I need help in identifying how I should set up this non public website.
Basically there are around 2000 images referenced in a database.
Each user will be able to check or uncheck each image with the use of a checkbox.
Some users might have different images checked or unchecked.
I want the checkbox to process an AJAX request to a user specific XML (PHP generated from the db) which contains a boolean variable for each image entry.
The PHP then references the XML and highlights checkedboxes and disables the uncheckedboxes.
Again each user will have different references for each image.
Im not sure if the above is the correct method to use.
I want the page to dynamically load the first 20 images and if the checkbox is changed, instantly updated and refreshed without a page reload. Then I'll paginate to the next 20.
If I'm on the right track I'll attempt a demo and post an update.
Thanks,
Depends how you want to do it. You'll need to brush up on your javascript as well to track the on change event. If you're bring in the images with ajax to begin with I would create an object for each and attach the event to element. Then on click you could post the image_id or what have you to the server. Alternatively you could use an attribute on the checkbox/image like data-imageid="1"
JSON or XML, both will work, it just depends how you want to design it. Though from my experience I would use JSON instead.
The JSON array you would return might look something like {1:true,2:false,3:true} etc, so foreach key value pair you would either check it be it true or not on false.
Consider editing your tags for javascript or jquery to see if you get some better answers. Or I could elaborate further if I'm on the right track.
Related
This is the situation, I've got a big array ( 280 items ) which creates a really big form by going trough loops.
I want the user to be able to disable certain items, so they can 'pre make' their form ( and skip the not used ones ), You are probably going to say i can just remove what's not needed. But they need different items from the array every time they use it.
So how would i make a page where they can just use checkbox to 'change' the form. ( if possible at all.)
Thanks,
Mike
edit:
Did not think of sharing code, here:
The array : http://pastebin.com/EnwHsqtK
the form : http://pastebin.com/y2XSFBG4
the page which makes a .txt file from the given answers. http://pastebin.com/UaUcsj2z ( not sure if anyone would need this. )
Might be a bit messy. I'm new in PHP, and only programming for a year. Also dont mind the language please.
If you want to permanently record form preferences/settings for each user, you'd want to create an additional table or column(s) in your database for this, give the users additional checkboxes on the form to indicate their preferences, receive this input and store it in the database, and of course finally disable certain fields based on their settings.
But if you just want to give the users a temporary way to disable certain fields (with no preferences saved permanently), you would use JavaScript in your output. You would add more form controls (checkboxes or buttons or whatever) to the HTML and then add JavaScript code snippets into that HTML to disable form elements when the user clicked on the controls. This kind of making changes when users click is called "triggers that fire based on events". The most commonly-used event is called "OnClick()" and the JavaScript code for it will execute when a user clicks on something.
Many folks who use JavaScript also find it helpful to use the functions in the jQuery library instead of raw JavaScript. To do this, you just add one line of HTML to the top of your page to include the JavaScript libraries from a publicly-hosted server, then you can use jQuery commands in your page.
The only thing to remember when you first start using JavaScript/jQuery is that it only runs on the client browser - its code cannot talk directly to the server, the database, or many things you can access in PHP. JavaScript/jQuery is specifically used for making your HTML pages more interactive. Plain HTML doesn't have much razzle-dazzle. JavaScript allows users to do things like enable and disable form fields on-the-fly.
I am currently using Jquery UI to display checkboxes, which right now, don't do anything!
you can see the current set up here: rickymason.net/letschat/main/home/
I am still trying to understand JSON, AJAX and Javascript...but i know they are required to make this work:
When the user checks one, or more of the checkboxes, I'd like it to refresh the thread list at the bottom of the page based on which list is checked.
I don't need exact code (though the more the merrier!), just a good outline on the process that needs to take place.
I'm using codeigniter, thus php and mysql. The thread list is generated based on a * query for the threads table. Then, it is filtered based on a session variable which contains all active filters (user input, AND i'd also like it to be selectable via the jquery select box).
Any help is greatly appreciated!
The magic word here is AJAX.
