it would be awesome if someone could help me with this - I've already spent more than a day on it. :(
In a phtml file in Magento, I'm displaying a long list of products with a checkbox next to each. I've already added some code to paginate this list. The problem is, when I move to say page 2, I need to 'remember' which boxes were selected in page 1, and select them when I move back to page 1. I know how to use javascript to detect if a checkbox is checked or not. I was planning to save an array of selected boxes in the magento session - adding to it when more boxes are checked and deleting when boxes are unchecked. But my session-changing code is PHP, and my checkbox-detector is javascript. I know I can't call my session-changing function from javascript - I've been told that I would need AJAX to do this. I don't know any AJAX at all. Is there any other way to do this?
I'd be happy to post relevant snippets of my code if anyone can help me. Thanks!
UPDATE:
Okay, so I decided to use AJAX after all, and I've added a lot of AJAX code already. The problem is, it's not working. Btw, I'm not using jQuery. When I write this in Magento:
xmlhttp.open("POST", 'adjust_session.php', true); xmlhttp.send(params);
exactly where do I need to put my adjust_session.php file? It's not working if I put it in the same folder as my phtml file (where I'm calling the open function).
Thanks!
How are you actually doing the pagination? If you have to make a round-trip to the server for the paginated data anyway, send a list of checked/unchecked with it and toggle in the session. Then, when rendering the new page, either check the boxes in the HTML directly, or just pass a list of currently checked boxes in as JS and parse it on the response.
Alternatively, if you are doing everything on one page (and using AJAX for pagination already), you could also hold onto an array in JS and recheck the boxes after you render them.
Hope that helps!
Thanks,
Joe
Related
I have a page with a list of blog posts.
What would be the best way to open the post content on the same page in a modal, without redirecting to the single post page?
What I thought it's to make it in vanilla JS, to have an event on each post, have the data for all the posts in some array or each inside an attribute and when the event is triggered, fill the data for that post in the modal and show it. Maybe I can use AlpineJS for this.
Seems rudimentary to have it in vanilla, is there a better way to do it?
I also thought about Livewire, but I'm afraid it will be slow, have looked on some videos on YT, and when the button was clicked, it was visible when the data was filling in, looked slow.
Have thought also to make API calls, but I'd have to make the authentication work on that specific route, which would complicate it too much I guess, since it's going to be used just for this page.
What are your thoughts, how would you do it?
All your suggestions would work. Just depends on what you prefer and are able to implement. Also, think around opening the Post content in a modal, how much data do you want to load in the modal? Such questions will assist in you deciding the best way to design the post page.
Okay I do not know how to explain this to you, It may be just my internet, or maybe my site is slower, or they really have a technique for doing this.
If you visit Facebook, Reddit, Youtube, Twitter, and if you click on links or any actions on those websites, the url changes but the browser tab doesn't show any loading circle.
How do they do that?
I am pretty sure my website is fast enought and at times it loads even faster than the bigger sites, but mine shows the loading circle on the browser tab.
Okay so I found the answer. Here is the technique for changing the url without reloading the page.
Updating address bar with new URL without hash or reloading the page
How do I modify the URL without reloading the page?
I am still trying to figure out though how to redirect the actual page without reloading the entire page. I am guessing they are loading it via ajax or something similar upon url change. I'll update this once I figure it out.
Edit: I am currently working on this feature for my site. The technique is to use ajax to load the content based on the url. I'll update this thread more as I update my site with this feature.
Edit 2: Damn, you will probably face the same problem I had trying to detect the url change without using onhashchange. If so, here you go:
How to detect URL change in JavaScript
This literally took me 4 hours just to figure that one out.....
Edit 3: I have now integrated this feature on my site. You can check it at
Grandweb
It is quite simple, but lots of work in appending the content once retrieved via ajax. So here is the process:
I am using pushState(); to change the url without reloading the page.
var url = $(this).attr('href');
var split_url = url.split('/');
var new_url = url.replace('https://grandweb.net/','');
window.history.pushState("object or string", "Title", "/write");
Using 'mouseup' was a bad idea, I changed my mind.
