How to check with if condition if response has a string , if response has a string then execute the if condition.basically if there is error from server i want to make $scope.ActiveFile true.
main.js
$scope.onError = function(e) {
console.log('Error while uploading attachment', e.XMLHttpRequest.response);
$scope.errorMessage = JSON.parse(e.XMLHttpRequest.response).techErrorMsg;
if ($scope.errorMessage >= 1){
$scope.applyActiveFile = true;
}
};
response.json
Server response: {"errorCode":500,"errorMsg":"Service failed. Please contact administrator.","techErrorMsg":"Sheet : PROCESS_INVENTORY not found in the File"}
To solve your specific query this should work
if ($scope.errorMessage != null/blank) //whatever suits you
{
$scope.applyActiveFile = true;
}
Now answering what your question heading says - to check if property is string
if (typeof response === string)
/*typeof tells the type of operator, it will return number in case of number and string in case of string*/
{
$scope.applyActiveFile = true;
}
As mic4ael said, you could use some condition such as:
if ($scope.errorMessage)
$scope.applyActiveFile = true;
You could use some regular expression such as:
if ((/^\s*$/).test($scope.errorMessage))
$scope.applyActiveFile = false;
...which would check if the string is empty or has only white spaces and turn your trigger to false. You'd only want to check one or two values with this, though cause it'll be performance-heavy otherwise.
Many other solutions...
Something like this
for (var i in $scope.errorMessages){
if (typeof $scope.errorMessages[i] === "string"){
alert($scope.errorMessages[i]);
}
}
To test in browser console input:
var a = {"errorCode":500,"errorMsg":"Service failed. Please contact administrator.","techErrorMsg":"Sheet : PROCESS_INVENTORY not found in the File","thirdFieldNotString":1};
for (var i in a){
if (typeof a[i] === "string"){
alert('Value is string');
}
};
Related
I'm populating a table with data - using fixed-data-table, which is a React.js component. However, that isn't so important at this stage.
The table has a search box where the issue stems from.
First, here's the interesting part of the code.
for (var index = 0; index < size; index++) {
if (!filterBy || filterBy == undefined) {
filteredIndexes.push(index);
}
else {
var backendInfo = this._dataList[index];
var userListMap = hostInfo.userList;
var userListArr = Object.values(userListMap);
function checkUsers(){
for (var key in userListArr) {
if (userListArr.hasOwnProperty(key) && userListArr[key].text.toLowerCase().indexOf(filterBy) !== -1) {
return true;
}
}
return false;
}
if (backendInfo.firstName.indexOf(filterBy) !== -1 || backendInfo.lastName.toLowerCase().indexOf(filterBy) !== -1 || backendInfo.countryOrigin.toLowerCase().indexOf(filterBy) !== -1
|| backendInfo.userListMap.indexOf(filterBy) !== -1) {
filteredIndexes.push(index);
}
}
}
This is rendered and the last part is throwing errors if you input something in the table, and a column returns null from the user input.
The thing is, I can make the code work if I change the last part to ..
try {
if (backendInfo.firstName.indexOf(filterBy) !== -1 || backendInfo.lastName.toLowerCase().indexOf(filterBy) !== -1 || backendInfo.countryOrigin.toLowerCase().indexOf(filterBy) !== -1
|| backendInfo.userListMap.indexOf(filterBy) !== -1) {
filteredIndexes.push(index);
}
}
catch(err) {
console.log('Exception')
}
With the try/catch, it works 100% as intended and handles the indexOf returning null... But this can't be the way to properly handle it - I'm assuming this sort of exception handling is, well, supposed to be for rare exceptions, and shouldn't really be used on the front-end as much as the backend.
How do I handle indexOf returning null in the above Javascript code? It might return null in any of the sources columns that are being populated.
