i have stored values in mysql and i want to retrive that value in webpage
but the webpage is creted only using javascript
so how can i use that database's value in javascript
You need to have a server side script in the middle so you can retrieve the value using ajax.
What you're asking for is only possible with a restful nosql database like CouchDB.
You really need to give more information as to what you want to do, but as you implied that the page isn't dynamic the method would be to use ajax to request a dynamic page (written in a sever side langugage) that retrieves the data from the database and outputs it in the required format.
You'll need to either...
a) Have a separate, server-side script which can run the appropriate query, and then pass through the data to the page through an AJAX-type call (jQuery et cetera have functions to simplify the AJAX side of things, if you so desire),
OR
b) Put some server-side code into the page that is evaluated before the page is served and writes the data into the page within something that the Javascript can access it from (i.e. the definition of a variable or some such).
Related
I am now on a php page that has presented the user with some choices and I have saved the users input in 5 javascript variables:
product_format
product_print
product_paper_weight
product_paper_type
product_quantity
I want to send them to a a calculate.php page that will do the calculation of the price and then include calculate.php on my page and present the user with the price dynamically. I have read send javaScript variable to php variable
that I can use:
window.location.href = "calculate.php?name=" + javascriptVariable (and the rest);
And then I could use php get to calculate by querying the database. I also need this to be done continously as soon as the user changes an option I need to recalculate the price and present a new price.
Is this possible? Is there a better approach? Am I thinking right? Should I instead calculate the price by loading the php-sql data into javascript and calculate in javascript instead? Which is quicker and more secure?
The page http://www.reclam.se/trycksaker.php?product_id=1
This is a perfect application for AJAX. Much easier if you use jQuery, though you can do it in pure Javascript. Essentially, create a Javascript function that takes place when a field is changed (e.g., $('.product').change(function() { }); if you set class="product" on all the relevant input fields) and in that function use $.ajax to post the data to your PHP form.
You can do all the calculations in Javascript. If the data is dependent on database lookups or relatively complex math then AJAX makes more sense. If the calculations are very simple then you can embed the calculations directly in the .change function.
Using window.location.href= will cause a full page load, which does not sound like what you want.
As we all know this very well that php code runs on server side and javascript on client side. To transfer data between client and server, we need some kind of data transfer protocol and thats where Http comes in. You can send data to php server from client side either by Form or Ajax call with http get or post method.And once data are sent to php server, you can catch those data using php super globals $_GET or $_POST.
I have a variable in my JavaScript which contains the id of the clicked row in the master grid. I want to pass it to the groovy service page that handles my child grid so that it can filter the rows based on that id. How do I do that?
The problem is that your javascript-based grid runs on the client, while the page is rendered server-side. Therefore, some communication must take place in order to instruct your application to filter rows based on what the user selects.
Grails uses the MVC architecture, this means that there is a controller that takes care of answering the requests generated from the client. To answer these requests, the Controller can make use of the Views (.gsp files). So when you call to the URL controller/index you may make use of an index.gsp view to render your page.
What you need to do is to make an ajax call to a controller method (e.g. controller/getFilteredRows) that gets as input the selected row (could be its id) and based on some logic fetches all the required information and sends them back to the client encoded for example using JSON.
Now the client knows the rows it has to display, hence you can update your grid.
I have a page where people can login and their login request is sent with jQuery's $.ajax to a processing page. On that page all of the errors collected during the login attempt are stored in $_SESSION['error'].
How can I access this variable to alert users of the errors after the attempt is made. I know how to access a session variale, I mean how do I access a php variable without reloading the page. The only way I currently am aware of is to inject them on page load, but there must be some way to access them with JavaScript after they have changed due to an Ajax request.
Unfortunately you cannot directly access the PHP $_SESSION[] array from JavaScript. This is by design, because one of the major points of using a Session, is that the data is saved on the server side, unmodifiable by the end user, and therefore your Javascript.
What you could do however, is include the error list in your ajax response. Chances are you are doing an ajax request that returns a 'json' type format. Just include your error list in your json returned, and use the JavaScript to display them. I recommend not sharing the entire $_SESSION array, since it could give away some key information about the interworkings of your PHP.
Also, if you are not currently doing an ajax request that expects json, back, then consider switching it up so that you are expecting and returning json. You can provide much more hidden data this way, instead of just some HTML or text.
Hope this helps
I'm new to JavaScript and AJAX. My experience is mostly in PHP. How can you do a MySQL query from JavaScript without revealing in the View HTML Source of the web browser the connection information for the MySQL database such as the db user's password? Thanks!
You make your JavaScript request the information from a PHP script, which checks the user's login cookie (like any other page would) and queries MySQL, returning the information to the JavaScript in whatever form it needs (JSON, usually).
In this case you don't perform the actual database query from the JavaScript code. The fact that it's using AJAX doesn't move database connectivity to the client, it just allows you to request information from the server without refreshing the page (as well as potentially moving some of the UI logic to the client).
Your AJAX call would simply make a request to a PHP file in your website which could:
Render part of a page, where the JavaScript code from the other page which called it would insert that markup into the open page. Or;
Render data, usually in JSON format, which the JavaScript code from the other page would read and use.
So let's say you have PageA.php which has a bunch of HTML and JavaScript. You want some of that JavaScript to make an AJAX call to the server to get data. You'd create a PageB.php which behaves just like any other PHP code, but instead of using HTML between the PHP code fragments (or in echo statements) it would use JSON syntax to represent the data being returned.
The JavaScript code on PageA.php would make an AJAX call to PageB.php, read the data that's returned, and use it in the HTML of PageA.php entirely client-side without having to refresh PageA.php.
I'm building an ASP.NET MVC 4 website that needs to be available offline (HTML 5 manifests/caching), so I will be unable to take advantage of server side HTML generation.
Right now, I just have generic/cacheable HTML on the View (.cshtml) and I'm making jQuery AJAX calls on document ready to load the data from the server and using mustache.js to generate the HTML.
Being constrained to doing HTML generation only in the client side, I'm unable to use Url.RouteUrl to generate links and also constrained to having to parse the current URL manually when navigating to a details page, and using the Id (or whatever the parameter is) to make the AJAX call to retrieve the information for the specific record that I need.
Since I'm still using MVC URL Routing (and would like to keep using it) to return the corresponding View (as in, http://localhost:27954/Route/Test2/7?mytext=hellow), I'll need a javascript or jQuery function to both be able to parse URL's and retrieve the value for a given querystring parameter, and ideally another method to generate URLs.
Since I'm obviously not the first person in this situation, I was wondering if anyone had any proven methods already that they could share, or any recommendations.
Thanks!