我正在尝试检索正在此页面上的javascript中生成图表的数据：
https://www.energy-charts.de/price.htm
我找到了SVG元素，它们用它们的M和L元素画线，但是我不知道从哪里开始寻找保存实际数据的javascript数组。 （我假设某处必须有一个数组）。
对于要在哪里开始寻找这些数据的提示和提示，我深表感谢。
答案 0 :(得分：2)
简短回答
数据存储在https://www.energy-charts.de/price/week_2019_21.json的JSON文件中
长期回答
如果打开开发人员工具（F12），则可以从文件#include<initializer_list>
#include<iostream>
#include<vector>
// Declarations:
// Stores a collection of numbers in the form radix*RADIX_MULTIPLIER + suffix,
// where 0 <= suffix < RADIX_MULTIPLIER.
class Block {
public:
using SUFFIX_VECTOR_T = std::vector<unsigned short>;
constexpr static unsigned int RADIX_MULTIPLIER = 100;
private:
const unsigned short radix;
// Contains all the suffixes associated with this radix.
SUFFIX_VECTOR_T suffixes;
public:
Block(unsigned short radix);
unsigned short getRadix() const;
void pushSuffix(const unsigned short suffix);
std::size_t size() const;
unsigned int operator[](std::size_t idx) const;
SUFFIX_VECTOR_T::const_iterator begin() const;
SUFFIX_VECTOR_T::const_iterator cbegin() const;
SUFFIX_VECTOR_T::const_iterator end() const;
SUFFIX_VECTOR_T::const_iterator cend() const;
};
using DATA_VECTOR_T = std::vector<Block>;
class MyIterator :
public std::iterator<std::input_iterator_tag, unsigned int> {
const DATA_VECTOR_T& data;
DATA_VECTOR_T::const_iterator block_it;
Block::SUFFIX_VECTOR_T::const_iterator suffix_it;
public:
MyIterator(
const DATA_VECTOR_T& data,
const DATA_VECTOR_T::const_iterator start_block_it);
MyIterator& operator++();
MyIterator operator++(int);
bool operator==(const MyIterator& rhs) const;
bool operator!=(const MyIterator& rhs) const;
unsigned int operator*() const;
};
// Read-only container which stores a sorted collection of numbers
// memory-efficiently in Blocks.
class MyContainer {
public:
using const_iterator = MyIterator;
private:
DATA_VECTOR_T data;
public:
// The initializer list must be sorted in non-descending order.
MyContainer(std::initializer_list<unsigned int> il);
unsigned int operator[](std::size_t idx) const;
MyContainer::const_iterator begin() const;
MyContainer::const_iterator cbegin() const;
MyContainer::const_iterator end() const;
MyContainer::const_iterator cend() const;
};
// Definitions:
// class Block
Block::Block(unsigned short radix): radix(radix) {}
unsigned short Block::getRadix() const {
return radix;
}
void Block::pushSuffix(const unsigned short suffix) {
suffixes.push_back(suffix);
}
std::size_t Block::size() const {
return suffixes.size();
}
unsigned int Block::operator[](std::size_t idx) const {
return
(unsigned int)(radix)*RADIX_MULTIPLIER +
(unsigned int)(suffixes[idx]);
}
Block::SUFFIX_VECTOR_T::const_iterator Block::begin() const {
return suffixes.begin();
}
Block::SUFFIX_VECTOR_T::const_iterator Block::cbegin() const {
return begin();
}
Block::SUFFIX_VECTOR_T::const_iterator Block::end() const {
return suffixes.end();
}
Block::SUFFIX_VECTOR_T::const_iterator Block::cend() const {
return end();
}
// class MyContainer
// The initializer list must be sorted in non-descending order.
