Develop Reference

Check all values in && comparison?

JavaScript is known to only check the first variable in a && comparison in case the first variable returns false. Is there a way to 'ask' JavaScript to check both variables i.e. when they are methods?
For example: Suppose you have 2 methods that validate 2 separate user inputs:
const validateEmail = value => {
if(value.contains('#')){
setShowEmailError(false);
return true;
}
setShowEmailError(true);
return false;
};
const validatePswd = value => {
if(value !== ''){
setShowPswdError(false);
return true;
}
setShowPswdError(true);
return false;
};
Then check both conditions:
if(validateEmail(email) && validatePswd(pswd)){
//validate entire form and render errors
}
However, the above will not execute the validatePswd method if the first method validateEmail returns false.
Is there a way to check if both values are true and run both methods? Having JavaScript run both methods would be a breeze in some cases.

You can execute them in an array and then accumulate the result with && by reduce function.
const validateEmail = value => {
if(value.includes('#')){
//setShowEmailError(false);
return true;
}
//setShowEmailError(true);
console.log('wrong email')
return false;
};
const validatePswd = value => {
if(value !== ''){
//setShowPswdError(false);
return true;
}
// setShowPswdError(true);
console.log('wrong password');
return false;
};
// you can execute any number of validations within the array.
const result = [validateEmail('something'), validatePswd('')].reduce((acc, f) => acc && f, true);
console.log(result)
UPDATE
Or as #lux suggested using every method.
const validateEmail = value => {
if(value.includes('#')){
//setShowEmailError(false);
return true;
}
//setShowEmailError(true);
console.log('wrong email')
return false;
};
const validatePswd = value => {
if(value !== ''){
//setShowPswdError(false);
return true;
}
// setShowPswdError(true);
console.log('wrong password');
return false;
};
// you can execute any number of validations within the array.
const result = [validateEmail('something'), validatePswd('')].every(r => r);
console.log(result)

I don't know if you are looking for something like this:
const valEmail = validateEmail(email);
const valPsw = validatePswd(pswd);
if(valEmail && valPsw ){
//validate entire form and render errors
}

how can i avoid error "can't convert undefined to an object "

some of the document does not consists planDetails planId properties and its returning error "can't convert undefined to an object , but i have to fetch that document if these properties exists or not , how can i avoid this error
this.profile.find({ userId: ObjectId(req.id) }).populate("planId").lean().exec(function(err, profileFound) {
console.log(profileFound);
if (err) return callback(err);
if (profileFound && profileFound.length === 0) {
return callback(false, common.errorMsg("PROFILE DOES NOT EXIST"));
} else {
var profileData = profileFound[0];
profileData["isPlanTaken"] = false;
profileData["planDetails"] = {};
if(profileData.hasOwnProperty("planId") && profileData.planId){
if(Object.keys(profileData.planId).length>0){
profileData["isPlanTaken"]=true;
profileData["planDetails"]=profileData.planId;
}
}
return callback(
false,
common.successMsg("PROFILE FETCHED",profileData )
);
}
});

I think there was missing the initialization of profileData variable only...
const profileData = {};
profileData["isPlanTaken"] = false;
console.log(profileData);
profileData["planDetails"] = {};
if(profileData.hasOwnProperty("planId") && Object.keys(profileData.planId)){
profileData["isPlanTaken"]=true;
profileData["planDetails"]=profileData.planId;
}
console.log(profileData);
And I think that is also enough to check a property is exists in an object. Can you please give me more data for example, because I don't really know what do you need.
const profileData = {};
profileData.isPlanTaken = false;
console.log(profileData);
profileData.planId = 5; // for example
if (profileData.planId) {
profileData.isPlanTaken = true;
profileData.planDetails = profileData.planId;
}
console.log(profileData);

Conditional validation using single piece of code - AngularJS

The code contains two functions. First one is defined as follows
scope.validateContactName = function() {
scope.address.invalidName = false;
if (!scope.address.name) {
scope.address.invalidName = true;
}
}
which is invoked by the function validateContactName();
Now i have another function
scope.validateContactPhone = function() {
scope.address.invalidPhone = false;
if (!scope.address.phone) {
scope.address.invalidPhone = true;
}
}
which is invoked by the function validateContactPhone();
Instead of two functions, is there a way i can use a single function and do conditional validation?
Something like
validateContactInfo('name');
function validateContactInfo(attr) {
//do validation based on the attribute
// There is only one single piece of code for both conditions
}

