Summary of my website: A user fills in some information which after hitting "submit" the information is submitted to the backend via AJAX. Upon the back end receiving the information, it generates a DOCX using the information and serves that DOCX file back to the user.
Here is my AJAX Code in my HTML File
$.ajax({
type:'POST',
url:'/submit/',
data:{
data that I submit
},
dateType: 'json',
success:function() {
document.location = "/submit";
}
})
My Views Function for /submit/ that uses send_file to return file
def submit(request):
#Receive Data
#Create a File with the Data and save it to the server
return send_file(request)
def send_file(request):
lastName = get_last_name() +'.docx'
filename = get_full_path() # Select your file here.
wrapper = FileWrapper(open(filename , 'rb'))
response = HttpResponse(wrapper, content_type='application/vnd.openxmlformats-officedocument.wordprocessingml.document')
response['Content-Disposition'] = 'attachment; filename=' + lastName
response['Content-Length'] = os.path.getsize(filename)
return response
This has worked flawlessly for sometime now. However I started having problems when I increased the amount of "web-workers"/processes from 1 to 4 in my hosting account. Whats happening is a different web-worker is being used to send the file, which is creating a new instance of the site to do that. The problem with that is that the new instance does not contain the file path that is created with the web worker that creates the file.
Like I said, this worked flawlessly when my webApp only had one "web worker" or one process. Now I only have roughly a 50% success rate.
Its almost like a process is trying to send the file before it has been created. Or the process does not have access to the file name that the process that created it does.
Any help would be much appreciated. Thanks!
Code Trying to send path_name through request and then back to the server.
Submit View returning file info back to ajax.
def submit(request):
# Receive DATA
# Generate file with data
lastName = get_last_name() +'.docx'
filename = get_full_path() # Select your file here.
return HttpResponse(json.dumps({'lastname': lastName,'filename':filename}), content_type="application/json")
Success Function of AJAX
success:function(fileInfo) {
name_last = fileInfo['lastname']
filepath= fileInfo['filepath']
document.location = "/send";
}
So can I get the fileINfo to send with the "/send" ?
Each web worker is a separate process. They do not have access to variables set in another worker. Each request could go to any worker so there is no guarantee that you'd be using the file name that was set for a particular user. If you need to transfer information between requests, you need to store it outside of the worker's memory - you could do that in a cookie, or in a database or a file.
Related
I was trying to download this data from the website.
https://www.nseindia.com/market-data/oi-spurts
How can scrape this using python?
The JavaScript function downloadCSV is part of gijgo.min.js. It invokes getCSV, which goes through the fields in the table and generates a CSV file on the fly.
Fortunately, you don't have to deal with CSVs or scraping anything from the page. To get the data you want, all you have to do is make an HTTP GET request to the same RESTful API that your browser makes a request to when visiting the page:
def main():
import requests
url = "https://www.nseindia.com/api/live-analysis-oi-spurts-underlyings"
headers = {
"user-agent": "Mozilla/5.0"
}
response = requests.get(url, headers=headers)
response.raise_for_status()
data = response.json()["data"]
print(f"There are {len(data)} items in total.")
print(f"The first item is:\n{data[0]}")
return 0
if __name__ == "__main__":
import sys
sys.exit(main())
Output:
There are 143 items in total.
The first item is:
{'symbol': 'MOTHERSUMI', 'latestOI': 7182, 'prevOI': 4674, 'changeInOI': 2508, 'avgInOI': 53.66, 'volume': 12519, 'futValue': 53892.6066, 'optValue': 3788085280, 'total': 55585.0344, 'premValue': 1692.4278, 'underlyingValue': 104}
>>>
One way to find the final download link to a certain file is to open the debugger of your web browser and to click on the download link while looking into the Networking tab of the debugger.
Normally you will see the request the javascript of the page called as same as the url, the content of the request and so on...
From here you just need to replicate what request was sent by the javascript.
So I have three different separate files:
functions.php (all functions for the database)
main.html (my main program)
main.js (all javascript functions)
Now, I want to call a function in PHP through AJAX. To do that, I need to pass $conn.
$conn = sqlsrv_connect($serverName, $connectionInfo);
It's a resource, so I can't use json_encode.
The way I set the everything up now is that the php-file is required in the html so I can use the functions and when I change the
value of a dropdown, the js is called.
How can I pass the $conn variable to Javascript?
Regards
It doesn't work like that.
You should never be directly making calls to the database from the front-end.
