here is what I'm trying to do.
My ADF page is embedded inside a web page and I must set some values in the parent window.
To do so I have a javascript function that does the work just fine.
to get the value I need to push, I must call an external API with some parameter that depend on a user click.
I implement the call in my manage bean, I get the value and I push it in an input field on my page.
I also setup a clientListener(valueChange) on the inputfield to call my javascript function.
In theory it should do just fine.
the issue is that after the user invoked my serverListener event that call the API, the clientListener is not invoked when the value is pushed inside the inputfield.
I've let the field visible for testing and I can enter the value myself and it work but when the bean push the value in the field the valueChange event doesn't get trigger.
The question from there is how do I get the event to trigger after the bean retrived the value, or how do I call the javascript function from the bean directly ?
here is a sample of the code I use
<af:resource type="javascript">
function pushValue(evt){
// push values to parent page
window.external.main.setFieldValue("fieldName", evt.getSource().getValue());
}
function callServerAPI(){
// call the serverListener
AdfCustomEvent.queue(it2, "callAPI", {somevalues}, true);
}
</af:resource>
<af:inputText label="My hidden field"
id="it2"
binding="#{pageFlowScope.MyAppBean.hiddenField}"
clientComponent="true">
<af:clientListener method="pushValue" type="valueChange"/>
<af:serverListener type="callAPI"
method="#{pageFlowScope.MyAppBean.callAPI}"/>
</af:inputText>
here is the sample for the bean
private RichInputText hiddenField;
public void callAPI(ClientEvent clientEvent) throws Exception {
String fieldValue = clientEvent.getParameters().get("somevalues").toString();
try {
// call the API and get the value needed in the hidden field
hiddenField.setValue(fetchValue(fieldValue));
} catch (Exception e) {
e.printStackTrace();
}
// refresh field
AdfFacesContext.getCurrentInstance().addPartialTarget(hiddenField);
}
Thanks in advance for the help !
This article https://cedricleruth.com/how-to-execute-client-javascript-in-an-adf-java-bean-action/ answer your question : "how do I call the javascript function from the bean directly ?" as follow :
/*** In YOURJSF.jsf button, or other component that need to execute a javascript on action, add : ****/
<af:commandButton text="ClickMe" id="cb1" actionListener="#{YOURSCOPE.YOURJAVABEAN.clickToExecuteJavascriptAction}"/>
/*** In YOURJAVABEAN.java class add : ***/
public void clickToExecuteJavascriptAction(ActionEvent actionEvent) {
this.executeClientJavascript("console.log('You just clicked : " + actionEvent.getSource() + " ')");
//Note: if you use a java string value in this function you should escape it to avoid breaking the javascript.
//Like this : stringValue.replaceAll("[^\\p{L}\\p{Z}]", " ")
}
//You should put this function in a util java class if you want to use it in multiple bean
public static void executeClientJavascript(String script) {
FacesContext facesContext = FacesContext.getCurrentInstance();
ExtendedRenderKitService service = Service.getRenderKitService(facesContext, ExtendedRenderKitService.class);
service.addScript(facesContext, script);
}
I am trying to send a value from the client side using javascript or JQuery, to the server (ideally to a method in my codebehind). I am using C# .net 4.0.
In my client side JQuery I have:
$.post("test.aspx/testMethod",
{
name: "Donald Duck",
city: "Duckburg"
}
);
In my server side (test.aspx.cs) method, I have
public void testMethod()
{
string name = Request.Form("name");
string city = Request.Form("city");
}
But with this I get a compilation error: "Non-invocable member 'System.Web.HttpRequest.Form' cannot be used like a method."
How can I rectify this? Or reach the same objective? Using the $.ajax({...}) is not an option as the value is needed by a non-static method.
There is a very simple answer to this. After searching for hours thru dozens of questions posted along the same lines and many people offering overly complicated ajax post back solutions, I came up with this. Basically a one liner. Hope it helps someone:
In your javascript you just call the method:
PageMethods.SomeMethod('test');
Your "SomeMethod" would be a code behind method like this:
[WebMethod]
public static string SomeMethod(string param1)
{
string result = "The test worked!";
return result;
}
Rules:
You have to identify your code behind method with a WebMethod attribute. It has to be static. And you have to register a script manager in your page as follows:
<asp:ScriptManager ID="MyScriptManager" runat="server" EnablePageMethods="true" />
Since I am working with an aspx webforms page to do some really simple javascript functions like retrieving / stashing geo location, I put it inside the Form element as required.
you can use like this - https://rvieiraweb.wordpress.com/2013/01/21/consuming-webservice-net-json-using-jquery/
try it :)
I dont know if Web Forms support this type of JSON request. I have tried long back but I have to add asmx file that time. Currently you have WCF, but if you don't want to change your webforms project and still want restful api, then merge MVC project for your restful task. You dont have to shift everything but it work together. Here it is explained how?
