I have the following function (which I didn't write) to extract a URL parameter value:
function getURLParameter(name) {
return decodeURIComponent((new RegExp('[?|&]' + name + '=' + '([^&;]+?)(&|#|;|$)').exec(location.search) || [, ""])[1].replace(/\+/g, '%20')) || null
}
I have virtually no experience with regular expressions. This code currently does a case sensitive search for the parameter name. I'd like to have RegExp do a case insensitive search for the name of the parameter. Could someone show me how I might change this to accomplish that?
Add i flag for regexp(more info):
new RegExp('your regexp', 'i')
Here's something that I've been using that may help, as I need to do something very similar to pull down a substring of the current page's URL to then pass into a variable to be used in several of my functions.
Here's the generic format of my URLs:
file:///Users/myname/folder/teamname.html
And here's what how I'm parsing them:
function parseURL() {
var match = window.location.href.match(/(\w+).html$/);
if (match) {
return match[1];
}
return null;
}
This will do this:
1) Check the URL for the current page
2) Parse the URL into two different fragments of an array: "teamname" and "html"
3) I then return match[1] which is "teamname"
How I'm using it:
From there, I declare a variable for the parseURL function like this:
var teamSched = parseURL();
So now, I can make dynamic calls for any page with the same URL syntax I've outlined above to have specific code executed with the page-specific variable from parseURL(). Then, I use that variable to generate unique datasets from objects in my code who's key match the "team name" variable created by parseURL().
Someone definitely correct me if I'm wrong, but case sensitivity shouldn't be a factor here, as long as the value you're pulling from your URL via parseURL matched the variable, object key, etc. you're trying to access.
I hope that helps!
Related
I am trying to clean a URL and only keep some parameters that I need in order to parse them
so I was using pick method providing it the url, and the filter which is a regex test method
here I am testing to check if the key in the query parameter matches the regular expression
const groupRegex = new RegExp('^(GRP_)[a-zA-Z0-9/-]','g');
export const parseGroups= (url:string)=>{
let pickedURL = qs.pick(url,(key,value)=>groupRegex.test(key));
console.log(pickedURL);
}
var url=`http://localhost:3000/tat?GRP_Bob[]=SW&GRP_sa[]=QW&GRP_sa[]=AA&projects[]=MP,PM&releases[]=2021.4,2022.1`
parseGroups(url)
for example http://localhost:3000/tat?GRP_Bob[]=SW&GRP_sa[]=QW&GRP_sa[]=AA&projects[]=MP,PM&releases[]=2021.4,2022.1
it should return http://localhost:3000/tat?GRP_Bob=SW&GRP_sa=QW&GRP_sa=AA
yet it only tests for the first request parameter only and logs
http://localhost:3000/tat?GRP_Bob%5B%5D=SW
I am trying to clean the url from any other parameters that doesn't match my regular expression
so I can parse the URL and extract the object
so it can be like this for example
{
GRP_Bob:["SW"],
GRP_sa:["QW","AA"]
}
Instead of having other parameters parsed also which are not necessary. I know I can just parse the url normally, and then loop on the returned query object, and remove any key that doesn't match the regex, but is there anything wrong I am doing in the above snippet?
UPDATE:
I changed the filter function to be (key,value)=>key.startsWith('GRP_'))
export const parseGroups= (url:string)=>{
let pickedURL = qs.pick(url,(key,value)=>key.startsWith('GRP_'));
console.log(pickedURL);
let parsedURL = qs.parseUrl(pickedURL)
console.log(parsedURL.query)
}
var url=`http://localhost:3000/tat?GRP_Bob[]=SW&GRP_sa[]=QW&GRP_sa[]=AA&projects[]=MP,PM&releases[]=2021.4,2022.1`
parseGroups(url)
and the pickedURL logged this http://localhost:3000/tat?GRP_Bob%5B%5D=SW&GRP_sa%5B%5D=QW&GRP_sa%5B%5D=AA which is likely to be correct.
it came out like that
GRP_Bob[]: "SW"
GRP_sa[]: (2) ['QW', 'AA']
So I am confused actually what's going on with the regular expression approach, and why the keys in the second approach have [] in it?
Ah yeh! This one is a rare gotcha and totally unexpected every time I see it. RegExp actually has state. See Why does JavaScript's RegExp maintain state between calls? and Why does Javascript's regex.exec() not always return the same value?.