Maybe smth like this could work:
scope.validateField = function(field, errorField) {
scope.address[errorField] = false;
if (!scope.address[field]) {
scope.address[errorField] = true;
}
}
Or a shorter version:
scope.validateField = function(field, errorField) {
scope.address[errorField] = !scope.address[field];
}

I would suggest something like this(ES6):
scope.address = [
{
type: "phone",
invalid: false
},
{
type: "name",
invalid: false
}
];
const validate = type => {
let data = scope.address.find(a => a.type === type);
if(!data.type) {
data.invalid = true;
}
};
validate("phone");
validate("name");

Assuming contact information is used in a form to get input from the user. I would recommend to use angular's own form validation
If it is not the case, here is a generic way of checking if values exists in a object. Which you can add in project''s utilities
const contactInfo = {
name: 'My name',
phone: '123123123',
address: ''
}
function validateExistence(obj){
const emptyKeys = [];
for(let key in obj){
if(!obj[key]) emptyKeys.push(key)
}
return emptyKeys
}
console.log(validateExistence(contactInfo));

condense if, else JS with similar condition rules

trying to find a way to condense this. wasnt sure of the best way to do it. basically if criteria is met i display an alert with a parameter that is the message. i was thinking of maybe trying it in function. this is part of a larger function react component. i was also thinking if i could find a way to condense the else if's i could use a ternary. thanks in advance for the assistance.
const handleUpdatePassword = () => {
const allFilled = !reject(passwords).length;
const passwordsMatch = newPassword === conPassword;
const isDifferent = curPassword !== newPassword;
const meetsPasswordRequirements = validatePassword();
const usesName = isUsingName();
const usesUserID = isPartOfUserID();
const isValidPassword = meetsPasswordRequirements && isDifferent;
if (allFilled) {
if (!isDifferent) {
Alert.alert(difPassWord);
} else if (!passwordsMatch) {
Alert.alert(noMatch);
} else if (!meetsPasswordRequirements) {
Alert.alert(pasReqs);
} else if (usesName || usesUserID) {
Alert.alert(pasName);
}
} else {
Alert.alert(fieldNotComplete);
}
if (isValidPassword) {
changePasswordPost(
{
userId,
curPassword,
newPassword
},
partyId
);
}
};

You can create an array of objects for your validation rules, each containing a function which returns a boolean indicating whether that validation passes, and a string with the error message to display.
Then loop over the rules array and alert the message for the first rule that returns false. If they all return true, do the post.

You can split each if statement into a function, then chain them. For example
// here we make a closure to validate, and return a Promise
// condition can be a function
const validate = (condition, error) => ()=> new Promise((res, rej)=>{
if(condition()){
res();
}else{
rej(error);
}
});
const handleUpdatePassword = () => {
const validateFieldsComplete = validate(
()=>!reject(passwords).length,
fieldNotComplete
);
const validateDifPassword = validate(
()=> curPassword !== newPassword,
difPassWord
);
// ...
validateFieldsComplete()
.then(validateDifPassword)
.then(...)
.catch(Alert.alert)
}
It would be much cleaner with pipe. You can take a look at ramda. Or if you are intrested in functional way, you might consider using Monad.

I'd recommend DRYing up the Alert.alert part since all branches have that in common, and just come up with an expression that evaluates to the alert message. Compactness isn't always everything, but if you want it, then nested conditional operators can fit the bill. I'm also rearranging your conditions so that it can be a flat chain of if/elses:
const message
= reject(passwords).length ? fieldNotComplete
: curPassword === newPassword ? difPassWord
: newPassword !== conPassword ? noMatch
: !validatePassword() ? pasReqs
: (isUsingName() || isPartOfUserID()) ? pasName
: null;
const isValid = !message;
if (!isValid) {
Alert.alert(message);
}
(feel free to use any other sort of code formatting pattern; nested conditionals always look awkward no matter which pattern you use, IMO.)
Edit:
Also inlined conditionals which will short-circuit evaluation and make it even more compact.

