Develop Reference

Two events on a single button in react

I'm trying to create a button which can have two events on a single button so that I can add and remove a marker, I can do it with jQuery but can't work it out in react.
var Button = React.createClass({
getInitialState() {
return {
name: 'add marker'
};
},
render: function() {
return <button type="button" onClick={this.onClick}>{this.state.name}</button>
},
onClick: function(ev) {
// event 1
alert('marker added');
// event 2
alert('remove marker');
this.setState({name:'markert removed'})
}
});
http://jsfiddle.net/zidski/5z3f7zL4/1/

Assuming you want to use the same button to add/remove a marker, then you can do something like this:
var Button = React.createClass({
getInitialState() {
return {
marker: false
};
},
onClick: function() {
this.setState({
marker: !this.state.marker
});
},
render: function() {
return <button type="button" onClick={this.onClick}>{this.state.marker ? 'Add marker' : 'Remove marker'}</button>
}
});
Store a boolean value and update that when clicking the button. You can manage the buttons text based off that boolean.

you can access to the element with event.target,
if you would set the value of the button to something like 'add' or 'remove' you can capture it via event.target.value
for ex.
handleClick(event) {
let actionType = event.target.value; // 'add' or 'remove', now you can control the flow with switch case or regular if's */
}
render(){
return (<button value='add' onClick={this.handleClick}>{name}</button>)
}

Cannot interact between react components

This is for a react JS project (jsfiddle). The textbox should update with the true/false checked value of the checkbox, but it does not do so. Can someone explain why?
var AutoGenerateCheckbox = React.createClass ({
getInitialState: function() {
return {checked: false};
},
update() {
this.state.checked = !this.state.checked;
alert(this.state.checked);
this.props.onUpdate(this.state.checked);
},
render() {
return (
<input type="checkbox" checked={this.state.checked} onChange={this.update} />
);
}
});
var TBox = React.createClass({displayName: 'TextBox',
render: function() {
return (
<div>
Checkbox value: {this.props.data}
</div>
);
}
});
var KApp = React.createClass({
getInitialState: function() {
return {autoChecked: false};
},
handleAutogenChange: function(val) {
alert('handleAutogenChange:' + val);
this.setState({autoChecked : val});
},
render: function() {
return (
<div>
<AutoGenerateCheckbox onUpdate={this.handleAutogenChange}/>
<TBox data={this.state.autoChecked}/>
</div>
);
}
});
ReactDOM.render(
<KApp />,
document.getElementById('content')
);

The reason you don't see anything printed out is because you are trying to print a boolean value here
<div>
Checkbox value: {this.props.data}
</div>
try
<div>
Checkbox value: {this.props.data.toString()}
</div>
instead.
As an extra tip, you don't really need to hold the state of the checkbox in both its own state and its parent component's state. You really only need to have it in the parent component's state.
See the fiddle I made.

React is not determining the Boolean value to be printable information, try this instead:
<div>
Checkbox value: {this.props.data.toString()}
</div>

