Why is setting state on array not working? - react-native

I am trying to make a system where you would pass in a bunch of coins and they would get added to the state array (selectedTickers). Once I would set selectedTickers to another array, it would still print out the original array. Anyone know how to get this to print out the new array?
Code:
function addTickerToList(ticker) {
const exists = selectedTickers.filter((a) => a === ticker);
console.log(exists);
if (exists.length > 0) {
console.log("first");
let newList = selectedTickers.filter((a) => a !== ticker);
setSelectedTickers(newList);
console.log(selectedTickers);
} else {
console.log("second");
console.log(ticker);
selectedTickers.push(ticker);
}
}

setSelectedTickers is asynchronous.
You are logging selectedTickers before the function fully executed, try to log it on the web page to ensure that the re-render is done.

Related

Vuex model update won't reload computed property

I have the following component to quickly configure stops on a delivery/pickup route and how many items are picked up and dropped
and this is the data model, note the 2 is the one next to 'a' on the previous image.
If a click the + or - button, in the first item, it behaves as expected,
But second item doesn't work as expected
I've already checke a couple of posts on object property update likes this ones
Is it possible to mutate properties from an arbitrarily nested child component in vue.js without having a chain of events in the entire hierarchy?
https://forum.vuejs.org/t/nested-props-mutations-hell-internet-need-clarification/99346
https://forum.vuejs.org/t/is-mutating-object-props-bad-practice/17448
among others, and came up with this code:
ADD_ITEM_TO_SELECTED_STOP(state, payload) {
let count = state.selectedStop.categories[payload.catIndex].items[payload.itemIndex].count;
const selectedCat = state.selectedStop.categories[payload.catIndex];
const currentItem = selectedCat.items[payload.itemIndex];
currentItem.count = count + 1;
selectedCat.items[payload.itemIndex] = currentItem;
Vue.set(state.selectedStop.categories, payload.catIndex, selectedCat);
},
and as the button event:
addToItem(item) {
this.$store.dispatch("addItemToSelectedStop", {
catIndex: item.catIndex,
itemIndex: item.itemIndex
})
},
And finally my computed property code:
items() {
let finalArray = [];
this.selectedStop.categories.forEach(
(cat, catIndex) => {
let selected = cat.items.filter((item) => item.count > 0 );
if (selected.length > 0) {
//here we add the catIndex and itemIndex to have it calling the rigth shit
selected = selected.map(val => {
let itemIndex = cat.items.findIndex( itemToFind => itemToFind.id === val.id);
return {
...val,
catIndex: catIndex,
itemIndex: itemIndex,
}})
finalArray = finalArray.concat(selected);
}
});
return finalArray;
}
What confuses me the most is that I have almost the same code in another component, and there it's working as expected, and although the model is changed, the computed property is only recalculated on the first item,
After reading this gist and taking a look again at the posts describing this kind of issue, I decided to give it a try and just make a copy of the whole stored object not just the property, update it, then set it back on vuex using Vue.set, and that did the trick, everything is now working as expected, this is my final store method.
ADD_ITEM_TO_SELECTED_STOP(state, payload) {
let selectedLocalStop = JSON.parse(JSON.stringify(state.selectedStop));
let count = selectedLocalStop.categories[payload.catIndex].items[payload.itemIndex].count;
selectedLocalStop.categories[payload.catIndex].items[payload.itemIndex].count = count + 1;
Vue.set(state,"selectedStop", selectedLocalStop );
//Now we search for this step on the main list
const stepIndex = state.stops.findIndex(val => val.id === selectedLocalStop.id);
Vue.set(state.stops,stepIndex, selectedLocalStop );
},
I had to add the last bit after updating the whole object, because, originally, the array items were updated when the selected item was changed, I guess some sort of reference, but with the object creation, that relationship no longer works "automatic" so I need to update the array by hand

Vue axios delete request not working. How do I fix it?