I'd setup a validations object that has the tests and error messages and then loop over it. If validation fails, it'll throw the last validation error message. Using this method, you only have to maintain your tests in one place and not mess with a block of conditional statements.
const handleUpdatePassword = () => {
const validations = {
allFilled: {
test() {
return newPass && oldPass
},
error: 'Must fill out all fields'
},
correct: {
test() {
return curPass === oldPass
},
error: 'Incorrect password'
},
[...]
}
const invalid = () => {
let flag = false
for (let validation in validations) {
if (!validations[validation].test()) {
flag = validations[validation].error
}
}
return flag
}
if (invalid()) {
Alert.alert(invalid())
} else {
changePasswordPost(
{
userId,
curPass,
newPass
},
partyId
)
}
}

hi everyone this was the method i used for a solution
const messages = [
{
alertMessage: difPassWord,
displayRule: different()
},
{
alertMessage: noMatch,
displayRule: match()
},
{
alertMessage: pasReqs,
displayRule: validatePassword()
},
{
alertMessage: pasName,
displayRule: !isUsingName() || !isPartOfUserID()
}
];
if (allFilled) {
const arrayLength = messages.length;
for (let i = 0; i < arrayLength; i++) {
if (messages[i].displayRule === false) {
Alert.alert(messages[i].alertMessage);
}
}

How do I ensure an array has no null values?

I would like test my Array (input value) before submit my form.
My array with value :
const fields = [
this.state.workshopSelected,
this.state.countrySelected,
this.state.productionTypeSelected,
this.state.numEmployeesSelected,
this.state.startAt
];
I've try this :
_.forEach(fields, (field) => {
if (field === null) {
return false;
}
});
alert('Can submit !');
...
I think my problem is because i don't use Promise. I've try to test with Promise.all(fields).then(());, but i'm always in then.
Anyone have idea ?
Thank you :)

The problem is that even though you're terminating the lodash _.forEach loop early, you don't do anything else with the information that you had a null entry.
Instead of lodash's _.forEach, I'd use the built-in Array#includes (fairly new) or Array#indexOf to find out if any of the entries is null:
if (fields.includes(null)) { // or if (fields.indexOf(null) != -1)
// At least one was null
} else {
// All were non-null
alert('Can submit !');
}
For more complex tests, you can use Array#some which lets you provide a callback for the test.
Live example with indexOf:
const state = {
workshopSelected: [],
countrySelected: [],
productionTypeSelected: [],
numEmployeesSelected: [],
startAt: []
};
const fields = [
state.workshopSelected,
state.countrySelected,
state.productionTypeSelected,
state.numEmployeesSelected,
state.startAt
];
if (fields.indexOf(null) != -1) {
console.log("Before: At least one was null");
} else {
console.log("Before: None were null");
}
fields[2] = null;
if (fields.indexOf(null) != -1) {
console.log("After: At least one was null");
} else {
console.log("After: None were null");
}

You do not need to use promises unless there is an asynchronous operation (for example if you are getting that array from your server).
If you already have that array you can do something like:
// Using lodash/underscore
var isValid = _.every(fields, (field) => (field!==null)}
// OR using the Array.every method
var isValid = fields.every((field)=>(field!==null))
// Or using vanilla JS only
function checkArray(array){
for(var i = 0; i < array.length ; i ++){
if(array[i]===null){
return false;
}
}
return true;
}
var isValid = checkArray(fields);
// After you get that value, you can execute your alert based on it
if(!isValid){
alert('Something went wrong..');
}

Try this simple snippet
var isAllowedToSubmit = true;
_.forEach(fields, (field) => {
if (!field) {
isAllowedToSubmit = false;
}
});
if(isAllowedToSubmit)
alert('Can submit !');

You can do that without library:
if (fields.some(field => field === null)) {
alert('Cannot submit');
} else {
alert('Can submit');
}

You don't need to use lodash, you can do this in simple vanilla javascript. Simply iterate over each field and if an error occurs set your errors bool to true
let errors = false;
fields.forEach(field) => {
if(field === null || field === '') {
errors = true;
}
});
if (!errors) {
alert('Yay no errors, now you can submit');
}
For an es6 you can use.
const hasNoError = fields.every((field, index, selfArray) => field !== null);
if (!hasNoError) {
alert('yay It works');
};
Have a look at Array.every documentation Array every MDN documentation