Think of it as three separate levels. Your HTML/JS is the front-end, your PHP is your server, and your Database is on its own level.
So when the user does something on the front-end, say changes the value of a field and you want to update that in the database the following actions should happen:
Event triggers on JS
AJAX is called as a result of the event being triggered
PHP server receives the AJAX request and executes code to modify database
(optional) PHP server sends something back to the front-end to tell it that the request was successful
Read up on the concept of MVC: https://developer.mozilla.org/en-US/docs/Web/Apps/Fundamentals/Modern_web_app_architecture/MVC_architecture
Try this in php code as I assume functions.php
$conn = sqlsrv_connect($serverName, $connectionInfo);
echo $conn;//Don't try echo anything other
In Javascript
$.ajax({
type: "POST",
url: "functions.php",
success: function(data)
{
var conn = data; // here is your conn which comes from php file
}
});
First of all include jquery latest version from cdn
Create an API Url, and use POST method
site.com/api/insert.php // to insert into table
Use $.post() api of jquery to send data
var url = ""; // enter your URL HERE
var postData = {}; // object of post data with table name, cols and values
$.post(url, postData, function(data, status) {
// do what ever you want with data
})
ps: you can also create diff insertion / selection / update / delete api for different table. (recommended)
Read more about $.post() here
I want download the file from server (I knew that we can't use AJAX, and serve is Servlet) and which dynamically generate according to the parameters.
Now I have the parameters in format JSON, like:
{"limitTo":"name","searchFor":["AAA","BBB","CCC"],...}
So, how can we send the request to the server with those paraleters? Do we need create some inputs?
Thanks, I found the solution which uses dojo/request/iframe, without window.open
And the code likes :
require(["dojo/request/iframe"], function(iframe){
// cancel the last request
iframe._currentDfd = null;
iframe("something.xml", {
handleAs: "xml",
data : "your json"
}).then(function(xmldoc){
// Do something with the XML document
}, function(err){
// Handle the error condition
});
// Progress events are not supported using the iframe provider
});
And then we can see download window.
Here is an article about dojo/request/iframe
I'm brand new to express and node, so please bear with me :D
i have an index.ejs file. I need to pass a string from my index.ejs file, to my viewActivity.ejs file. That string will then be used in the javascript portion of my viewActivity.ejs file. I'm not really sure how to go about this though. Is what I want to do even possible? Or do I have to do this via another file and not just directly view to view ?
here is my code. I want to pass the "stringToPass" to another view when a button is clicked.
function getPosts() {
var query = new Parse.Query(Post);
query.find({
success: function(results){
for (var i in results) {
var title = results[i].get("activityTitle");
var stringToPass = results[i].id
}
}, error: function(error) {
console.log("Query Error:"+error.message);
}
});
}
So far I've learned that express acts as the request handler. E.g.: pass you the file or anything based on the given request.
As soon as the request has been finished being handled, express would not know what the client does with the given result. Hence, once it sent the html file or json file or other request has been responded, all the remaining activities will be handled by a client side script that talks back to the express server in other form of requests. UPDATE: you can make this client side script to extract a DOM element and pass it onto your follow up request (when a user click a submit button, etc) that is handled by a different route.
I have very similar problem as this: Allowing users to download files - ASP.NET , but in my case I am generating xlsx file with ajax, and on ajax-called aspx page I am using:
Response.Clear();
Response.ContentType = "application/octet-stream";
string filename = User.Identity.Name + "_Report.xlsx";
Response.AddHeader("Content-Disposition", "attachment; filename=\"" + filename + "\"");
Response.WriteFile(AppDomain.CurrentDomain.BaseDirectory + "Reports\\" + filename);
Response.End();
When this file is generated, control is returned to ajax calling page and from there I wan't to show save file dialog based on this ajax response and allow user to download this generated file. I don't want to save file on disk with ajax called page and then redirect ajax calling page to that file, because of popup blocker in IE. I am using jquery for ajax calls:
$.ajax({
type:"POST",
url: "AjaxReport.aspx",
data:dataString,
success: function(data) {
//don't want to use this
// $('#RedirectIFrame').attr('src','Reports/Report.xlsx?cache='+Math.random());
//want to use data variable containing ajax response (bytes of Report file) showing
//save dialog to download this file from browser
}
});
How to do this?
Currently JavaScript can't access to the user's file system, meaning you can't prompt users to save a file coming from a network stream.
In other words. You'll need to do that redirect and write your file stream to the HTTP response and let the user decide what to do :)