React JS: Reusable components

I have created the form validation with a structure like this
var Signin = React.createClass({
render: function() {
return (
<Form>
<Input type="text" name="email" labelName="Email" rules="isEmail" error:"Email not valid" />
<Input type="password" name="password" labelName="Password" rules="isLength:6" error:"Passowrd not valid"/>
</Form>
);
}
});
because, for example, the "Email" input will be used in different part of application, I would avoid to add the same attributes (name, type, labelName, rules and error) every time. So I would create something like this
var InputEmail = React.createClass({
render: function () {
return (
<Input type="text" name="email" labelName="Email" rules="isEmail" error="Email not valid"/>
)
}
});
var InputPassword = React.createClass({
render: function () {
return (
<Input type="password" name="password" labelName="Password" rules="isLength:6" error="Passwordnot valid"/>
)
}
});
So the Signin Component should be
var Signin = React.createClass({
render: function() {
return (
<Form>
<InputEmail />
<InputPassword />
</Form>
);
}
});
but in this way, I get two errors:
I can't find anymore in the Form the props.name of Input because
there isn't in InputEmail;
in the render function of Input the state is null
How could I create a reausable/inherits components? I failed using both the composition pattern and the mixins
I added my full code: Form
var Form = React.createClass({
getInitialState: function () {
return {
isValid : false,
isSubmitting: false
}
},
componentWillMount: function(){
this.model = {};
this.inputs = {};
this.registerInputs(this.props.children);
},
registerInputs: function(children){
React.Children.forEach(children, function (child) {
if (child.props.name) {
child.props.attachToForm = this.attachToForm;
child.props.detachFromForm = this.detachFromForm;
child.props.validate = this.validate;
}
if (child.props.children) {
this.registerInputs(child.props.children);
}
}.bind(this));
},
attachToForm: function (component) {
this.inputs[component.props.name] = component;
this.model[component.props.name] = component.state.value;
this.validate(component);
},
detachFromForm: function (component) {
delete this.inputs[component.props.name];
delete this.model[component.props.name];
},
validate: function (component) {
var isValid = true;
// validation code
component.setState({
isValid: isValid,
}, this.validateForm);
},
validateForm: function () {
var formIsValid = true;
var inputs = this.inputs;
Object.keys(inputs).forEach(function (name) {
if (!inputs[name].state.isValid) {
formIsValid = false;
}
});
this.setState({
isValid: formIsValid
});
},
updateModel: function (component) {
Object.keys(this.inputs).forEach(function (name) {
this.model[name] = this.inputs[name].state.value;
}.bind(this));
},
submit: function (event) {
event.preventDefault();
this.setState({
isSubmitting : true
});
this.updateModel();
console.log(this.model);
},
render: function () {
return (
<form className="ui form" onSubmit={this.submit}>
{this.props.children}
<button className="ui button" type="submit" disabled={this.state.isSubmitting}>Accedi</button>
</form>
);
}
});
Input
var Input = React.createClass({
getInitialState: function(){
return {
value : this.props.value || "",
isValid: true
}
},
setValue: function (event) {
this.setState({
value: event.target.value
}, function () {
this.props.validate(this);
}.bind(this));
},
componentWillMount: function () {
if (this.props.required) {
this.props.validations = this.props.validations ? this.props.validations + ',' : '';
this.props.validations += 'isLength:1';
}
// ERROR: TypeError: this.props.attachToForm is not a function
this.props.attachToForm(this);
},
componentWillUnmount: function () {
this.props.detachFromForm(this);
},
render: function () {
var className = "field";
if(this.props.className){
className += " " + this.props.className;
}
if(this.props.required){
className += " required";
}
var Label;
if(this.props.labelName){
Label = (<label htmlFor={this.props.name}>{this.props.labelName}</label>);
}
var Error;
if(!this.state.isValid){
Error = (<div className="ui">{this.props.error || this.props.name + " not valid"}</div>);
};
return (
<div className={className}>
{Label}
<input type={this.props.type || "text"} id={this.props.name} name={this.props.name} onChange={this.setValue} value={this.state.value} />
{Error}
</div>
);
}
});
With this works
ReactDOM.render(
<Form>
<Input type="text" name="email" labelName="Email" rules="isEmail" error:"Email not valid"/>
</Form>,
document.getElementById('app')
);
In this way I get:
"TypeError: this.props.attachToForm is not a function
this.props.attachToForm(this);"
ReactDOM.render(
<Form>
<InputEmail/>
</Form>,
document.getElementById('app')
);
P.S: I tried to add this code on jsfiddle but I get "!TypeError: can't define property "attachToForm": Object is not extensible"
jsfiddle

There are 2 main issues with your setup:
Your <Form> is set up in such a way, that the children of the form need to have props, otherwise it does not work.
The <InputEmail> wrapper is incomplete. It needs to pass along all props to the <Input>, including the Form functions passed down.
Ad 1: Fix the form, to ensure validation methods are added
The reason you get the error is because the children of your <Form> need to have props.name. It then registers the functions of the form (including attachToForm), by adding them to the children. This is done in the method registerInputs().
In the original variant, the <Input> component has props, so all goes well.
In the adapted variant, the wrapper <InputEmail> no longer has props, so the attachToForm() and other functions are not added to props, and you get the error when the <Input> tries to invoke the function.
Simplest way to fix this: add at least 1 prop in the render function, and check this in the registerInputs(), e.g.:
ReactDOM.render(
<Form>
<InputEmail initialValue={'name#domain.com'}/>
</Form>,
document.getElementById('app')
);
And in registerInputs(), change the line:
if (child.props.name) {
to:
if (child.props.initialValue) {
2. Extend <InputEmail> wrapper to pass down functions as well
Simplest way to do this is to add {...this.props}, like this:
var InputEmail = React.createClass({
render: function () {
return (
<Input {...this.props}
type="text" name="email" labelName="Email" rules="isEmail" error="Email not valid"/>
)
}
});
That way, the functions passed down by <Form> to the <InputEmail> component (as well as any other props), will be passed down to the <Input> component.
PS: The code inside registerInputs() that checks for child.props.children does not work as intended: at the time it is invoked, the <InputEmail> component does not have children. Like the name implies, it checks for children passed down as props. And the only prop passed was initialValue.
As minor issues I would suggest to make 2 more changes:
In registerInputs(), you directly modify props. This is generally not a good idea. Better is to make a copy of props, and add your form-methods to the copy. You can use React.Children.map to do this. See official docs here.
Instead of hard-coding the name="email" etc of your <Input> component, inside <InputEmail>, better is to put the default values of these in default values of props, using propTypes, as explained here in official docs.