In your case, you don't need the g flag, so removing that should also fix your problem since that makes the regex stateless.
Issue Description
I'm currently trying to make updates on passwords using sequelize.fn.
I've seen numerous sites, including the Sequelize's manual, yet I found too few articles that approaches my case, and none of them seems to solve it.
Moreover, the function to encrypt the passwords need nested function, so I need to gradually construct the nested function
by putting the successive arguments into variables.
I have not found anything on constructing the functions, thus using sequelize.fn outside the arguments of the functions find and updates.
Additional context
In my case, " crypt('password', gen_salt('bf', 4)) " (in Postgres) needs to become
sequelize.fn('crypt', 'password', sequelize.fn('gen_salt', 'bf', 4)) and to be stored into a variable
When I inject it into the update function, an Fn Object is injected, and the result in the database seems to be a memory address instead of the result of the crypt function.
I may post a code example so you can have a better understanding of what I'm trying to do and I think should be added into the documentation
I did not made this doc issue to resolve my issue, only to point out what I think is lacking in the documentation
I will ask StackOverflow for help regarding my issue.
//Take a format and a value, and applies the functions inside the format onto the value
function recursSequelizeFn (format, value) {
const sequelize = db.sequelize;
let nextId = 0;
let matches;
let finalArgs = {};
//The RegEx finds the function calls of which parameters aren't functions themselves
//As the format string is modified on each loop, I need to initialize the RegEx on each loop
while ((matches = (/(\w+)\(([^(,)]+)?(?:,([^(,)]+))*\)/g).exec(format)) !== null) {
//matches[0] is the whole expression
//matches[1] is the function's name
//matches[>=2] are the arguments
let func = matches[1];
let args = matches.slice(2);
for (let argNo in args) {
//Transforms DB's columns into Sequelize-interpreted columns
//I do not check the column that is found, because I do not have others columns than the one that is being treated
args[argNo] = args[argNo].replace(/seqCol_(\w+)/g, (correspondance, p1, decalage, chaine)=>{return value;});
//If the parameter was previously saved, we replace its reference by its value
args[argNo] = args[argNo].replace(/(#\d+)/g, (correspondance, p1, decalage, chaine)=>{return finalArgs[p1];});
}
//finally, we save the value of the function and replace the whole expression by a reference
finalArgs['#'+nextId]=sequelize.fn(func, ...args);
format = format.replace(matches[0], '#'+nextId);
nextId++;
}
//When the treatment is finished, we return the last value saved into the array
//Or we return the original value if we have not made any change (the array will be empty)
return finalArgs['#'+(nextId-1)]||value;
}
Object.keys(req.message.attributes).map((key)=>{
//req.message.attributes[key] contains the formatting needed to be put onto the value
//e.g. crypt(password, gen_salt('bf', 4))
//req.body[key] contains the value
//e.g. '1234'
let seqValue = util.recursSequelizeFn(req.message.attributes[key], req.body[key]);
req.body[key] = seqValue;
});
//mainModel is a sequelize model
mainModel.update(req.body, {where: {id:req.params.id}, logging:console.log})
.then() //...
I want to so some query that is as same as LIKE from the good old school rdbms, so I have to use some sort of regex for that.
When I try this, it works fine
Countdowns.find({"name":{ "$regex": /ANW/ }},{ sort: {regDate: -1 }});
the value returns correctly. However when I build the mongoDb selector (the first JSON param for the function) it never works.
var key = Session.get('searchKey');
var field = Session.get('searchField');
var temp = '{"'+ field +'":{ "$regex": /'+key+'/ }}';
var selector = JSON.parse(JSON.stringify(temp));
Countdowns.find(selector,{ sort: {regDate: -1 }});
When i test it out (using try-catch during JSON.parse), the JSON object was built without any error but somehow the function (find()) fails to operate when i pass it as variable.
Is there other way to build the selector?
I have tested on the console and this is what I got.
Try to make it this way
var key = Session.get('key'), field = Session.get('field');
var selector = {};
selector[field] = { $regex : new RegExp(key) };
With this you will get:
And that should be acceptable for minimongo.
Why JSON.parse didn't work? At the point you where passing temp this is what it looked like:
You already had a string before passing it to JSON.stringify. But wait! You would say, if I instead pass it to JSON.parse it will work? Let see:
Nope. The forward slash has to be properly formatted and even then you'll get a string for the $regex, and you want a RegExp object.