If a key cannot be found, JS will throw an error. Try-catch is a good way to fix these errors, but there is an alternative:
You could check if keys exist in an object prior to pushing a value into it.
var data = { };
var key = "test";
// your method works great
try {
var value = data.firstname.indexOf(key);
} catch (err) {}
// another method, I'd prefer the try/catch
var value = data.firstname ? data.firstname.indexOf(key) : undefined;
// test if the object is the type of object you are looking for
// this is in my opinion the best option.
if(data.firstname instanceof Array){
var value = data.firstname.indexOf(key);
}
// you can use the last option in your code like this:
var firstnameHasKey = data.firstname instanceof Array && ~data.firstname.indexOf(key);
var lastnameHasKey = data.lastname instanceof Array && ~data.lastname.indexOf(key);
if(firstnameHasKey || lastnameHasKey){
// logics
}
If you test the instanceof && indexOf, there will never be an error. If firstname is undefined, the indexOf will never be checked.
Ofcourse you can use this for other types:
var myDate = new Date();
myDate instanceof Date; // returns true
myDate instanceof Object; // returns true
myDate instanceof String; // returns false
MDN documentation
What it is supposed to do -
Example
url1(pages,"ALT") returns "www.xyz.ac.uk"
url1(pages,"xyz") returns ""
The error - TypeError: Cannot call method 'toUpperCase' of undefined
This is just for some coursework, Im stuck with these errors. Any help would be much appreciated
function index(string,pattern,caseSensitive) {
if(caseSensitive == false) {
var v = string.toUpperCase();
} else {
var v = string;
}
return indexNumber = v.indexOf(pattern);
}
var pages = [ "|www.lboro.ac.uk|Loughborough University offers degree programmes and world class research.", "!www.xyz.ac.uk!An alternative University" , "%www%Yet another University"];
alert(url1(pages, "ALT"));
function url1(pages,pattern) {
var siteContent = [];
for(i=0;i<pages.length;i++) {
var seperator = pages[i].charAt(0);
if(pages[i].indexOf(seperator)>0){
siteContent = pages[i].split(pages[i].indexOf(seperator));
}
if( index(siteContent[2],pattern,false)>=0){
return siteContent[1];
}else{
return "";
}
}
}
if(pages[i].indexOf(seperator)>0){
siteContent = pages[i].split(pages[i].indexOf(seperator));
}
if( index(siteContent[2],pattern,false)>=0){
return siteContent[1];
}else{
return "";
}
If pages[i].indexOf(seperator)<=0, siteContent is still whatever it was from the last iteration. If that happens on the first iteration, siteContent is still [], and siteContent[2] is undefined.
Another problem: the expression pages[i].indexOf(seperator) returns a number, and pages[i].split expects a delimiting string as an argument. Since the number doesn't appear in your input, you'll always get a single-element array, and siteContent[2] will always be undefined. Get rid of .indexOf(seperator), change it to siteContent = pages[i].split(seperator).
One more: get rid of the else { return ""; }. Add a return ""; after the for loop.
Finally, in the first if statement condition, change .indexOf(seperator) > 0 to .indexOf(seperator, 1) !== -1. Since you're getting seperator from the first character of the string, it will be found at 0. You want the second occurrence, so start the search at 1. In addition, .indexOf returns -1 if it doesn't find the substring. You'll need to account for this in both if conditions.
Side note, as this is not causing your problem: never use == false. JS will coerce stuff like 0 and "" to == false. If that's what you want, just use the ! operator, because the expression has nothing to do with the value false.
My final answer is http://jsfiddle.net/QF237/
Right here:
alert(url1(pages, ALT)); // ALT ISN'T DEFINED
I believe you forgot to quote it:
alert(url1(pages, "ALT"));
You should split the string passing the separator character itself. Your function then will look like:
function url1(pages,pattern) {
var siteContent = [];
for(i=0;i<pages.length;i++) {
var seperator = pages[i].charAt(0);
console.log(seperator);
if(pages[i].indexOf(seperator)>=0){
siteContent = pages[i].split(seperator); //fixed here
}
console.log(siteContent);
if( index(siteContent[2],pattern,false)>=0){
return siteContent[1];
}else{
return "";
}
}
}
Tell us if it worked, please.
