I have a page where a user can upload a file along with some other input. Because I wanted this to be AJAX-like, I resorted to using an iFrame to accomplish this.
After the file is uploaded and an iFrame is loaded with a response page, I need to update a DIV outside of the iFrame with an AJAX call. The reason for separate updates, is that the result of the outside DIV depends on the input that the user provided with the file input.
Can this be done? Am I approaching this the wrong way?
Thank you!
UPD: Can the returned client code from within the iFrame "see" elements outside that iFrame?
Write your code in the onload event of the page loaded into the iframe. Then top will give you the top frame or parent will give you the parent frame.
Yes , it can be done. But you can do away with,the need for an AJAX-call , to update the outside the div.
Have your, servlet(assuming you are using JSP/servlets) that accepts the mutlipart request(the servlet that accepts the upload), return the intended response (to be shown on the refreshed iFrame), and ALONG WITH IT, the necessary information from the file input. This way you have all the necessary details on the client, in one response. A simple javascript function can achieve , updating the outer div with the information from the file input.
Related
I have a custom component (that is, an xhtml file with ui:composition inside) where I have a file upload field. When a file is selected it is uploaded via AJAX like this
<uc:fileUpload
id="#{id}fileUploadComponent"
idSuffix="#{id}fileUploadSuffix"
value="#{fileUpload.docsFilePart}"
accept="#{fieldWrapper.acceptedFileTypes}"
widgetVar="#{id}documentUploadWidget"
nullAllowed="#{!((fieldDef.mandatory and
fieldWrapper.getCurrentFileCount() lt 1) and isSaving)}"
maxSize="#{customField.maxFileSize}" >
<f:ajax listener="#{fileUpload.uploadNewFile(fieldWrapper)}" render="#{localId}fileUploadMain messages"/>
</uc:fileUpload>
Below this upload there's a <div> with the same id as specified in the render attribute of the ajax call, where links for downloading the files are shown. What happens is weird - after a file is selected, it is uploaded, the <div> is updated correctly with a link to the newly uploaded file. However when I click "Cancel" or "Save" on the page, their according actions are called, a correct response is returned to the browser (with status 200) but the browser seems to ignore it - the page is not visually updated or anything...
The custom component is quite big piece of code with not-so-easy-to-rewrite logic so replacing it at this point will be... hard...
One thing to not might be that uploading the file happens in a separate controller, while the main page controller is another one. This is because the separate controller is supposed to handle uploads from the custom component.
I can't really understand what exactly happens, even less why, and I'll appreciate any ideas!
For what it's worth, I am using Mojarra on Wildfly 11 (the one provided by the AS)
As it turns out, the reason is that file uploading via JSF AJAX causes the creation of an iframe called "JSFFrameId" and that frame being set as the target of the nesting form. After the AJAX request completes the target is not removed/cleared thus causing responses to go into that iframe and breaking the view.
At this point I am not sure what causes this, but a workaround for me is to have onevent in the <f:ajax> definition, that clears the form target, like this:
<f:ajax
listener="#{fileUpload.uploadNewFile(fieldWrapper)}"
onevent="function(e){if (e.status == 'complete') { $(e.source).parents('form').attr('target','');}"
render="#{localId}fileUploadMain messages">
I will check what other states may need handling but basically this solves the problem. It may be useful if someone shares their suspicions on what may have caused JSF to leave behind this iframe and not reset the target of the form.
For a website, which doesn't use AJAX I'm using OnDocumentComplete event to know when the page loading is complete.
My question is, how can I detect when website, which uses AJAX requests is ready (e.g. when a website which is fetching some search results by using AJAX finished its work) ?
Ok here is a trick i developed my self.
1-in your html page make a div and set its text to "false".
2-in you server side put a javascript at the end of your returning code. for example your site returns following text upon an ajax call.
a
b
c
d
e
so after this text put a javascript code that will change the text of div from "false" to "true"
so what will happen is that once you receive all the data from ajax call you will also receive the javascript code and that code will run and set the value of div.
so in your page once all data is received you will see the indicator div. and you will know that you have received all data. you can also run functions in similar way upon completion of data.
Imagine I define video-type node, which displays for example a title and description, along with the video itself. And imagine I have a block of video teasers, where each teaser links to one such video node. And imagine this block is added to the bottom of any page displaying a video-type node: when the user clicks on one of the video teasers, the page reloads with a new video-type node.
Finally, imagine all of the above but without having to reload the full page.
If you go to http://whitehouse.gov/video, you will see what I am trying to accomplish. When you click on one of the video teasers, the url changes to the url for the new node, but the full page does not reload. Only the top section of the page, displaying the new node, gets reloaded.
My question: How do they do this?? How can I load the node content into a particular div on page, without reloading the entire page?
You can use hook_menu to implement a MENU_CALLBACK to it's own handler function in Drupal. You would return JSON or XML or an HTML fragment or whatever you want with the HTML for the new video. Then use JS to update the DOM with the new content received from the server. Updating the URL can be done with JS as well.
So basically you are going to handle video clicks on the client side with JS. The JS would make a request to your MENU_CALLBACK and you would receive whatever data you choose to implement back from the server. JS takes the data and updates the DOM.
With something like jQuery, you could use the $.get method and use the success attribute to update the window history in modern browsers.
After I load a page through a WebBrowser, and I click a link that fires an AJAX script, I need to detect when the AJAX java script finishes loading HTML changes into a div. Since no DocumentCompleted event is fired when the AJAX script is run, I don't know when it finish running. Is there a way I can attach an event to be raised after I know 100% that the javascript finished changing the div?
The project is in C#.
Thanks
I did something similar recently (using jQuery):
$('#mydiv').change(function(){
// do stuff
}
);
Granted, I also use jQuery to set the HTML of that div. I suppose one non-jQuery approach for you could be to set HTML through your own function, which in turn can fire an onchange event.
#New in town: From my experience that is not correct. I use this on multiple DIVs that never get focus in the first place, and it works well and consistently. The normal behavior is as you describe, and normally only applies to the INPUT and SELECT elements, but this is not the case with jQuery.
There is no event. You must patch the JavaScript callback that the browser runs when the reply for the AJAX request comes in. This will contains code like "div.innerHTML = ...". Just put your code below that.
Good day,
I was wondering if there is a way to make Ajax move on to the next code segment only when all the elements included in the server-side code page are fully loaded. When the retrieved data is text-only there’s no problem, but sometimes there are photos included.
This is part of the code I have been using:
xajx.onreadystatechange = function(){
if(xajx.readyState==4){
document.all.div1.innerHTML = xajx.responseText;
document.all.div1.style.display = “”;
}
}
The thing is that when the response is retrieved (readyState set to 4) and div1 is displayed, the Photo has not been completely loaded yet, so actually the user can see the process of the picture slowly appearing, as he would in any other “normal” case. What I want to do is making div1 available for display only once all the components are fully loaded while meanwhile the system does its stuff in the background. Before Ajax I used hidden iframes like everybody, so I could enclose an onload event handler within the iframe tag (or in an external script), so div1 would appear only after the iframe has fully loaded, photos included.
Any idea?
You can use the 'onload' event on images themselves. You'll need to work out how to attach that event when you are downloading the code dynamically as in your case.