I don't know about latest version of Web Forms but before VS2012, you can't do ajax type call to page. As far as I know.
Please let me know if any further details needed.
Found Solution... (Hope someone finds it useful)
JAVA SCRIPT
function myFunction() {
var str= "fname=Henry&lname=Ford";
log("MyString=" + str);
}
function log(message) {
var client = new XMLHttpRequest();
client.open("POST", "Default.aspx", true); // Default.aspx being the page being posted to
client.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
client.send(message);
}
C# Default.aspx.cs (CODE BEHIND TO Default.aspx)
protected void Page_Load(object sender, EventArgs e)
{
getText();
}
public void getText()
{
if (HttpContext.Current.Request.Form.Keys.Count > 0)
{
string code = HttpContext.Current.Request.Form["MyString"];
// code = "fname=Henry"
// For looping etc, see below
}
}
WHAT ELSE YOU CAN GET....
HttpContext.Current.Request.Form.Count // 2
HttpContext.Current.Request.Form.Keys.Count // 2
HttpContext.Current.Request.Form.AllKeys[0] // "MyString"
HttpContext.Current.Request.Form.Keys[0] // "MyString"
HttpContext.Current.Request.Form.AllKeys[1] // "lname"
HttpContext.Current.Request.Form.Keys[1] // "lname"
HttpContext.Current.Request.Form[0] // "fname=Henry"
HttpContext.Current.Request.Form[1] // "Ford"
Loop through keys...
foreach (string key in Request.Form.Keys)
{
DoSomething(Request.Form[key]);
}
The above code works in that it passes a value(s) from the client side javascript to the server side code-behind, but then unable to use the value because you lose it.
The following modification to the above code is required to use the value (essentially store it in a separate static class until needed).
C# Default.aspx.cs (CODE BEHIND TO Default.aspx)
protected void Page_Load(object sender, EventArgs e)
{
getText();
}
public void getText()
{
if (HttpContext.Current.Request.Form.Keys.Count > 0)
{
// Reset staticValue
Class1.staticValue = "";
Class1.staticValue = HttpContext.Current.Request.Form["MyString"];
// Call Class1.staticValue anywhere else and you get expected answer= "fname=Henry"
}
}
STATIC CLASS (App_Code/Class1.cs) - another object to store value (otherwise the HttpContext object removes it from anything)
public class Class1
{
private static string myValue = "";
public Class1()
{
//
// TODO: Add constructor logic here
//
}
public static string staticValue
{
get
{
return myValue;
}
set
{
myValue = value;
}
}
}
I would like execute code behind method (like save data to database) from window.onbeforeunload. I cann't use PageMethods because of non-sharedmembers (txtboxed, cmbboxes etc) in the save method. How to handle this situation? It is literally killing my time.
Please help me out.
The only way to do something server related in the onbeforeunload event is to make a new request to the server, like using page methods. The page is already on the way to go away, so there is no other way to communicate with the server.
Refactor out the actual saving into a separate static method, that you can call both from the regular events and from the page methods. Example:
public static void ActualSave(string somedata, string otherdata) {
// save
}
public void SaveButton_Click(object sender, EventArgs e) {
string somedata = SomeControl.Text;
string otherdata = OtherControl.Text;
ActualSave(somedata, otherdata);
}
I am using an ajax htmleditor in asp.net web application so i am trying to get the text the user has entered in the editor then i will send that text back to the client javascript function that will show the text in a div. But I am getting this error "Object reference not set to an instance of an object."
Firstly i tried to access the text of textbox linked with htmleditorextender through javascript but it was not working for me so i moved to ajax webmethod but this time also i am facing a problem. Please Help me.
[System.Web.Services.WebMethod]
public static string seteditor()
{
String x="";
try
{
Content c = new Content();
x = c.txteditor.Text;
}
catch (Exception ex) { x=ex.Message; }
return x;
}
Here, txteditor is the ID of asp:textbox which is linked with ajaxcontroltoolkit htmleditorextender.
You cannot get your aspx controls inside a static method.
