I am new to file handling in Salesforce. I am currently working on downloading files of all records of a custom object. I read many blogs and found there are a couple of ways to do it. I decided to go with the shepherd URLFOR() approach as it seems simple and easy but now I have all the ContentDocumentId in a string format and I don't know how to use URLFOR() in the Lightning web component. Every blog and post gives the URL but I was not able to find how to use it once it is made. Is it used in Apex or HTML pages?
Can someone guide me?
Here is the URL I have formed
{!URLFOR('/sfc/servlet.shepherd/version/download/' & StringOfContentDocumentIds &'?')}
This is the expression syntax used in VisualForce and in Aura component.
You're talking about Lightning Web Component (known as LWC) so this syntax is not valid.
I would advise to use the standard approach which is using the navigation service.
If you really want to use the shepherd trick, then you need to write something like this:
fileDownload.js
import { LightningElement } from 'lwc'
export default class FileDownLoad extends LightningElement {
contentVersionIds = []
get urlOfContentDocumentFile () {
return `/sfsites/c/sfc/servlet.shepherd/version/download/${this.contentVersionIds.join('/')}?`
}
}
fileDownload.html
<template>
Download
</template>
Please note that I changed the url to add /sfsites/c before as you seems to talk about a community. If it's not, then you can just remove that part.
P.S: I don't know how you get the list of contentVersionIds so I didn't cover that part.
I am using Typescript and REACT and I want to utilize and wrap some custom html elements in my TSX. For example, I am using a library with a customer html element called ch5-button an it is used in a vanilla html file as such
<ch5-button class="shadow-pulse-button" type="default" shape="circle" label="" iconClass="fas fa-award">
</ch5-button>
I did a ton of searching, but seems like i am not even smart enough to get the search correct to find how to do this. I am not even sure if I have the correct import statement to get those elements -- the closest I got was :
declare var CrComLib: typeof import('#crestron/ch5-crcomlib');
...
const ch5Button = new CrComLib.Ch5Button();
console.log("ch5Button");
console.log(ch5Button);
The console.log display <ch5-button></ch5-button> soI have no idea if I am even on the right track to using this thing. The ch5Button is a class with a lot of methods that look pretty much like what an html element would have but I just dont know what to do with it and how to learn a method for using it. I found some sites that explain how to use observables and such but I am sketchy on if I am heading down the right path. I have attached am image of what some if the properties and methods of the ch5Button looks like in chrome debugger.
Can anyone point me in the right direction? I would create a REACT component that wraps this class and can use props to set the correct attributes etc.
I am very comfortable building REACT apps but admittedly, I am not an advanced developer with it yet but doing my best to learn.
While designing the application in react js to increase the reusability I have used the Tabs and then passed the tabs and headers something like this
const tabs ={
"tabHeader1": TabContent1,
"tabHeader2": TabContent2
}
<SwipableTabs tabs={tabs} />
Now my confusion arose when I had to render them permission based , In order to avoid if else juggling I have designed a component like below :
<ProtectedAction>
{children}
</ProtectedAction>
my ProtectedAction component will check for permission and will render the children based on that. Which is exactly what react suggest(be declarative).
Now when I see the above example like tabs which is data driven I am forced to use if else again which I wanted to get rid of.
Please suggest if any better approach is possible .
I'm brand new to both pouchdb and react. I found the react-pouchdb-changes module which seems exactly like what I want to be using.
However, the example code it provides is far too sparse - I'm really at a loss as to how it would be incorporated into a basic react application.
Can someone provide a more complete example usage with some basic explanations of what each piece does?
This module seems to be merely a wrapper for the changes method. You can get a live example here. The link comes right from the documentation.
If that's not enough info you can check out the API reference with examples and example responses.
It's up to you how you want react-pouchdb-changes to integrate with React. All it does is provide you with a component to put your onChange handler on. These parts of the code example are the relevant ones:
<PouchDBChanges
…
onChange={change => console.log(change) /* do something useful with the change here instead of just logging it! */}
>
{/* your <App> component here */}
</PouchDBChanges>
Just use the component in your JSX code (wrap your main component or any container component with it).
