Wikipedia jsonp - Extrahieren der Seite ID

Question

Ich habe versucht, herauszufinden, wie Sie alle Daten von einer Seite in eine JSONP erhalten. ich zur Zeit den richtigen Link haben, aber ich habe in 2 Ausgaben lief .. Dies ist die URL ich bin mit dem JSONP (mit Stapelüberlauf als Beispiel) zu erhalten:

https://en.wikipedia.org/w/api.php?action=query&prop=extracts&titles=stack%20overflow&format=json&callback=JSONP_CALLBACK

1. Ausgabe: wenn ich res.data tun, bekomme ich alle Informationen, aber ich kann nicht scheinen, um herauszufinden, wie die Seitennummer übergeben werden:

JSONP_CALLBACK (
{ 
"batchcomplete": "", 
"query": { 
"normalized": [ 
{ 
"from": "stack overflow", 
"to": "Stack overflow" 
} 
], 
"pages": { 
"1436888": { // This is where I get stuck.. 
"pageid": 1436888, 
"ns": 0, 
"title": "Stack overflow", 
"extract": "<p>In software, a <b>stack overflow</b> occurs if the call stack pointer exceeds the stack bound. The call stack may consist of a limited amount of address space, often determined at the start of the program. The size of the call stack depends on many factors, including the programming language, machine architecture, multi-threading, and amount of available memory. When a program attempts to use more space than is available on the call stack (that is, when it attempts to access memory beyond the call stack's bounds, which is essentially a buffer overflow), the stack is said to <i>overflow</i>, typically resulting in a program crash.</p>\n<p></p>\n<h2><span id=\"Infinite_recursion\">Infinite recursion</span></h2>\n\n<p>The most common cause of stack overflow is excessively deep or infinite recursion, in which a function calls itself so many times that the space needed to store the variables and information associated with each call is more than can fit on the stack.</p>\n<p>An example of infinite recursion in C.</p>\n\n<p>The function <i>foo</i>, when it is invoked, continues to invoke itself, allocating additional space on the stack each time, until the stack overflows resulting in a segmentation fault. However, some compilers implement tail-call optimization, allowing infinite recursion of a specific sort—tail recursion—to occur without stack overflow. This works because tail-recursion calls do not take up additional stack space.</p>\n<p>C compiler options will effectively enable tail-call optimization; compiling the above simple program using gcc with <code>-O1</code> will result in a segmentation fault, but not when using <code>-O2</code> or <code>-O3</code>, since these optimization levels imply the <code>-foptimize-sibling-calls</code> compiler option. Other languages, such as Scheme, require all implementations to include tail-recursion as part of the language standard.</p>\n<h2><span id=\"Very_deep_recursion\">Very deep recursion</span></h2>\n<p>A recursive function that terminates in theory but causes a call stack buffer overflow in practice can be fixed by transforming the recursion into a loop and storing the function arguments in a stack. This is always possible, because the class of primitive recursive functions is equivalent to the class of LOOP computable functions. Consider this example in C++-like pseudocode:</p>\n<p>A primitive recursive function like the one on the left side can always be transformed into a loop like on the right side.</p>\n<h2><span id=\"Very_large_stack_variables\">Very large stack variables</span></h2>\n<p>The other major cause of a stack overflow results from an attempt to allocate more memory on the stack than will fit, for example by creating local array variables that are too large. For this reason some authors recommend that arrays larger than a few kilobytes should be allocated dynamically instead of as a local variable.</p>\n<p>An example of a very large stack variable in C:</p>\n\n<p>The declared array consumes 8 mebibytes of data (assuming each double is 8 bytes); if this is more memory than is available on the stack (as set by thread creation parameters or operating system limits), a stack overflow will occur.</p>\n<p>Stack overflows are made worse by anything that reduces the effective stack size of a given program. For example, the same program being run without multiple threads might work fine, but as soon as multi-threading is enabled the program will crash. This is because most programs with threads have less stack space per thread than a program with no threading support. Because kernels are generally multi-threaded, people new to kernel development are usually discouraged from using recursive algorithms or large stack buffers.</p>\n<h2><span id=\"See_also\">See also</span></h2>\n\n<ul><li>Buffer overflow</li>\n<li>Call stack</li>\n<li>Heap overflow</li>\n<li>Stack buffer overflow</li>\n<li>Double fault</li>\n</ul><h2><span id=\"References\">References</span></h2>\n\n<p>Kernel Programming Guide https://developer.apple.com/library/mac/documentation/Darwin/Conceptual/KernelProgramming/KernelProgramming.pdf</p>\n<h2><span id=\"External_links\">External links</span></h2>\n<ul><li>The reasons why 64-bit programs require more stack memory</li>\n</ul>" 
    } 
    } 
    } 
} 
) 

Mit meinem Ergebnis kann ich auf die folgende bekommen: res.data.query.pages aber Natürlich, wenn ich einmal auf die Nummer der Seite bin (was zufällig ist), kann ich nicht herausfinden, wie o Holen Sie sich die Informationen.

Problem 2: Ich möchte natürlich die extract vom JSONP bekommen, aber wie man oben gesehen nach oben haben könnte, hat es all diese Tags, ect und wird nicht eine gute Ausgangs geben .. Gibt es eine Möglichkeit zum Anzeigen das als html?

Answer 1

Um die Seiten-ID zu extrahieren Sie den folgenden Code verwenden:

var theObj = res.data.query.pages; 
var thePageId = theObj[Object.keys(theObj)[0]].pageid; 
// Object.keys(theObj)[0] will extract the value of the first property which is variable in your case and you don't know it. So we have the object which we know it has the property "pageid". 

Hier haben Sie eine Geige, die die ID der Seite Warnungen: https://jsfiddle.net/fg6mdrxj/

In Bezug auf die zweite Frage, sobald Sie bekommen Den Wert der Eigenschaft können Sie leicht manipulieren. Im gleichen Geige haben Sie ein Update hier: https://jsfiddle.net/fg6mdrxj/1/, die den Wert des Extraktes Eigenschaft nimmt und hängen Sie es mit dem id-Extrakt zum div:

JS:

var toHtml = theObj[Object.keys(theObj)[0]].extract; 
document.getElementById("extract").innerHTML = toHtml; 

HTML:

<div id="extract"></div> 

Natürlich kann der Wert von Extrakt auf andere Weise manipuliert werden, sobald Sie es bekommen haben.