If you are Calling a static method from jquery means the Page and its Controls don't even exist. You need to look another workaround for your problem.
EDIT:
I always pass my control values to page methods like this:
Assume I have two text controls: txtGroupName and txtGroupLevel
...My JS with Jquery will be :
var grpName = $("#<%=txtGroupName.ClientID%>").val();
var grpLevel = $("#<%= txtGroupLevel.ClientID %>").val();
data: "{'groupName':'" + grpName + "','groupLevel':'" + grpLevel + "'}",
Where groupName and groupRights are my webmethod parameters.
EDIT2:
Include your script like this:
<script type="text/javascript" src="<%= ResolveUrl("~/Scripts/jquery-1.4.1.js") %>"></script>
I suggest you to use the latest jquery version.
Web methods do not interact with the page object or the control hierarchy like this. That's why they're static in the first place. You need to pass the text from the client as a parameter to the web method, not read it from the textbox.
This issue was torturing me from last 18 hours continuouslyFirst I tried javascript than webmethod and than on user1042031's suggestion I tried jquery and than again I tried javascript and look how much easily it can be done with a single line of code.
var a = document.getElementById('<%= txteditor.ClientID %>').value;
read this stackoverflow article Getting Textbox value in Javascript
I apologize to everyone who responded me in this question but i have not found that article in my initial search.
I'm writing a web page in ASP.NET. I have some JavaScript code, and I have a submit button with a click event.
Is it possible to call a method I created in ASP with JavaScript's click event?
Well, if you don't want to do it using Ajax or any other way and just want a normal ASP.NET postback to happen, here is how you do it (without using any other libraries):
It is a little tricky though... :)
i. In your code file (assuming you are using C# and .NET 2.0 or later) add the following Interface to your Page class to make it look like
public partial class Default : System.Web.UI.Page, IPostBackEventHandler{}
ii. This should add (using Tab-Tab) this function to your code file:
public void RaisePostBackEvent(string eventArgument) { }
iii. In your onclick event in JavaScript, write the following code:
var pageId = '<%= Page.ClientID %>';
__doPostBack(pageId, argumentString);
This will call the 'RaisePostBackEvent' method in your code file with the 'eventArgument' as the 'argumentString' you passed from the JavaScript. Now, you can call any other event you like.
P.S: That is 'underscore-underscore-doPostBack' ... And, there should be no space in that sequence... Somehow the WMD does not allow me to write to underscores followed by a character!
The __doPostBack() method works well.
Another solution (very hackish) is to simply add an invisible ASP button in your markup and click it with a JavaScript method.
<div style="display: none;">
<asp:Button runat="server" ... OnClick="ButtonClickHandlerMethod" />
</div>
From your JavaScript, retrieve the reference to the button using its ClientID and then call the .click() method on it.
var button = document.getElementById(/* button client id */);
button.click();
The Microsoft AJAX library will accomplish this. You could also create your own solution that involves using AJAX to call your own aspx (as basically) script files to run .NET functions.
I suggest the Microsoft AJAX library. Once installed and referenced, you just add a line in your page load or init:
Ajax.Utility.RegisterTypeForAjax(GetType(YOURPAGECLASSNAME))
Then you can do things like:
<Ajax.AjaxMethod()> _
Public Function Get5() AS Integer
Return 5
End Function
Then, you can call it on your page as:
PageClassName.Get5(javascriptCallbackFunction);
The last parameter of your function call must be the javascript callback function that will be executed when the AJAX request is returned.
You can do it asynchronously using .NET Ajax PageMethods. See here or here.
I think blog post How to fetch & show SQL Server database data in ASP.NET page using Ajax (jQuery) will help you.