React.JS this.state is undefined

I currently have this component in React.JS which shows all the Images passed to it in an array and onMouseOver it shows a button below. I planed on using setState to check the variable hover if is true or false and toggle the button of that image accordingly however I keep getting the following error:
Uncaught TypeError: Cannot read property 'state' of undefined
var ImageList = React.createClass({
getInitialState: function () {
return this.state = { hover: false };
},
getComponent: function(index){
console.log(index);
if (confirm('Are you sure you want to delete this image?')) {
// Save it!
} else {
// Do nothing!
}
},
mouseOver: function () {
this.setState({hover: true});
console.log(1);
},
mouseOut: function () {
this.setState({hover: false});
console.log(2);
},
render: function() {
var results = this.props.data,
that = this;
return (
<ul className="small-block-grid-2 large-block-grid-4">
{results.map(function(result) {
return(
<li key={result.id} onMouseOver={that.mouseOver} onMouseOut={that.mouseOut} ><img className="th" alt="Embedded Image" src={"data:" + result.type + ";" + "base64," + result.image} /> <button onClick={that.getComponent.bind(that, result.patientproblemimageid)} className={(this.state.hover) ? 'button round button-center btshow' : 'button round button-center bthide'}>Delete Image</button></li>
)
})}
</ul>
);
}
});

You get the error because you're storing the reference to this in a that variable which you're using to reference your event handlers, but you're NOT using it in the ternary expression to determine the className for the button element.
your code:
<button
onClick={ that.getComponent.bind(that, result.patientproblemimageid) }
className={ (this.state.hover) ? // this should be that
'button round button-center btshow' :
'button round button-center bthide'}>Delete Image
</button>
When you change this.state.hover to that.state.hover you won't get the error.
On a side note, instead of storing the reference to this in a that variable you can simple pass a context parameter to the map() method.
results.map(function (result) {
//
}, this);

In ES5 format you cannot set this.state directly
var ImageList = React.createClass({
getInitialState: function () {
return { hover: false };
},
render : function(){
return(<p>...</p>);
});
However with new ES6 syntax you can essentially manage this:
class ImageList extends React.Component{
constructor (props) {
super(props);
this.state = {hover : false};
}
render (){ ... }
}

ReactJS: onClick change element

I've just started learning React and have a question.
I want to do the following:
If a user clicks on a paragraph I want to change the element to an input field that has the contents of the paragraph prefilled.
(The end goal is direct editing if the user has certain privileges)
I'm come this far but am totally at a loss.
var AppHeader = React.createClass({
editSlogan : function(){
return (
<input type="text" value={this.props.slogan} onChange={this.saveEdit}/>
)
},
saveEdit : function(){
// ajax to server
},
render: function(){
return (
<header>
<div className="container-fluid">
<div className="row">
<div className="col-md-12">
<h1>{this.props.name}</h1>
<p onClick={this.editSlogan}>{this.props.slogan}</p>
</div>
</div>
</div>
</header>
);
}
});
How can I override the render from the editSlogan function?

If I understand your questions correctly, you want to render a different element in case of an "onClick" event.
This is a great use case for react states.
Take the following example
React.createClass({
getInitialState : function() {
return { showMe : false };
},
onClick : function() {
this.setState({ showMe : true} );
},
render : function() {
if(this.state.showMe) {
return (<div> one div </div>);
} else {
return (<a onClick={this.onClick}> press me </a>);
}
}
})
This will change the components state, and makes React render the div instead of the a-tag. When a components state is altered(using the setState method), React calculates if it needs to rerender itself, and in that case, which parts of the component it needs to rerender.
More about states
https://facebook.github.io/react/docs/interactivity-and-dynamic-uis.html

You can solve it a little bit more clear way:
class EditableLabel extends React.Component {
constructor(props) {
super(props);
this.state = {
text: props.value,
editing: false
};
this.initEditor();
this.edit = this.edit.bind(this);
this.save = this.save.bind(this);
}
initEditor() {
this.editor = <input type="text" defaultValue={this.state.text} onKeyPress={(event) => {
const key = event.which || event.keyCode;
if (key === 13) { //enter key
this.save(event.target.value)
}
}} autoFocus={true}/>;
}
edit() {
this.setState({
text: this.state.text,
editing: true
})
};
save(value) {
this.setState({
text: value,
editing: false
})
};
componentDidUpdate() {
this.initEditor();
}
render() {
return this.state.editing ?
this.editor
: <p onClick={this.edit}>{this.state.text}</p>
}
}
//and use it like <EditableLabel value={"any external value"}/>;