EDIT: It seeems your index() also has a little problem. Please try the function below.
function index(string,pattern,caseSensitive) {
var v;
if(caseSensitive == false) {
v = string.toUpperCase();
pattern = pattern.toUpperCase(); //to clarify: pattern should be uppercased also if caseSensitiveness is false
} else {
v = string;
}
return v.indexOf(pattern);
}
EDIT 2:
And url1() is finally like this:
function url1(pages,pattern) {
var siteContent = [];
for(i=0;i<pages.length;i++) {
var seperator = pages[i].charAt(0);
if(pages[i].indexOf(seperator)>=0){
siteContent = pages[i].split(seperator);
}
if( index(siteContent[2],pattern,false)>=0){
return siteContent[1];
}
}
return "";
}
In this case, the first occurrence of pattern in all pages will be returned.
I'm building an application in which I want to display some errors when a user enters invalid values in an input box. A correct value is appended as 'entry' to a div if no errors were found. In total there are 3 cases when to display errors:
The input value is empty
The input value is a number
The input value already exists
These errors are displayed with if else statements.
1.and 2. were easy, but the problem case (3.) only validates against the first element of class .cat_entry.
if(cat_input == '') { // generate errors
errorDisplay(error_input_empty);
} else if(!isNaN(cat_input)) {
errorDisplay(error_input_number);
} else if($('.cat_entry') == cat_input) { // THIS IS THE PROBLEMATIC LINE
// .cat_entry is the class of the entries that have been appended
errorDisplay(error_duplicate);
} else {
// stuff
};
So I believe I need a for loop/ .each() (no problem so far), but how do I include this as a condition in an if statement? Something like.. if( for(i=0;i<$('.cat_entry').length;i++) { ... }; ... How to return true (or something similar) when one of the entries matches the input value, then pass the return value to the if statement?
EDIT: here is a jsFiddle with the relevant code. I updated it with $.inArray() method. I'd like to try and use this instead of a for / .each() loop.
You can try this:
var a=$('.cat_entry'),o={};
for(i=0;i<a.length;i++) {
var s=a[i].val();
if(s in o){
errorDisplay(error_duplicate);
return;
}
o[s]=true;
}
or
var o={};
$('.cat_entry').each(function(){
var s=$(this).val();
if(s in o){
errorDisplay(error_duplicate);
return;
}
o[s]=true;
}
You can actually use the jQuery inArray function for this, such as:
else if($.inArray(cat_input, $('.cat_entry') != -1)
}
The solution was to add this to the function:
var isDuplicate = false;
$('.cat_entry').each(function() {
if(!$(this).text().indexOf(cat_input)) {
isDuplicate = true;
}
// And in the if else loop:
else if(isDuplicate == true)
//and just before the function ends
isDuplicate = false;
Thanks to all for the help you offered.
What is the shorter and faster way to know if a cookie has a value or exists?
I'm using this to know if exists:
document.cookie.indexOf('COOKIENAME=')== -1
This to know if has a value
document.cookie.indexOf('COOKIENAME=VALUE')== -1
Any better? Any problems on this method?
I would suggest writing a little helper function to avoid what zzzzBov mentioned in the comment
The way you use indexOf, it would only evaluate correct if you check for the containment of a String in a cookie, it doesn't match a complete name, in that case the above would return false therefore giving you the wrong result.
