery to select element - than you should use double slash before colon:
jQuery("my-form-id\\:my-text-input-block\\:my-input-id")
instead of:
jQuery("my-form-id:my-text-input-block:my-input-id")
In case of Richfaces you can use el expression on jsf page:
#{rich:element('native-jsf-input-id')}
to select javascript element, for example:
#{rich:element('native-jsf-input-id')}.value = "Enter something here";
You can view the HTML source when this is generated and see what the id is set to, so you can use that in your JavaScript. As it's in a form it is probably prepending the form id to it.
I know this is not the JSF way but if you want to avoid the ID pain you can set a special CSS class for the selector. Just make sure to use a good name so that when someone reads the class name it is clear that it was used for this purpose.
<h:inputText id="emailAddresses" class="emailAddressesForSelector"...
In your JavaScript:
jQuery('.emailAddressesForSelector');
Of course you would still have to manually manage class name uniqueness.
I do think this is maintainable as long as you do not use this in reusable components. In that case you could generate the class names using a convention.
<h:form id="myform">
<h:inputText id="name" value="#{beanClass.name}"
a:placeholder="Enter Client Title"> </h:inputText>
</h:form>
This is a small example of jsf. Now I will write javascript code to get the value of the above jsf component:
var x = document.getElementById('myform:name').value; //here x will be of string type
var y= parseInt(x,10); //here we converted x into Integer type and can do the
//arithmetic operations as well

Use View model in Javascript

Scenario:
A partial view has a model, I need to use the value from the model in the javascript which is in seperate .js file.
Currently, I'm using javascript inline so that the value in the model can be used, but what if, the javascript is moved to a seperate file. In this case how do I get those values.
Code
#model IEnumerable<BookSpec.DomainEntities.ContactModel.ContactDataModel>
<label for="SpecFinder">Contact</label>
<select id="SpecFinder" name="state">
#foreach (var name in Model)
{
<option value="#name.GroupID">#name.GroupName</option>
}
</select>
<script type="text/javascript">
$(document).ready(function () {
$("#SpecFinder").change(function(){
getData(this.value,'#Model.ProductID');
});
})
</script>
This is my current example code looks like, and I want to completely move the inline javascript to a seperate file. How can I do it, I also need the values from the model.
Declare global javascript variable model on view as below. Then you can use it anywhere.
<script type="text/javascript">
var model = #Html.Raw(Json.Encode(Model));
</script>
I will recommend to use above solution. But if you still want to not include any script in partial view then you can render the model inside any hidden div. And access its text and convert it to object using JSON.parse as below. Code like below is not a good practice and like patch work.
HTML
<div id="model" style="display:none;">
#Html.Raw(Json.Encode(Model))
</div>
Script
var model = JSON.parse($("#model").text());
I think #Karan response is a good option. But if you want no inline Javascript, you could assign your model to a hidden HTML input and then retrive the value in whatever other external JS file you want.
With something like Html.Hidden, for example:
#Html.Hidden("myModel", new Microsoft.Web.Mvc.MvcSerializer().Serialize(model, SerializationMode.Signed));
You can choose another serialization mode in the SerializationMode enum.
(Code not tried, but should be close)

How to access the elements in Java Script while using JSF2.0 [duplicate]

