I'm starting to develop with node.j,I meet an issue regarding the using of the module 'formidable'.
I have this error:
Error: Cannot find module 'formidable'
Here is the module list installed using 'npm ls installed' :
├─┬ express@2.5.9 │ ├── connect@1.8.7 │ ├── mime@1.2.4 │ ├── mkdirp@0.3.0 │ └── qs@0.4.2 ├── formidable@1.0.9 ├─┬ node-inspector@0.1.10 │ ├── paperboy@0.0.3 │ └─┬ socket.io@0.8.7 │ ├── policyfile@0.0.4 │ ├── redis@0.6.7 │ └─┬ socket.io-client@0.8.7 │ ├── uglify-js@1.0.6 │ ├── websocket-client@1.0.0 │ └── xmlhttprequest@1.2.2 ├─┬ npm@1.1.21 │ ├── abbrev@1.0.3 │ ├── archy@0.0.2 │ ├── block-stream@0.0.5 │ ├── chownr@0.0.1 │ ├── fstream@0.1.18 │ ├─┬ fstream-npm@0.0.6 │ │ └── fstream-ignore@0.0.5 │ ├── graceful-fs@1.1.8 │ ├── inherits@1.0.0 │ ├── ini@1.0.2 │ ├── lru-cache@1.0.5 │ ├── minimatch@0.2.2 │ ├── mkdirp@0.3.0 │ ├─┬ node-gyp@0.4.1 │ │ ├── ansi@0.0.4 │ │ └── glob@3.1.9 │ ├── node-uuid@1.3.3 │ ├── nopt@1.0.10 │ ├── proto-list@1.0.0 │ ├── read@0.0.2 │ ├── request@2.9.153 │ ├── rimraf@2.0.1 │ ├── semver@1.0.13 │ ├── slide@1.1.3 │ ├── tar@0.1.13 │ ├── uid-number@0.0.3 │ └── which@1.0.5 └─┬ socket.io@0.9.6 ├── policyfile@0.0.4 ├── redis@0.6.7 └─┬ socket.io-client@0.9.6 ├─┬ active-x-obfuscator@0.0.1 │ └── zeparser@0.0.5 ├── uglify-js@1.2.5 ├─┬ ws@0.4.14 │ ├── commander@0.5.2 │ └── options@0.0.3 └── xmlhttprequest@1.2.2
I add that it is the only module who generate this error.
Also, I don't really understand the way are encapsulated some module, it appears that npm is installing the module directly in the directory I'm using the module installation command, and I notice that formidable has been installed in the express/connect/ module on its first installation.
Can you give me more information about the module installation tree.
Thank for your replies
Cheers
To understand module resolution, have a look at the Modules documentation, especially Loading from node_modules
Folders.
For example, if the file at
'/home/ry/projects/foo.js'
calledrequire('bar.js')
, then node would look in the following locations, in this order:
/home/ry/projects/node_modules/bar.js
/home/ry/node_modules/bar.js
/home/node_modules/bar.js
/node_modules/bar.js
NPM takes advantage of this by installing modules into:
./node_modules/{module}
So, when you use npm install formidable
, it will create and install the module into:
./node_modules/formidable
But, this means that only scripts within the current directory, including sub-directories, will succeed in using require('formidable')
:
./foo.js
./lib/bar.js
./src/baz.js
./src/sub/qux.js
You can however install modules as "global," but you have to explicitly ask for it with -g
or --global
:
npm install -g formidable
Then, any script on the system should be able to require('formidable')
.
As for the tree output, you current have 5 installed modules available from the current directory:
express
formidable
node-inspector
npm
socket.io
Everything else in the tree is a list of these modules' dependencies, and their dependencies, etc., but only these 5 are available for require(...)
within your scripts.
The accepted answer looks very comprehensive and correct, but this worked for me:
npm install -d
d stands for dependencies (I think)