JavaScript Code
<script src="http://code.jquery.com/jquery-3.3.1.js" />
<script language="javascript" type="text/javascript">
function GetCompanies() {
$("#UpdatePanel").html("<div style='text-align:center; background-color:yellow; border:1px solid red; padding:3px; width:200px'>Please Wait...</div>");
$.ajax({
type: "POST",
url: "Default.aspx/GetCompanies",
data: "{}",
dataType: "json",
contentType: "application/json; charset=utf-8",
success: OnSuccess,
error: OnError
});
}
function OnSuccess(data) {
var TableContent = "<table border='0'>" +
"<tr>" +
"<td>Rank</td>" +
"<td>Company Name</td>" +
"<td>Revenue</td>" +
"<td>Industry</td>" +
"</tr>";
for (var i = 0; i < data.d.length; i++) {
TableContent += "<tr>" +
"<td>"+ data.d[i].Rank +"</td>" +
"<td>"+data.d[i].CompanyName+"</td>" +
"<td>"+data.d[i].Revenue+"</td>" +
"<td>"+data.d[i].Industry+"</td>" +
"</tr>";
}
TableContent += "</table>";
$("#UpdatePanel").html(TableContent);
}
function OnError(data) {
}
</script>
ASP.NET Server Side Function
[WebMethod]
[ScriptMethod(ResponseFormat= ResponseFormat.Json)]
public static List<TopCompany> GetCompanies()
{
System.Threading.Thread.Sleep(5000);
List<TopCompany> allCompany = new List<TopCompany>();
using (MyDatabaseEntities dc = new MyDatabaseEntities())
{
allCompany = dc.TopCompanies.ToList();
}
return allCompany;
}
Static, strongly-typed programming has always felt very natural to me, so at first I resisted learning JavaScript (not to mention HTML and CSS) when I had to build web-based front-ends for my applications. I would do anything to work around this like redirecting to a page just to perform and action on the OnLoad event, as long as I could code pure C#.
You will find however that if you are going to be working with websites, you must have an open mind and start thinking more web-oriented (that is, don't try to do client-side things on the server and vice-versa). I love ASP.NET webforms and still use it (as well as MVC), but I will say that by trying to make things simpler and hiding the separation of client and server it can confuse newcomers and actually end up making things more difficult at times.
My advice is to learn some basic JavaScript (how to register events, retrieve DOM objects, manipulate CSS, etc.) and you will find web programming much more enjoyable (not to mention easier). A lot of people mentioned different Ajax libraries, but I didn't see any actual Ajax examples, so here it goes. (If you are not familiar with Ajax, all it is, is making an asynchronous HTTP request to refresh content (or perhaps perform a server-side action in your scenario) without reloading the entire page or doing a full postback.
Client-Side:
<script type="text/javascript">
var xmlhttp = new XMLHttpRequest(); // Create object that will make the request
xmlhttp.open("GET", "http://example.org/api/service", "true"); // configure object (method, URL, async)
xmlhttp.send(); // Send request
xmlhttp.onstatereadychange = function() { // Register a function to run when the state changes, if the request has finished and the stats code is 200 (OK). Write result to <p>
if (xmlhttp.readyState == 4 && xmlhttp.statsCode == 200) {
document.getElementById("resultText").innerHTML = xmlhttp.responseText;
}
};
</script>
That's it. Although the name can be misleading the result can be in plain text or JSON as well, you are not limited to XML. jQuery provides an even simpler interface for making Ajax calls (among simplifying other JavaScript tasks).
The request can be an HTTP-POST or HTTP-GET and does not have to be to a webpage, but you can post to any service that listens for HTTP requests such as a RESTful API. The ASP.NET MVC 4 Web API makes setting up the server-side web service to handle the request a breeze as well. But many people do not know that you can also add API controllers to web forms project and use them to handle Ajax calls like this.
Server-Side:
public class DataController : ApiController
{
public HttpResponseMessage<string[]> Get()
{
HttpResponseMessage<string[]> response = new HttpResponseMessage<string[]>(
Repository.Get(true),
new MediaTypeHeaderValue("application/json")
);
return response;
}
}
Global.asax
Then just register the HTTP route in your Global.asax file, so ASP.NET will know how to direct the request.
void Application_Start(object sender, EventArgs e)
{
RouteTable.Routes.MapHttpRoute("Service", "api/{controller}/{id}");
}
With AJAX and Controllers, you can post back to the server at any time asynchronously to perform any server side operation. This one-two punch provides both the flexibility of JavaScript and the power the C# / ASP.NET, giving the people visiting your site a better overall experience. Without sacrificing anything, you get the best of both worlds.
References
Ajax,
jQuery Ajax,
Controller in Webforms
The Microsoft AJAX library will accomplish this. You could also create your own solution that involves using AJAX to call your own aspx (as basically) script files to run .NET functions.
This is the library called AjaxPro which was written an MVP named Michael Schwarz. This was library was not written by Microsoft.
I have used AjaxPro extensively, and it is a very nice library, that I would recommend for simple callbacks to the server. It does function well with the Microsoft version of Ajax with no issues. However, I would note, with how easy Microsoft has made Ajax, I would only use it if really necessary. It takes a lot of JavaScript to do some really complicated functionality that you get from Microsoft by just dropping it into an update panel.
