I'm trying to use HTML 5's local database feature on a Mac Dashboard widget.
I'm programming in Dashcode the following javascript:
if (window.openDatabase)
{
database = openDatabase("MyDB", "1.0", "Sample DB", 1000);
if (database)
{
...database code here...
}
}
Unfortunately the database-variable remains always null after the call to openDatabase-method. I'm starting to think that local databases are not supported in Widgets...
Any ideas?
/pom
No you will not be able to do the above. And even if you could then you would not be able to distribute the widget without distributing the database assuming it was a MySQL or SGLite. (not sure what you mean by HTML 5's local Db.
here are a number of ways round this:-
You can add a data source which can be a JSON file, or an XML file or and RSS feed. So to do this with JSON for example you would write a page on a server in PHP or something that accessed a database so that when the URL was called the result was a JSON string. Take the JSON string and parse it and use it in the Widget. This will let you get data but not save it.
Another way would be to use the user preferences. This allows you to save and retrieve data in the individual widget.
So
var preferenceKey = "key"; // replace with the key for a preference
var preferenceValue = "value"; // replace with a preference to save
// Preference code
widget.setPreferenceForKey(preferenceValue, preferenceKey);
You can then retrieve it with
var preferenceForKey = "key"; // replace with the key for a preference
// Preference code
preferenceForKey = widget.preferenceForKey(preferenceForKey);
The external call, you could also use REST will let you read any amount of data in and the preferences will let you save data for later reuse that will survive log out's and shut downs.
The Apple site has a lot of information about Widgets and tutorials as well thjat are worth working through.
Hope this helps.
Related
I have created a script to count down whatever value I submit into a form and then output "the submitted value + the date of the moment I clicked on the submit button" as a result.
But now I want to store the result into my database every time I use the form by using SQL query and then echo all of these results in another page named "log.php" using SELECT SQL query.
var timelog = [];
function myF() {
countdown(s);
log = document.getElementById("log").innerHTML = s + 'at ' + new Date();
timelog.push(log);
}
function logged() {
document.getElementById("timeloggg").innerHTML = timelog;
}
I have tried to assign the result to a variable, but obviously, I cant use this variable outside of the script.
With some googling, I was told to use Ajax, but sadly I couldn't figure out how to insert the data using ajax, because all of the code examples out there are only about calling data from the database.
So any advice on how to insert the result into my database? I'm still a beginner so please explain in detail if you don't mind.
It is possible, of course, to insert data into your database from client side js, BUT DONT! I can't think of a way to do it that would not expose your database credentials, leaving you open to malicious actors.
What you need to do is set up a php script on your server, then send the data (either by POST or GET) you want inserted to that with an xhr request, and let that php script do the insert. HOWEVER, there is quite a bit to securing even that. Google "how to sanitize mysql inputs in php" and read several articles on it.
Depending on what you need to do, you can sanitize the inputs yourself, but the recommended way to do it is with prepared statements, which you will need to read the documentation for your specific implementation, whether it's mysqli or pdo in mySQL or some other library (say if you're using SQL, postGRE, Oracle, etc).
HTH
=================================================
Here is how to do it in js, BUT DONT DO THIS, unless you are never going to expose this code outside of your local computer.
var connection = new ActiveXObject("ADODB.Connection");
var connectionstring = "Provider=host;Data Source=table;User Id=user;Password=pass;";
connection.Open(connectionstring);
var rs = new ActiveXObject("ADODB.Recordset");
var sql = {{your sql statement}};
rs.Open(sql, connection);
connection.close;
==============================================
For php, do something like this, replacing host, user, pass, db with your actual credentials and hostname and database:
$db = new mysqli({host}, {user}, {pass}, {database});
if($db->connect_errno > 0){ die ("Unable to connect to database [{$db->connect_error}]"); }
to set the connection. If this is a publicly accessible php server, then there are rules about how to set up the connection so that you don't accidentally expose your credentials, but I'm going to skip that for now. You would basically save this into a file that's not accessible from the outside (above the document root, for instance) and then include it, but database security is a complex topic.
To get the values you passed in the query string of your ajax call:
$val1 = $_GET['val1'];
$val2 = $_GET['val2'];
Then to do the insert with a parameterized query:
$query = $db->prepare("
INSERT INTO your_table (field1, field2)
VALUES (?, ?)
");
$query->bind_param('ss', $val1, $val2);
$query->execute();
Now, here you're going to have to look at the documentation. 'ss' means that it's going to treat both of those values you're inserting as strings. I don't know the table set up, so you'll have to look up the right code for whatever you are actually inserting, like if they were integers, then 'ii', or 'si' would mean the first value was a string and the second one was an int.
