I'm new to programming, I'm trying to build a web app using nodejs/expressjs.
so basically on the post route, after some processing on backend it gives an array of object in result variable, I want to use this result variable data and construct a table in html file and send this table.html file as a response to client
the problem I'm encountering is how can I use this result variable to add element of table in html file dynamically (since array size changes everytime )
approach i was using
i created table.html and table.js that is linked with same html file.. but when table.html is send as a response that html file and table.js file is rendered on client side and not able to pass the result value that i get from server to that table.js file ( i get a document not defined error)
i tried to use EJS template .. how to create a function that used ejs variable to loop through array data and show table.. i'm unable to do
if anyone can help me to show result=[{name:'james', id:23},{name:'joe',id:35}]
to html file as response
main.js
app.post('/dataTbale',(req,res) => {
// after some processing i get array of obj that i store in result variable
const result=[{name:'james', id:23},{name:'joe',id:35}];
res.send('table.html);
})
table.html
<html>
<body>
<h2>table</h2>
<div id="show_table"></div>
<script src="table.js"></script>
</body>
</html>
table.js
const tableDiv=document.queryselector('#show_tabel');
result.forEach((obj) => { //<==== i want to pass that result data here.
tableDiv.innerHTML += result;
});
P.S just want to know if this works then i can create table
You might use a template engine like (ejs) or any other template engines to show the dynamic data that returns back from the server and for the case that you want to render the results in different page you should store the data in any kind of storages like local storage or database to be able to use it in different places.
I use an html table where it's content can be changed with mouse drag and drop implemented. Technically, you can move the data from any table cell to another. The table size 50 row * 10 column with each cell given a unique identifier. I want to export it to .xlsx format with C# EPPlus library, and give back the exported file to client.
So I need the pass the whole table data upon a button press and post it to either a web api or an mvc controller, create an excel file (like the original html table data) and send it back to download with browser.
So the idea is to create an array which contains each of table cell's value ( of course there should be empty cells in that array), and post that array to controller.
The problem with that approach lies in the download, if I call the api or mvc controller with regular jquery's ajax.post it did not recognize the response as a file.
C# code after ajax post:
[HttpPost]
public IHttpActionResult PostSavedReportExcel([FromBody]List<SavedReports> savedReports, [FromUri] string dateid)
{
//some excel creation code
HttpResponseMessage response = new HttpResponseMessage(HttpStatusCode.OK)
{
Content = new StreamContent(new MemoryStream(package.GetAsByteArray()))
};
response.Content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
response.Content.Headers.ContentDisposition = new System.Net.Http.Headers.ContentDispositionHeaderValue("attachment")
{
FileName = dateid + "_report.xlsx"
};
ResponseMessageResult responseMessageResult = ResponseMessage(response);
return responseMessageResult;
}
Usually, for this kind of result I could use window.location = myurltocontroller to download properly , but that is only for GET requests, POST anything is not possible.
I found some answers which could help me in this topic:
JavaScript post request like a form submit
This points out I should go with creating a form, which passes the values, but I do not know how to do so in case of arrays (the table consists 50*10 = 500 values which I have to pass in the form)
I tried some only frontend solutions to the html-excel export problem, which of course does not require to build files on api side, but free jquery add-ins are deprecated, not customizeable, handle only .xls formats, etc.
I found EPPlus nuget package a highly customizeable tool, that is why I want to try this is at first place.
So the question is: how can I post an array of 500 elements, that the controller will recognize, generate the file, and make it automatically download from browser?
If you can provide some code that would be fantastic, but giving me the right direction is also helpful.
Thank you.
You can use fetch() (docs) to send the request from the JS frontend. When the browser (JS) has received the response, it can then offer its binary content as a download. Something like this:
fetch("http://your-api/convert-to-excel", // Send the POST request to the Backend
{
method:"POST",
body: JSON.stringify(
[[1,2],[3,4]] // Here you can put your matrix
)
})
.then(response => response.blob())
.then(blob => {
// Put the response BLOB into a virtual download from JS
if (navigator.appVersion.toString().indexOf('.NET') > 0) {
window.navigator.msSaveBlob(blob, "my-excel-export.xlsx");
} else {
var a = window.document.createElement('a');
a.href = URL.createObjectURL(blob);
a.download = "my-excel-export.xlsx";
a.click();
}});
So the JS part of the browser actually first downloads the file behind the scenes, and only when it's done, it's triggering the "download" from the browsers memory into a file on the HD.
This is a quite common scenario with REST APIs that require bearer token authentication.
I started to write a scraper for the site to collect data on cars. As it turned out, the data structure can change, since the sellers do not fill all the fields, because of what there are fields that can change, and during the scraper as a result in the csv file, the values are in different fields.
page example:
https://www.olx.ua/obyavlenie/prodam-voikswagen-touran-2011-goda-IDBzxYq.html#87fcf09cbd
https://www.olx.ua/obyavlenie/fiat-500-1-4-IDBjdOc.html#87fcf09cbd
data example:
Data example
One approach was to check the field name with text () = "Category name", but I'm not sure how to correctly write the result to the correct cells.
