Manipulating a JSON file with jq

Question

I'm using jq to manipulate a JSON file. I need to run a single command that searches an array, finds an object that has a key that equals “someData”, and then delete a key that is in the object, for example, delete a “maxHeight” key from the object where key equals “someData”. Here is an example JSON file, I would like to search the 'tracks' array and find the object where label =“cucumber_ChineseLong_v2.gff3” and then remove the 'maxHeight: “200px” ' from that object. Is this even possible to run in a single command using jq?

Update : My desired output would be the original JSON file with that 'maxHeight' key:value removed.

Update : A few commands I've tried..

jq '. as $dot|[range(0;length)|select(.maxHeight == "200px")|$dot[.]]' trackList.json > new.json

jq '.tracks[]  | select(.label == "cucumber_ChineseLong_v2.gff3")' trackList.json > test.json

• The Last command can isolate the correct Array, Now I need to know how to delete a key from a object using jq.

JSON File

{
  "tracks": [
    {
      "storeClass": "JBrowse/Store/Sequence/StaticChunked",
      "chunkSize": 20000,
      "urlTemplate": "seq/{refseq_dirpath}/{refseq}-",
      "label": "DNA",
      "type": "SequenceTrack",
      "category": "Reference sequence",
      "seqType": "dna",
      "key": "Reference sequence"
    },
    {
      "style": {
        "className": "feature",
        "showLabels": false,
        "arrowheadClass": null,
        "featureCss": "padding:3px;"
      },
      "menuTemplate": [
        {
          "label": "View details"
        },
        {
          "label": "Highlight a gene"
        },
        {
          "iconClass": "dijitIconBookmark",
          "content": "function(track,feature,div) { window.parent.angular.element(window.frameElement).scope().specificNote( feature[2] ) }",
          "action": "contentDialog",
          "title": "(feature{name})",
          "label": "Create Note"
        }
      ],
      "hooks": {
        "modify": " function(track,feature,div){ var checkArr=[\"Reference\",\"Missing\",\"Heterozygous\",\"NonReference\"];for(var i=0;i<feature.length;i++){for(var j=0;j<checkArr.length;j++){  if( i>3) { if( feature[i] ===  checkArr[j] ) {  if(feature[i]==\"NonReference\"){div.style.backgroundColor=\"red\"}else if(feature[i]==\"Reference\"){div.style.backgroundColor=\"green\"}else if(feature[i]==\"Heterozygous\"){div.style.backgroundColor=\"orange\"}else if(feature[i]==\"Missing\"){div.style.backgroundColor=\"grey\"} }}}}} "
      },
      "key": "CG0001.gff",
      "storeClass": "JBrowse/Store/SeqFeature/NCList",
      "trackType": null,
      "maxHeight": "200px",
      "urlTemplate": "tracks/CG0001.gff/{refseq}/trackData.json",
      "compress": 0,
      "label": "CG0001.gff",
      "type": "FeatureTrack"
    },
    {
      "style": {
        "className": "feature",
        "showLabels": false,
        "arrowheadClass": null,
        "featureCss": "padding:3px;"
      },
      "menuTemplate": [
        {
          "label": "View details"
        },
        {
          "label": "Highlight a gene"
        },
        {
          "iconClass": "dijitIconBookmark",
          "content": "function(track,feature,div) { window.parent.angular.element(window.frameElement).scope().specificNote( feature[2] ) }",
          "action": "contentDialog",
          "title": "(feature{name})",
          "label": "Create Note"
        }
      ],
      "hooks": {
        "modify": " function(track,feature,div){ var checkArr=[\"Reference\",\"Missing\",\"Heterozygous\",\"NonReference\"];for(var i=0;i<feature.length;i++){for(var j=0;j<checkArr.length;j++){  if( i>3) { if( feature[i] ===  checkArr[j] ) {  if(feature[i]==\"NonReference\"){div.style.backgroundColor=\"red\"}else if(feature[i]==\"Reference\"){div.style.backgroundColor=\"green\"}else if(feature[i]==\"Heterozygous\"){div.style.backgroundColor=\"orange\"}else if(feature[i]==\"Missing\"){div.style.backgroundColor=\"grey\"} }}}}} "