Use jQuery to bind to the events of the form elements
Send the event through AJAX calls to the server
Parse the response from the server and use javascript to update the page
Okay I'm not really sure how to approach this. I have a user-generated post board where people post, it drops down onto a list of a bunch of posts. When you click on the ID number of the post it will bring you to a separate page with just that post and the comments on the post. I want it so when you hover over the href it drops down something that tells the user there are x amount of comments on this post. This way people know if there is comments without switching pages and also being able to be able to click the href still and go to the postid page.
I assume some ajax/jquery/javascript would be used to accomplish this but since I'm fairly new to ajax and jquery I'm not certain how this would be done. Thank you!
For a hover effect, it would be better if that information was already stored on the page and just hidden. Then when the user does hover, you can just un-hide it and have it positioned where you want, and then hide it again when their mouse leaves the area. Using AJAX requests for this purpose would waste away a lot of HTTP requests for such a tiny amount of information.
Really, you could do the hover effect using pure CSS if you wanted too (I would).
Since a hover happens fairly often, I wouldn't use it as the default event to fire an AJAX-request. This would increase the HTTP-traffic enormous. See if you can fetch this information when the page is build (and put it in then) or use something else like a "preview"-button for the event.
Anyways, this would be the basic workflow if you want/need to use AJAX:
Write a PHP-script (or any other language you use) which fetches the number of comments (and what else you want to display) from the database (or where your data is stored).
This script should then be called via AJAX (with $.ajax() from jQuery for example). As the expected return-type you would then use json.
The script which fetches your data would then create an object, use PHP's json_encode()-function to encode this object to JSON and echo it out.
This JSON-object will then be available in the success-method of the ajax()-method from jQuery. Then, you can access its members (e.g. the comment-count).
This is more of curiosity that anything, but I can think of several places (mainly in admin sections) where this could be useful. I know the title is confusing so this is what I mean:
Say you have a form that posts to example_cb.php. example_cb.php is a very large callback page that generates multiple thumbnails of an image, puts them in their respective directories, adds them to a database, etc. You already have the form posting by jquery with a function like this
$.post('example_cb.php', $(this).serialize(), function(data) {
// Success
}, 'json');
Before posting it updates a div to say "processing" of something. Then after it successfully completes the div fades out. However you want the div to show what is happening on the server side. i.e. Converting 200X200 thumb > Converting 350x350 thumb > Adding Records to Database > etc.
How can you accomplish this?
I know it's a loaded question, but I'm confident there are people on here smart enough to figure it out. If you need more info please comment :)
You could do something like -
Write each 'event' update to a database table
Write a page that retrieves the last n events from table
Use something like 'load' to call page update an onscreen div
with the updated progress.
Use 'setTimeout` to keep updating.
This could be accomplished most easily with using the push method, but I'm not too familiar with ajax push or comet technology, so I'll give you a pull solution.
Basically you need to create the initial ajax request to start the processing. Then, you need to have another request running in a tight loop that checks against a php page for the current status. For example, on the php page doing the processing, you can update a _SESSION key that stores the current processing information (like "Converting 200X200 thumb") at each step. Another php page will exist purely to print that information and you can retrieve it with the JS running in a loop.
pusher like services may be used for bi-directional communication.
I'm putting it down for reference, though this would be overkill for such a simple scenerio.
I want to make a webpage where an user can add the title from a book he has read. These changes are reflected in real time on a list that contains all books he has introduced on the database, without the need to press any "reload" button. By example: there is no need to refresh (F5) the page to see the last book added.
I don't know if I can do this in PHP or in any other language, so I would like to know which is the best suited for something like this.
Thank you.
I think you are looking for Ajax. Would be able to asynchronously update the section of the page (the post in this case) without the need for page refresh.
You will want to do this with javascript, using the onchange event, and for a discussion on this you can look at: Call Javascript onchange event by programatically changing textbox value.
Basically, you react to the data being changed, then just send it immediately over using ajax to the server, but, you need to be aware of two things.
First, how will you handle errors, such as there is no book with that title, or the length is too long. I tend to put the error message in or by the place where they had the bad data.
The other is that you need to pass back the id when the data was inserted, so that when they change it again you can just do an update, so you will need to store that. I tend to put the database id I need in the element id, but you can keep it in an array in javascript, since it will maintain state for you.