Im having issues with delete request, my post, get are working fine.
What am I doing wrong?
removeUser(id) {
axios.delete('https://jsonplaceholder.typicode.com/users' + id)
.then(function(response) {
const user = response.data;
this.users.splice(id, user);
});
if response.status === 204, then delete is succeed.
for the client, here is an axios example, notice there is a ' after users
destroy() {
return request.delete('/api/users/' + id)
}
for the server, here is an Laravel example:
if( $article->delete() ) {
return response()->json(null, 204);
} else {
abort(409);
}
I can see only 1 problem on the code you provided.
You're trying to modify the Vue instance $data users object by executing this.users.splice(id, user);. But you're inside the callback function and this no longer represents the Vue instance.
To fix this & make the users object actually modify after the response comes you'll need to do it like this :
removeUser(id) {
let that = this;
axios.delete('https://jsonplaceholder.typicode.com/users' + id)
.then(function(response) {
const user = response.data;
that.users.splice(id, user);
});
Now , I don't have any code from the back-end so I'll just make some assumptions :
The route might not be well defined > if you're using NodeJS then you should check your routes , it should look like this :
router.route('/users:id').delete(async function(req,res,next){ /* ... */ });
You might have a route problem because / is missing before the user value
1 hint : Again , if you're using NodeJS , you could use this inside your .delete route :
res.status(200).json({ errorCode : null , errorMessage : null , users : [] });
To see if you're receiving it on front-end.
I think you do need to append the trailing '/' to the URL, that way the URL is properly formed, such as "https://jsonplaceholder.typicode.com/users/123" (rather than "users123" at the end).
Aside from that, the first parameter to Array.prototype.splice is the position where item removal should begin. The second (optional) parameter, deleteCount, is the number of items to remove. Beyond deleteCount, you can pass a collection of objects which are to be inserted after the start position and after items have been removed.
You just need to find the object in your this.users array and remove it. If you want to use Array.prototype.splice for that, then you can use Array.prototype.findIndex to find the index of the user in the array then remove it:
// Find the index of the item to remove
const indexOfUserToRemove = this.users.findIndex(u => u.id === id);
// Call splice to remove the item
this.users.splice(indexOfUserToRemove, 1);

Trying to change my immutable array in React Native

I have a function that runs every time your location changes and I'm trying to set a value in my array when a certain if statement is found true. All I seem to be doing is removing everything from my variable except the value that I am changing. Bad explanation so here is some code...
The data starts like this:
this.state = { selectedItem: [] }
And will change to something like this during normal app use:
selectedItem: [{address: 'Somewhere', latitude: -37.826835, longitude: 144.992030, found: false }]
Here is where I am trying to change the data (This will always run after some data is added):
const newSelectedItem = () => {
let copyB = {...this.state.selectedItem};
copyB.found = true;
return copyB;
};
this.setState({selectedItem: newSelectedItem});
When I try to run:
{this.state.selectedItem.address}
I see the initial value which would be the address "Somewhere" but when my function runs based on location change it disappears. What have I actually done to my data in my above function?
Have I just made it selectedItem: [{found:true}] or something dumb like that?
You were doing fine except for one single thing , in this function :
const newSelectedItem = () => {
let copyB = {...this.state.selectedItem};
copyB.found = true;
return copyB;
};
this.setState({selectedItem: newSelectedItem});
here copyB is now an object , but yours selected Item was an array. So the problem is now selectedItem is now an object when you do setState with newSelctedItem.
SO copyB.found = true; wouldnt evaluate anything rather, try copyB[0].found = true; so there the value will be accessed and return true accordingly.
And when you try to access the state , replace {this.state.selectedItem.address}
with {this.state.selectedItem[0].address} ,
Hope i helps. feel free to ask any doubts.
You can play around with this pen codepen
Well, this is pretty weird since you still get the initial value. There are some problems in your code:
You want to store your variables in a array: It's fine, but the problem comes from the way you retrieve and set your value. Since selectedItem, your {this.state.selectedItem.address} because this is an object destructuring. To do that, you have to destruct your array first, e.g: item = selectedItem[0] or using map, etc... After that, you can try: item.address.
Another problem is from your newSelectedItem. Since let copyB = {...this.state.selectedItem}; will destruct your selectedItem, take all its properties and set to newSelectedItem, it will make your selectedItem become an object, not an array anymore.
If your selectedItem stores only 1 object, so don't use array. This selectedItem will become:
selectedItem: {
address: 'Somewhere',
latitude: -37.826835,
longitude: 144.992030,
found: false
}
It looks like a JSON object, hence you can do: selectedItem.address
In case you still don't get it, place a little debug or a console.log("selectedItem", this.state.selectedItem) to see what happend, and you will find out.
I think in the end I was mapping a function to the data and not the data itself. This was my eventual solution...
const newMyWaypoinys = this.state.myWaypoints.map(a => {
let copyA = {...a};
if (copyA.address === wp.address) {
if (copyA.address === this.state.selectedItem.address) {
this.setState(prevState => ({
selectedItem: {
...prevState.selectedItem,
found: true
}
}))
}
copyA.found = true;
}
return copyA;
});
this.setState({
myWaypoints: newMyWaypoinys,
});

How to prevent closing of cell edit mode on validation errors with custom vue components in ag-grid