      },
      "key": "CG0002.gff",
      "storeClass": "JBrowse/Store/SeqFeature/NCList",
      "trackType": null,
      "maxHeight": "200px",
      "urlTemplate": "tracks/CG0002.gff/{refseq}/trackData.json",
      "compress": 0,
      "label": "CG0002.gff",
      "type": "FeatureTrack"
    },
    {
      "style": {
        "className": "feature",
        "showLabels": false,
        "arrowheadClass": null,
        "featureCss": "padding:3px;"
      },
      "menuTemplate": [
        {
          "label": "View details"
        },
        {
          "label": "Highlight a gene"
        },
        {
          "iconClass": "dijitIconBookmark",
          "content": "function(track,feature,div) { window.parent.angular.element(window.frameElement).scope().specificNote( feature[2] ) }",
          "action": "contentDialog",
          "title": "(feature{name})",
          "label": "Create Note"
        }
      ],
      "hooks": {
        "modify": " function(track,feature,div){ var checkArr=[\"Reference\",\"Missing\",\"Heterozygous\",\"NonReference\"];for(var i=0;i<feature.length;i++){for(var j=0;j<checkArr.length;j++){  if( i>3) { if( feature[i] ===  checkArr[j] ) {  if(feature[i]==\"NonReference\"){div.style.backgroundColor=\"red\"}else if(feature[i]==\"Reference\"){div.style.backgroundColor=\"green\"}else if(feature[i]==\"Heterozygous\"){div.style.backgroundColor=\"orange\"}else if(feature[i]==\"Missing\"){div.style.backgroundColor=\"grey\"} }}}}} "
      },
      "key": "CG0003.gff",
      "storeClass": "JBrowse/Store/SeqFeature/NCList",
      "trackType": null,
      "maxHeight": "200px",
      "urlTemplate": "tracks/CG0003.gff/{refseq}/trackData.json",
      "compress": 0,
      "label": "CG0003.gff",
      "type": "FeatureTrack"
    },
    {
      "style": {
        "className": "feature",
        "showLabels": false,
        "arrowheadClass": null,
        "featureCss": "padding:3px;"
      },
      "menuTemplate": [
        {
          "label": "View details"
        },
        {
          "label": "Highlight a gene"
        },
        {
          "iconClass": "dijitIconBookmark",
          "content": "function(track,feature,div) { window.parent.angular.element(window.frameElement).scope().specificNote( feature[2] ) }",
          "action": "contentDialog",
          "title": "(feature{name})",
          "label": "Create Note"
        }
      ],
      "hooks": {
        "modify": " function(track,feature,div){ var checkArr=[\"Reference\",\"Missing\",\"Heterozygous\",\"NonReference\"];for(var i=0;i<feature.length;i++){for(var j=0;j<checkArr.length;j++){  if( i>3) { if( feature[i] ===  checkArr[j] ) {  if(feature[i]==\"NonReference\"){div.style.backgroundColor=\"red\"}else if(feature[i]==\"Reference\"){div.style.backgroundColor=\"green\"}else if(feature[i]==\"Heterozygous\"){div.style.backgroundColor=\"orange\"}else if(feature[i]==\"Missing\"){div.style.backgroundColor=\"grey\"} }}}}} "
      },
      "key": "CG0004.gff",
      "storeClass": "JBrowse/Store/SeqFeature/NCList",
      "trackType": null,
      "maxHeight": "200px",
      "urlTemplate": "tracks/CG0004.gff/{refseq}/trackData.json",
      "compress": 0,
      "label": "CG0004.gff",
      "type": "FeatureTrack"
    },
    {
      "style": {
        "className": "feature",
        "showLabels": false,
        "arrowheadClass": null,
        "featureCss": "padding:3px;"
      },
      "menuTemplate": [
        {
          "label": "View details"
        },
        {
          "label": "Highlight a gene"
