为什么Instagram的分页会一遍又一遍地返回同一页面？

Question

代码

我已经创建了一个PHP类来与Instagram的API进行通信.我正在使用一个名为api_request(如下所示)的私有函数与Instagram的API进行通信:

private function api_request( $request = null ) {

    if ( is_null( $request ) ) {
        $request = $this->request["httpRequest"];
    }
    $body = wp_remote_retrieve_body( wp_remote_get( $request, array(
                "timeout" => 10,
                "content-type" => "application/json"
            )
        )
    );

    try {
        $response = json_decode( $body, true );
        $this->data["pagination"] = $response["pagination"]["next_url"];
        $this->data["response"] = $response["data"];

        $this->setup_data( $this->data );

    } catch ( Exception $ex ) {
        $this->data = null;
    }
}

这两行代码......

$this->data["pagination"] = $response["pagination"]["next_url"];
$this->data["response"] = $response["data"];

...在此数组中设置我的数据:

private $data = array (
    "response"      => null,
    "pagination"    => null,
    "photos"        => array()
);

问题

每当我请求下一页时,使用以下功能:

public function pagination_query() {
    $this->api_request( $this->data["pagination"] );
    $output = json_encode( $this->data["photos"] );

    return $output;
}

Instagram给了我第一页,一遍又一遍.知道这里的问题是什么吗？

更新#1

我意识到,因为我的setup_data函数(在api_request函数中使用)将我的照片对象推送到$this->data["photos"]数组的末尾:

private function setup_data( $data ) {

    foreach ( $data["response"] as $obj ) {

        /* code that parses the api, goes here */


        /* pushes new object onto photo stack */
        array_push( $this->data["photos"], $new_obj );
    }
}

...在请求新页面时,有必要创建一个空数组:

public function pagination_query() {

    $this->data["photos"] = array(); // kicks out old photo objects

    $this->api_request( $this->data["pagination"] );
    $output = json_encode( $this->data["photos"] );

    return $output;
}

我能够检索第二页但所有后续pagination_query调用只返回第二页.什么想法可能是错的？

更新#2

我发现使用一个while语句来使api_request函数调用本身,允许我逐页检索:

private function api_request( $request = null ) {

    if ( is_null( $request ) ) {
        $request = $this->request["httpRequest"];
    }

    $body = wp_remote_retrieve_body( wp_remote_get( $request, array(
                "timeout" => 18,
                "content-type" => "application/json"
            )
        )
    );

    try {
        $response = json_decode( $body, true );

        $this->data["response"] = $response["data"];
        $this->data["next_page"] = $response["pagination"]["next_url"];

        $this->setup_data( $this->data );

        // while state returns page after page just fine
        while ( count( $this->data["photos"] ) < 80 ) {
            $this-> api_request( $this->data["next_page"] );
        }

    } catch ( Exception $ex ) {
        $this->data = null;
    }
}

但是,这并没有修复我的pagination_query功能,看起来好像我的try-catch块正在创建一个闭包,我不知道该怎么做.

Answer 1

在您的第一个代码片段中，您有：

    $this->data["response"] = $response["data"];
    $this->data["next_page"] = $response["pagination"]["next_url"];

注意两个键：response和next_page

然后在你的第二个片段中你有：

    $this->data["pagination"] = $response["pagination"]["next_url"];
    $this->data["response"] = $response["data"];

现在next_page是pagination

现在如果你使用

$this->api_request( $this->data["pagination"] );

但你正在使用 $this->data["next_page"] = $response["pagination"]["next_url"];当然不会得到正确的结果。

无论如何，请尝试 var_dump 您的 $request 的内容：

public function pagination_query() {
    var_dump($this->data["pagination"]);
    $this->api_request( $this->data["pagination"] );
    $output = json_encode( $this->data["photos"] );

    return $output;
}

如果您有调试器，还请检查 api_request 内部，这是每次传递的 url