ReactJS: Join map output with concatenating value - javascript

In my ReactJS application I am getting the mobile numbers as a string which I need to break and generate a link for them to be clickable on the mobile devices. But, instead I am getting [object Object], [object Object] as an output, whereas it should be xxxxx, xxxxx, ....
Also, I need to move this mobileNumbers function to a separate location where it can be accessed via multiple components.
For example: Currently this code is located in the Footer component and this code is also need on the Contact Us component.
...
function isEmpty(value) {
return ((value === undefined) || (value === null))
? ''
: value;
};
function mobileNumbers(value) {
const returning = [];
if(isEmpty(value))
{
var data = value.split(',');
data.map((number, index) => {
var trimed = number.trim();
returning.push(<NavLink to={`tel:${trimed}`} key={index}>{trimed}</NavLink>);
});
return returning.join(', ');
}
return '';
};
...
What am I doing wrong here?
Is there any way to create a separate file for the common constants / functions like this to be accessed when needed?

First question:
What am I doing wrong here?
The issue what you have is happening because of Array.prototype.join(). If creates a string at the end of the day. From the documentation:
The join() method creates and returns a new string by concatenating all of the elements in an array (or an array-like object), separated by commas or a specified separator string. If the array has only one item, then that item will be returned without using the separator.
Think about the following:
const navLinks = [{link:'randomlink'}, {link:'randomlink2'}];
console.log(navLinks.join(','))
If you would like to use concatenate with , then you can do similarly like this:
function mobileNumbers(value) {
if(isEmpty(value)) {
const data = value.split(',');
return data.map((number, index) => {
const trimed = number.trim();
return <NavLink to={`tel:${trimed}`} key={index}>{trimed}</NavLink>;
}).reduce((prev, curr) => [prev, ', ', curr]);
}
return [];
};
Then you need to use map() in JSX to make it work.
Second question:
Is there any way to create a separate file for the common constants / functions like this to be accessed when needed?
Usually what I do for constants is that I create in the src folder a file called Consts.js and put there as the following:
export default {
AppLogo: 'assets/logo_large.jpg',
AppTitle: 'Some app name',
RunFunction: function() { console.log(`I'm running`) }
}
Then simply import in a component when something is needed like:
import Consts from './Consts';
And using in render for example:
return <>
<h1>{Consts.AppTitle}</h1>
</>
Similarly you can call functions as well.
+1 suggestion:
Array.prototype.map() returns an array so you don't need to create one as you did earlier. From the documentation:
The map() method creates a new array populated with the results of calling a provided function on every element in the calling array.
I hope this helps!

Related

array different data inside a single array

how can I get all this array in one array without getting it one after the other like this in the code below? i mean saving the whole data inside one variable without giving a specific index of the array
here's the code
const favoriteProductone = data?.getAllLikeProduct[0]
const favoriteProductTwo = data?.getAllLikeProduct[1]
const favoriteProductThree = data?.getAllLikeProduct[2]
console.log(favoriteProductone?.Like[0])
console.log(favoriteProductTwo?.Like[0])
console.log(favoriteProductThree?.Like[0])
Just iterate the array like so:
if (!data) {
throw "data is falsy - there is nothing to process";
}
data.getAllLikeProduct.forEach(p => {
console.log(p.Like[0])
});