I then have to trigger the first function using 'mouseup' to retreieve the content via ajax, and then listen to succeeding onpopstate() for the next ones, because some mouse actions such as Mouse 4 or Mouse 5 are bound to the browser's Back and Forward button, and does not trigger via 'mouseup'.
$(window).on('mouseup', function(evt) {
get_content();
}
window.onpopstate = function(event) {
get_content();
}
The first one is responsible for triggering the function on first try because onpopstate only listens only when the browser's history API is populated.
Using mouseup was a bad idea, basically, don't use it unless you really want to detect mouse action from anywhere on the document.
I instead use the anchor tags/links to trigger the first function for retrieveng content.
example:
<a class="dynamic_btn" href="website.com/post">Home</a>
then
$(document).on('click','.dynamic_btn',function(e){
e.preventDefault();
get_content();
});
Using onhashchange is possible IF you have hashes on your url. I do not use hashes on my url so basically onhashchange is useless in my use case, unless I do not know something.
After retrieving the contents, I append them via creating DOM elements to existing containers from the page.
This is much easier to do if you are planning to change few elements or containers in your pages. If you plan on doing this to change a full page layout, goodluck. It's doable, but it's a really pain in tha *ss.
Upon observing Facebook, I learned that they do not implement this technique in all of their links/features. It makes sense because this is harder to maintain most especially because most of the work here is being done client side. It is very nice though because the page doesn't load.
I have implemented it on a few 'essential' functions of my website such as the viewing of posts and returning to the homepage. I can implement it on the whole site, but I am still deciding on that. That is all, thank you very much for reading internet stranger.
On my page I would like to output all records of a specific folder
but the number should initially be limited to a certain quantity (to reduce the loading times). With a "Load more" button further records should be loaded.
Does anyone have a hint on how I can achieve this?
I have already found several approaches on the web in connection with AJAX, but since I'm not familiar with this yet, more questions than answers have emerged ...
For info: I use an own Template Extension / Distribution under Typo3 9.5.8
Thank you in advance for any help!!
The state of the art solution is the AJAX solution, where you load only the required records from the server and modify the page on the fly.
Another option would be an URL parameter which is evaluated by your extension.
With the parameter the full list is shown,
without only the first N and a button with the link to the same URL including the parameter for the full list.
Make sure the paramter is handled correctly and generates another cached version of the page. (keywords: cHash)
As you now have two pages with partially identical content: don't forget to tell the searchengines that the short variant should not be indexed.
You could use the Paginate Widget like documented here: https://docs.typo3.org/other/typo3/view-helper-reference/9.5/en-us/typo3/fluid/latest/Widget/Paginate.html
By overriding the paginate template file and only rendering the pagination.nextPage link, you could load the nextpage via AJAX.
In my app I have a list of products and when you click on a product, a Fancybox opens to show the product details.
Now when the user closes the Fancybox, I change the URL back from '#/product-name' to '#' and the list of products is rendered again, even though it is already there.
My question is:
How do I avoid the product list from being rendered again?
So somewhere either in the list action of my controller or the list view I want to check if the product list is already rendered and don't render it again.
It feels like something that should be possible to accomplish quite easily but I can't get it right.
All ideas appreciated!
EDIT: edited for clarification
Have a look at backbone:s saveLocation method. It doesn't trigger a hashchange event.
You only need to change the hash part of your url.
window.location.hash = ""
the problem I have is that I have two sets of values in a drop down list. If type 'A' is selected I want a text box to be populated with a value from the database and be read only. If Type 'B' is selected the box is to be empty and editable.
My original code is written in jsp/struts and I have sort of achieved this by using
onchange="javascript:submit()" to reload the page, but this has the obvious drawback of saving any changes you have made which means you can't really cancel.
I also have other problems with the serverside validation due to this method.