Problem: Sometimes you will want to access a component from javascript with
getElementById, but id's are generated dynamically in JSF, so you
need a method of getting an objects id. I answer below on how you can do this.
Original Question:
I want to use some code like below. How can I reference the inputText JSF component in my Javascript?
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core">
<head>
<title>Input Name Page</title>
<script type="javascript" >
function myFunc() {
// how can I get the contents of the inputText component below
alert("Your email address is: " + document.getElementById("emailAddress").value);
}
</script>
</head>
<h:body>
<f:view>
<h:form>
Please enter your email address:<br/>
<h:inputText id="emailAddresses" value="#{emailAddresses.emailAddressesStr}"/>
<h:commandButton onclick="myFunc()" action="results" value="Next"/>
</h:form>
</f:view>
</h:body>
</html>
Update: this post Client Identifiers in JSF2.0 discusses using a technique like:
<script type="javascript" >
function myFunc() {
alert("Your email address is: " + document.getElementById("#{myInptTxtId.clientId}").value);
}
</script>
<h:inputText id="myInptTxtId" value="backingBean.emailAddress"/>
<h:commandButton onclick="myFunc()" action="results" value="Next"/>
Suggesting that the attribute id on the inputText component
creates an object that can be accessed with EL using #{myInptTxtId},
in the above example. The article goes on to state that JSF 2.0 adds
the zero-argument getClientId() method to the UIComponent class.
Thereby allowing the #{myInptTxtId.clientId} construct suggested
above to get the actual generated id of the component.
Though in my tests this doesn't work. Can anyone else confirm/deny.
The answers suggested below suffer from drawback that the above
technique doesn't. So it would be good to know if the above technique
actually works.
You need to use exactly the ID as JSF has assigned in the generated HTML output. Rightclick the page in your webbrowser and choose View Source. That's exactly the HTML code which JS sees (you know, JS runs in webbrowser and intercepts on HTML DOM tree).
Given a
<h:form>
<h:inputText id="emailAddresses" ... />
It'll look something like this:
<form id="j_id0">
<input type="text" id="j_id0:emailAddress" ... />
Where j_id0 is the generated ID of the generated HTML <form> element.
You'd rather give all JSF NamingContainer components a fixed id so that JSF don't autogenerate them. The <h:form> is one of them.
<h:form id="formId">
<h:inputText id="emailAddresses" value="#{emailAddresses.emailAddressesStr}"/>
This way the form won't get an autogenerated ID like j_id0 and the input field will get a fixed ID of formId:emailAddress. You can then just reference it as such in JS.
var input = document.getElementById('formId:emailAddress');
From that point on you can continue using JS code as usual. E.g. getting value via input.value.
See also:
How to select JSF components using jQuery?
Update as per your update: you misunderstood the blog article. The special #{component} reference refers to the current component where the EL expression is been evaluated and this works only inside any of the attributes of the component itself. Whatever you want can also be achieved as follows:
var input = document.getElementById('#{emailAddress.clientId}');
with (note the binding to the view, you should absolutely not bind it to a bean)
<h:inputText binding="#{emailAddress}" />
but that's plain ugly. Better use the following approach wherein you pass the generated HTML DOM element as JavaScript this reference to the function
<h:inputText onclick="show(this)" />
with
function show(input) {
alert(input.value);
}
If you're using jQuery, you can even go a step further by abstracting them using a style class as marker interface
<h:inputText styleClass="someMarkerClass" />
with
$(document).on("click", ".someMarkerClass", function() {
var $input = $(this);
alert($input.val());
});
Answer: So this is the technique I'm happiest with. Doesn't require doing too much weird stuff to figure out the id of a component. Remember the whole point of this is so you can know the id of a component from anywhere on your page, not just from the actual component itself. This is key. I press a button, launch javascript function, and it should be able to access any other component, not just the one that launched it.
This solution doesn't require any 'right-click' and see what the id is. That type of solution is brittle, as the id is dynamically generated and if I change the page I'll have to go through that nonsense each time.
Bind the component to a backing bean.
Reference the bound component wherever you want.
So here is a sample of how that can be done.
Assumptions: I have an *.xhtml page (could be *.jsp) and I have defined a backing bean. I'm also using JSF 2.0.
*.xhtml page
<script>
function myFunc() {
var inputText = document.getElementById("#{backBean.emailAddyInputText.clientId}")
alert("The email address is: " + inputText.value );
}
</script>
<h:inputText binding="#{backBean.emailAddyInputText}"/>
<h:commandButton onclick="myFunc()" action="results" value="Next"/>
BackBean.java
UIInput emailAddyInputText;
Make sure to create your getter/setter for this property too.
Id is dynamically generated, so you should define names for all parent elements to avoid j_id123-like ids.
Note that if you use jQuery to select element - than you should use double slash before colon:
jQuery("my-form-id\\:my-text-input-block\\:my-input-id")
instead of:
jQuery("my-form-id:my-text-input-block:my-input-id")
In case of Richfaces you can use el expression on jsf page:
#{rich:element('native-jsf-input-id')}
to select javascript element, for example:
#{rich:element('native-jsf-input-id')}.value = "Enter something here";
You can view the HTML source when this is generated and see what the id is set to, so you can use that in your JavaScript. As it's in a form it is probably prepending the form id to it.
I know this is not the JSF way but if you want to avoid the ID pain you can set a special CSS class for the selector. Just make sure to use a good name so that when someone reads the class name it is clear that it was used for this purpose.
<h:inputText id="emailAddresses" class="emailAddressesForSelector"...
In your JavaScript:
jQuery('.emailAddressesForSelector');
Of course you would still have to manually manage class name uniqueness.
I do think this is maintainable as long as you do not use this in reusable components. In that case you could generate the class names using a convention.
<h:form id="myform">
<h:inputText id="name" value="#{beanClass.name}"
a:placeholder="Enter Client Title"> </h:inputText>
</h:form>
This is a small example of jsf. Now I will write javascript code to get the value of the above jsf component:
var x = document.getElementById('myform:name').value; //here x will be of string type
var y= parseInt(x,10); //here we converted x into Integer type and can do the
//arithmetic operations as well

js make all the url parameter's value have an " "

