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How to access component methods from “outside” in ReactJS?
...
class Parent extends React.Class {
constructor(props) {
this._child = React.createRef();
}
componentDidMount() {
console.log(this._child.current.someMethod()); // Prints 'bar'
}
render() {
return (
<div>
<Child ref=...
What does it mean for a data structure to be “intrusive”?
...to know about the list it is in, and inform it of changes.
ORM-systems usually revolve around intrusive data structures, to minimize iteration over large lists of objects. For instance, if you retrieve a list of all the employees in the database, then change the name of one of them, and want to sav...
mongodb: insert if not exists
... has built-in support for this. Pass an extra parameter to your update() call: {upsert:true}. For example:
key = {'key':'value'}
data = {'key2':'value2', 'key3':'value3'};
coll.update(key, data, upsert=True); #In python upsert must be passed as a keyword argument
This replaces your if-find-els...
How to refer environment variable in POM.xml?
I am using maven as build tool. I have set an environment variable called env . How can I get access to this environment variable's value in the pom.xml file?
...
Why do you have to call .items() when iterating over a dictionary in Python?
...te over the same items. Implementation-wise they are different operations (__contains__ vs. __iter__). But that little inconsistency would be somewhat confusing and, well, inconsistent.
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impr...
Android emulator and virtualbox cannot run at same time
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Thanks @MichaelHampton. I installed vagrant-libvert and it worked!
– jchook
Jan 13 '19 at 21:42
add a comment
|...
一个宏命令，就可以程序崩溃时生成dump文件 - C/C++ - 清泛网 - 专注C/C++及内核技术
...pFile
{
void CreateDumpFile(LPCWSTR lpstrDumpFilePathName, EXCEPTION_POINTERS *pException)
{
// 创建Dump文件
//
HANDLE hDumpFile = CreateFile(lpstrDumpFilePathName, GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
//...
C++ 通过主机名/域名获取IP - C/C++ - 清泛网 - 专注C/C++及内核技术
...2.h> 该头文件定义了Socket编程的功能 #pragma comment(lib,"ws2_32.lib") 连接ws2_32.lib库...代码如下：
#include <winsock2.h> //该头文件定义了Socket编程的功能
#pragma comment(lib,"ws2_32.lib") //连接ws2_32.lib库.只要程序中用到Winsock API 函数，...
Regex: ignore case sensitivity
...ow can I make the following regex ignore case sensitivity? It should match all the correct characters but ignore whether they are lower or uppercase.
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LINQ: Distinct values
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Oh so by "larger type" you may mean I still want all properties in the result even though I only want to compare a few properties to determine distinctness?
– The Red Pea
Sep 20 '16 at 14:31
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