I am using PHP and JavaScript in my application.
I want to delete entries from the database, a process which requires a significant amount of time, thus I would like to report the progress to the end-user.
I'd like to know how to achieve this, could anyone explain the theory to me?
You need 2 scripts:
First for delete
Second for status
First make a request to the first script, and then make a second request to the second script that will report you a progress.
Then you can use any of the jQuery plugin to display the progress bar.
Related
I am trying to make it so users can enter text files and a short message near it and it will be visible for everyone. I am using PHP and SQL (MariaDB/MySQL for the database) and I want it so every like ten for example inputs it will make a new page. So for example if there is ten files up on the page then if someone puts another one in it will automatically make a page two and have the oldest file submitted be there. How can I do this. I have seen other sites use a GET method and have it be something like ?page=2 . How can I do this myself?
What you're looking for is "Pagination".
Pagination using MySQL LIMIT, OFFSET
Though that can look a bit scary at first. However, if you use a framework such as Laravel it can easily be done, see:
https://laravel.com/docs/8.x/pagination#introduction
I am using PHP and AJAX requests to get the output of a program that is always running and print it on a webpage at 5 second intervals. Sometimes this log file can get up to 2mb in size. It doesn't seem practical to me for the AJAX request to fetch the whole contents of this file every 5 seconds if the user has already gotten the full contents at least once. The request just needs to get whatever contents the user hasn't gotten in a previous request.
Problem is, I have no clue on where to begin to find what contents the user hasn't received. Any hints, tips, or suggestions?
Edit: The output from the program starts off with a time (HH:MM:SS AM/PM), everything after has no pattern. The log file may span over days, so there might not be just one "02:00:00 PM" in the file, for example. I didn't write the program that is being logged, so there isn't a way for me to modify the format in which it prints it's output.
I think using a head request might get you started along the right path.
check this thread:
HTTP HEAD Request in Javascript/Ajax?
if you're using jquery, it's a simple type change in the ajax call:
$.ajax({url: "some url", type: "HEAD".....});
personally, I would check the file size & date modified against the previous response, and fetch the new data if it has been updated. I'm not sure if you can fetch only parts of a file via ajax, but I'm sure this can be accomplished via php pretty easily, possibly this thread may help:
How to read only 5 last line of the text file in PHP?
It depends how your program is made and how does it print your data, but you can use timestamps to reduce the amount of data. If you have some kind of IDs, you should probably use them insteam of timestamps.
I'm new here and I'm very new at programming but I need some serious hand-by-hand help here.
I was searching jquery and found a script to drag and drop stuff on the screen, basicly i just want to move some divs around, thats the easy part, the script I found has a callback function that writes onto the div that you just moved "dropped", this is exactly what I need but instead of writting dropped I want to save the 2 postion variables into a database (mysql), this is so that if I close the browser and open it again the div's will be on the last place I dropped them.
Can you help? Is there a jquery user interface with this already built in ?
I think this is easy to do with jquery ajax functions right? basicly I should send the serialized data (json right?) into a page that processes that data once its feed into it, then jason returns the handler with success or even with some output right?
It would be cool for the dragabble div to have a handler with last know position retrieve by jason from an external page that acts like a buffer to the database.
Is this the correct pipeline?
Best Regards
Joricam
you have kind of a vague question here, but I can try to help you get closer to the answer.
Imagine two sides of the puzzle:
When the page loads, the two (or more) DIVs are drawn on the screen. If you want them to draw in a specific order, you need to keep track of that in the database. So be sure your db has a field called something like display_order, and then display the DIVs in that order. (You can usually just add ORDER BY display_order to the SQL, so they are retrieved in the order you want, and then draw the DIVs right out in a loop.)
When someone drags and drops a DIV, you use AJAX/JSON/etc to tell your PHP script the new order. In this case, when that happens, rather than draw the word 'dropped' in the DIV, you should instead immediately update the display_order fields in the database. This way you are remembering each DIV's position.
Does that help/make sense?
