将数据从PHP发送到jQuery

Question

I have build a simple but working AJAX form using jQuery. The form is validated with jQuery before submit and then after successful submit again with PHP.

The only problem is the error handling. When the PHP-check returned that all fields are ok, I display a success message. If there was an error, I simply display "there was an error".
How can I send back data from PHP to jQuery so invalid fields can be marked as invalid?

Or is such form of error handling unnecessary as the dynamic highlighting needs JavaScript turned on and if JavaScript is turned on, the form can't be submitted wrong?

Basically, my valid checks look like this (simplified of course):

function checkSomething( $something ) {

        $valid = true;

        if ( strlen( $something ) === 0 ) {
            $valid = false;
        }


        return $valid;
} 

At the end of the script, I do it like this:

if ( checkSomething( $something ) && checkThis( $this ) && checkThat( $that ) ) {
    echo "success"; 
} else {
    echo "error";
}

And in my JavaScript/jQuery code it looks like this:

$.ajax({
    url: "form.php",
    type: "POST",
    data: string,
        success: function ( result ) {
            if ( result == "success" ) {
                alert( "success" );                     
            } else {
                alert( "error" );
            }
        }
});

Answer 1

I think you should have only one service in PHP. You send the data from the form, if there is any invalid data, you might want to return a JSON indicating which fields are wrong, so you can parse and show it. If it went ok, you just simply display that success message.

I'm not sure I get your problem, though.

Answer 2

Your form submission has 3 steps: JavaScript Validation & Submission, PHP validation/Processing, and JavaScript on complete ( 'so invalid fields can be marked as invalid')

It sounds like you have step 1 completed and most of step 2.

In your PHP code you should have some data structure, preferably an array, which holds which values are invalid. You can return this data to the browser by echo`ng it to the browser

<?php
...
...
if( count( $invalidFieldArray ) ){
    echo json_encode( array( 'status' => 'Fail',
                             'data' => $invalidFieldArray ) );
}else{
    echo json_encode( 'status' => 'Success' );
}

The code above will return the success/fail to your JavaScript form.

I personal use a jQuery form plugin to handle form submissions, and I recommend you give it a try. It has many nice out of the box features.

$.ajax({
    url: "form.php",
    type: "POST",
    data: string,
    dataType: json,
        success: function ( result ) {
            if ( result.status === "Success" ) {
                alert( "success" );                     
            } elseif (result.status === 'Fail'){
                for (field in result.data) {
                         /* Invalid field handling */
                         ...
                } 
            }
        }
});

Tip : Slightly off-topic, but when using comparisons in JavaScript always use triple equal ( === ), double equal ( == ) is not the same in JavaScript as in other languages; JavaScript does type coercion with double equals, which provides for inconsistent results.

Answer 3

您可以从PHP发送数据并将其存储在URL中，例如url.com/#value=1