It is so easy for both scenarios (that is, synchronous/asynchronous) if you want to trigger a server-side event handler, for example, Button's click event.
For triggering an event handler of a control:
If you added a ScriptManager on your page already then skip step 1.
Add the following in your page client script section
//<![CDATA[
var theForm = document.forms['form1'];
if (!theForm) {
theForm = document.form1;
}
function __doPostBack(eventTarget, eventArgument) {
if (!theForm.onsubmit || (theForm.onsubmit() != false)) {
theForm.__EVENTTARGET.value = eventTarget;
theForm.__EVENTARGUMENT.value = eventArgument;
theForm.submit();
}
}
//]]>
Write you server side event handler for your control
protected void btnSayHello_Click(object sender, EventArgs e)
{
Label1.Text = "Hello World...";
}
Add a client function to call the server side event handler
function SayHello() {
__doPostBack("btnSayHello", "");
}
Replace the "btnSayHello" in code above with your control's client id.
By doing so, if your control is inside an update panel, the page will not refresh. That is so easy.
One other thing to say is that: Be careful with client id, because it depends on you ID-generation policy defined with the ClientIDMode property.
I'm trying to implement this but it's not working right. The page is
posting back, but my code isn't getting executed. When i debug the
page, the RaisePostBackEvent never gets fired. One thing i did
differently is I'm doing this in a user control instead of an aspx
page.
If anyone else is like Merk, and having trouble over coming this, I have a solution:
When you have a user control, it seems you must also create the PostBackEventHandler in the parent page. And then you can invoke the user control's PostBackEventHandler by calling it directly. See below:
public void RaisePostBackEvent(string _arg)
{
UserControlID.RaisePostBackEvent(_arg);
}
Where UserControlID is the ID you gave the user control on the parent page when you nested it in the mark up.
Note: You can also simply just call methods belonging to that user control directly (in which case, you would only need the RaisePostBackEvent handler in the parent page):
public void RaisePostBackEvent(string _arg)
{
UserControlID.method1();
UserControlID.method2();
}
You might want to create a web service for your common methods.
Just add a WebMethodAttribute over the functions you want to call, and that's about it.
Having a web service with all your common stuff also makes the system easier to maintain.
If the __doPostBack function is not generated on the page you need to insert a control to force it like this:
<asp:Button ID="btnJavascript" runat="server" UseSubmitBehavior="false" />
Regarding:
var button = document.getElementById(/* Button client id */);
button.click();
It should be like:
var button = document.getElementById('<%=formID.ClientID%>');
Where formID is the ASP.NET control ID in the .aspx file.
Add this line to page load if you are getting object expected error.
ClientScript.GetPostBackEventReference(this, "");
You can use PageMethods.Your C# method Name in order to access C# methods or VB.NET methods into JavaScript.
Try this:
if(!ClientScript.IsStartupScriptRegistered("window"))
{
Page.ClientScript.RegisterStartupScript(this.GetType(), "window", "pop();", true);
}
Or this
Response.Write("<script>alert('Hello World');</script>");
Use the OnClientClick property of the button to call JavaScript functions...
You can also get it by just adding this line in your JavaScript code:
document.getElementById('<%=btnName.ClientID%>').click()
I think this one is very much easy!
Please try this:
<%= Page.ClientScript.GetPostBackEventReference(ddlVoucherType, String.Empty) %>;
ddlVoucherType is a control which the selected index change will call... And you can put any function on the selected index change of this control.
The simplest and best way to achieve this is to use the onmouseup() JavaScript event rather than onclick()
That way you will fire JavaScript after you click and it won't interfere with the ASP OnClick() event.
I try this and so I could run an Asp.Net method while using jQuery.
Do a page redirect in your jQuery code
window.location = "Page.aspx?key=1";
Then use a Query String in Page Load
protected void Page_Load(object sender, EventArgs e)
{
if (Request.QueryString["key"] != null)
{
string key= Request.QueryString["key"];
if (key=="1")
{
// Some code
}
}
}
So no need to run an extra code
This reply works like a breeze for me thanks cross browser:
The __doPostBack() method works well.
Another solution (very hackish) is to simply add an invisible ASP button in your markup and click it with a JavaScript method.
<div style="display: none;">
<asp:Button runat="server" ... OnClick="ButtonClickHandlerMethod" />
</div>
From your JavaScript, retrieve the reference to the button using its ClientID and then call the .Click() method on it:
var button = document.getElementByID(/* button client id */);
button.Click();
Blockquote