        },
        {
          "iconClass": "dijitIconBookmark",
          "content": "function(track,feature,div) { window.parent.angular.element(window.frameElement).scope().specificNote( feature[2] ) }",
          "action": "contentDialog",
          "title": "(feature{name})",
          "label": "Create Note"
        }
      ],
      "hooks": {
        "modify": " function(track,feature,div){ var checkArr=[\"Reference\",\"Missing\",\"Heterozygous\",\"NonReference\"];for(var i=0;i<feature.length;i++){for(var j=0;j<checkArr.length;j++){  if( i>3) { if( feature[i] ===  checkArr[j] ) {  if(feature[i]==\"NonReference\"){div.style.backgroundColor=\"red\"}else if(feature[i]==\"Reference\"){div.style.backgroundColor=\"green\"}else if(feature[i]==\"Heterozygous\"){div.style.backgroundColor=\"orange\"}else if(feature[i]==\"Missing\"){div.style.backgroundColor=\"grey\"} }}}}} "
      },
      "key": "CG0005.gff",
      "storeClass": "JBrowse/Store/SeqFeature/NCList",
      "trackType": null,
      "maxHeight": "200px",
      "urlTemplate": "tracks/CG0005.gff/{refseq}/trackData.json",
      "compress": 0,
      "label": "CG0005.gff",
      "type": "FeatureTrack"
    },
    {
      "style": {
        "className": "feature",
        "showLabels": false,
        "arrowheadClass": null,
        "featureCss": "padding:3px;"
      },
      "menuTemplate": [
        {
          "label": "View details"
        },
        {
          "label": "Highlight a gene"
        },
        {
          "iconClass": "dijitIconBookmark",
          "content": "function(track,feature,div) { window.parent.angular.element(window.frameElement).scope().specificNote( feature[2] ) }",
          "action": "contentDialog",
          "title": "(feature{name})",
          "label": "Create Note"
        }
      ],
      "hooks": {
        "modify": " function(track,feature,div){ var checkArr=[\"Reference\",\"Missing\",\"Heterozygous\",\"NonReference\"];for(var i=0;i<feature.length;i++){for(var j=0;j<checkArr.length;j++){  if( i>3) { if( feature[i] ===  checkArr[j] ) {  if(feature[i]==\"NonReference\"){div.style.backgroundColor=\"red\"}else if(feature[i]==\"Reference\"){div.style.backgroundColor=\"green\"}else if(feature[i]==\"Heterozygous\"){div.style.backgroundColor=\"orange\"}else if(feature[i]==\"Missing\"){div.style.backgroundColor=\"grey\"} }}}}} "
      },
      "key": "CG0010.gff",
      "storeClass": "JBrowse/Store/SeqFeature/NCList",
      "trackType": null,
      "maxHeight": "200px",
      "urlTemplate": "tracks/CG0010.gff/{refseq}/trackData.json",
      "compress": 0,
      "label": "CG0010.gff",
      "type": "FeatureTrack"
    },
    {
      "style": {
        "className": "feature",
        "showLabels": false,
        "color": "function(feature, variableName, glyphObject, track){if(feature.get(\"type\") === \"CDS\"){return \"#9CFBF5\";} else if(feature.get(\"type\") === \"exon\"){return \"#43A47F\";} else if(feature.get(\"type\") === \"intron\"){return \"#E8E8E8\";} else if(feature.get(\"type\") === \"five_prime_UTR\"){return \"#F192FE\";} else if(feature.get(\"type\") === \"three_prime_UTR\"){return \"#FEC892\";} else {return \"#FF0000\";}}",
        "arrowheadClass": null,
        "featureCss": "padding:3px;"
      },
      "menuTemplate": [
        {
          "label": "View details"
        },
        {
          "label": "Highlight a gene"
        },
        {
          "iconClass": "dijitIconBookmark",
          "content": "function(track,feature,div) { window.parent.angular.element(window.frameElement).scope().specificNote( feature[2] ) }",
          "action": "contentDialog",
          "title": "(feature{name})",
          "label": "Create Note"
        }
      ],
      "hooks": {