Preventing higher order array methods from throwing an error

Is there a way to prevent errors from being thrown while filtering?
The below function sometimes fails at conversationMember.Name.toLowerCase() when there is no conversationMember.
If it helps, this is also a computed property in a Vue application.
Should you need more information, please just ask!
filteredConversations() {
var self = this;
var filteredConvos = self.conversations;
filteredConvos = filteredConvos.filter(conversation => {
return conversation.MembershipData.some(conversationMember => {
return conversationMember.Name.toLowerCase().includes(
self.conversationSearchTerm.toLowerCase()
);
});
});
return filteredConvos;
},
This doesn't seem to have anything to do with arrays.
From your code I understand conversationMember.Name is supposed to be a string (because you're calling .toLowerCase() on it), which means incudes here is not Array.prototype.includes, but String.prototype.includes, especially since self.conversationSearchTerm seems to also be a string (you're also calling .toLowerCase() on it).
So, the problem is you're using includes on something that should be a string but is not. The simple fix is to default it to an empty string when it's falsy:
return (conversationMember.Name || '').toLowerCase().includes(
(self.conversationSearchTerm || '').toLowerCase()
);
As a side note, you don't need the var self = this;. this is available inside your filter since the filter is an arrow function. So your function (I'm guessing it's a computed but it can as well be a method) could look like this:
filteredConversations() {
return this.conversations.filter(c =>
c.MembershipData.some(md =>
(md.Name || '').toLowerCase().includes(
(this.conversationSearchTerm || '').toLowerCase()
)
)
);
}
One last note: this will still fail if any of your conversations does not have a MembershipData holding an array. To get around that, you could default it to an empty array on the fly:
...
(c.MembershipData || []).some(md =>
...
As expected, any conversation without an array in MembershipData will be filtered out by the function (not included in the result) - because .some(condition) will return false when called on an empty array.

Why is the value of a specific key for a doc getting 'undefined' [duplicate]

Is there something that I'm missing that would allow item to log as an object with a parameter, but when I try to access that parameter, it's undefined?
What I've tried so far:
console.log(item) => { title: "foo", content: "bar" } , that's fine
console.log(typeof item) => object
console.log(item.title) => "undefined"
I'll include some of the context just in case it's relevant to the problem.
var TextController = function(myCollection) {
this.myCollection = myCollection
}
TextController.prototype.list = function(req, res, next) {
this.myCollection.find({}).exec(function(err, doc) {
var set = new Set([])
doc.forEach(function(item) {
console.log(item) // Here item shows the parameter
console.log(item.title) // "undefined"
set.add(item.title)
})
res.json(set.get());
})
}
Based on suggestion I dropped debugger before this line to check what item actually is via the node repl debugger. This is what I found : http://hastebin.com/qatireweni.sm
From this I tried console.log(item._doc.title) and it works just fine.. So, this seems more like a mongoose question now than anything.
There are questions similar to this, but they seem to be related to 'this' accessing of objects or they're trying to get the object outside the scope of the function. In this case, I don't think I'm doing either of those, but inform me if I'm wrong. Thanks
Solution
You can call the toObject method in order to access the fields. For example:
var itemObject = item.toObject();
console.log(itemObject.title); // "foo"
Why
As you point out that the real fields are stored in the _doc field of the document.
But why console.log(item) => { title: "foo", content: "bar" }?
From the source code of mongoose(document.js), we can find that the toString method of Document call the toObject method. So console.log will show fields 'correctly'. The source code is shown below:
var inspect = require('util').inspect;
...
/**
* Helper for console.log
*
* #api public
*/
Document.prototype.inspect = function(options) {
var isPOJO = options &&
utils.getFunctionName(options.constructor) === 'Object';
var opts;
if (isPOJO) {
opts = options;
} else if (this.schema.options.toObject) {
opts = clone(this.schema.options.toObject);
} else {
opts = {};
}
opts.minimize = false;
opts.retainKeyOrder = true;
return this.toObject(opts);
};
/**
* Helper for console.log
*
* #api public
* #method toString
*/
Document.prototype.toString = function() {
return inspect(this.inspect());
};
Make sure that you have defined title in your schema:
var MyCollectionSchema = new mongoose.Schema({
_id: String,
title: String
});
Try performing a for in loop over item and see if you can access values.
for (var k in item) {
console.log(item[k]);
}
If it works, it would mean your keys have some non-printable characters or something like this.
From what you said in the comments, it looks like somehow item is an instance of a String primitive wrapper.
E.g.
var s = new String('test');
typeof s; //object
s instanceof String; //true
To verify this theory, try this:
eval('(' + item + ')').title;
It could also be that item is an object that has a toString method that displays what you see.
EDIT: To identify these issues quickly, you can use console.dir instead of console.log, since it display an interactive list of the object properties. You can also but a breakpoint and add a watch.
Use findOne() instead of find().
The find() method returns an array of values, even if you have only one possible result, you'll need to use item[0] to get it.
The findOne method returns one object or none, then you'll be able to access its properties with no issues.
Old question, but since I had a problem with this too, I'll answer it.
This probably happened because you're using find() instead of findOne(). So in the end, you're calling a method for an array of documents instead of a document, resulting in finding an array and not a single document. Using findOne() will let you get access the object normally.
A better way to tackle an issue like this is using doc.toObject() like this
doc.toObject({ getters: true })
other options include:
getters: apply all getters (path and virtual getters)
virtuals: apply virtual getters (can override getters option)
minimize: remove empty objects (defaults to true)
transform: a transform function to apply to the resulting document before returning
depopulate: depopulate any populated paths, replacing them with their original refs (defaults to false)
versionKey: whether to include the version key (defaults to true)
so for example you can say
Model.findOne().exec((err, doc) => {
if (!err) {
doc.toObject({ getters: true })
console.log('doc _id:', doc._id) // or title
}
})
and now it will work
You don't have whitespace or funny characters in ' title', do you? They can be defined if you've quoted identifiers into the object/map definition. For example:
var problem = {
' title': 'Foo',
'content': 'Bar'
};
That might cause console.log(item) to display similar to what you're expecting, but cause your undefined problem when you access the title property without it's preceding space.
I think using 'find' method returns an array of Documents.I tried this and I was able to print the title
for (var i = 0; i < doc.length; i++) {
console.log("iteration " + i);
console.log('ID:' + docs[i]._id);
console.log(docs[i].title);
}
If you only want to get the info without all mongoose benefits, save i.e., you can use .lean() in your query. It will get your info quicker and you'll can use it as an object directly.
https://mongoosejs.com/docs/api.html#query_Query-lean
As says in docs, this is the best to read-only scenarios.
Are you initializing your object?
function MyObject()
{
this.Title = "";
this.Content = "";
}
var myo1 = new MyObject();
If you do not initialize or have not set a title. You will get undefined.
When you make tue query, use .lean() E.g
const order = await Order.findId("84578437").lean()
find returns an array of object , so to access element use indexing, like
doc[0].title