Also I use the built-in Google developer tool, and with the help of the command document.getElementsByClassName('margintop5')[0].innerText
I brought out the whole contents of the table, but the results are not structured.
So, if the output can be in json format then it would solve my problem?
innerText result
In addition, when I studied the page code, I came across a javascript script in which all the necessary data is already structured, but I do not know how to get them.
<script type="text/javascript">
var GPT = GPT || {};
GPT.targeting = {"cat_l0":"transport","cat_l1":"legkovye-avtomobili","cat_l2":"volkswagen","cat_l0_id":"1532","cat_l1_id":"108","cat_l2_id":"1109","ad_title":"volkswagen-jetta","ad_img":"https:\/\/img01-olxua.akamaized.net\/img-olxua\/676103437_1_644x461_volkswagen-jetta-kiev.jpg","offer_seek":"offer","private_business":"private","region":"ko","subregion":"kiev","city":"kiev","model":["jetta"],"modification":[],"motor_year":[2006],"car_body":["sedan"],"color":["6"],"fuel_type":["543"],"motor_engine_size":["1751-2000"],"transmission_type":["546"],"motor_mileage":["175001-200000"],"condition":["first-owner"],"car_option":["air_con","climate-control","cruise-control","electric_windows","heated-seats","leather-interior","light-sensor","luke","on-board-computer","park_assist","power-steering","rain-sensor"],"multimedia":["acoustics","aux","cd"],"safety":["abs","airbag","central-locking","esp","immobilizer","servorul"],"other":["glass-tinting"],"cleared_customs":["no"],"price":["3001-5000"],"ad_price":"4500","currency":"USD","safedealads":"","premium_ad":"0","imported":"0","importer_code":"","ad_type_view":"normal","dfp_user_id":"e3db0bed-c3c9-98e5-2476-1492de8f5969-ver2","segment":[],"dfp_segment_test":"76","dfp_segment_test_v2":"46","dfp_segment_test_v3":"46","dfp_segment_test_v4":"32","adx":["bda2p24","bda1p24","bdl2p24","bdl1p24"],"comp":["o12"],"lister_lifecycle":"0","last_pv_imps":"2","user-ad-fq":"2","ses_pv_seq":"1","user-ad-dens":"2","listingview_test":"1","env":"production","url_action":"ad","lang":"ru","con_inf":"transportxxlegkovye-avtomobilixx46"};
data in json dict
How can I get the data from the pages using python and scrapy?
You can do it by extracting the JS code from the <script> block, using a regex to get only the JS object with the data and then loading it using the json module:
query = 'script:contains("GPT.targeting = ")::text'
js_code = response.css(query).re_first('targeting = ({.*});')
data = json.loads(js_code)
This way, data is a python dict containing the data from the JS object.
More about the re_first method here: https://doc.scrapy.org/en/latest/topics/selectors.html#using-selectors-with-regular-expressions
I am trying to send Javascript Array via AJAX POST to django view.
I store this array in hidden input using JSON.stringify:
$('#id_uuids').val(JSON.stringify(arr));
this is how I try to send it:
$.post("/ajax/generateGallery",{uuids: $('#id_uuids').val()},function(response){
resp = JSON.parse(response);
alert(resp.html);
},"json");
Browser console shows that data which is being send looks like:
uuids:["6ecbe35b-0b77-4810-aa9a-918fecaeef13","e41f52f7-721b-4d44-b7d6-bbb275182d66"]
However, I am not able to use this in my django view. I've tried:
uuids = request.POST.getlist('uuids')
logger.info(uuids)
logger.info(type(uuids))
which returns:
[08/Aug/2014 15:20:00] INFO [app.rest_client:307] [u'["89a26646-6000-4c48-804a-69abcc496fd8"]']
[08/Aug/2014 15:20:00] INFO [app.rest_client:308] <type 'list'>
[08/Aug/2014 15:20:00] INFO [app.rest_client:312] Generate HTML gallery for photo ["89a26646-6000-4c48-804a-69abcc496fd8"]
So, Django treats very list sent as single element. How can I force python code to treat this data as list and be able to iterate on?
try to JSON-decode the posted data
uuids = json.loads(request.POST.get('uuids'))
that is if you loaded some json module before, e.g.
import simplejson as json
I'm using a plugin called 'tidy table' to display my JSON content. Basically, I want to tabulate the content of the JSON file into a html table, that can be sortable.
The code they've supplied only displays JSON content embedded into it (http://jsfiddle.net/2NH4u/). However, I have an external file I want to include (this is MY code http://jsfiddle.net/NNvSV/).
The code that's tripping me up is:
$.getJSON('onesies.json', function(res) {
// generate HTML table
$('#container')
.TidyTable({
columnTitles : res.headers,
columnValues : res.rows
});