If you have difficulties with setting up a React example, try using create-react-app. You'll have a running React app within a few seconds. A good place to add your <PouchDBChanges> component would be src/App.js - just wrap the outermost <div> with the component.
coming from angular i used to have a class for every entity in my DB, such class encapsulated all entity behaviour.
for example users Class can look like
export class User{
static notValid(u){
return !!((u.id && u.id > 0 && u.fullname && u.fullname.length > 2 && u.picture) === false);
}
static fromArray(arr){
let pack = [];
for(let i=0;i<arr.length;i++){
pack.push(new User(arr[i]));
}
return pack;
}
constructor(u){
this.id = u.id || 0;
this.fullname = u.fullname+'' || 'N/A';
this.picture = u.picture+'' || '/imgs/logo.png';
this.role = u.role || 'N/A';
this.username = u.username+'' || '';
this.email = u.email+'' || '';
this.dob = u.dob || 0;
this.gender = u.gender+'' || '';
///START SETTING FLAGS AND VALIDATING DATA;
this.isValid = !User.notValid(this);
this.saved = this.id > 0;
let n = this.fullname;
this.nickname = n.split(' ').shift()+' '+n.split(' ').pop();
}
save(){
///IF NO ID, POST TO SERVER
if(!this.saved)return $http.post('/user',this.toJson);
return $http.put('user/'+this.id,this.toJson());
//tojson is defined in prototype;
}
identity(){
return {id:this.id,fullname:this.fullname,picture:this.picture,nickname:this.nickname};
}
}
}
so that my controller doenot know about how to save or update User, all it have is to trigger save() on user object.
Now React world, where every thing inside app is a component;
1. how can i replicate such approach inside react component ?
i read alot that there is presentational components and smart components. but what about Data Model component ?
2. if i port all my current class's to react should i also implement render method ? can i have multiple render functions to return different html based on page.
example above User can appear inside Profile will all details, and as a card in users list, so i should keep html for both inside class prototype ?
You seem to be a bit confused about React and what it is designed to do which is perfectly normal, coming from the Angular world.
The thing is, as far as React is concerned there is no such thing as a data model, only components. These components can have state (or they may not) and these components are rendered to the DOM.
Various types of components seem to have confused you as well. React is only concerned with how data is presented. Presentation and container components are distinguished from each other to make it easier for us to reason about how to manage application state.
To answer your specific questions:
1) If you are really adamant about keeping your existing structure and make it work with React, you don't actually need to do a lot of work. Your data model components are just JavaScript objects. You can pass them around and you can give them to components. When some event happens in the components, you can call the relevant methods in your objects. You will need to make sure that Angular specific methods are ported to pure JavaScript though.
I advise against this approach. It will work at first but you will find yourself in a maintenance hell in no time. Believe me, I'm building large scale React apps in my job and I have been bitten by similar decisions when I first started writing React components.
2) Certainly you could add a couple of React methods to your class definitions and also throw in the presentation code (that is, HTML) and presentation state. Then you would be able to render these components.
But that really is not the way to go about it. React doesn't decide on anything for you whereas Angular is very opinionated about this. First and foremost you should follow some tutorials on React. Looks like you have a sizable application in your hands, so I would advise you to look into Flux and Redux as well.
After that you should sit down and design how your application should work and how your state should look. After that it will be a breeze to go through the actual coding part.
You can NOT have multiple render methods in a React component, that makes absolutely no sense. React is pure JavaScript and JavaScript doesn't have any concept of overriding class members in the sense of classical OOP. Heck, JavaScript doesn't even have the concept of a class, that has been included in ES6 so people coming from class oriented programming languages wouldn't need to properly learn how the prototype chain works.
React components, and JavaScript objects in general, can only have one key. You can try this in your browser's console.
let a = {b: 1, b: 2};
console.log(a);
The object a will only have one b key and the value for that key will be 2.
Having said all this, you can delegate the actual rendering of a component to other objects based on some conditions using normal JavaScript coding methods. But this isn't how React is supposed to work. Your render method can be able to decide on what to render based on your conditions.
First of all, let me tell you that I can't answer your question.
It looks like you're new to React. I've never used this approach to create a class for every entity in DB, in React, ever. It's new to me. Maybe it works, maybe it doesn't. But what I'd suggest you is to get your hands dirty first with example projects in react. That'll answer most of your questions.
However, I can answer some of your questions-
Data Model component ?
Obviously, there is no such thing as Data Model component. React is all about unidirectional data flow. You want to use redux for state management in react. The components which are connected to this state are connected/smart components. Smart components pass the state to presentational/dumb components via props (properties). So there is that. All of the state comes from Redux or similar state management mechanism viz. Flux.
can i have multiple render functions to return different html based on
page.
No. One component contains only one render() method. That is precisely why I suggest you to please build some example apps in React.
If you want to learn React, here's what I'd recommend you, in that particular order-
React.js
Redux
Redux-thunk
Redux-saga
React is not a monolithic framework like Angular. It's just a library. And programmers are meant to throw different libraries together to build their apps.