Is there a way of making a jsp page reload on change, that way I could write javascript to change the way the page looks according to the values held in the session. That way the save/submit function will only be called when the page has properly been filled out and the server side validation will work as designed.
I know that this is something that AJAX is good at doing but I am trying to avoid it if possible.
AJAX is your only other option my friend, unless on the original page load you load all the other possible values of the Text Box so you don't need to go back to the database. Well, you could try putting the text box in an IFRAME, but you will probably run into more problems with that approach than just going with AJAX.
Without AJAX what you are asking is going to be difficult. Another option (which is ugly) is to write out all possible values for the second list box into a data structure like an array or dictionary.
Then write some javascript to get the values from the data structure when the user selects from the first list box. The amount of javascript you will have to write to get this done and to do it correctly in a cross browser way will be much more difficult than simply using AJAX.
Not sure why you'd try to avoid AJAX in today's world, the JS libraries out there today make it so simple it's crazy not to try it out.
I just had to replace a page that was written as Vincent pointed out. I assume at the time it made sense for the app, given the relative size of the data 4 years ago. Now that the app has scaled though, the page was taking upwards of 30 seconds to parse the data structures repeatedly (poorly written JS? maybe).
I replaced all the logic with a very simple AJAX call to a servlet that simply returns a JSON response of values for the 2nd drop down based on what was passed to it and the response is basically instant.
Good luck to ya.
One way is to change the form's action so that you submit the form to a different url than the "save" url. This lets you reload certain aspects of the form and return to the form itself, instead of committing the data.
<script>
function reload() {
document.forms[0].action="reloadFormData.jsp";
document.forms[0].submit();
}
</script>
<form action="saveData.jsp" method="post">
<select id="A" name="B" onchange="reload()"><!-- blah --></select>
<select id="B" name="B"><!-- blah B --></select>
<input type="submit">
</form>
If I understand you correctly, that you want either a dropdown (<select>) or a textfield (<input type="text">) depending on a choice (typically a checkbox or radiobuttons) somewhere above in a form?
I that case you may need to handle the two types of input differently on the server anyway, so why not have both the selectbox and textfield in the area of the form with different names and id and one of them hidden (display = none). Then toggle visibility when the choice changes. On the server you pick eiter the selectbox or textarea input (wich will both be present unless you disable (disabled="disabled") them too, wich I think is uneccesary) depending on the choice input.
Of course if you expect that the user usually just need the text-input, and a few times only, needing a massive list; it would be better to use ajax to retrieve the list. But if it's the other way around (you need the text-field only occationally), as I assumed above, it will be faster to have both present in the initial form.
If the drop down only contain easily generateable data, like years from now to houndreds of years back it could even be much faster (requiring less bandwidth on the server) to generate the data client side using a for loop in Javascript.
I know a taglib that can fit to your problem:
AjaxTags.
I use this taglib in my J2EE projects and it is very simple to integrate it into web applications.
This taglib give you several tags designed to execute AJAX request in your jsp files.
Here is the description of each tags: http://ajaxtags.sourceforge.net/usage.html
The tag which will help you is the ajax:select tag. It allows you to populate a select tag which depends on an other field without reloading the entire jsp page.
If you more informations about it, ask me and i'll try to answer quicky.
Along the lines of what Strindhaug said, but if you need dynamic data:
Could you have the backend write JS into the page, and then the JS would change the form as required? The backend could propagate some variables for descriptions and such, and then the JS could change/update the form accordingly. If you aren't familiar with this, libs like jQuery make things like this easier and more cross-browser than rolling-your-own (at least in my experience).
Aside:
If you're not using AJAX because it was hard to code (as I didn't for a while because my first experience was from scratch and wasn't pretty), as others have said, libs like MooTools and such make it really easy now. Also, there is not shame in using AJAX properly. It has a bad rap because people do stupid things with it, but if you can't simply write premade values into the form or you have to do live look ups, this is one of AJAX's proper uses.