        "modify": " function(track,feature,div){   var checkArr=[\"Reference\",\"Missing\",\"Heterozygous\",\"NonReference\"];for(var i=0;i<feature.length;i++){for(var j=0;j<checkArr.length;j++){  if( i>3) { if( feature[i] ===  checkArr[j] ) {  if(feature[i]==\"NonReference\"){div.style.backgroundColor=\"red\"}else if(feature[i]==\"Reference\"){div.style.backgroundColor=\"green\"}else if(feature[i]==\"Heterozygous\"){div.style.backgroundColor=\"orange\"}else if(feature[i]==\"Missing\"){div.style.backgroundColor=\"grey\"} }}}}} "
      },
      "key": "cucumber_ChineseLong_v2.gff3",
      "storeClass": "JBrowse/Store/SeqFeature/NCList",
      "trackType": null,
      "maxHeight": "200px",
      "urlTemplate": "tracks/cucumber_ChineseLong_v2.gff3/{refseq}/trackData.json",
      "compress": 0,
      "label": "cucumber_ChineseLong_v2.gff3",
      "type": "JBrowse/View/Track/CanvasFeatures"
    },
    {
      "storeClass": "JBrowse/Store/SeqFeature/VCFTabix",
      "urlTemplate": "Cucumber115_chronly.vcf.gz",
      "maxHeight": "200px",
      "type": "CanvasVariants",
      "label": "Cucumber115_chronly.vcf",
      "menuTemplate": [
        {
          "label": "View details"
        },
        {
          "label": "Zoom"
        },
        {
          "iconClass": "dijitIconFilter",
          "content": "function(track,feature,div) { window.parent.angular.element(window.frameElement).scope().selectSequence( div.f.data.end ) }",
          "action": "contentDialog",
          "title": "(feature{name})",
          "label": "Select Sequence"
        },
        {
          "iconClass": "dijitIconBookmark",
          "content": "function(track,feature,div) { window.parent.angular.element(window.frameElement).scope().specificNote( div.f.data.end ) }",
          "action": "contentDialog",
          "title": "(feature{name})",
          "label": "Create Note"
        }
      ]
    },
    {
      "style": {
        "className": "feature",
        "showLabels": false,
        "arrowheadClass": null,
        "featureCss": "padding:7px;"
      },
      "hooks": {
        "modify": " function(track,feature,div){ var checkArr=[\"Gene\",\"Variant\",\"Primer\"];for(var i=0;i<feature.length;i++){for(var j=0;j<checkArr.length;j++){  if( i>3) { if( feature[i] ===  checkArr[j] ) {  if(feature[i]==\"Gene\"){div.style.backgroundColor=\"pink\"}else if(feature[i]==\"Variant\"){div.style.backgroundColor=\"purple\"}else if(feature[i]==\"Primer\"){div.style.backgroundColor=\"blue\"} }}}}} "
      },
      "key": "Notes",
      "storeClass": "JBrowse/Store/SeqFeature/NCList",
      "trackType": null,
      "maxHeight": "200px",
      "urlTemplate": "tracks/Notes/{refseq}/trackData.json",
      "compress": 0,
      "type": "FeatureTrack",
      "label": "Notes"
    }
  ],
  "formatVersion": 1
}

Answer 1

Unfortunately you have not followed the guidelines at http://stackoverflow.com/help/mcve so it is difficult to tell from your description what output you are expecting, but the simplest way to delete a key from an object is to use del/1 as in the following:

.tracks
| map(select(.label=="cucumber_ChineseLong_v2.gff3") 
      | del(.maxHeight))

With your JSON as input, the result of the above query is rather long, so I won't include it in this response -- the "m" in "mcve" stands for "minimal".

Supplementary Q&A

Is it possible to return the original file with the 'maxHeight' removed?

For "editing" (as opposed to extraction), the trick is to use |= . There are many variations possible, for example:

.tracks |=
  map(if .label=="cucumber_ChineseLong_v2.gff3"
      then del(.maxHeight)
      else .
      end)

Some prefer the one-liner:

.tracks[] |= if .label=="cucumber_ChineseLong_v2.gff3" then del(.maxHeight) else . end