Filter an Array of Objects from an Array in TypeScript

I built a custom component that filters an array of objects. The filter uses buttons, sets from active to non-active and allows more than one option on/off at the same time.
StackBlitz of my attempt - https://stackblitz.com/edit/timeline-angular-7-ut6fxu
In my demo you will see 3 buttons/options of north, south and east. By clicking on one you make it active and the result should include or exclude a matching "location" either north, south and east.
I have created my methods and structure to do the filtering, I'm struggling with the final piece of logic.
So far I have created a method to create an array of filtered locations depending on what the user clicks from the 3 buttons.
Next this passes to my "filter array" that gets the logic that should compare this filtered array against the original to bring back the array of results that are still remaining.
Its not quite working and not sure why - I originally got this piece of functionality working by using a pipe, but fore reasons do not want to go in that direction.
//the action
toggle(location) {
let indexLocation = this.filteredLocations.indexOf(location);
if (indexLocation >= 0) {
this.filteredLocations = this.filteredLocations.filter(
i => i !== location
);
} else {
this.filteredLocations.push({ location });
}
this.filterTimeLine();
}
// the filter
filterTimeLine() {
this.filteredTimeline = this.timeLine.filter(x =>
this.contactMethodFilter(x)
);
}
//the logic
private contactMethodFilter(entry) {
const myArrayFiltered = this.timeLine.filter(el => {
return this.filteredLocations.some(f => {
return f.location === el.location;
});
});
}
https://stackblitz.com/edit/timeline-angular-7-ut6fxu
Sorry for my expression but u have a disaster in your code. jajaja!. maybe u lost that what u need but the logic in your functions in so wrong. comparing string with objects. filter a array that filter the same array inside... soo u need make a few changes.
One:
this.filteredLocations.push({location});
Your are pushing object. u need push only the string.
this.filteredLocations.push(location);
Two:
filterTimeLine() {
this.filteredTimeline = this.timeLine.filter(x =>
this.contactMethodFilter(x)
);
}
in this function you filter the timeLine array. and inside of contactMethodFilter you call filter method to timeLine again....
See a functional solution:
https://stackblitz.com/edit/timeline-angular-7-rg7k3j
private contactMethodFilter(entry) {
const myArrayFiltered = this.timeLine.filter(el => {
return this.filteredLocations.some(f => {
return f.location === el.location;
});
});
}
This function is not returning any value and is passed to the .filter
Consider returning a boolean based on your logic. Currently the filter gets undefined(falsy) and everything would be filtered out

