Node - fs.writeFile creates an empty file
I am trying to write a new file inside a search callback.
The process takes in and object, walks through it for some data, creates a new array, and then writes that array to a JSON file. The writing part doesn't work that well ...
// onComplete is the callback, job is a returned object.
onComplete: function(job) {
console.log("Creating file \"localize_template\"...");
var fs = require('fs');
var localArray = {};
var foundEntries = job.matches;
var stringCount = 0;
// Drill down to the strings that matched the search.
for (var foundEntry in foundEntries) {
// Stay on target...
if (foundEntries.hasOwnProperty(foundEntry)) {
var singleEntry = foundEntries[foundEntry];
// Almost...there...
for( var match in singleEntry ) {
if (singleEntry.hasOwnProperty(match)) {
// Direct hit! We've drilled down to the match string itself.
var theMatch = singleEntry[match].match;
// Now, get the terms inside the strings that were referenced.
var terms = theMatch.match(/".*?"/g);
// Iterate through those strings and add them as entries in the localArray.
for( var i=0; i<terms.length; i++ ) {
var term = terms[i].replace(/"/g, '');
localArray[term] = 'xx:'+term;
stringCount++;
}
}
}
}
}
fs.writeFile( 'i18n/localize_template.json', localArray, {encoding: 'utf8'}, function(err){
console.log("File localize_template.json create successfully.");
if(err) {
throw err;
} else {
console.log("File localize_template.json create successfully.");
}
});
}
The file is created but it is empty. I tried using a generic string Hello World!
instead localArray
for testing, but the file is still empty.
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To answer more clearly fs.writeFile
is asynchronous and the top level grunt stuff doesn't know to wait for asynchronous operations to start from onComplete
. You need to figure out how to tell that you have an asynchronous operation in progress other than this is a function that grunt-search
does not support . Otherwise, when you return with onComplete
, it grunt-search
will mark the task as done immediately and grunt will exit, after which the node process will exit before the asynchronous write completes.
Another thought is to use grunt.file.write()
. This is a synchronous API, so you don't need to deal with the problem of not being able to tell that your task has not been completed. Also, using this API will make your code magically maintain the grunts parameter --no-write
since it doesn't work when the user requests a dry run.
onComplete: function (matches) {
grunt.file.write('test', JSON.stringify(matches));
},
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Your problem must be that fs.writeFile is being run "asynchronously". Try changing localArray here (hardcode this to see if it works):
fs.writeFile( 'i18n/localize_template.json', localArray, callback)
And there it should work. Solution, I think you should use fs.writeFileSync or initialize localArray outside of the incomplete function before it starts up.
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