So the way one end ups doing this is what I wrote you before. First you define the variable that will hold your selector for the database as an object and with that you construct your selector.
I have made an interesting observation. When trying to update an array that is stored in the Meteor session storage, the following code will not propagate the changes:
var tags = Session.get("Tags");
tags.push("a");
Session.set("Tags", tags);
But if I change the first line to use Session.get("Tags").slice(), everything depending on the session will update accordingly. I guess this is due to the fact that Meteor tests some references for equality and therefore does not update anything.
Is there a better way to manage lists stored in the meteor session store?
If I now try to remove an element from the collection (using array.remove() from here), the behavior turns out to be a bit ... of ... I am doing this inside a Meteor template event, the code looks like this:
"click .taglist li" : function(e) {
var tags = Session.get("Tags").slice();
var index = cardTags.indexOf(this);
Meteor._debug(Session.get("Tags").slice().indexOf("a"));
Meteor._debug("Removing tag \"" + this + "\", index: " + index, ", typeof(this) = " + typeof(this).toString());
tags.remove(index);
Session.set("Tags", tags);
}
This outputs:
1
Removing tag "a", index: -1, typeof(this) = string
So somehow, the cardTags.indexOf(this); statement seems to return -1 for almost any case. I guess I am doing something fundamentally wrong, as I am quite now to javascript, but somehow I can not figure out whats going on here.
Why will those two calls to indexOf() behave different?
I believe this is the same as this situation in Backbone.js. In order for the change event to be triggered, Meteor needs to have a new reference for the array, not just an updated copy of the old one.
In brief, in order to have the 'correct' behaviour, you'll need to clone the array, make the changes you want, and then do Session.set('foo', myCopiedArray).
In short: Use var index = cardTags.indexOf(this.toString()); instead.
Long version:
When using strings in JavaScript, those are strings, whereas typeof 'test' returns string.
Let's take a look at the following code in order to get find out another way to represent strings in JavaScript:
var func = function () {
return this;
};
console.log(func.call('test'));
The console (at least FireBug) won't show us "test", but instead it shows String {0="t", 1="e", 2="s", 3="t" }. typeof would return "object".
The content of the this statement seems to need to be an object. In order to convert a string into a "String" object we can do console.log(new String('test'));, which is the same as the previously logged value.
To convert a string object into a string (data type), just use its prototype toString.
i am processing an object in JavaScript that has been returned from an API that may contain variable names that are not valid JavaScript variable names. (these names are valid in the naming convention of the system of the API i am using)
in one case, the name starts with a number, e.g. '5story'
what is the best way to convert this name to a valid JavaScript variable name?
(i am familiar with the form of legal JavaScript names. a useful answer to this question would be a (hopefully simple) algorithm e.g. prefix a $ to the name and then strip it when returning the form to the API)
(i note that it would be preferable if the JavaScript API did not create invalid names)
Note that I'm not sure if you're asking about html identifier names (you mention "form") or Javascript variable identifiers, but how about stripping any character that is not a word character (A-Z, a-z, 0-9, _) and prepending with an underscore?
var v = ' .-*&*$*$W 5 foo Bar';
v = '_' + v.replace(/\W/g, '');
v; // _W5fooBar
The .replace() will strip characters that are not legal in variable identifiers.
You could prepend with the $ symbol instead of underscore for a legal variable name too.
You could creat a wrapper object that also contained a back reference to the original name.
function MyApiClient()
{
var _self = this;
this.RegisterWrapper = function(strName, objValue, explicitName)
{
var newName = (explicitName != null) ? explicitName : '_' + strName.replace(/\W/g, '');
_self[newName] = {ApiName : strName, Value : objValue};
return _self[newName];
}
}
//implementation
var client = new MyApiClient();
client.RegisterWrapper('5story', [0,1,2,3,4,5]);
console.log(client._5story.Value); //output: Array() [0,1,2,3,4,5];
//or
var o = client.RegisterWrapper('5story', {a:'b'}, '_myName');
console.log(o.Value); //outpus Object a: 'b'
console.log(client._myName.Value); //outpus Object a: 'b'
This extends a couple additional benefits
Scope: when creating the new objects they will be encapsulated and not globals
Reference: if you have reference to this object - you can use it to hit your API (because it will contain the old name)
Flexibility: you can either register the wrappers dynamically through a loop as you parse a string returned from the api or explicitely like above.
Do you have any more information about the actual api?