Custom word translator in React

Update: scroll to see my solution, can it be improved?
So I have this issue, I am building a word translator thats translates english to 'doggo', I have built this in vanilla JS but would like to do it React.
My object comes from firebase like this
dictionary = [
0: {
name: "paws",
paws: ["stumps", "toes beans"]
}
1: {
name: "fur",
fur: ["floof"]
}
2: {
name: "what"
what: ["wut"]
}
]
I then convert it to this format for easier access:
dictionary = {
what : ["wut"],
paws : ["stumps", "toe beans"],
fur : ["floof"]
}
Then, I have two text-area inputs one of which takes input and I would like the other one to output the corresponding translation. Currently I am just logging it to the console.
This works fine to output the array of the corresponding word, next I have another variable which I call 'levelOfDerp' which is basically a number between 0 - 2 (set to 0 by default) which I can throw on the end of the console.log() as follows to correspond to the word within the array that gets output.
dictionary.map(item => {
console.log(item[evt.target.value][levelOfDerp]);
});
When I do this I get a "TypeError: Cannot read property '0' of undefined". I am trying to figure out how to get past this error and perform the translation in real-time as the user types.
Here is the code from the vanilla js which performs the translation on a click event and everything at once. Not what I am trying to achieve here but I added it for clarity.
function convertText(event) {
event.preventDefault();
let text = inputForm.value.toLowerCase().trim();
let array = text.split(/,?\s+/);
array.forEach(word => {
if (dictionary[word] === undefined) {
outputForm.innerHTML += `${word} `;
noTranslationArr.push(word);
} else {
let output = dictionary[word][levelOfDerp];
if (output === undefined) {
output = dictionary[word][1];
if (output === undefined) {
output = dictionary[word][0];
}
}
outputForm.innerHTML += `${output} `;
hashtagArr.push(output);
}
});
addData(noTranslationArr);
}
Also here is a link to the translator in vanilla js to get a better idea of the project https://darrencarlin.github.io/DoggoSpk/
Solution, but could be better..
I found a solution but I just feel this code is going against the reason to use react in the first place.. My main concern is that I am declaring variables to store strings inside of an array within the function (on every keystroke) which I haven't really done in React, I feel this is going against best practice?
translate = evt => {
// Converting the firebase object
const dict = this.state.dictionary;
let dictCopy = Object.assign(
{},
...dict.map(item => ({ [item["name"]]: item }))
);
let text = evt.target.value.toLowerCase().trim();
let textArr = text.split(/,?\s+/);
let translation = "";
textArr.forEach(word => {
if (dictCopy[word] === undefined) {
translation += `${word} `;
} else {
translation += dictCopy[word][word][this.state.derpLvl];
}
});
this.setState({ translation });
};
levelOfDerp is not defined, try to use 'levelOfDerp' as string with quotes.
let output = dictionary[word]['levelOfDerp' ];
The problem happens because setState() is asynchronous, so by the time it's executed your evt.target.value reference might not be there anymore. The solution is, as you stated, to store that reference into a variable.
Maybe consider writing another function that handles the object conversion and store it in a variable, because as is, you're doing the conversion everytime the user inputs something.

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