I have succesfully rendered my own component as the cellEditor and would like and on-leave I would like it to try to validate the value and prevent the closing if it fails.
If I look at this then https://www.ag-grid.com/javascript-grid-cell-editing/#editing-api there's cancelable callback functions for editing. But in this callback function is there a way to access the current instantiated component? I would think that would be the easiest way to handle this.
I'm using vee-validate so the validation function is async, just to keep in mind.
Use Full row editing.
Create a global variable like
var problemRow = -1;
Then Subscribe to this events:
onRowEditingStarted: function (event) {
if (problemRow!=-1 && event.rowIndex!=problemRow) {
gridOptions.api.stopEditing();
gridOptions.api.startEditingCell({
rowIndex: problemRow,
colKey: 'the column you want to focus',
});
}
},
onRowEditingStopped: function (event) {
if (problemRow==-1) {
if (event.data.firstName != "your validation") {
problemRow = event.rowIndex
gridOptions.api.startEditingCell({
rowIndex: problemRow,
colKey: 'the column you want to focus',
});
}
}
if (problemRow == event.rowIndex) {
if (event.data.firstName != "your validation") {
problemRow = event.rowIndex
gridOptions.api.startEditingCell({
rowIndex: problemRow,
colKey: 'the column you want to focus',
});
}
else{
problemRow=-1;
}
}
},
I had a similar issue - albeit in AngularJS and the non-Angular mode for ag-grid - I needed to prevent the navigation when the cell editor didn't pass validation.
The documentation is not very detailed, so in the end I added a custom cell editor with a form wrapped around the input field (to handle the niceties such as red highlighting etc), and then used Angular JS validation. That got me so far, but the crucial part was trying to prevent the user tabbing out or away when the value was invalid so the user could at least fix the issue.
I did this by adding a value parser when adding the cell, and then within that if the value was invalid according to various rules, throw an exception. Not ideal, I know - but it does prevent ag-grid from trying to move away from the cell.
I tried loads of approaches to solving this - using the tabToNextCell events, suppressKeyboardEvent, navigateToNextCell, onCellEditingStopped - to name a few - this was the only thing that got it working correctly.
Here's my value parser, for what it's worth:
var codeParser = function (args) {
var cellEditor = _controller.currentCellEditor.children['codeValue'];
var paycodeId = +args.colDef.field;
var paycodeInfo = _controller.paycodes.filter(function (f) { return f.id === paycodeId; })[0];
// Check against any mask
if (paycodeInfo && paycodeInfo.mask) {
var reg = new RegExp("^" + paycodeInfo.mask + '$');
var match = args.newValue.match(reg);
if (!match) {
$mdToast.show($mdToast.simple().textContent('Invalid value - does not match paycode format.').position('top right').toastClass('errorToast'))
.then(function(r) {
_controller.currentCellEditor.children['codeValue'].focus();
});
throw 'Invalid value - does not match paycode format.';
}
}
return true;
};
The _controller.currentCellEditor value is set during the init of the cell editor component. I do this so I can then refocus the control after the error has been shown in the toast:
CodeValueEditor.prototype.init = function (params) {
var form = document.createElement('form');
form.setAttribute('id', 'mainForm');
form.setAttribute('name', 'mainForm');
var input = document.createElement('input');
input.classList.add('ag-cell-edit-input');
input.classList.add('paycode-editor');
input.setAttribute('name', 'codeValue');
input.setAttribute('id', 'codeValue');
input.tabIndex = "0";
input.value = params.value;
if (params.mask) {
input.setAttribute('data-mask', params.mask);
input.setAttribute('ng-pattern','/^' + params.mask + '$/');
input.setAttribute('ng-class',"{'pattern-error': mainForm.codeValue.$error.pattern}");
input.setAttribute('ng-model', 'ctl.currentValue');
}
form.appendChild(input);
this.container = form;
$compile(this.container)($scope);
_controller.currentValue = null;
// This is crucial - we can then reference the container in
// the parser later on to refocus the control
_controller.currentCellEditor = this.container;
$scope.$digest();
};
And then cleared in the grid options onCellEditingStopped event:
onCellEditingStopped: function (event) {
$scope.$apply(function() {
_controller.currentCellEditor = null;
});
},
I realise it's not specifically for your components (Vue.js) but hopefully it'll help someone else. If anyone has done it a better way, I'm all ears as I don't like throwing the unnecessary exception!

Vuex mutation inside array of objects after backend update saves

I have an array of objects. When my api executes the update method and saves, I'm am broadcasting an event through laravel-echo-server and attempting to mutate state with the update object. I'm trying for real-time updates. Everything but the actual mutation is going according to plan. Here is the beginning of it:
updateExample (state, example) {
state.examples.map(e => {
if (e.id === example.id) {
// entirely replace the old object with the new
}
return false
})
},
What is an ideal way to do this? I could also pop the old object out of the array and push a new one, but that seems wonky.
Nevermind, figured it out:
updateExample (state, example) {
let index = state.examples.findIndex(e => e.id === example.id)
if (index !== -1) {
state.examples[index] = new Example(example)
return
}
state.examples.push(new Example(example))
}
Thanks for looking at it!