I have an iframe which includes src like this:
<iframe id="frame1" src="/jsp/transfer/a.jsp?isChange=true&bizId="+bizId></iframe>
bizId is a number. For example:
src = "/jsp/transfer/a.jsp?isChange=true&bizId=10"
I notice that Javascript will make put bizId's value in quotes: "10", "null", etc. I want to get the actual numeric value, not a string. Why is it represented as a string? What should I do?
If I understood your problem right (especially your last comment), you need to do this:
<iframe id="frame1" src="/jsp/transfer/a.jsp?isChange=true&bizId=<%=bizId>"></iframe>
Explanation:
<%= variable > - is a JSP syntax for inserting variables from JSP context into rendered HTML. This code (<%= variable >) will be replaced fully by contents of variable.
Added: (in response to comment)
If you need to put some variable into JavaScript file which is included from your original JSP file, you wont be able to use <%= variable > syntax in it. However, here is what you can do:
[yourjsp.jsp]
<script>
var bizId = <%=bizId>;
</script>
...
<script src="yourjavascript.js"></script>
[yourjavascript.js]
function someMethod() {
alert(bizId);
}
Basically, JSP code will be replaced, and you will define a global javascript variable called bizId containing the value of server-side bizId. Then, any other javascript code can use that variable.
in JS :
window.frames["myIframe"].src = "/jsp/transfer/a.jsp?isChange=true&bizId="+bizId;
you Can't add to the src something like +param.
option 1 ) via server side
option 2) via Js - change the SRC.
edit
<iframe name="myIframe" id="frame1" src=""></iframe>
in the bottom of the page :
<script type="text/javascript">
var bizId=444;
window.onload = function() {
window.frames["myIframe"].src = "/jsp/transfer/a.jsp?isChange=true&bizId="+bizId;
};
</script>

How to refer html element id specified in visualforce and pass onto javascript function?

I have apex tag that generate input text field.
<apex:page id="my_page">
<apex:inputText id="foo" id="c_txt"></apex:inputText>
</apex:page>
When someone clicks this field, I want to execute javascript.
But when I check the HTML source, this apex tag which becomes input tag has (I think) dynamically generated part.
<input type="text" size="50" value="Tue Nov 16 00:00:00 GMT 2010"
name="j_id0:j_id3:j_id4:c_txt" id="j_id0:j_id3:j_id4:c_txt">
As you can see id has junk part :(
id="j_id0:j_id3:j_id4:c_txt"
In my Javascript I'm trying to getElementById('c_txt') but this does not work of course. How to deal with this???
UPDATE
Seems like I can do this but not working...
<apex:includeScript value="{!URLFOR($Resource.datepickerjs)}"></apex:includeScript>
<apex:inputText id="foo" id="c_txt" onclick="javascript:displayDatePicker()" />
datepickerjs
var elem = getElementById('c_txt');
alert(elem);
The alert shows 'null' so something must be wrong.
Even this alert returns null...
var targetDateField = document.getElementById('{!$Component.my_page:c_txt}');
alert(targetDateField);
You can use the $Component notation in javascript, you use it like so:
var e = document.getElementById("{!$Component.ComponentId}");
One thing to be wary of though, is if your element is contained within several levels of Visualforce tags which have IDs:
<apex:pageBlock id="theBlock">
<apex:pageBlockSection id="theBlockSection">
<apex:commandLink action="{!someAction}" value="LINK!" id="theLink"/>
// snip
// in javascript you would reference this component using:
document.getElementById("{!$Component.theBlock.theSection.theLink}");
I got solution to my problem.
$Compoent global visualforce expression can only be used in visualforce code not inside of
Javascript as far as my search.
Below code works fine. It outputs the value in the inputText field to js alert message Now you can pass id attribute to the Javascript and process whatever the task needed.
Created Date: <apex:inputText id="dah" value="{!created}" size="50"
onclick="javascript:go('{!$Component.dah}')"></apex:inputText>
<script>
function go(field) {
var huh = document.getElementById(field).value;
alert(huh); //returns the string u put inside of input text field
}
</script>

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