function getCookie (name,value) {
if(document.cookie.indexOf(name) == 0) //Match without a ';' if its the firs
return -1<document.cookie.indexOf(value?name+"="+value+";":name+"=")
else if(value && document.cookie.indexOf("; "+name+"="+value) + name.length + value.length + 3== document.cookie.length) //match without an ending ';' if its the last
return true
else { //match cookies in the middle with 2 ';' if you want to check for a value
return -1<document.cookie.indexOf("; "+(value?name+"="+value + ";":name+"="))
}
}
getCookie("utmz") //false
getCookie("__utmz" ) //true
However, this seems to be a bit slow, so giving it an other approach with splitting them
Those are two other possibilities
function getCookie2 (name,value) {
var found = false;
document.cookie.split(";").forEach(function(e) {
var cookie = e.split("=");
if(name == cookie[0].trim() && (!value || value == cookie[1].trim())) {
found = true;
}
})
return found;
}
This one, using the native forEach loop and splitting the cookie array
function getCookie3 (name,value) {
var found = false;
var cookies = document.cookie.split(";");
for (var i = 0,ilen = cookies.length;i<ilen;i++) {
var cookie = cookies[i].split("=");
if(name == cookie[0].trim() && (!value || value == cookie[1].trim())) {
return found=true;
}
}
return found;
};
And this, using an old for loop, which has the advantage of being able to early return the for loop if a cookie is found
Taking a look on JSPerf the last 2 aren't even that slow and only return true if theres really a cookie with the name or value, respectively
I hope you understand what i mean
Apparently:
document.cookie.indexOf("COOKIENAME=VALUE");
For me, is faster, but only slightly.
As the test shows, surprisingly, it's even faster to split the cookie up into arrays first:
document.cookie.split(";").indexOf("COOKIENAME=VALUE");
I use Jquery cookie plugin for this.
<script type="text/javascript" src="jquery.cookie.js"></script>
function isCookieExists(cookiename) {
return (typeof $.cookie(cookiename) !== "undefined");
}
the following function does not work as I thought it should have. For some reason, the loop breaks whenever one the the validate function returns false. Why is that?
Here is my code :
function validateGroup(input) {
if (!input.value.match(/^[0-9]{0,2}$/)) {
$(input).addClass("invalidField");
return false;
}
$(input).removeClass("invalidField");
return true;
}
function validateClass(input) {
if (!input.value.match(/^[a-zA-Z0-9-]{0,9}$/)) {
$(input).addClass("invalidField");
return false;
}
$(input).removeClass("invalidField");
return true;
}
function validateData() {
var rows = document.getElementsByTagName("tbody")[0].getElementsByTagName("tr");
var valid = true;
for (var i = 0, arrayLength = rows.length; i < arrayLength; ++i) {
valid = valid && validateClass(rows[i].getElementsByTagName("input")[0]);
valid = valid && validateGroup(rows[i].getElementsByTagName("input")[1]);
valid = valid && validateGroup(rows[i].getElementsByTagName("input")[2]);
}
return valid;
}
Thanks a lot!
the statement valid && validateClass(...) will not call the validateClass method if valid is false. I think what you want to do is change the order of those to
valid = validateClass(rows[i].getElementsByTagName("input")[0]) && valid;
valid = validateGroup(rows[i].getElementsByTagName("input")[1]) && valid;
valid = validateGroup(rows[i].getElementsByTagName("input")[2]) && valid;
Javascript doesn't bother evaluating the rest of an && expression if it already knows that the result is false.
It looks like you want to run the validate functions on each iteration even if ‘valid’ was already set to false. However the && operation you are using will short-circuit, so although the loop will continue the validate functions will not be called on subsequent iterations.
A really simple alternative which would work the way you want would be:
for (var i = 0, arrayLength = rows.length; i < arrayLength; ++i) {
if(!validateClass(rows[i].getElementsByTagName("input")[0])) valid = false;
if(!validateGroup(rows[i].getElementsByTagName("input")[1])) valid = false;
if(!vvalidateGroup(rows[i].getElementsByTagName("input")[2])) valid = false;
}
It sounds like that is the intent of the function. The three lines of
valid = valid && validate...
mean that if any of the validate functions ever hits false valid will remain false for the rest of the loop.
I think it's because of the lazy evaluation scheme Javascript uses with &&. Try a single & instead.
Short-circuit evaluation: Support in common programming languages
It's called short-circuiting. Quick fix: replace each line with
valid = validateClass(rows[i].getElementsByTagName("input")[0]) && valid;