Here are the allowed values:
i - integer
d - double
s - string
b - BLOB
but look at the documentation for prepared statements anyway. I used msqli in this example.
You might want to check Ajax requests.
I would suggest to start here.
What you will do is basically create asynchronous requests from javascript to a php file on your server.
Ajax allows web pages to be updated asynchronously by exchanging small
amounts of data with the server behind the scenes. This means that it
is possible to update parts of a web page, without reloading the whole
page.
my website relies on a database which is a big JSON file like this:
var myjsonData =
[ {
"ID": 0,
"name": "Henry",
"surname": "McLarry",
"...": "...",
}]
I do generate this data every month at high cost to me, therefore I would like to avoid calling it straight in my html <head>, because this will allow any user to download the full database in no time.
I would like to build a "something" that can only call specific items from the json file (just the only one I want to show) without "exposing" the full .json onto client side.
today I use the call
var myvar= myjsonData.ID.Name
to get "Henry" into myvar, I would like to build something like
var myvar = mycallfunction(ID,Name)
I did try with PHP as intermediary but the ajax calls from javacript doesn't allow me to fetch the data.
Can I use JQuery with the JSON Url to get only the item I need?
What you can do is parse your json for an object. So you can get any value you want from json.
Example:
var myjsonData = '{"ID": 0,"name": "Henry","surname": "McLarry"}';
obj = JSON.parse(myjsonData);
console.log(myjsonData.ID); //print the id
console.log(myjsonData.name); //print the name
console.log(myjsonData.surname); //print the surname
So you have a NoSQL Database which has only one kind of Document that is the full JSON element you use in your website. In that scenario you have three options:
Depending on the NoSQL Database you're using you can limit the fields which will be returned(I.e: For MongoDB you can look here: https://docs.mongodb.com/manual/tutorial/project-fields-from-query-results/)
Change the way you store you data into more modular documents and make the logic to connect them in you application. So instead of one big document you'll have modular ones as Users, Products, Transactions and etc and you can use your application to query them individually.
Build a Server Side logic as an API to deal with your data and provide only what you need, so the API(Which can be node.js, php, or any you may like) will get the full JSON it`s endpoints will only the data you want. For example: myapi.com/getUser, myapi.com/getProducts and so on.
If you're able to provide more info on the technologies you're using that would help us. Hope that helped :).
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 need to develop a simple web page that accepts user information( name, age, birthdate, etc) and saves the data to a CSV or a text file to the server. I currently use Google sheets, but I need something that's more customizable and something that does some simple error checking. Are there any open source frameworks out there that I can use to put something together in a couple hours? I have a mechanical engineering background, and I'm not too familiar with web technologies. Any pointers will be greatly appreciated.
jQuery
JavaScript:
function saveUserData(url, data) {
var csv = [], // the array of values
del = "="; // the "delimiter" or "separator"
function handle(string) {
return encodeURI(string)
.replace(/,/g, "%2c");
}
for(var property in data)
csv.push(property + del + handle(data[property]));
// "name=John Doe,dob=Jan 1%2c 2000"
$.post(url, {data: csv.toString()})
.done(function(returned_data) {
// if you need this later
}, "json");
// "url" the the url to send the data to
// "data:" will likely be determined by the server you're using
// "json" will make "returned_data" a JSON object (if the server supports it)
}
Tesla88,
In your case, you need to write a server-side script. Below are 3 links that will show you how to
open, write, and close a file.
That's how far as I would elaborate on my answer, you need to show us that you actually did the work, and if you ran into issues, you can ask here again.
I hope the above helps.
-Anthony
Apologies if this seems basic to some, but I'm new to JS/node.js/JSON and still finding my way. I've searched this forum for an hour but cannot find a specific solution.
I have a basic website setup running of a local Node.js server along with 2x JSON data files with information about 32x local suburbs.
An example of an API GET request URL on the site would be:
.../api/b?field=HECTARES
The structure of the JSON files are like:
JSON Structure
In the JSON file there are 32x Features (suburbs), each with it's own list of Properties as shown above. What I am trying to do is use the API 'field' query to push all the HECTARES values each of the 32x Features into a single output variable. The code below is an example of how far I have got:
var fieldStats = [];
var fieldQ = req.query['field'];
for (i in suburbs.features) {
x = suburbs.features[i].properties.HECTARES;
fieldStats.push(x);
}
As you can see in the above "HECTARES" is hard-coded - I need to be able to pass the 'fieldQ' variable to this code but have no idea how to.
Advice appreciated!
Exactly the same syntax you are using just above:
suburbs.features[i].properties[fieldQ];