UPDATED: thinking more about your question, here is the pseudo code:
in "display.php":
Fetch the contents for each DIV from the database, with ORDER BY display_order on the rows.
Draw them on the screen, looping through each database row.
Also in this HTML, use the jQuery script you already have to call another PHP script (dragged.php) when a row is dragged.
in "dragged.php":
This script is called when a row is dragged on the screen.
Currently it puts the word "dropped" in the DIV that is dragged. That's not helpful, so remove that.
Instead, you now know (from the variables passed to you) that a specific DIV needs to be in a specific place.
So grab a list of the DIVs from the database, then change the order of them (by altering the display_order column) based on the new position(s) you know.
Save that back to the database, so when display.php is called again next time, it draws the DIVs in the order you want.
Hope this helps explain further. If you are still struggling, I respectfully suggest you try to write the code, and post a more specific question about the part that you're stuck on. This will help you get a good answer quickly. (You may also want to Google this one a lot; I'm sure there are code samples out there showing how to do all this.)
I have a php code that fetches data from mysql. The data has (say) 15 rows. I want to display only 5 rows at a time to the user, with links to each of the set (3 in this case) such that when a user clicks on either of the links, the same page will show the corresponding results. Since, php code has the final result set, I don't want a solution that involves me to navigate to other pages and possibly re-calculate the next set of solutions (5~10 or 10~15). How can I do this? Thanks in advance.
If I am using javascript or ajax, how can I achieve this? I don't know javascript much.
You can try loading everything in your page and simulating the pagination thanks to javascript.
An example in jQuery here
It sounds like you want to send the Data as a complete set to the client but not let him display everything to the user. So use Javascript to just show you the pages 1*page_number to 5*page_number (with a for-loop).
By far, the easiest solution in this situation is a Dom-based Grid system. I recommend checking out Datatables. In essence, the Datatables code will take a fully-formatted html table and reformat it to include only the amount of rows you tell it to, with paging on the bottom as you've requested. In addition, you can turn on such features as filtering, toggle-able length, sorting, and selection. Once you get the hang of it, the additional code takes no more than a minute per table and the features are outstanding.
This is really straightforward. Use PHP to output ALL of the table, with all the rows. The only gotcha here is to include the full html, including <thead> and <tbody> Give the table an id such as "example"
Now, include the files that you download from the datatables site--datatables.js and Jquery.js. Instantiate the jquery like this:
$(document).ready(function() {
$('#example').dataTable();
} );
That's it. As you can see from the examples, it's a really cool tool. Good luck.
I've got a script in php that continually grows an array as it's results are updated. It executes for a very long time on purpose as it needs to filter a few million strings.
As it loops through results it prints out strings and fills up the page until the scroll bar is super tiny. Instead of printing out the strings, I want to just show the number of successful results dynamically as the php script continues. I did echo(count($array)); and found the number at 1,232,907... 1,233,192 ... 1,234,874 and so forth printed out on many lines.
So, how do I display this increasing php variable as a single growing number on my webpage with Javascript?
Have your PHP script store that number somewhere, then use AJAX to retrieve it every so often.
You need to find a way to interface with the process, to get the current state out of it. Your script needs to export the status periodically, e.g. by writing it to a database.
The easiest way is to write the status to a text file every so often and poll this text file periodically using AJAX.
You can use the Forever Frame technique. Basically, you have a main page containing an iframe. The iframe loads gradually, intermittently adding an additional script tag. Each script tag modifies the content of the parent page.
There is a complete guide available.
That said, there are many good reasons to consider doing more pre-computation (e.g. in a cron job) to avoid doing the actual work during the request.
This isn't what you're looking for (I'm as interested in an answer to this..), but a solution that I've found works is to keep track of the count server-side, and only print every 1000/5000/whatever number works best, rather than one-by-one.
I'd suggest that you have a PHP script that returns the value in JSON format. Then in another php page you can do an AJAX call to the page and fetch the JSON value and display it. Your AJAX call can be programmed to run perhaps every 5 seconds or so depending on how fast your numbers output. Iframe though easier, is a bit outdated.