MyContainer::MyContainer(std::initializer_list<unsigned int> il) {
if (il.size() == 0) {
return;
}
unsigned short radix = *il.begin() / Block::RADIX_MULTIPLIER;
data.push_back(Block(radix));
for (const auto x : il) {
radix = x / Block::RADIX_MULTIPLIER;
if (data.back().getRadix() != radix) {
data.push_back(Block(radix));
}
unsigned short suffix = x % Block::RADIX_MULTIPLIER;
data.back().pushSuffix(suffix);
}
}
unsigned int MyContainer::operator[](std::size_t idx) const {
auto data_it = data.begin();
// Similarly to std::vector::operator[], if idx is out of bounds of the
// container, the behavior is undefined.
while (idx >= data_it->size()) {
idx -= data_it->size();
++data_it;
}
return (*data_it)[idx];
}
MyContainer::const_iterator MyContainer::begin() const {
return MyIterator(data, data.cbegin());
}
MyContainer::const_iterator MyContainer::cbegin() const {
return begin();
}
MyContainer::const_iterator MyContainer::end() const {
return MyIterator(data, data.end());
}
MyContainer::const_iterator MyContainer::cend() const {
return end();
}
// class MyIterator
MyIterator::MyIterator(
const DATA_VECTOR_T& data,
const DATA_VECTOR_T::const_iterator start_block_it):
data(data), block_it(start_block_it) {
if (data.cend() != block_it) {
suffix_it = block_it->cbegin();
}
}
MyIterator& MyIterator::operator++() {
if (data.cend() == block_it) {
return *this;
}
++suffix_it;
if (block_it->cend() == suffix_it) {
++block_it;
if (data.cend() != block_it) {
suffix_it = block_it->cbegin();
}
}
return *this;
}
MyIterator MyIterator::operator++(int) {
MyIterator tmp = *this;
operator++();
return tmp;
}
bool MyIterator::operator==(const MyIterator& rhs) const {
// If this iterator has reached the end:
if (data.cend() == block_it) {
// Only return true if both iterators point to the end of the same
// object.
return data.cend() == rhs.block_it;
}
return block_it == rhs.block_it
&& suffix_it == rhs.suffix_it;
}
bool MyIterator::operator!=(const MyIterator& rhs) const {
return !(*this == rhs);
}
unsigned int MyIterator::operator*() const {
const std::size_t idx = suffix_it - block_it->cbegin();
return (*block_it)[idx];
}
// Entry point:
int main() {
std::vector<unsigned int> v = {
1234, 1254, 1264, 1265, 1267, 1268, 1271, 1819, 1832, 1856, 1867, 1892,
3210, 3214, 3256, 3289
};
// Print the entire vector.
for (const auto x: v) {
std::cout << x << "\t";
}
std::cout << std::endl;
// Print a randomly accessed element from the vector.
std::cout << v[10] << std::endl;
MyContainer c = {
1234, 1254, 1264, 1265, 1267, 1268, 1271, 1819, 1832, 1856, 1867, 1892,
3210, 3214, 3256, 3289
};
// Print the entire container.
for (const auto x: c) {
std::cout << x << "\t";
}
std::cout << std::endl;
// Print a randomly accessed element from the container.
std::cout << c[10] << std::endl;
return 0;
}
中看到console.log个负载。其中大多数没有用，但price.js行似乎对我们有用。
打开got chartTitle from JSON! _chartTitle: Electricity production and spot prices in Germany in week 21 2019并搜索“ got chartTitle”，我发现了一个名为price.js的函数，该函数似乎正在加载JSON文件。我假设这些将从某种API返回，而不是直接存储在JS文件中。
从“ got chartTitle”向上滚动，我注意到这一行：
createChart。对我来说，这是从文件路径加载JSON。在搜索“文件路径”时，我发现它已声明为全局变量。将其输入到javascript控制台中，我看到值是“ ./price/week_2019_21.json”，因此导航至该URL（https://www.energy-charts.de/price/week_2019_21.json）应该是您要查找的数据！
此网址是通过以下代码块计算的：
d3.json(filepath, function(error, json) {默认值在if(defaultweek < 10){
filepath = "./price/week_" + defaultyear +"_0"+ defaultweek +".json"; //default file on first-load
}
else{
filepath = "./price/week_" + defaultyear +"_"+ defaultweek +".json"; //default file on first-load
}
中设置。
希望这会有所帮助！